Module: ActionView::Helpers::JavaScriptHelper

Includes:

PrototypeHelper

Included in:

UrlHelper

Defined in:

lib/action_view/helpers/javascript_helper.rb

Overview

Provides functionality for working with JavaScript in your views.

Ajax, controls and visual effects

• For information on using Ajax, see ActionView::Helpers::PrototypeHelper.
• For information on using controls and visual effects, see ActionView::Helpers::ScriptaculousHelper.

Including the JavaScript libraries into your pages

Rails includes the Prototype JavaScript framework and the Scriptaculous JavaScript controls and visual effects library. If you wish to use these libraries and their helpers (ActionView::Helpers::PrototypeHelper and ActionView::Helpers::ScriptaculousHelper), you must do one of the following:

• Use <%= javascript_include_tag :defaults %> in the HEAD section of your page (recommended): This function will return references to the JavaScript files created by the rails command in your public/javascripts directory. Using it is recommended as the browser can then cache the libraries instead of fetching all the functions anew on every request.
• Use <%= javascript_include_tag 'prototype' %>: As above, but will only include the Prototype core library, which means you are able to use all basic AJAX functionality. For the Scriptaculous-based JavaScript helpers, like visual effects, autocompletion, drag and drop and so on, you should use the method described above.
• Use <%= define_javascript_functions %>: this will copy all the JavaScript support functions within a single script block. Not recommended.

For documentation on javascript_include_tag see ActionView::Helpers::AssetTagHelper.

Constant Summary

JAVASCRIPT_PATH =

File.join(File.dirname(__FILE__), 'javascripts')

Constants included from PrototypeHelper

PrototypeHelper::AJAX_OPTIONS, PrototypeHelper::CALLBACKS

Instance Method Summary

• #button_to_function(name, *args, &block) ⇒ Object

  Returns a button that'll trigger a JavaScript function using the onclick handler.

• #define_javascript_functions ⇒ Object

  Includes the Action Pack JavaScript libraries inside a single

  Returns a button that'll trigger a JavaScript function using the onclick handler.

  The function argument can be omitted in favor of an update_page block, which evaluates to a string when the template is rendered (instead of making an Ajax request first).

  Examples: button_to_function "Greeting", "alert('Hello world!')" button_to_function "Delete", "if (confirm('Really?')) do_delete()" button_to_function "Details" do |page| page.visual_effect :toggle_slide end button_to_function "Details", :class => "details_button" do |page| page.visual_effect :toggle_slide end

  # File 'lib/action_view/helpers/javascript_helper.rb', line 113
  
  def button_to_function(name, *args, &block)
    html_options = args.last.is_a?(Hash) ? args.pop : {}
    function = args[0] || ''
  
    html_options.symbolize_keys!
    function = update_page(&block) if block_given?
    tag(:input, html_options.merge({ 
      :type => "button", :value => name, 
      :onclick => (html_options[:onclick] ? "#{html_options[:onclick]}; " : "") + "#{function};" 
    }))
  end
  

  #define_javascript_functions ⇒ Object

  Includes the Action Pack JavaScript libraries inside a single

  Escape carrier returns and single and double quotes for JavaScript segments.

  # File 'lib/action_view/helpers/javascript_helper.rb', line 151
  
  def escape_javascript(javascript)
    (javascript || '').gsub('\\','\0\0').gsub(/\r\n|\n|\r/, "\\n").gsub(/["']/) { |m| "\\#{m}" }
  end
  

  #javascript_cdata_section(content) ⇒ Object

  :nodoc:

  # File 'lib/action_view/helpers/javascript_helper.rb', line 172
  
  def javascript_cdata_section(content) #:nodoc:
    "\n//#{cdata_section("\n#{content}\n//")}\n"
  end
  

  #javascript_tag(content, html_options = {}) ⇒ Object

  Returns a JavaScript tag with the content inside. Example: javascript_tag "alert('All is good')"

  Returns:

  html_options may be a hash of attributes for the

  # File 'lib/action_view/helpers/javascript_helper.rb', line 168
  
  def javascript_tag(content, html_options = {})
    content_tag("script", javascript_cdata_section(content), html_options.merge(:type => "text/javascript"))
  end
  

  #link_to_function(name, *args, &block) ⇒ Object

  Returns a link that will trigger a JavaScript function using the onclick handler and return false after the fact.

  The function argument can be omitted in favor of an update_page block, which evaluates to a string when the template is rendered (instead of making an Ajax request first).

  Examples: link_to_function "Greeting", "alert('Hello world!')" Produces: Greeting

  link_to_function(image_tag("delete"), "if (confirm('Really?')) do_delete()")
  Produces:
    <a onclick="if (confirm('Really?')) do_delete(); return false;" href="#">
      <img src="/images/delete.png?" alt="Delete"/>
    </a>
  
  link_to_function("Show me more", nil, :id => "more_link") do |page|
  page[:details].visual_effect  :toggle_blind
  page[:more_link].replace_html "Show me less"
  end
  Produces:
    <a href="#" id="more_link" onclick="try {
      $(&quot;details&quot;).visualEffect(&quot;toggle_blind&quot;);
      $(&quot;more_link&quot;).update(&quot;Show me less&quot;);
    } 
    catch (e) { 
      alert('RJS error:\n\n' + e.toString()); 
      alert('$(\&quot;details\&quot;).visualEffect(\&quot;toggle_blind\&quot;);
      \n$(\&quot;more_link\&quot;).update(\&quot;Show me less\&quot;);');
      throw e 
    };
    return false;">Show me more</a>
  

  # File 'lib/action_view/helpers/javascript_helper.rb', line 82
  
  def link_to_function(name, *args, &block)
    html_options = args.last.is_a?(Hash) ? args.pop : {}
    function = args[0] || ''
  
    html_options.symbolize_keys!
    function = update_page(&block) if block_given?
    content_tag(
      "a", name, 
      html_options.merge({ 
        :href => html_options[:href] || "#", 
        :onclick => (html_options[:onclick] ? "#{html_options[:onclick]}; " : "") + "#{function}; return false;" 
      })
    )
  end
  

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