12.4 Built-in Behaviors (Actions)

The Add Behavior pop-up menu, shown in Figure 12-2, lists the actions (behaviors) available in the Behaviors panel.

Here are some important things to note:

• The menu is used to apply many different types of behaviors to unrelated elements. Although Dreamweaver dims the menu choices that you can't use, it may leave you confused about why a particular action is unavailable and how to make it active.

• The contents of this menu are determined by the .js files stored under Dreamweaver4/Configuration/Behaviors/Actions. (The comments in these files also explain the behavior's requirements and limitations.) You can delete the ones you never use, edit them, or add your own. You can also link to copies of these .js files for increased efficiency when using the same behavior on multiple web pages. Using external .js files prevents Dreamweaver from updating the JavaScript, so keep your .js files up to date when installing Dreamweaver updates.

Figure 12-2. Actions available in the Behaviors panel

• Use the Get More Behaviors option to download additional behaviors from the Dreamweaver Exchange.

• The Show Events For option is somewhat confusing. It does not affect which options are available in this menu; instead, it limits the available events (not actions) to trigger an action. It does nothing to prevent you from adding unsupported actions in the first place. See Table 12-3 instead.

• Behaviors cannot be applied to a document based upon a template. Apply behaviors to the template instead (see Chapter 8) and place those behaviors in a linked external .js file.

12.4.1 Behavior Summary

The built-in behaviors shown in Figure 12-2 are summarized in Table 12-3. Remember that some menu choices will be inactive depending on what object you have selected in your HTML document. Other behaviors are active only when certain HTML elements have been inserted. For example, the Show-Hide Layers behavior is active only if the page contains one or more layers. When we discuss each behavior, we'll tell you what is necessary to make it active in the Add Behavior menu.

Behaviors typically require that an element have an id attribute by which it can be referenced, but some behaviors reference elements by their name attribute. For example, NN6 requires that a layer's name attribute be set before using it with behaviors that manipulate layers. Download the free DW 4.01 updater to ensure that behaviors work with NN6.

All behaviors listed in Table 12-3 fail silently in IE3 for the Mac, but work in IE3 for Windows, NN3+ (Macintosh and Windows), and IE4+ (Macintosh and Windows) unless otherwise noted.

Table 12-3. Dreamweaver's default behaviors

Behavior	Descriptions
Call JavaScript	Inserts a call to another JavaScript function.
Change Property	Changes the specified property of the specified tag.
Check Browser	Optionally branches to different URLs based on the browser's brand and/or version.
Check Plugin	Optionally branches to different URLs based on the presence/absence of a plugin (fails in IE3/IE4 on Macintosh).
Control Shockwave or Flash[1]	Plays, stops, and rewinds Flash or Shockwave movies.
Drag Layer	Allows the user to drag layers.
Go To URL	Opens a document in a specified location.
Jump Menu[1]	Creates a jump menu.
Jump Menu Go[1]	Adds a Go button to an existing jump menu.
Open Browser Window	Opens the specified document with the specified window attributes in a new browser window.
Play Sound[1]	Plays audio files.
Popup Message	Creates a pop-up alert message box.
Preload Images[1]	Preloads images for rollovers and image swaps.
Set Nav Bar Image[1]	Creates a navigation bar.
Set Text of Frame	Sets the text content of a frame.
Set Text of Layer[2]	Sets the text content of a layer.
Set Text of Status Bar	Sets the text content of the browser's status bar.
Set Text of Text Field	Sets the text content of a text field within a form.
Show-Hide Layers[2]	Shows or hides one or more layers.
Swap Image[1]	Swaps an existing image for another image (see Figure 13-2).
Swap Image Restore[1]	Restores a swapped image (see Figure 13-3).
Go To Timeline Frame[3]	Goes to a keyframe in a timeline.
Play Timeline[3]	Plays the specified timeline.
Stop Timeline[1][3]	Stops the specified timeline.
Validate Form	Validates the format of text entry fields (see Table 16-2).
Show Events For	Indicates which browsers you intend to support. Dreamweaver limits the events for a given action based on the target browser.
Get More Behaviors	Accesses the Dreamweaver Exchange where you can download additional behaviors.

^[1] Fails silently in IE3 on both Macintosh and Windows.

^[2] Fails in all Version 3 browsers (requires CSS support).

^[3] In NN3 (both Macintosh and Windows) the image source animation and behavior invocation work, but the layer animation fails silently.

