diff options
Diffstat (limited to 'railties/doc/guides/source/creating_plugins')
16 files changed, 793 insertions, 1447 deletions
diff --git a/railties/doc/guides/source/creating_plugins/acts_as_yaffle.txt b/railties/doc/guides/source/creating_plugins/acts_as_yaffle.txt index 12d40deb18..de116af7db 100644 --- a/railties/doc/guides/source/creating_plugins/acts_as_yaffle.txt +++ b/railties/doc/guides/source/creating_plugins/acts_as_yaffle.txt @@ -1,32 +1,40 @@ -== Add an `acts_as_yaffle` method to ActiveRecord == +== Add an `acts_as_yaffle` method to Active Record == -A common pattern in plugins is to add a method called `acts_as_something` to models. In this case, you want to write a method called `acts_as_yaffle` that adds a `squawk` method to your models. +A common pattern in plugins is to add a method called 'acts_as_something' to models. In this case, you want to write a method called 'acts_as_yaffle' that adds a 'squawk' method to your models. -To keep things clean, create a new test file called 'acts_as_yaffle_test.rb' in your plugin's test directory and require your test helper. +To begin, set up your files so that you have: + +*vendor/plugins/yaffle/test/acts_as_yaffle_test.rb* [source, ruby] ------------------------------------------------------ -# File: vendor/plugins/yaffle/test/acts_as_yaffle_test.rb - require File.dirname(__FILE__) + '/test_helper.rb' -class Hickwall < ActiveRecord::Base - acts_as_yaffle -end - class ActsAsYaffleTest < Test::Unit::TestCase end ------------------------------------------------------ +*vendor/plugins/yaffle/lib/yaffle.rb* + [source, ruby] ------------------------------------------------------ -# File: vendor/plugins/lib/acts_as_yaffle.rb +require 'yaffle/acts_as_yaffle' +------------------------------------------------------ + +*vendor/plugins/yaffle/lib/yaffle/acts_as_yaffle.rb* +[source, ruby] +------------------------------------------------------ module Yaffle + # your code will go here end ------------------------------------------------------ -One of the most common plugin patterns for `acts_as_yaffle` plugins is to structure your file like so: +Note that after requiring 'acts_as_yaffle' you also have to include it into ActiveRecord::Base so that your plugin methods will be available to the rails models. + +One of the most common plugin patterns for 'acts_as_yaffle' plugins is to structure your file like so: + +*vendor/plugins/yaffle/lib/yaffle/acts_as_yaffle.rb* [source, ruby] ------------------------------------------------------ @@ -50,52 +58,45 @@ end With structure you can easily separate the methods that will be used for the class (like `Hickwall.some_method`) and the instance (like `@hickwell.some_method`). -Let's add class method named `acts_as_yaffle` - testing it out first. You already defined the ActiveRecord models in your test helper, so if you run tests now they will fail. +=== Add a class method === -Back in your `acts_as_yaffle` file, update ClassMethods like so: +This plugin will expect that you've added a method to your model named 'last_squawk'. However, the plugin users might have already defined a method on their model named 'last_squawk' that they use for something else. This plugin will allow the name to be changed by adding a class method called 'yaffle_text_field'. -[source, ruby] ------------------------------------------------------- -module ClassMethods - def acts_as_yaffle(options = {}) - send :include, InstanceMethods - end -end ------------------------------------------------------- +To start out, write a failing test that shows the behavior you'd like: -Now that test should pass. Since your plugin is going to work with field names, you need to allow people to define the field names, in case there is a naming conflict. You can write a few simple tests for this: +*vendor/plugins/yaffle/test/acts_as_yaffle_test.rb* [source, ruby] ------------------------------------------------------ -# File: vendor/plugins/yaffle/test/acts_as_yaffle_test.rb - require File.dirname(__FILE__) + '/test_helper.rb' +class Hickwall < ActiveRecord::Base + acts_as_yaffle +end + +class Wickwall < ActiveRecord::Base + acts_as_yaffle :yaffle_text_field => :last_tweet +end + class ActsAsYaffleTest < Test::Unit::TestCase + load_schema + def test_a_hickwalls_yaffle_text_field_should_be_last_squawk assert_equal "last_squawk", Hickwall.yaffle_text_field end - def test_a_hickwalls_yaffle_date_field_should_be_last_squawked_at - assert_equal "last_squawked_at", Hickwall.yaffle_date_field - end - def test_a_wickwalls_yaffle_text_field_should_be_last_tweet assert_equal "last_tweet", Wickwall.yaffle_text_field end - - def test_a_wickwalls_yaffle_date_field_should_be_last_tweeted_at - assert_equal "last_tweeted_at", Wickwall.yaffle_date_field - end end ------------------------------------------------------ To make these tests pass, you could modify your `acts_as_yaffle` file like so: +*vendor/plugins/yaffle/lib/yaffle/acts_as_yaffle.rb* + [source, ruby] ------------------------------------------------------ -# File: vendor/plugins/yaffle/lib/acts_as_yaffle.rb - module Yaffle def self.included(base) base.send :extend, ClassMethods @@ -103,70 +104,66 @@ module Yaffle module ClassMethods def acts_as_yaffle(options = {}) - cattr_accessor :yaffle_text_field, :yaffle_date_field + cattr_accessor :yaffle_text_field self.yaffle_text_field = (options[:yaffle_text_field] || :last_squawk).to_s - self.yaffle_date_field = (options[:yaffle_date_field] || :last_squawked_at).to_s - send :include, InstanceMethods end end - - module InstanceMethods - end end + +ActiveRecord::Base.send :include, Yaffle ------------------------------------------------------ -Now you can add tests for the instance methods, and the instance method itself: +=== Add an instance method === + +This plugin will add a method named 'squawk' to any Active Record objects that call 'acts_as_yaffle'. The 'squawk' method will simply set the value of one of the fields in the database. + +To start out, write a failing test that shows the behavior you'd like: + +*vendor/plugins/yaffle/test/acts_as_yaffle_test.rb* [source, ruby] ------------------------------------------------------ -# File: vendor/plugins/yaffle/test/acts_as_yaffle_test.rb - require File.dirname(__FILE__) + '/test_helper.rb' +class Hickwall < ActiveRecord::Base + acts_as_yaffle +end + +class Wickwall < ActiveRecord::Base + acts_as_yaffle :yaffle_text_field => :last_tweet +end + class ActsAsYaffleTest < Test::Unit::TestCase + load_schema def test_a_hickwalls_yaffle_text_field_should_be_last_squawk assert_equal "last_squawk", Hickwall.yaffle_text_field end - def test_a_hickwalls_yaffle_date_field_should_be_last_squawked_at - assert_equal "last_squawked_at", Hickwall.yaffle_date_field - end - def test_a_wickwalls_yaffle_text_field_should_be_last_squawk + def test_a_wickwalls_yaffle_text_field_should_be_last_tweet assert_equal "last_tweet", Wickwall.yaffle_text_field end - def test_a_wickwalls_yaffle_date_field_should_be_last_squawked_at - assert_equal "last_tweeted_at", Wickwall.yaffle_date_field - end - + def test_hickwalls_squawk_should_populate_last_squawk hickwall = Hickwall.new hickwall.squawk("Hello World") assert_equal "squawk! Hello World", hickwall.last_squawk - end - def test_hickwalls_squawk_should_populate_last_squawked_at - hickwall = Hickwall.new - hickwall.squawk("Hello World") - assert_equal Date.today, hickwall.last_squawked_at - end - - def test_wickwalls_squawk_should_populate_last_tweet - wickwall = Wickwall.new - wickwall.squawk("Hello World") - assert_equal "squawk! Hello World", wickwall.last_tweet - end + end + def test_wickwalls_squawk_should_populate_last_tweeted_at wickwall = Wickwall.new wickwall.squawk("Hello World") - assert_equal Date.today, wickwall.last_tweeted_at - end + assert_equal "squawk! Hello World", wickwall.last_tweet + end end ------------------------------------------------------ +Run this test to make sure the last two tests fail, then update 'acts_as_yaffle.rb' to look like this: + +*vendor/plugins/yaffle/lib/yaffle/acts_as_yaffle.rb* + [source, ruby] ------------------------------------------------------ -# File: vendor/plugins/yaffle/lib/acts_as_yaffle.rb - module Yaffle def self.included(base) base.send :extend, ClassMethods @@ -174,9 +171,8 @@ module Yaffle module ClassMethods def acts_as_yaffle(options = {}) - cattr_accessor :yaffle_text_field, :yaffle_date_field + cattr_accessor :yaffle_text_field self.yaffle_text_field = (options[:yaffle_text_field] || :last_squawk).to_s - self.yaffle_date_field = (options[:yaffle_date_field] || :last_squawked_at).to_s send :include, InstanceMethods end end @@ -184,10 +180,12 @@ module Yaffle module InstanceMethods def squawk(string) write_attribute(self.class.yaffle_text_field, string.to_squawk) - write_attribute(self.class.yaffle_date_field, Date.today) end end end + +ActiveRecord::Base.send :include, Yaffle ------------------------------------------------------ -Note the use of `write_attribute` to write to the field in model. +.Editor's note: +NOTE: The use of `write_attribute` to write to the field in model is just one example of how a plugin can interact with the model, and will not always be the right method to use. For example, you could also use `send("#{self.class.yaffle_text_field}=", string.to_squawk)`. diff --git a/railties/doc/guides/source/creating_plugins/basics.markdown b/railties/doc/guides/source/creating_plugins/basics.markdown deleted file mode 100644 index f59e8728d7..0000000000 --- a/railties/doc/guides/source/creating_plugins/basics.markdown +++ /dev/null @@ -1,861 +0,0 @@ -Creating Plugin Basics -==================== - -Pretend for a moment that you are an avid bird watcher. Your favorite bird is the Yaffle, and you want to create a plugin that allows other developers to share in the Yaffle goodness. - -In this tutorial you will learn how to create a plugin that includes: - -Core Extensions - extending String: - - # Anywhere - "hello".squawk # => "squawk! hello! squawk!" - -An `acts_as_yaffle` method for Active Record models that adds a "squawk" method: - - class Hickwall < ActiveRecord::Base - acts_as_yaffle :yaffle_text_field => :last_sang_at - end - - Hickwall.new.squawk("Hello World") - -A view helper that will print out squawking info: - - squawk_info_for(@hickwall) - -A generator that creates a migration to add squawk columns to a model: - - script/generate yaffle hickwall - -A custom generator command: - - class YaffleGenerator < Rails::Generator::NamedBase - def manifest - m.yaffle_definition - end - end - end - -A custom route method: - - ActionController::Routing::Routes.draw do |map| - map.yaffles - end - -In addition you'll learn how to: - -* test your plugins -* work with init.rb, how to store model, views, controllers, helpers and even other plugins in your plugins -* create documentation for your plugin. -* write custom rake tasks in your plugin - -Create the basic app ---------------------- - -In this tutorial we will create a basic rails application with 1 resource: bird. Start out by building the basic rails app: - -> The following instructions will work for sqlite3. For more detailed instructions on how to create a rails app for other databases see the API docs. - - rails plugin_demo - cd plugin_demo - script/generate scaffold bird name:string - rake db:migrate - script/server - -Then navigate to [http://localhost:3000/birds](http://localhost:3000/birds). Make sure you have a functioning rails app before continuing. - -Create the plugin ------------------------ - -The built-in Rails plugin generator stubs out a new plugin. Pass the plugin name, either CamelCased or under_scored, as an argument. Pass --with-generator to add an example generator also. - -This creates a plugin in vendor/plugins including an init.rb and README as well as standard lib, task, and test directories. - -Examples: - - ./script/generate plugin BrowserFilters - ./script/generate plugin BrowserFilters --with-generator - -Later in the plugin we will create a generator, so go ahead and add the --with-generator option now: - - script/generate plugin yaffle --with-generator - -You should see the following output: - - create vendor/plugins/yaffle/lib - create vendor/plugins/yaffle/tasks - create vendor/plugins/yaffle/test - create vendor/plugins/yaffle/README - create vendor/plugins/yaffle/MIT-LICENSE - create vendor/plugins/yaffle/Rakefile - create vendor/plugins/yaffle/init.rb - create vendor/plugins/yaffle/install.rb - create vendor/plugins/yaffle/uninstall.rb - create vendor/plugins/yaffle/lib/yaffle.rb - create vendor/plugins/yaffle/tasks/yaffle_tasks.rake - create vendor/plugins/yaffle/test/core_ext_test.rb - create vendor/plugins/yaffle/generators - create vendor/plugins/yaffle/generators/yaffle - create vendor/plugins/yaffle/generators/yaffle/templates - create vendor/plugins/yaffle/generators/yaffle/yaffle_generator.rb - create vendor/plugins/yaffle/generators/yaffle/USAGE - -For this plugin you won't need the file vendor/plugins/yaffle/lib/yaffle.rb so you can delete that. - - rm vendor/plugins/yaffle/lib/yaffle.rb - -> Editor's note: many plugin authors prefer to keep this file, and add all of the require statements in it. That way, they only line in init.rb would be `require "yaffle"` -> If you are developing a plugin that has a lot of files in the lib directory, you may want to create a subdirectory like lib/yaffle and store your files in there. That way your init.rb file stays clean - -Setup the plugin for testing ------------------------- - -Testing plugins that use the entire Rails stack can be complex, and the generator doesn't offer any help. In this tutorial you will learn how to test your plugin against multiple different adapters using ActiveRecord. This tutorial will not cover how to use fixtures in plugin tests. - -To setup your plugin to allow for easy testing you'll need to add 3 files: - -* A database.yml file with all of your connection strings -* A schema.rb file with your table definitions -* A test helper that sets up the database before your tests - -For this plugin you'll need 2 tables/models, Hickwalls and Wickwalls, so add the following files: - - # File: vendor/plugins/yaffle/test/database.yml - - sqlite: - :adapter: sqlite - :dbfile: yaffle_plugin.sqlite.db - sqlite3: - :adapter: sqlite3 - :dbfile: yaffle_plugin.sqlite3.db - postgresql: - :adapter: postgresql - :username: postgres - :password: postgres - :database: yaffle_plugin_test - :min_messages: ERROR - mysql: - :adapter: mysql - :host: localhost - :username: rails - :password: - :database: yaffle_plugin_test - - # File: vendor/plugins/yaffle/test/test_helper.rb - - ActiveRecord::Schema.define(:version => 0) do - create_table :hickwalls, :force => true do |t| - t.string :name - t.string :last_squawk - t.datetime :last_squawked_at - end - create_table :wickwalls, :force => true do |t| - t.string :name - t.string :last_tweet - t.datetime :last_tweeted_at - end - end - - # File: vendor/plugins/yaffle/test/test_helper.rb - - ENV['RAILS_ENV'] = 'test' - ENV['RAILS_ROOT'] ||= File.dirname(__FILE__) + '/../../../..' - - require 'test/unit' - require File.expand_path(File.join(ENV['RAILS_ROOT'], 'config/environment.rb')) - - config = YAML::load(IO.read(File.dirname(__FILE__) + '/database.yml')) - ActiveRecord::Base.logger = Logger.new(File.dirname(__FILE__) + "/debug.log") - - db_adapter = ENV['DB'] - - # no db passed, try one of these fine config-free DBs before bombing. - db_adapter ||= - begin - require 'rubygems' - require 'sqlite' - 'sqlite' - rescue MissingSourceFile - begin - require 'sqlite3' - 'sqlite3' - rescue MissingSourceFile - end - end - - if db_adapter.nil? - raise "No DB Adapter selected. Pass the DB= option to pick one, or install Sqlite or Sqlite3." - end - - ActiveRecord::Base.establish_connection(config[db_adapter]) - - load(File.dirname(__FILE__) + "/schema.rb") - - require File.dirname(__FILE__) + '/../init.rb' - - class Hickwall < ActiveRecord::Base - acts_as_yaffle - end - - class Wickwall < ActiveRecord::Base - acts_as_yaffle :yaffle_text_field => :last_tweet, :yaffle_date_field => :last_tweeted_at - end - -Add a `to_squawk` method to String ------------------------ - -To update a core class you will have to: - -* Write tests for the desired functionality -* Create a file for the code you wish to use -* Require that file from your init.rb - -Most plugins store their code classes in the plugin's lib directory. When you add a file to the lib directory, you must also require that file from init.rb. The file you are going to add for this tutorial is `lib/core_ext.rb` - -First, you need to write the tests. Testing plugins is very similar to testing rails apps. The generated test file should look something like this: - - # File: vendor/plugins/yaffle/test/core_ext_test.rb - - require 'test/unit' - - class CoreExtTest < Test::Unit::TestCase - # Replace this with your real tests. - def test_this_plugin - flunk - end - end - -Start off by removing the default test, and adding a require statement for your test helper. - - # File: vendor/plugins/yaffle/test/core_ext_test.rb - - require 'test/unit' - require File.dirname(__FILE__) + '/test_helper.rb' - - class CoreExtTest < Test::Unit::TestCase - end - -Navigate to your plugin directory and run `rake test` - - cd vendor/plugins/yaffle - rake test - -Your test should fail with `no such file to load -- ./test/../lib/core_ext.rb (LoadError)` because we haven't created any file yet. Create the file `lib/core_ext.rb` and re-run the tests. You should see a different error message: - - 1.) Failure ... - No tests were specified - -Great - now you are ready to start development. The first thing we'll do is to add a method to String called `to_squawk` which will prefix the string with the word "squawk! ". The test will look something like this: - - # File: vendor/plugins/yaffle/init.rb - - class CoreExtTest < Test::Unit::TestCase - def test_string_should_respond_to_squawk - assert_equal true, "".respond_to?(:to_squawk) - end - def test_string_prepend_empty_strings_with_the_word_squawk - assert_equal "squawk!", "".to_squawk - end - def test_string_prepend_non_empty_strings_with_the_word_squawk - assert_equal "squawk! Hello World", "Hello World".to_squawk - end - end - - # File: vendor/plugins/yaffle/init.rb - - require "core_ext" - - # File: vendor/plugins/yaffle/lib/core_ext.rb - - String.class_eval do - def to_squawk - "squawk! #{self}".strip - end - end - -When monkey-patching existing classes it's often better to use `class_eval` instead of opening the class directly. - -To test that your method does what it says it does, run the unit tests. To test this manually, fire up a console and start squawking: - - script/console - >> "Hello World".to_squawk - => "squawk! Hello World" - -If that worked, congratulations! You just created your first test-driven plugin that extends a core ruby class. - -Add an `acts_as_yaffle` method to ActiveRecord ------------------------ - -A common pattern in plugins is to add a method called `acts_as_something` to models. In this case, you want to write a method called `acts_as_yaffle` that adds a squawk method to your models. - -To keep things clean, create a new test file called `acts_as_yaffle_test.rb` in your plugin's test directory and require your test helper. - - # File: vendor/plugins/yaffle/test/acts_as_yaffle_test.rb - - require File.dirname(__FILE__) + '/test_helper.rb' - - class Hickwall < ActiveRecord::Base - acts_as_yaffle - end - - class ActsAsYaffleTest < Test::Unit::TestCase - end - - # File: vendor/plugins/lib/acts_as_yaffle.rb - - module Yaffle - end - -One of the most common plugin patterns for `acts_as_yaffle` plugins is to structure your file like so: - - module Yaffle - def self.included(base) - base.send :extend, ClassMethods - end - - module ClassMethods - # any method placed here will apply to classes, like Hickwall - def acts_as_something - send :include, InstanceMethods - end - end - - module InstanceMethods - # any method placed here will apply to instaces, like @hickwall - end - end - -With structure you can easily separate the methods that will be used for the class (like `Hickwall.some_method`) and the instance (like `@hickwell.some_method`). - -Let's add class method named `acts_as_yaffle` - testing it out first. You already defined the ActiveRecord models in your test helper, so if you run tests now they will fail. - -Back in your `acts_as_yaffle` file, update ClassMethods like so: - - module ClassMethods - def acts_as_yaffle(options = {}) - send :include, InstanceMethods - end - end - -Now that test should pass. Since your plugin is going to work with field names, you need to allow people to define the field names, in case there is a naming conflict. You can write a few simple tests for this: - - # File: vendor/plugins/yaffle/test/acts_as_yaffle_test.rb - - require File.dirname(__FILE__) + '/test_helper.rb' - - class ActsAsYaffleTest < Test::Unit::TestCase - def test_a_hickwalls_yaffle_text_field_should_be_last_squawk - assert_equal "last_squawk", Hickwall.yaffle_text_field - end - def test_a_hickwalls_yaffle_date_field_should_be_last_squawked_at - assert_equal "last_squawked_at", Hickwall.yaffle_date_field - end - def test_a_wickwalls_yaffle_text_field_should_be_last_tweet - assert_equal "last_tweet", Wickwall.yaffle_text_field - end - def test_a_wickwalls_yaffle_date_field_should_be_last_tweeted_at - assert_equal "last_tweeted_at", Wickwall.yaffle_date_field - end - end - -To make these tests pass, you could modify your `acts_as_yaffle` file like so: - - # File: vendor/plugins/yaffle/lib/acts_as_yaffle.rb - - module Yaffle - def self.included(base) - base.send :extend, ClassMethods - end - - module ClassMethods - def acts_as_yaffle(options = {}) - cattr_accessor :yaffle_text_field, :yaffle_date_field - self.yaffle_text_field = (options[:yaffle_text_field] || :last_squawk).to_s - self.yaffle_date_field = (options[:yaffle_date_field] || :last_squawked_at).to_s - send :include, InstanceMethods - end - end - - module InstanceMethods - end - end - -Now you can add tests for the instance methods, and the instance method itself: - - # File: vendor/plugins/yaffle/test/acts_as_yaffle_test.rb - - require File.dirname(__FILE__) + '/test_helper.rb' - - class ActsAsYaffleTest < Test::Unit::TestCase - - def test_a_hickwalls_yaffle_text_field_should_be_last_squawk - assert_equal "last_squawk", Hickwall.yaffle_text_field - end - def test_a_hickwalls_yaffle_date_field_should_be_last_squawked_at - assert_equal "last_squawked_at", Hickwall.yaffle_date_field - end - - def