Macromedia dreamweaver 8-extending dreamweaver User Manual

The Behaviors API

315

canAcceptBehavior()

Description

This function determines whether the action is allowed for the selected HTML element and 
specifies the default event that should trigger the action. Can also check for the existence of 
certain objects (such as SWF files) in the user’s document and not allow the action if these 
objects do not appear.

Arguments

■

The argument is the selected HTML element.

Returns

Dreamweaver expects one of the following values:

■

A 

true

 value if the action is allowed but has no preferred events.

■

A list of preferred events (in descending order of preference) for this action. Specifying 
preferred events overrides the default event (as denoted with an asterisk [*] in the Event 
file) for the selected object. See step 1 in 

■

A 

false

 value if the action is not allowed. 

If the 

canAcceptBehavior()

 function returns a 

false

 value, the action is dimmed in the 

Actions pop-up menu on the Behaviors panel.

Example

The following instance of the 

canAcceptBehavior()

 function returns a list of preferred 

events for the behavior if the document has any named images:

function canAcceptBehavior(){ 

var theDOM = dreamweaver.getDocumentDOM();
// Get an array of all images in the document
var allImages = theDOM.getElementsByTagName('IMG'); 
if (allImages.length > 0){

return "onMouseOver, onClick, onMouseDown";

}else{

return false;

}

}