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diff --git a/guides/source/layouts_and_rendering.md b/guides/source/layouts_and_rendering.md index f4dab57aa5..c3cde49630 100644 --- a/guides/source/layouts_and_rendering.md +++ b/guides/source/layouts_and_rendering.md @@ -1,3 +1,5 @@ +**DO NOT READ THIS FILE IN GITHUB, GUIDES ARE PUBLISHED IN http://guides.rubyonrails.org.** + Layouts and Rendering in Rails ============================== @@ -189,7 +191,7 @@ render file: "/u/apps/warehouse_app/current/app/views/products/show" The `:file` option takes an absolute file-system path. Of course, you need to have rights to the view that you're using to render the content. -NOTE: By default, the file is rendered without using the current layout. If you want Rails to put the file into the current layout, you need to add the `layout: true` option. +NOTE: By default, the file is rendered using the current layout. TIP: If you're running Rails on Microsoft Windows, you should use the `:file` option to render a file, because Windows filenames do not have the same format as Unix filenames. @@ -236,15 +238,35 @@ render inline: "xml.p {'Horrid coding practice!'}", type: :builder #### Rendering Text -You can send plain text - with no markup at all - back to the browser by using the `:text` option to `render`: +You can send plain text - with no markup at all - back to the browser by using +the `:plain` option to `render`: ```ruby -render text: "OK" +render plain: "OK" ``` -TIP: Rendering pure text is most useful when you're responding to Ajax or web service requests that are expecting something other than proper HTML. +TIP: Rendering pure text is most useful when you're responding to Ajax or web +service requests that are expecting something other than proper HTML. + +NOTE: By default, if you use the `:plain` option, the text is rendered without +using the current layout. If you want Rails to put the text into the current +layout, you need to add the `layout: true` option and use the `.txt.erb` +extension for the layout file. + +#### Rendering HTML -NOTE: By default, if you use the `:text` option, the text is rendered without using the current layout. If you want Rails to put the text into the current layout, you need to add the `layout: true` option. +You can send a HTML string back to the browser by using the `:html` option to +`render`: + +```ruby +render html: "<strong>Not Found</strong>".html_safe +``` + +TIP: This is useful when you're rendering a small snippet of HTML code. +However, you might want to consider moving it to a template file if the markup +is complex. + +NOTE: This option will escape HTML entities if the string is not HTML safe. #### Rendering JSON @@ -276,6 +298,22 @@ render js: "alert('Hello Rails');" This will send the supplied string to the browser with a MIME type of `text/javascript`. +#### Rendering raw body + +You can send a raw content back to the browser, without setting any content +type, by using the `:body` option to `render`: + +```ruby +render body: "raw" +``` + +TIP: This option should be used only if you don't care about the content type of +the response. Using `:plain` or `:html` might be more appropriate in most of the +time. + +NOTE: Unless overridden, your response returned from this render option will be +`text/html`, as that is the default content type of Action Dispatch response. + #### Options for `render` Calls to the `render` method generally accept four options: @@ -389,6 +427,9 @@ Rails understands both numeric status codes and the corresponding symbols shown | | 510 | :not_extended | | | 511 | :network_authentication_required | +NOTE: If you try to render content along with a non-content status code +(100-199, 204, 205 or 304), it will be dropped from the response. + #### Finding Layouts To find the current layout, Rails first looks for a file in `app/views/layouts` with the same base name as the controller. For example, rendering actions from the `PhotosController` class will use `app/views/layouts/photos.html.erb` (or `app/views/layouts/photos.builder`). If there is no such controller-specific layout, Rails will use `app/views/layouts/application.html.erb` or `app/views/layouts/application.builder`. If there is no `.erb` layout, Rails will use a `.builder` layout if one exists. Rails also provides several ways to more precisely assign specific layouts to individual controllers and actions. @@ -404,7 +445,7 @@ class ProductsController < ApplicationController end ``` -With this declaration, all of the views rendered by the products controller will use `app/views/layouts/inventory.html.erb` as their layout. +With this declaration, all of the views rendered by the `ProductsController` will use `app/views/layouts/inventory.html.erb` as their layout. To assign a specific layout for the entire application, use a `layout` declaration in your `ApplicationController` class: @@ -471,33 +512,33 @@ Layout declarations cascade downward in the hierarchy, and more specific layout end ``` -* `posts_controller.rb` +* `articles_controller.rb` ```ruby - class PostsController < ApplicationController + class ArticlesController < ApplicationController end ``` -* `special_posts_controller.rb` +* `special_articles_controller.rb` ```ruby - class SpecialPostsController < PostsController + class SpecialArticlesController < ArticlesController layout "special" end ``` -* `old_posts_controller.rb` +* `old_articles_controller.rb` ```ruby - class OldPostsController < SpecialPostsController + class OldArticlesController < SpecialArticlesController layout false def show - @post = Post.find(params[:id]) + @article = Article.find(params[:id]) end def index - @old_posts = Post.older + @old_articles = Article.older render layout: "old" end # ... @@ -507,10 +548,10 @@ Layout declarations cascade downward in the hierarchy, and more specific layout In this application: * In general, views will be rendered in the `main` layout -* `PostsController#index` will use the `main` layout -* `SpecialPostsController#index` will use the `special` layout -* `OldPostsController#show` will use no layout at all -* `OldPostsController#index` will use the `old` layout +* `ArticlesController#index` will use the `main` layout +* `SpecialArticlesController#index` will use the `special` layout +* `OldArticlesController#show` will use no layout at all +* `OldArticlesController#index` will use the `old` layout #### Avoiding Double Render Errors @@ -868,7 +909,10 @@ You can also specify multiple videos to play by passing an array of videos to th This will produce: ```erb -<video><source src="trailer.ogg" /><source src="movie.ogg" /></video> +<video> + <source src="/videos/trailer.ogg"> + <source src="/videos/movie.ogg"> +</video> ``` #### Linking to Audio Files with the `audio_tag` @@ -986,6 +1030,42 @@ One way to use partials is to treat them as the equivalent of subroutines: as a Here, the `_ad_banner.html.erb` and `_footer.html.erb` partials could contain content that is shared among many pages in your application. You don't need to see the details of these sections when you're concentrating on a particular page. +As you already could see from the previous sections of this guide, `yield` is a very powerful tool for cleaning up your layouts. Keep in mind that it's pure ruby, so you can use it almost everywhere. For example, we can use it to DRY form layout definition for several similar resources: + +* `users/index.html.erb` + + ```html+erb + <%= render "shared/search_filters", search: @q do |f| %> + <p> + Name contains: <%= f.text_field :name_contains %> + </p> + <%= end %> + ``` + +* `roles/index.html.erb` + + ```html+erb + <%= render "shared/search_filters", search: @q do |f| %> + <p> + Title contains: <%= f.text_field :title_contains %> + </p> + <%= end %> + ``` + +* `shared/_search_filters.html.erb` + + ```html+erb + <%= form_for(@q) do |f| %> + <h1>Search form:</h1> + <fieldset> + <%= yield f %> + </fieldset> + <p> + <%= f.submit "Search" %> + </p> + <% end %> + ``` + TIP: For content that is shared among all pages in your application, you can use partials directly from layouts. #### Partial Layouts @@ -1008,7 +1088,6 @@ You can also pass local variables into partials, making them even more powerful ```html+erb <h1>New zone</h1> - <%= error_messages_for :zone %> <%= render partial: "form", locals: {zone: @zone} %> ``` @@ -1016,7 +1095,6 @@ You can also pass local variables into partials, making them even more powerful ```html+erb <h1>Editing zone</h1> - <%= error_messages_for :zone %> <%= render partial: "form", locals: {zone: @zone} %> ``` @@ -1121,11 +1199,11 @@ With this change, you can access an instance of the `@products` collection as th You can also pass in arbitrary local variables to any partial you are rendering with the `locals: {}` option: ```erb -<%= render partial: "products", collection: @products, +<%= render partial: "product", collection: @products, as: :item, locals: {title: "Products Page"} %> ``` -Would render a partial `_products.html.erb` once for each instance of `product` in the `@products` instance variable passing the instance to the partial as a local variable called `item` and to each partial, make the local variable `title` available with the value `Products Page`. +In this case, the partial will have access to a local variable `title` with the value "Products Page". TIP: Rails also makes a counter variable available within a partial called by the collection, named after the member of the collection followed by `_counter`. For example, if you're rendering `@products`, within the partial you can refer to `product_counter` to tell you how many times the partial has been rendered. This does not work in conjunction with the `as: :value` option. |