callbacks.has.xml

<entry name="callbacks.has" type="method" return="Boolean">
  <signature>
    <added>1.7</added>
    <argument name="callback" type="Function">
      <desc>The callback to search for.</desc>
    </argument>
  </signature>
  <desc>Determine whether a supplied callback is in a list</desc>
  <longdesc></longdesc>
<example>
  <desc>Using <code>callbacks.has()</code> to check if a callback list contains a specific callback:</desc>
  <code><![CDATA[// a sample logging function to be added to a callbacks list
var foo = function( value1, value2 ){
    console.log( 'Received:' + value1 + ',' + value2 );
}

// a second function which will not be added to the list
var bar = function( value1, value2 ){
    console.log( 'foobar');
}

var callbacks = $.Callbacks();

// add the log method to the callbacks list
callbacks.add( foo );

// determine which callbacks are in the list

console.log( callbacks.has( foo ) ); // true
console.log( callbacks.has( bar ) ); // false
]]></code>
</example>
<category slug="callbacks-object"/>
<category slug="version/1.7"/>
</entry>