12.4.2 Events (Triggers)

Once you apply an action (behavior) to an element, Dreamweaver assumes the default events as shown in Table 12-4. To trigger the action using a different event, pick one from the Select Event pop-up menu (using the arrow that appears next to the currently selected action, as seen in Figure 12-3).

Figure 12-3. Picking an event to trigger an action

The Select Event menu lists different events, depending on the HTML object to which the behavior is applied and the setting under the Show Events For submenu.

Event names appearing in parentheses can be applied to <a> tags only. If you choose such an event, Dreamweaver automatically wraps a null link (with href="javascript:;") around the selected element and applies the behavior to the <a> tag instead. See Section 12.5.1.2 later in this chapter for an example.

To execute timer-based actions, apply a behavior to the Behaviors channel of a timeline, and trigger it with an onFrame event. See Chapter 17 for details on timelines.

12.4.2.1 The Show Events For submenu

The Show Events For submenu (which appears in both the Add Behavior and Select Event pop-up menus) lets you choose which browsers you intend to target. It limits the events shown on the Select Event pop-up menu to those supported by the specified browser(s). The older browsers support very few events; if you choose 4.0 and Later Browsers from the menu, it shows only the events that work in all 4.0 browsers. On the other hand, picking an individual browser, especially a recent version of IE, often displays a huge number of events to choose from.

Table 12-4 lists the events that are available for each type of tag when choosing the 4.0 and Later Browsers option from the Show Events For menu. If you select a different option, the available tags and events may differ substantially from those shown in the table. Search for "About Events" under Help Using Dreamweaver (F1) for a list of events and the browsers that support them.

Although several events can often trigger an action, Dreamweaver uses the most common event as the default, as indicated by the entry in a bold font in the right-hand column. For example, if you attach a behavior to a <body> tag, the triggering event defaults to onLoad (the action is triggered when the page loads unless you change the event).

Table 12-4. Events for 4.0 and later browsers

Objects	Tag	4.0 browser events
Link	<a>	onClick, onDblClick, onKeyDown, onKeyPress, onKeyUp, onMouseDown, onMouseOut, onMouseOver, onMouseUp
Image map area	<area>	onClick, onDblClick, onMouseOut, onMouseOver
Body	<body>	onBlur, onError, onFocus, onLoad, onResize, onUnload
Form	<form>	onReset, onSubmit
Frameset	<frameset>	onBlur, onFocus, onLoad, onResize, onUnload
Image	<img>	onAbort, onError, onLoad, onMouseDown, onMouseUp
Form: Button	<input type= "button">	onBlur, onClick, onFocus, onMouseDown, onMouseUp
Form: Checkbox	<input type= "checkbox">	onBlur, onClick, onFocus, onMouseDown, onMouseUp
Form: File selection	<input type= "file">	onBlur, onChange, onFocus, onKeyDown, onKeyPress, onKeyUp
Form: Password	<input type= "password">	onBlur, onChange, onFocus, onKeyDown, onKeyPress, onKeyUp
Form: Radio button	<input type= "radio">	onBlur, onClick, onFocus, onMouseDown, onMouseUp
Form: Reset button	<input type= "reset">	onBlur, onClick, onFocus, onMouseDown, onMouseUp
Form: Submit button	<input type= "submit">	onBlur, onClick, onFocus, onMouseDown, onMouseUp
Form: Text	<input type= "text">	onBlur, onChange, onFocus, onKeyDown, onKeyPress, onKeyUp, onSelect
Text Area	<textarea>	onBlur, onChange, onFocus, onKeyDown, onKeyPress, onKeyUp, onSelect
Select	<select>	onBlur, onChange, onFocus

Table 12-4 does not show many of the tags to which you can apply behaviors when targeting newer browsers (for example, IE4 or IE5 allow you to attach behaviors to dozens of tags, many of which aren't supported in other browsers). Conversely, if you target 3.0 browsers, many fewer events and tags are available. To see precisely what events are available for which tags in other browsers, you can inspect the .htm files in the following folder: Dreamweaver4/Configuration/Behaviors/Events.

You can download additional browser profiles from the Dreamweaver support site. For example, the Netscape 6 Pack, featuring updated behaviors, is available separately and as part of the Dreamweaver 4.01 update (see http://www.macromedia.com/support/dreamweaver/downloads/).