test_a_wickwalls_yaffle_text_field_should_be_last_squawk - assert_equal "last_tweet", Wickwall.yaffle_text_field - end - def test_a_wickwalls_yaffle_date_field_should_be_last_squawked_at - assert_equal "last_tweeted_at", Wickwall.yaffle_date_field - end - - def test_hickwalls_squawk_should_populate_last_squawk - hickwall = Hickwall.new - hickwall.squawk("Hello World") - assert_equal "squawk! Hello World", hickwall.last_squawk - end - def test_hickwalls_squawk_should_populate_last_squawked_at - hickwall = Hickwall.new - hickwall.squawk("Hello World") - assert_equal Date.today, hickwall.last_squawked_at - end - - def test_wickwalls_squawk_should_populate_last_tweet - wickwall = Wickwall.new - wickwall.squawk("Hello World") - assert_equal "squawk! Hello World", wickwall.last_tweet - end - def test_wickwalls_squawk_should_populate_last_tweeted_at - wickwall = Wickwall.new - wickwall.squawk("Hello World") - assert_equal Date.today, wickwall.last_tweeted_at - end - end - - # File: vendor/plugins/yaffle/lib/acts_as_yaffle.rb - - module Yaffle - def self.included(base) - base.send :extend, ClassMethods - end - - module ClassMethods - def acts_as_yaffle(options = {}) - cattr_accessor :yaffle_text_field, :yaffle_date_field - self.yaffle_text_field = (options[:yaffle_text_field] || :last_squawk).to_s - self.yaffle_date_field = (options[:yaffle_date_field] || :last_squawked_at).to_s - send :include, InstanceMethods - end - end - - module InstanceMethods - def squawk(string) - write_attribute(self.class.yaffle_text_field, string.to_squawk) - write_attribute(self.class.yaffle_date_field, Date.today) - end - end - end - -Note the use of write_attribute to write to the field in model. - -Create a view helper ------------------------ - -Creating a view helper is a 3-step process: - -* Add an appropriately named file to the lib directory -* Require the file and hooks in init.rb -* Write the tests - -First, create the test to define the functionality you want: - - # File: vendor/plugins/yaffle/test/view_helpers_test.rb - - require File.dirname(__FILE__) + '/test_helper.rb' - include YaffleViewHelper - - class ViewHelpersTest < Test::Unit::TestCase - def test_squawk_info_for_should_return_the_text_and_date - time = Time.now - hickwall = Hickwall.new - hickwall.last_squawk = "Hello World" - hickwall.last_squawked_at = time - assert_equal "Hello World, #{time.to_s}", squawk_info_for(hickwall) - end - end - -Then add the following statements to init.rb: - - # File: vendor/plugins/yaffle/init.rb - - require "view_helpers" - ActionView::Base.send :include, YaffleViewHelper - -Then add the view helpers file and - - # File: vendor/plugins/yaffle/lib/view_helpers.rb - - module YaffleViewHelper - def squawk_info_for(yaffle) - returning "" do |result| - result << yaffle.read_attribute(yaffle.class.yaffle_text_field) - result << ", " - result << yaffle.read_attribute(yaffle.class.yaffle_date_field).to_s - end - end - end - -You can also test this in script/console by using the "helper" method: - - script/console - >> helper.squawk_info_for(@some_yaffle_instance) - -Create a migration generator ------------------------ - -When you created the plugin above, you specified the --with-generator option, so you already have the generator stubs in your plugin. - -We'll be relying on the built-in rails generate template for this tutorial. Going into the details of generators is beyond the scope of this tutorial. - -Type: - - script/generate - -You should see the line: - - Plugins (vendor/plugins): yaffle - -When you run `script/generate yaffle` you should see the contents of your USAGE file. For this plugin, the USAGE file looks like this: - - Description: - Creates a migration that adds yaffle squawk fields to the given model - - Example: - ./script/generate yaffle hickwall - - This will create: - db/migrate/TIMESTAMP_add_yaffle_fields_to_hickwall - -Now you can add code to your generator: - - # File: vendor/plugins/yaffle/generators/yaffle/yaffle_generator.rb - - class YaffleGenerator < Rails::Generator::NamedBase - def manifest - record do |m| - m.migration_template 'migration:migration.rb', "db/migrate", {:assigns => yaffle_local_assigns, - :migration_file_name => "add_yaffle_fields_to_#{custom_file_name}" - } - end - end - - private - def custom_file_name - custom_name = class_name.underscore.downcase - custom_name = custom_name.pluralize if ActiveRecord::Base.pluralize_table_names - end - - def yaffle_local_assigns - returning(assigns = {}) do - assigns[:migration_action] = "add" - assigns[:class_name] = "add_yaffle_fields_to_#{custom_file_name}" - assigns[:table_name] = custom_file_name - assigns[:attributes] = [Rails::Generator::GeneratedAttribute.new("last_squawk", "string")] - assigns[:attributes] << Rails::Generator::GeneratedAttribute.new("last_squawked_at", "datetime") - end - end - end - -Note that you need to be aware of whether or not table names are pluralized. - -This does a few things: - -* Reuses the built in rails migration_template method -* Reuses the built-in rails migration template - -When you run the generator like - - script/generate yaffle bird - -You will see a new file: - - # File: db/migrate/20080529225649_add_yaffle_fields_to_birds.rb - - class AddYaffleFieldsToBirds < ActiveRecord::Migration - def self.up - add_column :birds, :last_squawk, :string - add_column :birds, :last_squawked_at, :datetime - end - - def self.down - remove_column :birds, :last_squawked_at - remove_column :birds, :last_squawk - end - end - -Add a custom generator command ------------------------- - -You may have noticed above that you can used one of the built-in rails migration commands `m.migration_template`. You can create your own commands for these, using the following steps: - -1. Add the require and hook statements to init.rb -2. Create the commands - creating 3 sets, Create, Destroy, List -3. Add the method to your generator - -Working with the internals of generators is beyond the scope of this tutorial, but here is a basic example: - - # File: vendor/plugins/yaffle/init.rb - - require "commands" - Rails::Generator::Commands::Create.send :include, Yaffle::Generator::Commands::Create - Rails::Generator::Commands::Destroy.send :include, Yaffle::Generator::Commands::Destroy - Rails::Generator::Commands::List.send :include, Yaffle::Generator::Commands::List - - # File: vendor/plugins/yaffle/lib/commands.rb - - require 'rails_generator' - require 'rails_generator/commands' - - module Yaffle #:nodoc: - module Generator #:nodoc: - module Commands #:nodoc: - module Create - def yaffle_definition - file("definition.txt", "definition.txt") - end - end - - module Destroy - def yaffle_definition - file("definition.txt", "definition.txt") - end - end - - module List - def yaffle_definition - file("definition.txt", "definition.txt") - end - end - end - end - end - - # File: vendor/plugins/yaffle/generators/yaffle/templates/definition.txt - - Yaffle is a bird - - # File: vendor/plugins/yaffle/generators/yaffle/yaffle_generator.rb - - class YaffleGenerator < Rails::Generator::NamedBase - def manifest - m.yaffle_definition - end - end - end - -This example just uses the built-in "file" method, but you could do anything that ruby allows. - -Add a Custom Route ------------------------- - -Testing routes in plugins can be complex, especially if the controllers are also in the plugin itself. Jamis Buck showed a great example of this in [http://weblog.jamisbuck.org/2006/10/26/monkey-patching-rails-extending-routes-2](http://weblog.jamisbuck.org/2006/10/26/monkey-patching-rails-extending-routes-2) - - # File: vendor/plugins/yaffle/test/routing_test.rb - - require "#{File.dirname(__FILE__)}/test_helper" - - class RoutingTest < Test::Unit::TestCase - - def setup - ActionController::Routing::Routes.draw do |map| - map.yaffles - end - end - - def test_yaffles_route - assert_recognition :get, "/yaffles", :controller => "yaffles_controller", :action => "index" - end - - private - - # yes, I know about assert_recognizes, but it has proven problematic to - # use in these tests, since it uses RouteSet#recognize (which actually - # tries to instantiate the controller) and because it uses an awkward - # parameter order. - def assert_recognition(method, path, options) - result = ActionController::Routing::Routes.recognize_path(path, :method => method) - assert_equal options, result - end - end - - # File: vendor/plugins/yaffle/init.rb - - require "routing" - ActionController::Routing::RouteSet::Mapper.send :include, Yaffle::Routing::MapperExtensions - - # File: vendor/plugins/yaffle/lib/routing.rb - - module Yaffle #:nodoc: - module Routing #:nodoc: - module MapperExtensions - def yaffles - @set.add_route("/yaffles", {:controller => "yaffles_controller", :action => "index"}) - end - end - end - end - - # File: config/routes.rb - - ActionController::Routing::Routes.draw do |map| - ... - map.yaffles - end - -You can also see if your routes work by running `rake routes` from your app directory. - -Generate RDoc Documentation ------------------------ - -Once your plugin is stable, the tests pass on all database and you are ready to deploy do everyone else a favor and document it! Luckily, writing documentation for your plugin is easy. - -The first step is to update the README file with detailed information about how to use your plugin. A few key things to include are: - -* Your name -* How to install -* How to add the functionality to the app (several examples of common use cases) -* Warning, gotchas or tips that might help save users time - -Once your README is solid, go through and add rdoc comments to all of the methods that developers will use. - -Before you generate your documentation, be sure to go through and add nodoc comments to those modules and methods that are not important to your users. - -Once your comments are good to go, navigate to your plugin directory and run - - rake rdoc - -Work with init.rb ------------------------- - -The plugin initializer script init.rb is invoked via `eval` (not require) so it has slightly different behavior. - -If you reopen any classes in init.rb itself your changes will potentially be made to the wrong module. There are 2 ways around this: - -The first way is to explicitly define the top-level module space for all modules and classes, like ::Hash - - # File: vendor/plugins/yaffle/init.rb - - class ::Hash - def is_a_special_hash? - true - end - end - -OR you can use `module_eval` or `class_eval` - - # File: vendor/plugins/yaffle/init.rb - - Hash.class_eval do - def is_a_special_hash? - true - end - end - -Store models, views, helpers, and controllers in your plugins ------------------------- - -You can easily store models, views, helpers and controllers in plugins. Just create a folder for each in the lib folder, add them to the load path and remove them from the load once path: - - # File: vendor/plugins/yaffle/init.rb - - %w{ models controllers helpers }.each do |dir| - path = File.join(directory, 'lib', dir) - $LOAD_PATH << path - Dependencies.load_paths << path - Dependencies.load_once_paths.delete(path) - end - -Adding directories to the load path makes them appear just like files in the the main app directory - except that they are only loaded once, so you have to restart the web server to see the changes in the browser. - -Adding directories to the load