Error Handling and Debugging - Hands On 31

gistfile1.md

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

Tags Used: <cfdump>

Functions Used: include, mail

1. Open up the /www/Application.cfc file in your code editor.
2. 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 ) {
   }
   

3. Inside the function, include the file sorry.cfm.
4. After the file, place the following code, which will email the error information to you:

   var errorEmail = new mail();
   errorEmail.setTo('you@domain.com');
   errorEmail.setFrom('system@domain.com');
   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('you@domain.com');
   	errorEmail.setFrom('system@domain.com');
   	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>