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Diffstat (limited to 'railties/guides/source/layouts_and_rendering.textile')
| -rw-r--r-- | railties/guides/source/layouts_and_rendering.textile | 38 |
1 files changed, 18 insertions, 20 deletions
diff --git a/railties/guides/source/layouts_and_rendering.textile b/railties/guides/source/layouts_and_rendering.textile index 1548da0eb5..d67668df91 100644 --- a/railties/guides/source/layouts_and_rendering.textile +++ b/railties/guides/source/layouts_and_rendering.textile @@ -90,7 +90,7 @@ If we want to display the properties of all the books in our view, we can do so <%= link_to 'New book', new_book_path %> </ruby> -NOTE: The actual rendering is done by subclasses of +ActionView::TemplateHandlers+. This guide does not dig into that process, but it's important to know that the file extension on your view controls the choice of template handler. In Rails 2, the standard extensions are +.erb+ for ERB (HTML with embedded Ruby), +.rjs+ for RJS (JavaScript with embedded ruby) and +.builder+ for Builder (XML generator). +NOTE: The actual rendering is done by subclasses of +ActionView::TemplateHandlers+. This guide does not dig into that process, but it's important to know that the file extension on your view controls the choice of template handler. In Rails 2, the standard extensions are +.erb+ for ERB (HTML with embedded Ruby), and +.builder+ for Builder (XML generator). h4. Using +render+ @@ -250,18 +250,6 @@ render :inline => "xml.p {'Horrid coding practice!'}", :type => :builder </ruby> -h5. Using +render+ with +:update+ - -You can also render JavaScript-based page updates inline using the +:update+ option to +render+: - -<ruby> -render :update do |page| - page.replace_html 'warning', "Invalid options supplied" -end -</ruby> - -WARNING: Placing JavaScript updates in your controller may seem to streamline small updates, but it defeats the MVC orientation of Rails and will make it harder for other developers to follow the logic of your project. We recommend using a separate RJS template instead, no matter how small the update. - h5. Rendering Text You can send plain text - with no markup at all - back to the browser by using the +:text+ option to +render+: @@ -296,7 +284,7 @@ TIP: You don't need to call +to_xml+ on the object that you want to render. If y h5. Rendering Vanilla JavaScript -Rails can render vanilla JavaScript (as an alternative to using +update+ with an +.rjs+ file): +Rails can render vanilla JavaScript: <ruby> render :js => "alert('Hello Rails');" @@ -406,7 +394,7 @@ end Now, if the current user is a special user, they'll get a special layout when viewing a product. You can even use an inline method to determine the layout: -You can also decide the layout by passing a Proc object, the block you give the Proc will be given the +controller+ instance, so you can make decisions based on the current request. For example: +You can also decide the layout by passing a Proc object, the block you give the Proc will be given the +controller+ instance, so you can make decisions based on the current request. For example: <ruby> class ProductsController < ApplicationController @@ -584,7 +572,7 @@ With this code, the browser will make a fresh request for the index page, the co The only downside to this code, is that it requires a round trip to the browser, the browser requested the show action with +/books/1+ and the controller finds that there are no books, so the controller sends out a 302 redirect response to the browser telling it to go to +/books/+, the browser complies and sends a new request back to the controller asking now for the +index+ action, the controller then gets all the books in the database and renders the index template, sending it back down to the browser which then shows it on your screen. -While in a small app, this added latency might not be a problem, it is something to think about when speed of response is of the essence. One way to handle this double request (though a contrived example) could be: +While in a small app, this added latency might not be a problem, it is something to think about when speed of response is of the essence. One way to handle this double request (though a contrived example) could be: <ruby> def index @@ -707,18 +695,28 @@ To include +http://example.com/main.js+: <%= javascript_include_tag "http://example.com/main.js" %> </erb> -The +defaults+ option loads the Prototype and Scriptaculous libraries: +If the application does not use the asset pipeline, the +:defaults+ option loads jQuery by default: <erb> <%= javascript_include_tag :defaults %> </erb> -The +all+ option loads every JavaScript file in +public/javascripts+, starting with the Prototype and Scriptaculous libraries: +And you can in any case override the expansion in <tt>config/application.rb</tt>: + +<ruby> +config.action_view.javascript_expansions[:defaults] = %w(foo.js bar.js) +</ruby> + +When using <tt>:defaults</tt>, if an <tt>application.js</tt> file exists in <tt>public/javascripts</tt> it will be included as well at then end. + +Also, the +:all+ option loads every JavaScript file in +public/javascripts+: <erb> <%= javascript_include_tag :all %> </erb> +Note that your defaults of choice will be included first, so they will be available to all subsequently included files. + You can supply the +:recursive+ option to load files in subfolders of +public/javascripts+ as well: <erb> @@ -862,7 +860,7 @@ Produces <video src="/videos/movie.ogg" /> </erb> -Like an +image_tag+ you can supply a path, either absolute, or relative to the +public/videos+ directory. Additionally you can specify the +:size => "#{width}x#{height}"+ option just like an +image_tag+. Video tags can also have any of the HTML options specified at the end (+id+, +class+ et al). +Like an +image_tag+ you can supply a path, either absolute, or relative to the +public/videos+ directory. Additionally you can specify the +:size => "#{width}x#{height}"+ option just like an +image_tag+. Video tags can also have any of the HTML options specified at the end (+id+, +class+ et al). The video tag also supports all of the +<video>+ HTML options through the HTML options hash, including: @@ -1135,7 +1133,7 @@ You can also pass in arbitrary local variables to any partial you are rendering 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+. -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. +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. You can also specify a second partial to be rendered between instances of the main partial by using the +:spacer_template+ option: |