once paths allow those changes to picked up as soon as you save the file - without having to restart the web server. - -Write custom rake tasks in your plugin -------------------------- - -When you created the plugin with the built-in rails generator, it generated a rake file for you in `vendor/plugins/yaffle/tasks/yaffle.rake`. Any rake task you add here will be available to the app. - -Many plugin authors put all of their rake tasks into a common namespace that is the same as the plugin, like so: - - # File: vendor/plugins/yaffle/tasks/yaffle.rake - - namespace :yaffle do - desc "Prints out the word 'Yaffle'" - task :squawk => :environment do - puts "squawk!" - end - end - -When you run `rake -T` from your plugin you will see - - yaffle:squawk "Prints out..." - -You can add as many files as you want in the tasks directory, and if they end in .rake Rails will pick them up. - -Store plugins in alternate locations -------------------------- - -You can store plugins wherever you want - you just have to add those plugins to the plugins path in environment.rb - -Since the plugin is only loaded after the plugin paths are defined, you can't redefine this in your plugins - but it may be good to now. - -You can even store plugins inside of other plugins for complete plugin madness! - - config.plugin_paths << File.join(RAILS_ROOT,"vendor","plugins","yaffle","lib","plugins") - -Create your own Plugin Loaders and Plugin Locators ------------------------- - -If the built-in plugin behavior is inadequate, you can change almost every aspect of the location and loading process. You can write your own plugin locators and plugin loaders, but that's beyond the scope of this tutorial. - -Use Custom Plugin Generators ------------------------- - -If you are an RSpec fan, you can install the `rspec_plugin_generator`, which will generate the spec folder and database for you. - -[http://github.com/pat-maddox/rspec-plugin-generator/tree/master](http://github.com/pat-maddox/rspec-plugin-generator/tree/master) - -References ------------------------- - -* [http://nubyonrails.com/articles/the-complete-guide-to-rails-plugins-part-i](http://nubyonrails.com/articles/the-complete-guide-to-rails-plugins-part-i) -* [http://nubyonrails.com/articles/2006/05/09/the-complete-guide-to-rails-plugins-part-ii](http://nubyonrails.com/articles/2006/05/09/the-complete-guide-to-rails-plugins-part-ii) -* [http://github.com/technoweenie/attachment_fu/tree/master](http://github.com/technoweenie/attachment_fu/tree/master) -* [http://daddy.platte.name/2007/05/rails-plugins-keep-initrb-thin.html](http://daddy.platte.name/2007/05/rails-plugins-keep-initrb-thin.html) - -Appendices ------------------------- - -The final plugin should have a directory structure that looks something like this: - - |-- MIT-LICENSE - |-- README - |-- Rakefile - |-- generators - | `-- yaffle - | |-- USAGE - | |-- templates - | | `-- definition.txt - | `-- yaffle_generator.rb - |-- init.rb - |-- install.rb - |-- lib - | |-- acts_as_yaffle.rb - | |-- commands.rb - | |-- core_ext.rb - | |-- routing.rb - | `-- view_helpers.rb - |-- tasks - | `-- yaffle_tasks.rake - |-- test - | |-- acts_as_yaffle_test.rb - | |-- core_ext_test.rb - | |-- database.yml - | |-- debug.log - | |-- routing_test.rb - | |-- schema.rb - | |-- test_helper.rb - | `-- view_helpers_test.rb - |-- uninstall.rb - `-- yaffle_plugin.sqlite3.db diff --git a/railties/doc/guides/source/creating_plugins/controllers.txt b/railties/doc/guides/source/creating_plugins/controllers.txt new file mode 100644 index 0000000000..ee408adb1d --- /dev/null +++ b/railties/doc/guides/source/creating_plugins/controllers.txt @@ -0,0 +1,59 @@ +== Add a controller == + +This section describes how to add a controller named 'woodpeckers' to your plugin that will behave the same as a controller in your main app. This is very similar to adding a model. + +You can test your plugin's controller as you would test any other controller: + +*vendor/plugins/yaffle/yaffle/woodpeckers_controller_test.rb:* + +[source, ruby] +---------------------------------------------- +require File.dirname(__FILE__) + '/test_helper.rb' +require 'woodpeckers_controller' +require 'action_controller/test_process' + +class WoodpeckersController; def rescue_action(e) raise e end; end + +class WoodpeckersControllerTest < Test::Unit::TestCase + def setup + @controller = WoodpeckersController.new + @request = ActionController::TestRequest.new + @response = ActionController::TestResponse.new + end + + def test_index + get :index + assert_response :success + end +end +---------------------------------------------- + +This is just a simple test to make sure the controller is being loaded correctly. After watching it fail with `rake`, you can make it pass like so: + +*vendor/plugins/yaffle/lib/yaffle.rb:* + +[source, ruby] +---------------------------------------------- +%w{ models controllers }.each do |dir| + path = File.join(File.dirname(__FILE__), 'app', dir) + $LOAD_PATH << path + ActiveSupport::Dependencies.load_paths << path + ActiveSupport::Dependencies.load_once_paths.delete(path) +end +---------------------------------------------- + + +*vendor/plugins/yaffle/lib/app/controllers/woodpeckers_controller.rb:* + +[source, ruby] +---------------------------------------------- +class WoodpeckersController < ActionController::Base + + def index + render :text => "Squawk!" + end + +end +---------------------------------------------- + +Now your test should be passing, and you should be able to use the Woodpeckers controller in your app. If you add a route for the woodpeckers controller you can start up your server and go to http://localhost:3000/woodpeckers to see your controller in action. diff --git a/railties/doc/guides/source/creating_plugins/core_ext.txt b/railties/doc/guides/source/creating_plugins/core_ext.txt new file mode 100644 index 0000000000..ca8efc3df1 --- /dev/null +++ b/railties/doc/guides/source/creating_plugins/core_ext.txt @@ -0,0 +1,123 @@ +== Extending core classes == + +This section will explain how to add a method to String that will be available anywhere in your rails app by: + + * Writing tests for the desired behavior + * Creating and requiring the correct files + +=== Creating the test === + +In this example you will add a method to String named `to_squawk`. To begin, create a new test file with a few assertions: + +*vendor/plugins/yaffle/test/core_ext_test.rb* + +[source, ruby] +-------------------------------------------------------- +require File.dirname(__FILE__) + '/test_helper.rb' + +class CoreExtTest < Test::Unit::TestCase + def test_to_squawk_prepends_the_word_squawk + assert_equal "squawk! Hello World", "Hello World".to_squawk + end +end +-------------------------------------------------------- + +Navigate to your plugin directory and run `rake test`: + +-------------------------------------------------------- +cd vendor/plugins/yaffle +rake test +-------------------------------------------------------- + +The test above should fail with the message: + +-------------------------------------------------------- + 1) Error: +test_to_squawk_prepends_the_word_squawk(CoreExtTest): +NoMethodError: undefined method `to_squawk' for "Hello World":String + ./test/core_ext_test.rb:5:in `test_to_squawk_prepends_the_word_squawk' +-------------------------------------------------------- + +Great - now you are ready to start development. + +=== Organize your files === + +A common pattern in rails plugins is to set up the file structure like this: + +-------------------------------------------------------- +|-- lib +| |-- yaffle +| | `-- core_ext.rb +| `-- yaffle.rb +-------------------------------------------------------- + +The first thing we need to to is to require our 'lib/yaffle.rb' file from 'rails/init.rb': + +*vendor/plugins/yaffle/rails/init.rb* + +[source, ruby] +-------------------------------------------------------- +require 'yaffle' +-------------------------------------------------------- + +Then in 'lib/yaffle.rb' require 'lib/core_ext.rb': + +*vendor/plugins/yaffle/lib/yaffle.rb* + +[source, ruby] +-------------------------------------------------------- +require "yaffle/core_ext" +-------------------------------------------------------- + +Finally, create the 'core_ext.rb' file and add the 'to_squawk' method: + +*vendor/plugins/yaffle/lib/yaffle/core_ext.rb* + +[source, ruby] +-------------------------------------------------------- +String.class_eval do + def to_squawk + "squawk! #{self}".strip + end +end +-------------------------------------------------------- + +To test that your method does what it says it does, run the unit tests with `rake` from your plugin directory. To see this in action, fire up a console and start squawking: + +-------------------------------------------------------- +$ ./script/console +>> "Hello World".to_squawk +=> "squawk! Hello World" +-------------------------------------------------------- + +=== Working with init.rb === + +When rails loads plugins it looks for the file named init.rb. However, when the plugin is initialized, 'init.rb' is invoked via `eval` (not `require`) so it has slightly different behavior. + +Under certain circumstances if you reopen classes or modules in 'init.rb' you may inadvertently create a new class, rather than reopening an existing class. A better alternative is to reopen the class in a different file, and require that file from `init.rb`, as shown above. + +If you must reopen a class in `init.rb` you can use `module_eval` or `class_eval` to avoid any issues: + +*vendor/plugins/yaffle/init.rb* + +[source, ruby] +--------------------------------------------------- +Hash.class_eval do + def is_a_special_hash? + true + end +end +--------------------------------------------------- + +Another way is to explicitly define the top-level module space for all modules and classes, like `::Hash`: + +*vendor/plugins/yaffle/init.rb* + +[source, ruby] +--------------------------------------------------- +class ::Hash + def is_a_special_hash? + true + end +end +--------------------------------------------------- diff --git a/railties/doc/guides/source/creating_plugins/custom_route.txt b/railties/doc/guides/source/creating_plugins/custom_route.txt index 7e399247ee..1fce902a4e 100644 --- a/railties/doc/guides/source/creating_plugins/custom_route.txt +++ b/railties/doc/guides/source/creating_plugins/custom_route.txt @@ -2,10 +2,10 @@ Testing routes in plugins can be complex, especially if the controllers are also in the plugin itself. Jamis Buck showed a great example of this in http://weblog.jamisbuck.org/2006/10/26/monkey-patching-rails-extending-routes-2. +*vendor/plugins/yaffle/test/routing_test.rb* + [source, ruby] -------------------------------------------------------- -# File: vendor/plugins/yaffle/test/routing_test.rb - require "#{File.dirname(__FILE__)}/test_helper" class RoutingTest < Test::Unit::TestCase @@ -33,18 +33,18 @@ class RoutingTest < Test::Unit::TestCase end -------------------------------------------------------- +*vendor/plugins/yaffle/init.rb* + [source, ruby] -------------------------------------------------------- -# File: vendor/plugins/yaffle/init.rb - require "routing" ActionController::Routing::RouteSet::Mapper.send :include, Yaffle::Routing::MapperExtensions -------------------------------------------------------- +*vendor/plugins/yaffle/lib/routing.rb* + [source, ruby] -------------------------------------------------------- -# File: vendor/plugins/yaffle/lib/routing.rb - module Yaffle #:nodoc: module Routing #:nodoc: module MapperExtensions @@ -56,10 +56,10 @@ module Yaffle #:nodoc: end -------------------------------------------------------- +*config/routes.rb* + [source, ruby] -------------------------------------------------------- -# File: config/routes.rb - ActionController::Routing::Routes.draw do |map| ... map.yaffles diff --git a/railties/doc/guides/source/creating_plugins/gem.txt b/railties/doc/guides/source/creating_plugins/gem.txt new file mode 100644 index 0000000000..93f5e0ee89 --- /dev/null +++ b/railties/doc/guides/source/creating_plugins/gem.txt @@ -0,0 +1 @@ +http://www.mbleigh.com/2008/6/11/gemplugins-a-brief-introduction-to-the-future-of-rails-plugins
