diff options
Diffstat (limited to 'guides/source')
| -rw-r--r-- | guides/source/4_2_release_notes.md | 27 | ||||
| -rw-r--r-- | guides/source/active_record_querying.md | 35 | ||||
| -rw-r--r-- | guides/source/association_basics.md | 8 | ||||
| -rw-r--r-- | guides/source/constant_autoloading_and_reloading.md | 19 | ||||
| -rw-r--r-- | guides/source/getting_started.md | 12 |
5 files changed, 71 insertions, 30 deletions
diff --git a/guides/source/4_2_release_notes.md b/guides/source/4_2_release_notes.md index 1e9107a8c6..d8700539c4 100644 --- a/guides/source/4_2_release_notes.md +++ b/guides/source/4_2_release_notes.md @@ -509,6 +509,17 @@ Please refer to the [Changelog][action-pack] for detailed changes. serving assets from your Rails server in production. ([Pull Request](https://github.com/rails/rails/pull/16466)) +* When calling the `process` helpers in an integration test the path needs to have + a leading slash. Previously you could omit it but that was a byproduct of the + implementation and not an intentional feature, e.g.: + + ```ruby + test "list all posts" do + get "/posts" + assert_response :success + end + ``` + Action View ----------- @@ -544,17 +555,6 @@ Please refer to the [Changelog][action-view] for detailed changes. * Placeholder I18n follows the same convention as `label` I18n. ([Pull Request](https://github.com/rails/rails/pull/16438)) -* When calling the `process` helpers in an integration test the path needs to have - a leading slash. Previously you could omit it but that was a byproduct of the - implementation and not an intentional feature, e.g.: - - ```ruby - test "list all posts" do - get "/posts" - assert_response :success - end - ``` - Action Mailer ------------- @@ -640,6 +640,10 @@ Please refer to the [Changelog][active-record] for detailed changes. `Relation` for performing queries and updates is the preferred API. ([Commit](https://github.com/rails/rails/commit/d5902c9e)) +* Deprecated `add_timestamps` and `t.timestamps` without passing the `:null` + option. The default of `null: true` will change in Rails 5 to `null: false`. + ([Pull Request](https://github.com/rails/rails/pull/16481)) + * Deprecated `Reflection#source_macro` without replacement as it is no longer needed in Active Record. ([Pull Request](https://github.com/rails/rails/pull/16373)) @@ -824,6 +828,7 @@ Please refer to the [Changelog][active-support] for detailed changes. `module Foo; extend ActiveSupport::Concern; end` boilerplate. ([Commit](https://github.com/rails/rails/commit/b16c36e688970df2f96f793a759365b248b582ad)) +* New [guide](constant_autoloading_and_reloading.html) about constant autoloading and reloading. Credits ------- diff --git a/guides/source/active_record_querying.md b/guides/source/active_record_querying.md index 8734addd4c..f6fbc29707 100644 --- a/guides/source/active_record_querying.md +++ b/guides/source/active_record_querying.md @@ -9,6 +9,7 @@ After reading this guide, you will know: * How to specify the order, retrieved attributes, grouping, and other properties of the found records. * How to use eager loading to reduce the number of database queries needed for data retrieval. * How to use dynamic finders methods. +* How to use method chaining to use multiple ActiveRecord methods together. * How to check for the existence of particular records. * How to perform various calculations on Active Record models. * How to run EXPLAIN on relations. @@ -1327,6 +1328,40 @@ You can specify an exclamation point (`!`) on the end of the dynamic finders to If you want to find both by name and locked, you can chain these finders together by simply typing "`and`" between the fields. For example, `Client.find_by_first_name_and_locked("Ryan", true)`. +Understanding The Method Chaining +--------------------------------- + +The ActiveRecord pattern implements [Method Chaining](http://en.wikipedia.org/wiki/Method_chaining). +This allow us to use multiple ActiveRecord methods in a simple and straightforward way. + +You can chain a method in a sentence when the previous method called returns `ActiveRecord::Relation`, +like `all`, `where`, and `joins`. Methods that returns a instance of a single object +(see [Retrieving a Single Object Section](#retrieving-a-single-object)) have to be be the last +in the sentence. + +This guide won't cover all the possibilities, just a few as example. + +### Retrieving filtered data from multiple tables + +```ruby +Person + .select('people.id, people.name, comments.text') + .joins(:comments) + .where('comments.create_at > ?', 1.week.ago) +``` + +### Retrieving specific data from multiple tables + +```ruby +Person + .select('people.id, people.name, companies.name') + .joins(:company) + .find_by('people.name' => 'John') # this should be the last +``` + +NOTE: Remember that, if `find_by` return more than one registry, it will take just the first +and ignore the others. + Find or Build a New Object -------------------------- diff --git a/guides/source/association_basics.md b/guides/source/association_basics.md index 3a2e522fa7..5c05f0c4b7 100644 --- a/guides/source/association_basics.md +++ b/guides/source/association_basics.md @@ -879,10 +879,12 @@ class Order < ActiveRecord::Base belongs_to :customer, counter_cache: :count_of_orders end class Customer < ActiveRecord::Base - has_many :orders + has_many :orders, counter_cache: :count_of_orders end ``` +NOTE: You only need to specify the :counter_cache option on the "has_many side" of the association when using a custom name for the counter cache. + Counter cache columns are added to the containing model's list of read-only attributes through `attr_readonly`. ##### `:dependent` @@ -1495,6 +1497,7 @@ The `has_many` association supports these options: * `:as` * `:autosave` * `:class_name` +* `:counter_cache` * `:dependent` * `:foreign_key` * `:inverse_of` @@ -1522,6 +1525,9 @@ class Customer < ActiveRecord::Base end ``` +##### `:counter_cache` +This option can be used to configure a custom named `:counter_cache`. You only need this option when you customized the name of your `:counter_cache` on the [belongs_to association](#options-for-belongs-to). + ##### `:dependent` Controls what happens to the associated objects when their owner is destroyed: diff --git a/guides/source/constant_autoloading_and_reloading.md b/guides/source/constant_autoloading_and_reloading.md index afb5b6a694..effa66f19c 100644 --- a/guides/source/constant_autoloading_and_reloading.md +++ b/guides/source/constant_autoloading_and_reloading.md @@ -6,15 +6,10 @@ This guide documents how constant autoloading and reloading works. After reading this guide, you will know: * Key aspects of Ruby constants - * What is `autoload_paths` - * How constant autoloading works - * What is `require_dependency` - * How constant reloading works - * Solutions to common autoloading gotchas -------------------------------------------------------------------------------- @@ -225,7 +220,7 @@ constants on the fly. ### Constants are Stored in Modules Constants belong to modules in a very literal sense. Classes and modules have -a constant table, think of it as a hash table. +a constant table; think of it as a hash table. Let's analyze an example to really understand what that means. While in a casual setting some abuses of language are customary, the exposition is going @@ -405,11 +400,11 @@ is raised. We are going to cover how constant autoloading works in more detail later, but the idea is that when a constant like `Post` is hit and missing, if there's a -*post.rb* file for example in *app/models* Rails is going to find it, evaluate +`post.rb` file for example in `app/models` Rails is going to find it, evaluate it, and have `Post` defined as a side-effect. Alright, Rails has a collection of directories similar to `$LOAD_PATH` in which -to lookup that *post.rb*. That collection is called `autoload_paths` and by +to lookup that `post.rb`. That collection is called `autoload_paths` and by default it contains: * All subdirectories of `app` in the application and engines. For example, @@ -585,8 +580,8 @@ file is loaded. If the file actually defines `Post` all is fine, otherwise ### Qualified References When a qualified constant is missing Rails does not look for it in the parent -namespaces. But there's a caveat: unfortunately, when a constant is missing -Rails is not able to say if the trigger was a relative or qualified reference. +namespaces. But there is a caveat: When a constant is missing, Rails is +unable to tell if the trigger was a relative reference or a qualified one. For example, consider @@ -954,8 +949,8 @@ end require_dependency ‘square’ ``` -Only the leaves that are **at least grandchildren** have to be loaded that -way. Direct subclasses do not need to be preloaded and, if the hierarchy is +Only the leaves that are **at least grandchildren** need to be loaded this +way. Direct subclasses do not need to be preloaded. If the hierarchy is deeper, intermediate classes will be autoloaded recursively from the bottom because their constant will appear in the class definitions as superclass. diff --git a/guides/source/getting_started.md b/guides/source/getting_started.md index a5e35f75a0..31f78ba11c 100644 --- a/guides/source/getting_started.md +++ b/guides/source/getting_started.md @@ -90,18 +90,18 @@ current version of Ruby installed: TIP: A number of tools exist to help you quickly install Ruby and Ruby on Rails on your system. Windows users can use [Rails Installer](http://railsinstaller.org), while Mac OS X users can use [Tokaido](https://github.com/tokaido/tokaidoapp). +For more installation methods for most Operating Systems take a look at +[ruby-lang.org](https://www.ruby-lang.org/en/documentation/installation/). ```bash $ ruby -v ruby 2.0.0p353 ``` -If you don't have Ruby installed have a look at -[ruby-lang.org](https://www.ruby-lang.org/en/installation/) for possible ways to -install Ruby on your platform. - -Many popular UNIX-like OSes ship with an acceptable version of SQLite3. Windows -users and others can find installation instructions at the [SQLite3 website](https://www.sqlite.org). +Many popular UNIX-like OSes ship with an acceptable version of SQLite3. +On Windows, if you installed Rails through Rails Installer, you +already have SQLite installed. Others can find installation instructions +at the [SQLite3 website](https://www.sqlite.org). Verify that it is correctly installed and in your PATH: ```bash |