Error Handling and Debugging - Hands On 31

In this hands on, you are going to add an Error Handling solution to the web site.

Tags Used: <cfdump>

Functions Used: include, mail

Open up the /www/Application.cfc file in your code editor.
After the onRequestStart function, create a new function called onError. The function will accept 2 arguments. The first is of type any and is called Exception. The second is of type String and is called EventName. Your code should look similar to this:
```
function onError( any Exception, string EventName ) {
}
```
Inside the function, include the file sorry.cfm.

After the file, place the following code, which will email the error information to you:

var errorEmail = new mail();
errorEmail.setTo('[email protected]');
errorEmail.setFrom('[email protected]');
errorEmail.setSubject('An Error has Occured');
errorEmail.setBody('
	Message: #arguments.exception.message# <br />
	Details: #arguments.exception.detail# <br />
	Type: #arguments.exception.type# <br />
');
errorEmail.setType('html');
errorEmail.send();

	</li>
	<li>
		Your function should look similar to this:

function onError( any Exception, string EventName ) {
	include 'sorry.cfm';
	var errorEmail = new mail();
	errorEmail.setTo('[email protected]');
	errorEmail.setFrom('[email protected]');
	errorEmail.setSubject('An Error has Occured');
	errorEmail.setBody('
		Message: #arguments.exception.message# <br />
		Details: #arguments.exception.detail# <br />
		Type: #arguments.exception.type# <br />
	');
	errorEmail.setType('html');
	errorEmail.send();

}

	</li>
	<li>
		Open up the <span class="code">/www/throwError.cfm</span> file in your browser. You should now see a 'sorry' page.
	</li>
	<li>
		Open up your ColdFusion Administrator and login. The URL for the ColdFusion Administrator is most likely <a href="http://localhost:8500/CFIDE/administrator/" target="_new">http://localhost:8500/CFIDE/administrator/</a>.
	</li>
	<li>
		Click on 'Mail' under Server Settings.
	</li>
	<li>
		Click on the 'View Undeliverable Mail'.
	</li>
	<li>
		The first item in the list should be your error email. Review the contents of the email that is sent when an email is thrown.
	</li>
	<li>
		Open up the <span class="code">/www/throwError.cfm</span> file in your code editor.
	</li>
	<li>
		Change the contents of the file to the following code:

<cfdump value="2" />

	</li>
	<li>
		Open up the <span class="code">/www/throwError.cfm</span> file in your browser and notice that an error is thrown. <span class="code">onError</span> does not catch tag syntax errors. For that, we must rely on the site-wide error handler.
	</li>
	<li>
		Create a new file called <span class="code">sitewideErrorHandler.cfm</span> in the <span class="code">/</span> folder.
	</li>
	<li>
		Open the <span class="code">/sitewideErrorHandler.cfm</span> file in your code editor.
	</li>
	<li>
		Add the following line of text to the file:

An error has occurred!

	</li>
	<li>
		Go back to your ColdFusion Administrator.
	</li>
	<li>
		Click on 'Settings' under Server Settings.
	</li>
	<li>
		Go to the Site-wide Error Handler input and enter the following value:

/learncfinaweek/sitewideErrorHandler.cfm

	</li>
	<li>
		Go back to the <span class="code">/www/throwError.cfm</span> page in your browser and refresh.
	</li>
	<li>
		You will now see the message 'An error has occurred!'. The site wide error handler has caught the exception and displayed a friendlier message to the user. You can now find details about the specific error from the server log files.
	</li>
</ol>

learncfinaweek/gist:4121420