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Diffstat (limited to 'railties/guides/source/action_view_overview.textile')
| -rw-r--r-- | railties/guides/source/action_view_overview.textile | 206 |
1 files changed, 89 insertions, 117 deletions
diff --git a/railties/guides/source/action_view_overview.textile b/railties/guides/source/action_view_overview.textile index 2b2c197f46..40cde6ad84 100644 --- a/railties/guides/source/action_view_overview.textile +++ b/railties/guides/source/action_view_overview.textile @@ -165,7 +165,7 @@ will produce <em>emphasized</em> <em><b>emph & bold</b></em> <a href="http://rubyonrails.org">A link</a> -<target option="fast" name="compile" \> +<target option="fast" name="compile" /> </html> Any method with a block will be treated as an XML markup tag with nested markup in the block. For example, the following: @@ -211,7 +211,7 @@ xml.rss("version" => "2.0", "xmlns:dc" => "http://purl.org/dc/elements/1.1/") do end </ruby> -h5. Template caching +h5. Template Caching By default, Rails will compile each template to a method in order to render it. When you alter a template, Rails will check the file's modification time and recompile it in development mode. @@ -235,7 +235,7 @@ This will render a file named +_menu.html.erb+ at that point within the view is That code will pull in the partial from +app/views/shared/_menu.html.erb+. -h5. Using Partials to Simplify Views +h5. Using Partials to simplify Views One way to use partials is to treat them as the equivalent of subroutines: as a way to move details out of a view so that you can grasp what's going on more easily. For example, you might have a view that looked like this: @@ -454,6 +454,83 @@ input("post", "title") # => <input id="post_title" name="post[title]" size="30" type="text" value="Hello World" /> </ruby> +h4. RecordTagHelper + +This module provides methods for generating a container tag, such as a +<div>+, for your record. This is the recommended way of creating a container for render your Active Record object, as it adds an appropriate class and id attributes to that container. You can then refer to those containers easily by following the convention, instead of having to think about which class or id attribute you should use. + +h5. content_tag_for + +Renders a container tag that relates to your Active Record Object. + +For example, given +@post+ is the object of +Post+ class, you can do: + +<ruby> +<%= content_tag_for(:tr, @post) do %> + <td><%= @post.title %></td> +<% end %> +</ruby> + +This will generate this HTML output: + +<html> +<tr id="post_1234" class="post"> + <td>Hello World!</td> +</tr> +</html> + +You can also supply HTML attributes as an additional option hash. For example: + +<ruby> +<%= content_tag_for(:tr, @post, :class => "frontpage") do %> + <td><%= @post.title %></td> +<% end %> +</ruby> + +Will generate this HTML output: + +<html> +<tr id="post_1234" class="post frontpage"> + <td>Hello World!</td> +</tr> +</html> + +You can pass a collection of Active Record objects. This method will loop through your objects and create a container for each of them. For example, given +@posts+ is an array of two +Post+ objects: + +<ruby> +<%= content_tag_for(:tr, @posts) do |post| %> + <td><%= post.title %></td> +<% end %> +</ruby> + +Will generate this HTML output: + +<html> +<tr id="post_1234" class="post"> + <td>Hello World!</td> +</tr> +<tr id="post_1235" class="post"> + <td>Ruby on Rails Rocks!</td> +</tr> +</html> + +h5. div_for + +This is actually a convenient method which calls +content_tag_for+ internally with +:div+ as the tag name. You can pass either an Active Record object or a collection of objects. For example: + +<ruby> +<%= div_for(@post, :class => "frontpage") do %> + <td><%= @post.title %></td> +<% end %> +</ruby> + +Will generate this HTML output: + +<html> +<div id="post_1234" class="post frontpage"> + <td>Hello World!