\ No newline at end of file diff --git a/railties/doc/guides/source/creating_plugins/custom_generator.txt b/railties/doc/guides/source/creating_plugins/generator_method.txt index 6d9613ea01..126692f2c4 100644 --- a/railties/doc/guides/source/creating_plugins/custom_generator.txt +++ b/railties/doc/guides/source/creating_plugins/generator_method.txt @@ -1,26 +1,41 @@ == Add a custom generator command == -You may have noticed above that you can used one of the built-in rails migration commands `m.migration_template`. You can create your own commands for these, using the following steps: +You may have noticed above that you can used one of the built-in rails migration commands `migration_template`. If your plugin needs to add and remove lines of text from existing files you will need to write your own generator methods. - 1. Add the require and hook statements to init.rb. - 2. Create the commands - creating 3 sets, Create, Destroy, List. - 3. Add the method to your generator. +This section describes how you you can create your own commands to add and remove a line of text from 'routes.rb'. This example creates a very simple method that adds or removes a text file. -Working with the internals of generators is beyond the scope of this tutorial, but here is a basic example: +To start, add the following test method: + +*vendor/plugins/yaffle/test/generator_test.rb* [source, ruby] ----------------------------------------------------------- -# File: vendor/plugins/yaffle/init.rb -require "commands" -Rails::Generator::Commands::Create.send :include, Yaffle::Generator::Commands::Create -Rails::Generator::Commands::Destroy.send :include, Yaffle::Generator::Commands::Destroy -Rails::Generator::Commands::List.send :include, Yaffle::Generator::Commands::List +def test_generates_definition + Rails::Generator::Scripts::Generate.new.run(["yaffle", "bird"], :destination => fake_rails_root) + definition = File.read(File.join(fake_rails_root, "definition.txt")) + assert_match /Yaffle\:/, definition +end +----------------------------------------------------------- + +Run `rake` to watch the test fail, then make the test pass add the following: + +*vendor/plugins/yaffle/generators/yaffle/templates/definition.txt* + ----------------------------------------------------------- +Yaffle: A bird +----------------------------------------------------------- + +*vendor/plugins/yaffle/lib/yaffle.rb* [source, ruby] ----------------------------------------------------------- -# File: vendor/plugins/yaffle/lib/commands.rb +require "yaffle/commands" +----------------------------------------------------------- + +*vendor/plugins/yaffle/lib/commands.rb* +[source, ruby] +----------------------------------------------------------- require 'rails_generator' require 'rails_generator/commands' @@ -44,26 +59,31 @@ module Yaffle #:nodoc: file("definition.txt", "definition.txt") end end + + module Update + def yaffle_definition + file("definition.txt", "definition.txt") + end + end end end end ------------------------------------------------------------ +Rails::Generator::Commands::Create.send :include, Yaffle::Generator::Commands::Create +Rails::Generator::Commands::Destroy.send :include, Yaffle::Generator::Commands::Destroy +Rails::Generator::Commands::List.send :include, Yaffle::Generator::Commands::List +Rails::Generator::Commands::Update.send :include, Yaffle::Generator::Commands::Update ----------------------------------------------------------- -# File: vendor/plugins/yaffle/generators/yaffle/templates/definition.txt -Yaffle is a bird ------------------------------------------------------------ +Finally, call your new method in the manifest: + +*vendor/plugins/yaffle/generators/yaffle/yaffle_generator.rb* [source, ruby] ----------------------------------------------------------- -# File: vendor/plugins/yaffle/generators/yaffle/yaffle_generator.rb - class YaffleGenerator < Rails::Generator::NamedBase def manifest m.yaffle_definition end end ----------------------------------------------------------- - -This example just uses the built-in "file" method, but you could do anything that Ruby allows. diff --git a/railties/doc/guides/source/creating_plugins/helpers.txt b/railties/doc/guides/source/creating_plugins/helpers.txt new file mode 100644 index 0000000000..51b4cebb01 --- /dev/null +++ b/railties/doc/guides/source/creating_plugins/helpers.txt @@ -0,0 +1,51 @@ +== Add a helper == + +This section describes how to add a helper named 'WoodpeckersHelper' to your plugin that will behave the same as a helper in your main app. This is very similar to adding a model and a controller. + +You can test your plugin's helper as you would test any other helper: + +*vendor/plugins/yaffle/test/woodpeckers_helper_test.rb* + +[source, ruby] +--------------------------------------------------------------- +require File.dirname(__FILE__) + '/test_helper.rb' +include WoodpeckersHelper + +class WoodpeckersHelperTest < Test::Unit::TestCase + def test_tweet + assert_equal "Tweet! Hello", tweet("Hello") + end +end +--------------------------------------------------------------- + +This is just a simple test to make sure the helper is being loaded correctly. After watching it fail with `rake`, you can make it pass like so: + +*vendor/plugins/yaffle/lib/yaffle.rb:* + +[source, ruby] +---------------------------------------------- +%w{ models controllers helpers }.each do |dir| + path = File.join(File.dirname(__FILE__), 'app', dir) + $LOAD_PATH << path + ActiveSupport::Dependencies.load_paths << path + ActiveSupport::Dependencies.load_once_paths.delete(path) +end + +ActionView::Base.send :include, WoodpeckersHelper +---------------------------------------------- + + +*vendor/plugins/yaffle/lib/app/helpers/woodpeckers_helper.rb:* + +[source, ruby] +---------------------------------------------- +module WoodpeckersHelper + + def tweet(text) + "Tweet! #{text}" + end + +end +---------------------------------------------- + +Now your test should be passing, and you should be able to use the Woodpeckers helper in your app. diff --git a/railties/doc/guides/source/creating_plugins/index.txt b/railties/doc/guides/source/creating_plugins/index.txt index f2ed6ed8bb..19484e2830 100644 --- a/railties/doc/guides/source/creating_plugins/index.txt +++ b/railties/doc/guides/source/creating_plugins/index.txt @@ -1,81 +1,49 @@ The Basics of Creating Rails Plugins ==================================== -Pretend for a moment that you are an avid bird watcher. Your favorite bird is the Yaffle, and you want to create a plugin that allows other developers to share in the Yaffle goodness. - -In this tutorial you will learn how to create a plugin that includes: - - * Core Extensions - extending String with a `to_squawk` method: -+ -[source, ruby] -------------------------------------------- -# Anywhere -"hello!".to_squawk # => "squawk! hello!" -------------------------------------------- - -* An `acts_as_yaffle` method for ActiveRecord models that adds a `squawk` method: -+ -[source, ruby] -------------------------------------------- -class Hickwall < ActiveRecord::Base - acts_as_yaffle :yaffle_text_field => :last_sang_at -end - -Hickwall.new.squawk("Hello World") -------------------------------------------- - -* A view helper that will print out squawking info: -+ -[source, ruby] -------------------------------------------- -squawk_info_for(@hickwall) -------------------------------------------- - -* A generator that creates a migration to add squawk columns to a model: -+ -------------------------------------------- -script/generate yaffle hickwall -------------------------------------------- - -* A custom generator command: -+ -[source, ruby] -------------------------------------------- -class YaffleGenerator < Rails::Generator::NamedBase - def manifest - m.yaffle_definition - end -end -------------------------------------------- - -* A custom route method: -+ -[source, ruby] -------------------------------------------- -ActionController::Routing::Routes.draw do |map| - map.yaffles -end -------------------------------------------- - -In addition you'll learn how to: - - * test your plugins. - * work with 'init.rb', how to store model, views, controllers, helpers and even other plugins in your plugins. - * create documentation for your plugin. - * write custom Rake tasks in your plugin. - - -include::preparation.txt[] - -include::string_to_squawk.txt[] +A Rails plugin is either an extension or a modification of the core framework. Plugins provide: + + * a way for developers to share bleeding-edge ideas without hurting the stable code base + * a segmented architecture so that units of code can be fixed or updated on their own release schedule + * an outlet for the core developers so that they don’t have to include every cool new feature under the sun + +After reading this guide you should be familiar with: + + * Creating a plugin from scratch + * Writing and running tests for the plugin + * Storing models, views, controllers, helpers and even other plugins in your plugins + * Writing generators + * Writing custom Rake tasks in your plugin + * Generating RDoc documentation for your plugin + * Avoiding common pitfalls with 'init.rb' + +This guide describes how to build a test-driven plugin that will: + + * Extend core ruby classes like Hash and String + * Add methods to ActiveRecord::Base in the tradition of the 'acts_as' plugins + * Add a view helper that can be used in erb templates + * Add a new generator that will generate a migration + * Add a custom generator command + * A custom route method that can be used in routes.rb + +For the purpose of this guide pretend for a moment that you are an avid bird watcher. Your favorite bird is the Yaffle, and you want to create a plugin that allows other developers to share in the Yaffle goodness. First, you need to get setup for development. -include::acts_as_yaffle.txt[] -include::view_helper.txt[] +include::test_setup.txt[] + +include::core_ext.txt[] + +include::acts_as_yaffle.txt[] include::migration_generator.txt[] -include::custom_generator.txt[] +include::generator_method.txt[] + +include::models.txt[] + +include::controllers.txt[] + +include::helpers.txt[] include::custom_route.txt[] diff --git a/railties/doc/guides/source/creating_plugins/migration_generator.txt b/railties/doc/guides/source/creating_plugins/migration_generator.txt index 598a0c8437..f4fc32481c 100644 --- a/railties/doc/guides/source/creating_plugins/migration_generator.txt +++ b/railties/doc/guides/source/creating_plugins/migration_generator.txt @@ -1,42 +1,79 @@ -== Create a migration generator == +== Create a generator == -When you created the plugin above, you specified the --with-generator option, so you already have the generator stubs in your plugin. +Many plugins ship with generators. When you created the plugin above, you specified the --with-generator option, so you already have the generator stubs in 'vendor/plugins/yaffle/generators/yaffle'. -We'll be relying on the built-in rails generate template for this tutorial. Going into the details of generators is beyond the scope of this tutorial. +Building generators is a complex topic unto itself and this section will cover one small aspect of generators: creating a generator that adds a time-stamped migration. -Type: +To create a generator you must: - script/generate + * Add your instructions to the 'manifest' method of the generator + * Add any necessary template files to the templates directory + * Test the generator manually by running various combinations of `script/generate` and `script/destroy` + * Update the USAGE file to add helpful documentation for your generator -You should see the line: +=== Testing generators === - Plugins (vendor/plugins): yaffle +Many rails plugin authors do not test their generators, however testing generators is quite simple. A typical generator test does the following: -When you run `script/generate yaffle` you should see the contents of your USAGE file. For this plugin, the USAGE file looks like this: + * Creates a new fake rails root directory that will serve as destination + * Runs the generator forward and backward, making whatever assertions are necessary + * Removes the fake rails root +For the generator in this section, the test could look something like this: + +*vendor/plugins/yaffle/test/yaffle_generator_test.rb* + +[source, ruby] ------------------------------------------------------------------ -Description: - Creates a migration that adds yaffle squawk fields to the given model +require File.dirname(__FILE__) + '/test_helper.rb' +require 'rails_generator' +require 'rails_generator/scripts/generate' +require 'rails_generator/scripts/destroy' -Example: - ./script/generate yaffle hickwall +class GeneratorTest < Test::Unit::TestCase - This will create: - db/migrate/TIMESTAMP_add_yaffle_fields_to_hickwall + def fake_rails_root + File.join(File.dirname(__FILE__), 'rails_root') + end + + def file_list + Dir.glob(File.join(fake_rails_root, "db", "migrate", "*")) + end + + def setup + FileUtils.mkdir_p(fake_rails_root) + @original_files = file_list + end + + def teardown + FileUtils.rm_r(fake_rails_root) + end + + def test_generates_correct_file_name + Rails::Generator::Scripts::Generate.new.run(["yaffle", "bird"], :destination => fake_rails_root) + new_file = (file_list - @original_files).first + assert_match /add_yaffle_fields_to_bird/, new_file + end + +end ------------------------------------------------------------------ -Now you can add code to your generator: +You can run 'rake' from the plugin directory to see this fail. Unless you are doing more advanced generator commands it typically suffices to just test the Generate script, and trust that rails will handle the Destroy and Update commands for you. + +=== Adding to the manifest === + +This example will demonstrate how to use one of the built-in generator methods named 'migration_template' to create a migration file. To start, update your generator file to look like this: + +*vendor/plugins/yaffle/generators/yaffle/yaffle_generator.rb* [source, ruby] ------------------------------------------------------------------ -# File: vendor/plugins/yaffle/generators/yaffle/yaffle_generator.rb - class YaffleGenerator < Rails::Generator::NamedBase def manifest record do |m| m.migration_template 'migration:migration.rb', "db/migrate", {:assigns => yaffle_local_assigns, :migration_file_name => "add_yaffle_fields_to_#{custom_file_name}" - } + } end end @@ -52,38 +89,68 @@ class YaffleGenerator < Rails::Generator::NamedBase assigns[:class_name] = "add_yaffle_fields_to_#{custom_file_name}" assigns[:table_name] = custom_file_name assigns[:attributes] = [Rails::Generator::GeneratedAttribute.new("last_squawk", "string")] - assigns[:attributes] << Rails::Generator::GeneratedAttribute.new("last_squawked_at", "datetime") end end end ------------------------------------------------------------------ -Note that you need to be aware of whether or not table names are pluralized. +The generator creates a new file in 'db/migrate' with a timestamp and an 'add_column' statement. It reuses the built in rails `migration_template` method, and reuses the built-in rails migration template. -This does a few things: +It's courteous to check to see if table names are being pluralized whenever you create a generator that needs to be aware of table names. This way people using your generator won't have to manually change the generated files if they've turned pluralization off. - * Reuses the built in rails `migration_template` method. - * Reuses the built-in rails migration template. +=== Manually test the generator === -When you run the generator like +To run the generator, type the following at the command line: + +------------------------------------------------------------------ +./script/generate yaffle bird +------------------------------------------------------------------ - script/generate yaffle bird +and you will see a new file: -You will see a new file: +*db/migrate/20080529225649_add_yaffle_fields_to_birds.rb* [source, ruby] ------------------------------------------------------------------ -# File: db/migrate/20080529225649_add_yaffle_fields_to_birds.rb - class AddYaffleFieldsToBirds < ActiveRecord::Migration def self.up add_column :birds, :last_squawk, :string - add_column :birds, :last_squawked_at, :datetime end def self.down - remove_column :birds, :last_squawked_at remove_column :birds, :last_squawk end end ------------------------------------------------------------------ + + +=== The USAGE file === + +Rails ships with several built-in generators. You can see all of the generators available to you by typing the following at the command line: + +------------------------------------------------------------------ +script/generate +------------------------------------------------------------------ + +You should see something like this: + +------------------------------------------------------------------ +Installed Generators + Plugins (vendor/plugins): yaffle + Builtin: controller, integration_test, mailer, migration, model, observer, plugin, resource, scaffold, session_migration +------------------------------------------------------------------ + +When you run `script/generate yaffle` you should see the contents of your 'vendor/plugins/yaffle/generators/yaffle/USAGE' file. + +For this plugin, update the USAGE file looks like this: + +------------------------------------------------------------------ +Description: + Creates a migration that adds yaffle squawk fields to the given model + +Example: + ./script/generate yaffle hickwall + + This will create: + db/migrate/TIMESTAMP_add_yaffle_fields_to_hickwall +------------------------------------------------------------------ diff --git a/railties/doc/guides/source/creating_plugins/models.txt b/railties/doc/guides/source/creating_plugins/models.txt new file mode 100644 index 0000000000..458edec80a --- /dev/null +++ b/railties/doc/guides/source/creating_plugins/models.txt @@ -0,0 +1,76 @@ +== Add a model == + +This section describes how to add a model named 'Woodpecker' to your plugin that will behave the same as a model in your main app. When storing models, controllers, views and helpers in your plugin, it's customary to keep them in directories that match the rails directories. For this example, create a file structure like this: + +--------------------------------------------------------- +vendor/plugins/yaffle/ +|-- lib +| |-- app +| | |-- controllers +| | |-- helpers +| | |-- models +| | | `-- woodpecker.rb +| | `-- views +| |-- yaffle +| | |-- acts_as_yaffle.rb +| | |-- commands.rb +| | `-- core_ext.rb +| `-- yaffle.rb +--------------------------------------------------------- + +As always, start with a test: + +*vendor/plugins/yaffle/yaffle/woodpecker_test.rb:* + +[source, ruby] +---------------------------------------------- +require File.dirname(__FILE__) + '/test_helper.rb' + +class WoodpeckerTest < Test::Unit::TestCase + load_schema + + def test_woodpecker + assert_kind_of Woodpecker, Woodpecker.new + end +end +---------------------------------------------- + +This is just a simple test to make sure the class is being loaded correctly. After watching it fail with `rake`, you can make it pass like so: + +*vendor/plugins/yaffle/lib/yaffle.rb:* + +[source, ruby] +---------------------------------------------- +%w{ models }.each do |dir| + path = File.join(File.dirname(__FILE__), 'app', dir) + $LOAD_PATH << path + ActiveSupport::Dependencies.load_paths << path + ActiveSupport::Dependencies.load_once_paths.delete(path) +end +---------------------------------------------- + +Adding directories to the load path makes them appear just like files in the the main app directory - except that they are only loaded once, so you have to restart the web server to see the changes in the browser. Removing directories from the 'load_once_paths' allow those changes to picked up as soon as you save the file - without having to restart the web server. This is particularly useful as you develop the plugin. + + +*vendor/plugins/yaffle/lib/app/models/woodpecker.rb:* + +[source, ruby] +---------------------------------------------- +class Woodpecker < ActiveRecord::Base +end +---------------------------------------------- + +Finally, add the following to your plugin's 'schema.rb': + +*vendor/plugins/yaffle/test/schema.rb:* + +[source, ruby] +---------------------------------------------- +ActiveRecord::Schema.define(:version => 0) do + create_table :woodpeckers, :force => true do |t| + t.string :name + end +end +---------------------------------------------- + +Now your test should be passing, and you should be able to use the Woodpecker model from within your rails app, and any changes made to it are reflected immediately when running in development mode.
