Module: ActionView::Helpers::JavaScriptHelper

Included in:
ActionView::Helpers
Defined in:
actionpack/lib/action_view/helpers/javascript_helper.rb

Constant Summary collapse

JS_ESCAPE_MAP =
{
  '\\'    => '\\\\',
  '</'    => '<\/',
  "\r\n"  => '\n',
  "\n"    => '\n',
  "\r"    => '\n',
  '"'     => '\\"',
  "'"     => "\\'"
}

Instance Method Summary collapse

Instance Method Details

#button_to_function(name, function = nil, html_options = {}) ⇒ Object

Returns a button whose onclick handler triggers the passed JavaScript.

The helper receives a name, JavaScript code, and an optional hash of HTML options. The name is used as button label and the JavaScript code goes into its onclick attribute. If html_options has an :onclick, that one is put before function.

button_to_function "Greeting", "alert('Hello world!')", :class => "ok"
# => <input class="ok" onclick="alert('Hello world!');" type="button" value="Greeting" />

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# File 'actionpack/lib/action_view/helpers/javascript_helper.rb', line 84

def button_to_function(name, function=nil, html_options={})
  onclick = "#{"#{html_options[:onclick]}; " if html_options[:onclick]}#{function};"

  tag(:input, html_options.merge(:type => 'button', :value => name, :onclick => onclick))
end

#escape_javascript(javascript) ⇒ Object Also known as: j

Escapes carriage returns and single and double quotes for JavaScript segments.

Also available through the alias j(). This is particularly helpful in JavaScript responses, like:

$('some_element').replaceWith('<%=j render 'some/element_template' %>');

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# File 'actionpack/lib/action_view/helpers/javascript_helper.rb', line 28

def escape_javascript(javascript)
  if javascript
    result = javascript.gsub(/(\\|<\/|\r\n|\342\200\250|[\n\r"'])/u) {|match| JS_ESCAPE_MAP[match] }
    javascript.html_safe? ? result.html_safe : result
  else
    ''
  end
end

#javascript_cdata_section(content) ⇒ Object

:nodoc:


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# File 'actionpack/lib/action_view/helpers/javascript_helper.rb', line 71

def javascript_cdata_section(content) #:nodoc:
  "\n//#{cdata_section("\n#{content}\n//")}\n".html_safe
end

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

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 -%>

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# File 'actionpack/lib/action_view/helpers/javascript_helper.rb', line 59

def javascript_tag(content_or_options_with_block = nil, html_options = {}, &block)
  content =
    if block_given?
      html_options = content_or_options_with_block if content_or_options_with_block.is_a?(Hash)
      capture(&block)
    else
      content_or_options_with_block
    end

  (:script, javascript_cdata_section(content), html_options.merge(:type => Mime::JS))
end

Returns a link whose onclick handler triggers the passed JavaScript.

The helper receives a name, JavaScript code, and an optional hash of HTML options. The name is used as the link text and the JavaScript code goes into the onclick attribute. If html_options has an :onclick, that one is put before function. Once all the JavaScript is set, the helper appends “; return false;”.

The href attribute of the tag is set to “#” unless html_options has one.

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

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# File 'actionpack/lib/action_view/helpers/javascript_helper.rb', line 102

def link_to_function(name, function, html_options={})
  onclick = "#{"#{html_options[:onclick]}; " if html_options[:onclick]}#{function}; return false;"
  href = html_options[:href] || '#'

  (:a, name, html_options.merge(:href => href, :onclick => onclick))
end