</td> +</div> +</html> + h4. AssetTagHelper This module provides methods for generating HTML that links views to assets such as images, JavaScript files, stylesheets, and feeds. @@ -478,7 +555,6 @@ javascript_include_tag :monkey # => <script type="text/javascript" src="/javascripts/tail.js"></script> </ruby> - h5. register_stylesheet_expansion Register one or more stylesheet files to be included when symbol is passed to +stylesheet_link_tag+. This method is typically intended to be called from plugin initialization to register stylesheet files that the plugin installed in +public/stylesheets+. @@ -615,7 +691,7 @@ atom_feed do |feed| feed.title("Posts Index") feed.updated((@posts.first.created_at)) - for post in @posts + @posts.each do |post| feed.entry(post) do |entry| entry.title(post.title) entry.content(post.body, :type => 'html') @@ -822,7 +898,7 @@ h5. select_year Returns a select tag with options for each of the five years on each side of the current, which is selected. The five year radius can be changed using the +:start_year+ and +:end_year+ keys in the +options+. <ruby> -# Generates a select field for five years on either side of +Date.today+ that defaults to the current year +# Generates a select field for five years on either side of Date.today that defaults to the current year select_year(Date.today) # Generates a select field from 1900 to 2009 that defaults to the current year @@ -870,7 +946,7 @@ h4. FormHelper Form helpers are designed to make working with models much easier compared to using just standard HTML elements by providing a set of methods for creating forms based on your models. This helper generates the HTML for forms, providing a method for each sort of input (e.g., text, password, select, and so on). When the form is submitted (i.e., when the user hits the submit button or form.submit is called via JavaScript), the form inputs will be bundled into the params object and passed back to the controller. -There are two types of form helpers: those that specifically work with model attributes and those that don't. This helper deals with those that work with model attributes; to see an example of form helpers that don‘t work with model attributes, check the ActionView::Helpers::FormTagHelper documentation. +There are two types of form helpers: those that specifically work with model attributes and those that don't. This helper deals with those that work with model attributes; to see an example of form helpers that don't work with model attributes, check the ActionView::Helpers::FormTagHelper documentation. The core method of this helper, form_for, gives you the ability to create a form for a model instance; for example, let's say that you have a model Person and want to create a new instance of it: @@ -914,7 +990,7 @@ check_box("post", "validated") h5. fields_for -Creates a scope around a specific model object like form_for, but doesn‘t create the form tags themselves. This makes fields_for suitable for specifying additional model objects in the same form: +Creates a scope around a specific model object like form_for, but doesn't create the form tags themselves. This makes fields_for suitable for specifying additional model objects in the same form: <ruby> <%= form_for @person, :url => { :action => "update" } do |person_form| %> @@ -929,7 +1005,7 @@ Creates a scope around a specific model object like form_for, but doesn‘t crea h5. file_field -Returns an file upload input tag tailored for accessing a specified attribute. +Returns a file upload input tag tailored for accessing a specified attribute. <ruby> file_field(:user, :avatar) @@ -1037,7 +1113,7 @@ Sample usage (selecting the associated Author for an instance of Post, +@post+): collection_select(:post, :author_id, Author.all, :id, :name_with_initial, {:prompt => true}) </ruby> -If @post.author_id is already 1, this would return: +If <tt>@post.author_id</tt> is 1, this would return: <html> <select name="post[author_id]"> @@ -1080,8 +1156,6 @@ Sample usage: option_groups_from_collection_for_select(@continents, :countries, :name, :id, :name, 3) </ruby> -TODO check above textile output looks right - Possible output: <html> @@ -1132,13 +1206,13 @@ h5. select Create a select tag and a series of contained option tags for the provided object and method. -Example with @post.person_id => 1: +Example: <ruby> select("post", "person_id", Person.all.collect {|p| [ p.name, p.id ] }, { :include_blank => true }) </ruby> -could become: +If <tt>@post.person_id</tt> is 1, this would become: <html> <select name="post[person_id]"> @@ -1189,7 +1263,7 @@ h5. file_field_tag Creates a file upload field. -If you are using file uploads then you will also need to set the multipart option for the form tag: +Prior to Rails 3.1, if you are using file uploads, then you will need to set the multipart option for the form tag. Rails 3.1+ does this automatically. <ruby> <%= form_tag { :action => "post" }, { :multipart => true } do %> @@ -1400,102 +1474,6 @@ number_with_precision(111.2345) # => 111.235 