\ No newline at end of file diff --git a/railties/doc/guides/source/creating_plugins/odds_and_ends.txt b/railties/doc/guides/source/creating_plugins/odds_and_ends.txt index eb127f73ca..e328c04a79 100644 --- a/railties/doc/guides/source/creating_plugins/odds_and_ends.txt +++ b/railties/doc/guides/source/creating_plugins/odds_and_ends.txt @@ -1,36 +1,5 @@ == Odds and ends == -=== Work with init.rb === - -The plugin initializer script 'init.rb' is invoked via `eval` (not `require`) so it has slightly different behavior. - -If you reopen any classes in init.rb itself your changes will potentially be made to the wrong module. There are 2 ways around this: - -The first way is to explicitly define the top-level module space for all modules and classes, like `::Hash`: - -[source, ruby] ---------------------------------------------------- -# File: vendor/plugins/yaffle/init.rb - -class ::Hash - def is_a_special_hash? - true - end -end ---------------------------------------------------- - -OR you can use `module_eval` or `class_eval`: - ---------------------------------------------------- -# File: vendor/plugins/yaffle/init.rb - -Hash.class_eval do - def is_a_special_hash? - true - end -end ---------------------------------------------------- - === Generate RDoc Documentation === Once your plugin is stable, the tests pass on all database and you are ready to deploy do everyone else a favor and document it! Luckily, writing documentation for your plugin is easy. @@ -50,38 +19,16 @@ Once your comments are good to go, navigate to your plugin directory and run: rake rdoc - -=== Store models, views, helpers, and controllers in your plugins === - -You can easily store models, views, helpers and controllers in plugins. Just create a folder for each in the lib folder, add them to the load path and remove them from the load once path: - -[source, ruby] ---------------------------------------------------------- -# File: vendor/plugins/yaffle/init.rb - -%w{ models controllers helpers }.each do |dir| - path = File.join(directory, 'lib', dir) - $LOAD_PATH << path - Dependencies.load_paths << path - Dependencies.load_once_paths.delete(path) -end ---------------------------------------------------------- - -Adding directories to the load path makes them appear just like files in the the main app directory - except that they are only loaded once, so you have to restart the web server to see the changes in the browser. - -Adding directories to the load once paths allow those changes to picked up as soon as you save the file - without having to restart the web server. - - === Write custom Rake tasks in your plugin === When you created the plugin with the built-in rails generator, it generated a rake file for you in 'vendor/plugins/yaffle/tasks/yaffle.rake'. Any rake task you add here will be available to the app. Many plugin authors put all of their rake tasks into a common namespace that is the same as the plugin, like so: +*vendor/plugins/yaffle/tasks/yaffle.rake* + [source, ruby] --------------------------------------------------------- -# File: vendor/plugins/yaffle/tasks/yaffle.rake - namespace :yaffle do desc "Prints out the word 'Yaffle'" task :squawk => :environment do diff --git a/railties/doc/guides/source/creating_plugins/preparation.txt b/railties/doc/guides/source/creating_plugins/preparation.txt deleted file mode 100644 index 77e3a3561f..0000000000 --- a/railties/doc/guides/source/creating_plugins/preparation.txt +++ /dev/null @@ -1,169 +0,0 @@ -== Preparation == - -=== Create the basic app === - -In this tutorial we will create a basic rails application with 1 resource: bird. Start out by building the basic rails app: - ------------------------------------------------- -rails plugin_demo -cd plugin_demo -script/generate scaffold bird name:string -rake db:migrate -script/server ------------------------------------------------- - -Then navigate to http://localhost:3000/birds. Make sure you have a functioning rails app before continuing. - -NOTE: The aforementioned instructions will work for sqlite3. For more detailed instructions on how to create a rails app for other databases see the API docs. - - -=== Create the plugin === - -The built-in Rails plugin generator stubs out a new plugin. Pass the plugin name, either 'CamelCased' or 'under_scored', as an argument. Pass `\--with-generator` to add an example generator also. - -This creates a plugin in 'vendor/plugins' including an 'init.rb' and 'README' as well as standard 'lib', 'task', and 'test' directories. - -Examples: ----------------------------------------------- -./script/generate plugin BrowserFilters -./script/generate plugin BrowserFilters --with-generator ----------------------------------------------- - -Later in the plugin we will create a generator, so go ahead and add the `\--with-generator` option now: - ----------------------------------------------- -script/generate plugin yaffle --with-generator ----------------------------------------------- - -You should see the following output: - ----------------------------------------------- -create vendor/plugins/yaffle/lib -create vendor/plugins/yaffle/tasks -create vendor/plugins/yaffle/test -create vendor/plugins/yaffle/README -create vendor/plugins/yaffle/MIT-LICENSE -create vendor/plugins/yaffle/Rakefile -create vendor/plugins/yaffle/init.rb -create vendor/plugins/yaffle/install.rb -create vendor/plugins/yaffle/uninstall.rb -create vendor/plugins/yaffle/lib/yaffle.rb -create vendor/plugins/yaffle/tasks/yaffle_tasks.rake -create vendor/plugins/yaffle/test/core_ext_test.rb -create vendor/plugins/yaffle/generators -create vendor/plugins/yaffle/generators/yaffle -create vendor/plugins/yaffle/generators/yaffle/templates -create vendor/plugins/yaffle/generators/yaffle/yaffle_generator.rb -create vendor/plugins/yaffle/generators/yaffle/USAGE ----------------------------------------------- - -For this plugin you won't need the file 'vendor/plugins/yaffle/lib/yaffle.rb' so you can delete that. - ----------------------------------------------- -rm vendor/plugins/yaffle/lib/yaffle.rb ----------------------------------------------- - -.Editor's note: -NOTE: Many plugin authors prefer to keep this file, and add all of the require statements in it. That way, they only line in init.rb would be `require "yaffle"`. If you are developing a plugin that has a lot of files in the lib directory, you may want to create a subdirectory like lib/yaffle and store your files in there. That way your init.rb file stays clean - - -=== Setup the plugin for testing === - -Testing plugins that use the entire Rails stack can be complex, and the generator doesn't offer any help. In this tutorial you will learn how to test your plugin against multiple different adapters using ActiveRecord. This tutorial will not cover how to use fixtures in plugin tests. - -To setup your plugin to allow for easy testing you'll need to add 3 files: - - * A 'database.yml' file with all of your connection strings. - * A 'schema.rb' file with your table definitions. - * A test helper that sets up the database before your tests. - -For this plugin you'll need 2 tables/models, Hickwalls and Wickwalls, so add the following files: - -*vendor/plugins/yaffle/test/database.yml:* - ----------------------------------------------- -sqlite: - :adapter: sqlite - :dbfile: yaffle_plugin.sqlite.db - -sqlite3: - :adapter: sqlite3 - :dbfile: yaffle_plugin.sqlite3.db - -postgresql: - :adapter: postgresql - :username: postgres - :password: postgres - :database: yaffle_plugin_test - :min_messages: ERROR - -mysql: - :adapter: mysql - :host: localhost - :username: rails - :password: - :database: yaffle_plugin_test ----------------------------------------------- - -*vendor/plugins/yaffle/test/test_helper.rb:* - -[source, ruby] ----------------------------------------------- -ActiveRecord::Schema.define(:version => 0) do - create_table :hickwalls, :force => true do |t| - t.string :name - t.string :last_squawk - t.datetime :last_squawked_at - end - create_table :wickwalls, :force => true do |t| - t.string :name - t.string :last_tweet - t.datetime :last_tweeted_at - end -end - -# File: vendor/plugins/yaffle/test/test_helper.rb - -ENV['RAILS_ENV'] = 'test' -ENV['RAILS_ROOT'] ||= File.dirname(__FILE__) + '/../../../..' - -require 'test/unit' -require File.expand_path(File.join(ENV['RAILS_ROOT'], 'config/environment.rb')) - -config = YAML::load(IO.read(File.dirname(__FILE__) + '/database.yml')) -ActiveRecord::Base.logger = Logger.new(File.dirname(__FILE__) + "/debug.log") - -db_adapter = ENV['DB'] - -# no db passed, try one of these fine config-free DBs before bombing. -db_adapter ||= - begin - require 'rubygems' - require 'sqlite' - 'sqlite' - rescue MissingSourceFile - begin - require 'sqlite3' - 'sqlite3' - rescue MissingSourceFile - end - end - -if db_adapter.nil? - raise "No DB Adapter selected. Pass the DB= option to pick one, or install Sqlite or Sqlite3." -end - -ActiveRecord::Base.establish_connection(config[db_adapter]) - -load(File.dirname(__FILE__) + "/schema.rb") - -require File.dirname(__FILE__) + '/../init.rb' - -class Hickwall < ActiveRecord::Base - acts_as_yaffle -end - -class Wickwall < ActiveRecord::Base - acts_as_yaffle :yaffle_text_field => :last_tweet, :yaffle_date_field => :last_tweeted_at -end ----------------------------------------------- diff --git a/railties/doc/guides/source/creating_plugins/string_to_squawk.txt b/railties/doc/guides/source/creating_plugins/string_to_squawk.txt deleted file mode 100644 index 50516cef69..0000000000 --- a/railties/doc/guides/source/creating_plugins/string_to_squawk.txt +++ /dev/null @@ -1,103 +0,0 @@ -== Add a `to_squawk` method to String == - -To update a core class you will have to: - - * Write tests for the desired functionality. - * Create a file for the code you wish to use. - * Require that file from your 'init.rb'. - -Most plugins store their code classes in the plugin's lib directory. When you add a file to the lib directory, you must also require that file from 'init.rb'. The file you are going to add for this tutorial is 'lib/core_ext.rb'. - -First, you need to write the tests. Testing plugins is very similar to testing rails apps. The generated test file should look something like this: - -[source, ruby] --------------------------------------------------------- -# File: vendor/plugins/yaffle/test/core_ext_test.rb - -require 'test/unit' - -class CoreExtTest < Test::Unit::TestCase - # Replace this with your real tests. - def test_this_plugin - flunk - end -end --------------------------------------------------------- - -Start off by removing the default test, and adding a require statement for your test helper. - -[source, ruby] --------------------------------------------------------- -# File: vendor/plugins/yaffle/test/core_ext_test.rb - -require 'test/unit' -require File.dirname(__FILE__) + '/test_helper.rb' - -class CoreExtTest < Test::Unit::TestCase -end --------------------------------------------------------- - -Navigate to your plugin directory and run `rake test`: - --------------------------------------------------------- -cd vendor/plugins/yaffle -rake test --------------------------------------------------------- - -Your test should fail with `no such file to load -- ./test/../lib/core_ext.rb (LoadError)` because we haven't created any file yet. Create the file 'lib/core_ext.rb' and re-run the tests. You should see a different error message: - --------------------------------------------------------- -1.) Failure ... -No tests were specified --------------------------------------------------------- - -Great - now you are ready to start development. The first thing we'll do is to add a method to String called `to_squawk` which will prefix the string with the word ``squawk!''. The test will look something like this: - -[source, ruby] --------------------------------------------------------- -# File: vendor/plugins/yaffle/init.rb - -class CoreExtTest < Test::Unit::TestCase - def test_string_should_respond_to_squawk - assert_equal true, "".respond_to?