MACROMEDIA DREAMWEAVER MX 2004-EXTENDING DREAMWEAVER Manual - page 236

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Chapter 14:  Behaviors

How Behaviors work

When a user selects an HTML element in a Dreamweaver document and clicks the Plus (+) 

button, the following events occur:

1

Dreamweaver calls the 

canAcceptBehavior()

 function in each Action file to see whether this 

action is appropriate for the document or the selected element. 

If the return value of this function is the value 

false

, Dreamweaver dims the action in the 

Actions pop-up menu. (For example, the Control Shockwave action is dimmed when the user’s 

document has no SWF files.) If the return value is a list of events, Dreamweaver compares each 

event with the valid events for the currently selected HTML element and target browser until 

it finds a match. Dreamweaver populates the Events pop-up menu with the matched event 

from the 

canAcceptBehavior()

 function at the top of the list; if no match exists, the default 

event for the HTML element (marked in the Event file with an asterisk [*]) becomes the top 

item. The remaining events in the menu are assembled from the Event file.

2

The user selects an action from the Actions pop-up menu.

3

Dreamweaver calls the 

windowDimensions()

 function to determine the size of the Parameters 

dialog box. If the 

windowDimensions()

 function is not defined, the size is 

determined automatically.

A dialog box always appears, with OK and Cancel buttons appearing at the right edge, 

regardless of the contents of the 

BODY

 element.

4

Dreamweaver displays a dialog box that contains the 

BODY

 elements of the Action file. If the 

Action file’s 

BODY

 tag contains an 

onLoad

 handler, Dreamweaver executes it.

5

The user fills in the parameters for the action. Dreamweaver executes event handlers that are 

associated with the form fields as the user encounters them.

6

The user clicks OK.

7

Dreamweaver calls the 

behaviorFunction()

 and 

applyBehavior()

 functions in the selected 

Action file. These functions return strings that are inserted into the user’s document.

8

If the user later double-clicks the action in the Actions column, Dreamweaver reopens the 

Parameters dialog box and executes the 

onLoad

 handler. Dreamweaver then calls the 

inspectBehavior()

 function in the selected Action file, which fills in the fields with the data 

that the user previously entered.

Inserting multiple functions in the user’s file

Actions can insert multiple functions—the main behavior function plus any number of helper 

functions—into the 

HEAD

 section. Two or more behaviors can even share helper functions as long 

as the function definition is exactly the same in each Action file. One way of ensuring that shared 

functions are identical is to store each helper function in an external JavaScript file and insert it 

into the appropriate Action files using