Module | ActionView::Helpers::JavaScriptHelper
In: | lib/action_view/helpers/javascript_helper.rb

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.

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

### Methods

array_or_string_for_javascript button_to_function escape_javascript javascript_tag link_to_function options_for_javascript

### Included Modules

PrototypeHelper

### Constants

JAVASCRIPT_PATH | = | File.join(File.dirname(__FILE__), 'javascripts')
JS_ESCAPE_MAP | = | { '\\' => '\\\\', '</' => '<\/', "\r\n" => '\n', "\n" => '\n', "\r" => '\n', '"' => '\\"', "'" => "\\'" }

### Public Instance methods

button_to_function(name, *args, &block)

Returns a button with the given `name` text that‘ll trigger a JavaScript `function` using the onclick handler.

The first argument `name` is used as the button‘s value or display text.

The next arguments are optional and may include the javascript function definition and a hash of html_options.

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).

The `html_options` will accept a hash of html attributes for the link tag. Some examples are :class => "nav_button", :id => "articles_nav_button"

Note: if you choose to specify the javascript function in a block, but would like to pass html_options, set the `function` parameter to nil

Examples:

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

escape_javascript(javascript)

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

javascript_tag(content_or_options_with_block = nil, html_options = {}, &block)

Returns a JavaScript tag with the `content` inside. Example:

      javascript_tag "alert('All is good')"

Returns:

      <script type="text/javascript">
      //<![CDATA[
      alert('All is good')
      //]]>
      </script>

`html_options` may be a hash of attributes for the <script> tag. Example:

      javascript_tag "alert('All is good')", :defer => 'defer'
      # => <script defer="defer" type="text/javascript">alert('All is good')</script>

Instead of passing the content as an argument, you can also use a block in which case, you pass your `html_options` as the first parameter.

      <% javascript_tag :defer => 'defer' do -%>
        alert('All is good')
      <% end -%>

link_to_function(name, *args, &block)

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

The first argument `name` is used as the link text.

The next arguments are optional and may include the javascript function definition and a hash of html_options.

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).

The `html_options` will accept a hash of html attributes for the link tag. Some examples are :class => "nav_button", :id => "articles_nav_button"

Note: if you choose to specify the javascript function in a block, but would like to pass html_options, set the `function` parameter to nil

Examples:

      link_to_function "Greeting", "alert('Hello world!')"
        Produces:
          <a onclick="alert('Hello world!'); return false;" href="#">Greeting</a>

      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>

### Protected Instance methods

array_or_string_for_javascript(option)
options_for_javascript(options)

[Validate]