(:to_squawk) - end - - def test_string_prepend_empty_strings_with_the_word_squawk - assert_equal "squawk!", "".to_squawk - end - - def test_string_prepend_non_empty_strings_with_the_word_squawk - assert_equal "squawk! Hello World", "Hello World".to_squawk - end -end --------------------------------------------------------- - -[source, ruby] --------------------------------------------------------- -# File: vendor/plugins/yaffle/init.rb - -require "core_ext" --------------------------------------------------------- - -[source, ruby] --------------------------------------------------------- -# File: vendor/plugins/yaffle/lib/core_ext.rb - -String.class_eval do - def to_squawk - "squawk! #{self}".strip - end -end --------------------------------------------------------- - -When monkey-patching existing classes it's often better to use `class_eval` instead of opening the class directly. - -To test that your method does what it says it does, run the unit tests. To test this manually, fire up a console and start squawking: - --------------------------------------------------------- -$ ./script/console ->> "Hello World".to_squawk -=> "squawk! Hello World" --------------------------------------------------------- - -If that worked, congratulations! You just created your first test-driven plugin that extends a core ruby class. diff --git a/railties/doc/guides/source/creating_plugins/test_setup.txt b/railties/doc/guides/source/creating_plugins/test_setup.txt new file mode 100644 index 0000000000..64236ff110 --- /dev/null +++ b/railties/doc/guides/source/creating_plugins/test_setup.txt @@ -0,0 +1,230 @@ +== Preparation == + +=== Create the basic app === + +The examples in this guide require that you have a working rails application. To create a simple rails app execute: + +------------------------------------------------ +gem install rails +rails yaffle_guide +cd yaffle_guide +script/generate scaffold bird name:string +rake db:migrate +script/server +------------------------------------------------ + +Then navigate to http://localhost:3000/birds. Make sure you have a functioning rails app before continuing. + +.Editor's note: +NOTE: The aforementioned instructions will work for sqlite3. For more detailed instructions on how to create a rails app for other databases see the API docs. + + +=== Generate the plugin skeleton === + +Rails ships with a plugin generator which creates a basic plugin skeleton. Pass the plugin name, either 'CamelCased' or 'under_scored', as an argument. Pass `\--with-generator` to add an example generator also. + +This creates a plugin in 'vendor/plugins' including an 'init.rb' and 'README' as well as standard 'lib', 'task', and 'test' directories. + +Examples: +---------------------------------------------- +./script/generate plugin yaffle +./script/generate plugin yaffle --with-generator +---------------------------------------------- + +To get more detailed help on the plugin generator, type `./script/generate plugin`. + +Later on this guide will describe how to work with generators, so go ahead and generate your plugin with the `\--with-generator` option now: + +---------------------------------------------- +./script/generate plugin yaffle --with-generator +---------------------------------------------- + +You should see the following output: + +---------------------------------------------- +create vendor/plugins/yaffle/lib +create vendor/plugins/yaffle/tasks +create vendor/plugins/yaffle/test +create vendor/plugins/yaffle/README +create vendor/plugins/yaffle/MIT-LICENSE +create vendor/plugins/yaffle/Rakefile +create vendor/plugins/yaffle/init.rb +create vendor/plugins/yaffle/install.rb +create vendor/plugins/yaffle/uninstall.rb +create vendor/plugins/yaffle/lib/yaffle.rb +create vendor/plugins/yaffle/tasks/yaffle_tasks.rake +create vendor/plugins/yaffle/test/core_ext_test.rb +create vendor/plugins/yaffle/generators +create vendor/plugins/yaffle/generators/yaffle +create vendor/plugins/yaffle/generators/yaffle/templates +create vendor/plugins/yaffle/generators/yaffle/yaffle_generator.rb +create vendor/plugins/yaffle/generators/yaffle/USAGE +---------------------------------------------- + +To begin just change one thing - move 'init.rb' to 'rails/init.rb'. + +=== Setup the plugin for testing === + +If your plugin interacts with a database, you'll need to setup a database connection. In this guide you will learn how to test your plugin against multiple different database adapters using Active Record. This guide will not cover how to use fixtures in plugin tests. + +To setup your plugin to allow for easy testing you'll need to add 3 files: + + * A 'database.yml' file with all of your connection strings + * A 'schema.rb' file with your table definitions + * A test helper method that sets up the database + +*vendor/plugins/yaffle/test/database.yml:* + +---------------------------------------------- +sqlite: + :adapter: sqlite + :dbfile: vendor/plugins/yaffle/test/yaffle_plugin.sqlite.db + +sqlite3: + :adapter: sqlite3 + :dbfile: vendor/plugins/yaffle/test/yaffle_plugin.sqlite3.db + +postgresql: + :adapter: postgresql + :username: postgres + :password: postgres + :database: yaffle_plugin_test + :min_messages: ERROR + +mysql: + :adapter: mysql + :host: localhost + :username: root + :password: password + :database: yaffle_plugin_test +---------------------------------------------- + +For this guide you'll need 2 tables/models, Hickwalls and Wickwalls, so add the following: + +*vendor/plugins/yaffle/test/schema.rb:* + +[source, ruby] +---------------------------------------------- +ActiveRecord::Schema.define(:version => 0) do + create_table :hickwalls, :force => true do |t| + t.string :name + t.string :last_squawk + t.datetime :last_squawked_at + end + create_table :wickwalls, :force => true do |t| + t.string :name + t.string :last_tweet + t.datetime :last_tweeted_at + end + create_table :woodpeckers, :force => true do |t| + t.string :name + end +end +---------------------------------------------- + +*vendor/plugins/yaffle/test/test_helper.rb:* + +[source, ruby] +---------------------------------------------- +ENV['RAILS_ENV'] = 'test' +ENV['RAILS_ROOT'] ||= File.dirname(__FILE__) + '/../../../..' + +require 'test/unit' +require File.expand_path(File.join(ENV['RAILS_ROOT'], 'config/environment.rb')) + +def load_schema + config = YAML::load(IO.read(File.dirname(__FILE__) + '/database.yml')) + ActiveRecord::Base.logger = Logger.new(File.dirname(__FILE__) + "/debug.log") + + db_adapter = ENV['DB'] + + # no db passed, try one of these fine config-free DBs before bombing. + db_adapter ||= + begin + require 'rubygems' + require 'sqlite' + 'sqlite' + rescue MissingSourceFile + begin + require 'sqlite3' + 'sqlite3' + rescue MissingSourceFile + end + end + + if db_adapter.nil? + raise "No DB Adapter selected. Pass the DB= option to pick one, or install Sqlite or Sqlite3." + end + + ActiveRecord::Base.establish_connection(config[db_adapter]) + load(File.dirname(__FILE__) + "/schema.rb") + require File.dirname(__FILE__) + '/../rails/init.rb' +end +---------------------------------------------- + +Now whenever you write a test that requires the database, you can call 'load_schema'. + +=== Run the plugin tests === + +Once you have these files in place, you can write your first test to ensure that your plugin-testing setup is correct. By default rails generates a file in 'vendor/plugins/yaffle/test/yaffle_test.rb' with a sample test. Replace the contents of that file with: + +*vendor/plugins/yaffle/test/yaffle_test.rb:* + +[source, ruby] +---------------------------------------------- +require File.dirname(__FILE__) + '/test_helper.rb' + +class YaffleTest < Test::Unit::TestCase + load_schema + + class Hickwall < ActiveRecord::Base + end + + class Wickwall < ActiveRecord::Base + end + + def test_schema_has_loaded_correctly + assert_equal [], Hickwall.all + assert_equal [], Wickwall.all + end + +end +---------------------------------------------- + +To run this, go to the plugin directory and run `rake`: + +---------------------------------------------- +cd vendor/plugins/yaffle +rake +---------------------------------------------- + +You should see output like: + +---------------------------------------------- +/opt/local/bin/ruby -Ilib:lib "/opt/local/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake/rake_test_loader.rb" "test/yaffle_test.rb" +-- create_table(:hickwalls, {:force=>true}) + -> 0.0220s +-- create_table(:wickwalls, {:force=>true}) + -> 0.0077s +-- initialize_schema_migrations_table() + -> 0.0007s +-- assume_migrated_upto_version(0) + -> 0.0007s +Loaded suite /opt/local/lib/ruby/gems/1.8/gems/rake-0.8.3/lib/rake/rake_test_loader +Started +. +Finished in 0.002236 seconds. + +1 test, 1 assertion, 0 failures, 0 errors +---------------------------------------------- + +By default the setup above runs your tests with sqlite or sqlite3. To run tests with one of the other connection strings specified in database.yml, pass the DB environment variable to rake: + +---------------------------------------------- +rake DB=sqlite +rake DB=sqlite3 +rake DB=mysql +rake DB=postgresql +---------------------------------------------- + +Now you are ready to test-drive your plugin! diff --git a/railties/doc/guides/source/creating_plugins/view_helper.txt b/railties/doc/guides/source/creating_plugins/view_helper.txt deleted file mode 100644 index b03a190e1a..0000000000 --- a/railties/doc/guides/source/creating_plugins/view_helper.txt +++ /dev/null @@ -1,61 +0,0 @@ -== Create a `squawk_info_for` view helper == - -Creating a view helper is a 3-step process: - - * Add an appropriately named file to the 'lib' directory. - * Require the file and hooks in 'init.rb'. - * Write the tests. - -First, create the test to define the functionality you want: - -[source, ruby] ---------------------------------------------------------------- -# File: vendor/plugins/yaffle/test/view_helpers_test.rb - -require File.dirname(__FILE__) + '/test_helper.rb' -include YaffleViewHelper - -class ViewHelpersTest < Test::Unit::TestCase - def test_squawk_info_for_should_return_the_text_and_date - time = Time.now - hickwall = Hickwall.new - hickwall.last_squawk = "Hello World" - hickwall.last_squawked_at = time - assert_equal "Hello World, #{time.to_s}", squawk_info_for(hickwall) - end -end ---------------------------------------------------------------- - -Then add the following statements to init.rb: - -[source, ruby] ---------------------------------------------------------------- -# File: vendor/plugins/yaffle/init.rb - -require "view_helpers" -ActionView::Base.send :include, YaffleViewHelper ---------------------------------------------------------------- - -Then add the view helpers file and - -[source, ruby] ---------------------------------------------------------------- -# File: vendor/plugins/yaffle/lib/view_helpers.rb - -module YaffleViewHelper - def squawk_info_for(yaffle) - returning "" do |result| - result << yaffle.read_attribute(yaffle.class.yaffle_text_field) - result << ", " - result << yaffle.read_attribute(yaffle.class.yaffle_date_field).to_s - end - end -end ---------------------------------------------------------------- - -You can also test this in script/console by using the `helper` method: - ---------------------------------------------------------------- -$ ./script/console ->> helper.squawk_info_for(@some_yaffle_instance) ---------------------------------------------------------------- |