Visualforce Controllers

The holidays are officially over and now that I have had a few days to recuperate it’s time to get back to work. The application we have been creating is pretty much ready to go… Go back to the Scheduled Invoices tab, and create a new invoice with an effective date two months in the past. Set the Duration to six months; fill out the remaining fields, and click "Save." Mark one of your pending payments as paid and you should now see three lists of payments: Past Due, Pending, and Paid. Granted this application is quite simple…but it was completed in a fraction of time and cost it would take for a traditional application.

So now that the first series of posts have been completed I wanted to jump into Visualforce Controllers. If you remember from previous entries a major component of how our application was rendered was through the use of Visualforce pages. Well a Controller is just Apex Code that analyzes and writes data in the force.com database. Also I need to make sure my blog is longer than a paragraph.

When working with Salesforce it is often required that you will need to display data from the force.com database or even insert data in database variables. Controllers can do these sorts of tasks much more quickly. There are two methods of the Controller that interact with the database variables. The ‘Getter’ method takes the value of the variables and displays it on the Visualforce page. The “Setter” method allows the developer to change the value of the variable using different Visualforce components. These methods operate similarly to the Getter and Setter methods in Java and C++.

A nice thing about the force.com platform is that it provides Standard Controllers, which are basic default controller that have already been implemented.  Though somewhat limited in functionality, you can perform certain changes to the native interface like editing records. Also you can use Apex classes to customize the controller.

My preferred method to the aforementioned Controllers is to create a Custom Controller that is completely user defined. The following is an example of a basic Custom Controller:

Page Code:

<apex:page controller="MyController">
   <apex:form>
         Name: <apex:inputText value="{!name}"/>
        <apex: outputText value="{!mssg}"/>
        <apex:commandLink action="{!Display}" value="Show Message" />
   </apex:form>
</apex:page>

MyController Code:

public class MyController{

      public String name {get ; set;}
      public String mssg {get ; set;}
      public PageReference Display() {
           mssg=’Time To Be Awesome’ + name;
           return null;
      }
}

Awesome!