What are behaviors?
A behavior is an action
that is triggered by and event. When a behavior is
added to a web page dreamweaver adds a small peice
of javascript code that controls how and when an object
acts when the user interacts with it. User interaction
can be in the form of a mouse click, hover or when
an object has finshed loading. Javascript can detech
user interacts in the form of events, depending on
which event is deteched a specific function is be
called that controls how the object reacts.
event + action = behavior
For example:
[Creating a simple behavior]
[Removing a behavior]
There a number of different events that can be used
in dreamweaver here are some of the more commonly used
ones.
Mouse events
- onClick
- onMouseOver
- onMouse Down
- onMouseUp
- onMouseOut
Object Events
- onLoad
- onUnload
- onSelect
- onChange
- onSubmit
Web Page Events
A single event can have a single action but behaviors
can also be used to assiciate a series of actions with
an event and set the order in which the actions occur
creating complex behaviors. Which can be a great way
to build usability, inteactivity and accesibility into
your website.
Common Applications Of Behaviors
In Web Pages
Playing a sound on mouse
over or mouse click
In Dreamweaver sounds can also be
controled by behaviors in fact dreamweaver has a built
in way to create a simple "play sound when" behavior.
However when using this feature the behavior does
not give a method by which the sound can be turned
off before it has finished playing. So if you use
a piece of music when the behavior is triggered by
a rollover, click or onload event the song will play
all the way to the end and then stop. When using
sound in this way it is recommended to use short
sound effects such as clicks as they respond to the
user interaction swfly and end quickly otherwise
the user is stuck waiting for the sound to load then
listening to the song with no way of stopping it
other than refreshing the page This should be avioded
as it generates a poor user experience.
Sound effects can be used with image based buttons
or pictures but when using flash buttons it would
be more consistent to use an embedded mp3 file in
the same swf file and use flash's native events to
control it.
To learn how to play a sound using behaviors in Dreamwever
see: [Playing sound when mouse is clicked]
(depreciated)
Showing & Hiding Elements
Using Behaviors
To show an hide an image or object you need
to create two behaviors. One controls when to make
the object appear and the other controls when to make
the object dissappear.
For example:
See [Making layers
visible on mouse over]
Sawp Images Using Behaviors
[Creating An Image rollover]
Pop Up Messages Using Behaviors
[Creating a Popup Message]
Popup Menus Using Behaviors
(depreciated)
[Creating a popup menu]
Validating Form Entries using Behaviors
[Validating form entries]
[Validating email addresses]
[Validating phone numbers]
[Making fields required]
Limitations and Problems Associated
with Using Evets and Behaviors
- Requires javascript to run
- Not all events are supported by all browsers
- Can slow a browsing experice
- Other methids give more sophistcated control over
behavior (flash)
Behaviors are client side scripts that run in web
browser. The scripts senses user events and then controls
an object actions. This is all done using the web browser
andthe users CPU . This means that websites running
client side scripts make the user run the cpu intensitve
application leaving the server free to simply deliver
scripts to visitors.
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