Transcript AJAX - MD ColdFusion User's Group

AJAX
Daniel Daugherty
[email protected]
What is AJAX
Asynchronous JavaScript and XML
Other terms to know
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XMLHttpRequest
JSON
What is AJAX used for
Data retrivial
Send data to the server for processing.
Form Validation
Anything you might load a new page for.
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It is possible to build “One Page” Ajax
Applications.
What is AJAX NOT
AJAX is NOT DHTML
AJAX is commonly used allong with
DHTML to provide enhanced user
interface. But they are 2 separate things.
How to implement AJAX
Write XMLHttpRequest your self.
Use a AJAX Framework.
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Many many many many frameworks out
there.
DWR for JAVA
AJAX.CFC + DWR.CFC for Coldfusion.
DWR Setup
Download DWR –
http://getahead.ltd.uk/dwr/
Install DWR.jar in your J2EE server
classpath.
Edit web.xml to add the DWR as a servlet.
Edit DWR.XML to list objects to be made
available via AJAX.
AJAX.CFC /DWR.CFC
Unzip AJAX.zip into a folder in your web
root.
Edit DWR.XML to list objects to be made
available via AJAX
How do I call DWR/AJAX.CFC
JS templates are needed
engine.js
util.js optional but recomeneded.
JAVA
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dwr/interface/[JavascriptName].js
ColdFusion
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ajax_js_stub.cfm?component=[JavascriptName]
wddx.js
Demo
Security
Limit the type of things available via AJAX.
Java
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Supports restriction with J2EE roles
Security Filter.
ColdFusion
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Application.cfm or Application.CFC
cflogin roles
Error Handling
Client Side
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DWREngine.setWarningHandler()
DWREngine.setErrorHandler()
Server Side
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May need to adjust server side error trapping
to be AJAX aware.
Debugging
Server side
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LOG files are your friend.
Client Side
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Firefox Javascript Debugger
Firebugs
HTTP Trace utility
Javascript alert()
DDumper.js - Comes with AJAX.CFC