Application.cfc - Hands On 16

gistfile1.md

In this hands on we will create an Application.cfc file, create some application wide variables, and implement some of the Application.cfc event handlers.

Tags Used: <cfset>, <cfquery

Functions Used: createTimeSpan, structKeyExists, createObject

1. Create a new file called Application.cfc in /www/.
2. Open up the /www/Application.cfc file in your code editor. Note: for this hands on we will be doing all our coding in script format.
3. Create a component declaration. Your code should look similar to this:

   component{
   }
   

4. Create two variables in the this scope called name and datasource. Set both variables to 'learncfinaweek'.
5. Create another variable in the this scope called applicationTimeout and give it a value of:

   CreateTimeSpan(10, 0, 0, 0);
   

   	</li>
   	<li>
   		Create another variable in the this scope called <span class="code">sessionManagement</span> and set it to true.
   	</li>
   	<li>
   		Create another variable in the this scope called <span class="code">sessionTimeout</span> and give it a value of:
   

   CreateTimeSpan(0, 0, 30, 0);
   

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

   component{
   	this.name='learncfinaweek';
   	this.datasource='learncfinaweek';
   	this.applicationTimeout = CreateTimeSpan(10, 0, 0, 0);
   	this.sessionManagement = true;
   	this.sessionTimeout = CreateTimeSpan(0, 0, 30, 0);
   }
   

   	</li>
   	<li>
   		Create a function called <span class="code">onApplicationStart</span> that accepts no arguments and returns true.
   	</li>
   	<li>
   		Inside the <span class="code">onApplicationStart</span> function, create two variables set in the application scope. The first variable should be called <span class="code">myName</span> and should have the value of your name. The second variable should be called <span class="code">myPosition</span> and should have the value of 'A Developer'.
   	</li>
   	<li>
   		Your code should look similar to this:
   

   component{
   	this.name='learncfinaweek';
   	this.datasource='learncfinaweek';
   	this.applicationTimeout = CreateTimeSpan(10, 0, 0, 0);
   	this.sessionManagement = true;
   	this.sessionTimeout = CreateTimeSpan(0, 0, 30, 0);
   	
   	function onApplicationStart() {
   		application.myName = 'Simon';
   		application.myPosition = 'A Developer';
   		return true;
       }
   }
   

   	</li>
   	<li>
   		Below the <span class="code">onApplicationStart</span> function,create a new function called <span class="code">onRequestStart</span> which accepts one string parameter called 'targetPage'.
   	</li>
   	<li>
   		Inside the function, create an <span class="code">if</span> statement that calls the <span class="code">StructKeyExists</span> function. The <span class="code">structKeyExists</span> function should be passed the URL scope as its first parameter and the string 'reload' as its second parameter.
   	</li>
   	<li>
   		Inside the <span class="code">if</span> statement, a call should be made to the <span class="code">onApplicationStart</span> function.
   	</li>
   	<li>
   		Your code should look similar to this:
   

   function onRequestStart(string targetPage){
   	if(structKeyExists(url,'reload')){
   		onApplicationStart();
   	}
    }
   

   	</li>
   	<li>
   		Open up the <span class="code">/www/index.cfm</span> file in your code editor.
   	</li>
   	<li>
   		Remove the <span class="code">&lt;cfset></span> tags at the top of the page.
   	</li>
   	<li>
   		Locate the <span class="code">myName</span> variable output on or around line 15 and change it to <span class="code">application.myName</span>.
   	</li>
   	<li>
   		Locate the <span class="code">myPosition</span> variable output on or around line 16 and change it to <span class="code">application.myPosition</span>.
   	</li>
   	<li>
   		In your browser, navigate to the <span class="code">/www/index.cfm</span> page. The index page should display as normal.
   	</li>
   	<li>
   		Go to the <span class="code">/www/application.cfc</span> file in your code editor and change the <span class="code">application.myPosition</span> variable to have the value of 'A Great Developer'.
   	</li>
   	<li>
   		In your browser, refresh the <span class="code">index.cfm</span> page. Notice that nothing has changed. This is because the application has already started, so the <span class="code">onApplicationStart</span> method does not get called.
   	</li>
   	<li>
   		In your browser, append <span class="code">?reload=1</span> to the <span class="code">index.cfm</span> in the location bar. Hit return to load the page. Notice that the position has now updated to the new value.
   	</li>
   	<li>
   		Open up the <span class="code">/www/resume.cfm</span> file in your code editor. Locate both <span class="code">&ltcfquery></span> tags and remove the <span class="code">datasource</span> attributes.
   	</li>
   	<li>
   		In a browser, navigate to the <span class="code">/www/resume.cfm</span> page. Notice that the page loads normally. Both queries are now using the application wide data source.
   	</li>
   	<li>
   		In the <span class="code">onApplicationStart</span> function in the <span class="code">/www/Application.cfc</span> file, create a new application variable called 'utilities'. Set the value of <span class="code">application.utilities</span> to:
   

   CreateObject('cfc.utilities');
   

   	</li>
   	<li>
   		Your code should look similar to:
   

   function onApplicationStart() {
   	application.myName = 'Simon';
   	application.myPosition = 'A Great Developer';
   	application.utilities = CreateObject('cfc.utilities');
   	return true;
   }
   

   	</li>
   	<li>
   		Open up the <span class="code">/www/about.cfm</span> file in your code editor and remove the <span class="code">&lt;cfset></span> tag on or around line 4.
   	</li>
   	<li>
   		Locate the <span class="code">utilities.convertStringToASCII</span> function call on or around line 58 and change it to <span class="code">application.utilities.convertStringToASCII</span>.
   	</li>
   	<li>
   		In a browser, navigate to the <span class="code">/www/about.cfm</span> page, remembering to include <span class="code">?reload=1</span> in the URL as we have made an <span class="code">application.cfc</span> change.
   	</li>
   	<li>
   		Notice that the page loads normally. The <span class="code">convertStringToASCII</span> function is now stored in the application scope and can be accessed from any page within the application.
   	</li>
   </ol>
   

   Homework

   1. Remove the datasource attribute from all query tags.
   2. Update the email address in the /www/contact.cfm file to use the convertStringToASCII function.