number_with_precision(111.2345, 2) # => 111.23 </ruby> -h5. evaluate_remote_response - -Returns +eval(request.responseText)+ which is the JavaScript function that form_remote_tag can call in +:complete+ to evaluate a multiple update return document using +update_element_function+ calls. - -h5. form_remote_tag - -Returns a form tag that will submit using XMLHttpRequest in the background instead of the regular reloading POST arrangement. Even though it‘s using JavaScript to serialize the form elements, the form submission will work just like a regular submission as viewed by the receiving side. - -For example, this: - -<ruby> -form_remote_tag :html => { :action => url_for(:controller => "some", :action => "place") } -</ruby> - -would generate the following: - -<html> -<form action="/some/place" method="post" onsubmit="new Ajax.Request('', - {asynchronous:true, evalScripts:true, parameters:Form.serialize(this)}); return false;"> -</html> - -h5. link_to_remote - -Returns a link to a remote action that's called in the background using XMLHttpRequest. You can generate a link that uses AJAX in the general case, while degrading gracefully to plain link behavior in the absence of JavaScript. For example: - -<ruby> -link_to_remote "Delete this post", - { :update => "posts", :url => { :action => "destroy", :id => post.id } }, - :href => url_for(:action => "destroy", :id => post.id) -</ruby> - -h5. observe_field - -Observes the field specified and calls a callback when its contents have changed. - -<ruby> -observe_field("my_field", :function => "alert('Field changed')") -</ruby> - -h5. observe_form - -Observes the form specified and calls a callback when its contents have changed. The options for observe_form are the same as the options for observe_field. - -<ruby> -observe_field("my_form", :function => "alert('Form changed')") -</ruby> - -h5. periodically_call_remote - -Periodically calls the specified url as often as specified. Usually used to update a specified div with the results of the remote call. The following example will call update every 20 seconds and update the news_block div: - -<ruby> -periodically_call_remote(:url => 'update', :frequency => '20', :update => 'news_block') -# => PeriodicalExecuter(function() {new Ajax.Updater('news_block', 'update', {asynchronous:true, evalScripts:true})}, 20) -</ruby> - -h5. remote_form_for - -Creates a form that will submit using XMLHttpRequest in the background instead of the regular reloading POST arrangement and a scope around a specific resource that is used as a base for questioning about values for the fields. - -<ruby> -<%= remote_form_for(@post) do |f| %> - ... -<% end %> -</ruby> - -h5. remote_function - -Returns the JavaScript needed for a remote function. Takes the same arguments as +link_to_remote+. - -<ruby> -<select id="options" onchange="<%= remote_function(:update => "options", :url => { :action => :update_options }) %>"> - <option value="0">Hello</option> - <option value="1">World</option> -</select> -# => <select id="options" onchange="new Ajax.Updater('options', '/testing/update_options', {asynchronous:true, evalScripts:true})"> -</ruby> - -h5. submit_to_remote - -Returns a button input tag that will submit form using XMLHttpRequest in the background instead of a regular POST request that reloads the page. - -For example, the following: - -<ruby> -submit_to_remote 'create_btn', 'Create', :url => { :action => 'create' } -</ruby> - -would generate: - -<html> -<input name="create_btn" onclick="new Ajax.Request('/testing/create', - {asynchronous:true, evalScripts:true, parameters:Form.serialize(this.form)}); - return false;" type="button" value="Create" /> -</html> - h3. Localized Views Action View has the ability render different templates depending on the current locale. @@ -1517,9 +1495,3 @@ end Then you could create special views like +app/views/posts/show.expert.html.erb+ that would only be displayed to expert users. You can read more about the Rails Internationalization (I18n) API "here":i18n.html. - -h3. Changelog - -* April 16, 2011: Added 'Using Action View with Rails', 'Templates' and 'Partials' sections. "Sebastian Martinez":http://wyeworks.com -* September 3, 2009: Continuing work by Trevor Turk, leveraging the Action Pack docs and "What's new in Edge Rails":http://ryandaigle.com/articles/2007/8/3/what-s-new-in-edge-rails-partials-get-layouts -* April 5, 2009: Starting work by Trevor Turk, leveraging Mike Gunderloy's docs |