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Overriding Standard buttons with Visualforce Page and redirecting based on User

12:17 AM

Overriding a Standard button is pretty straightforward.. but when you override a standard button with a visualforce page all users in your organization would see this page...

So, let's suppose you want one set of users to view a page (for ex: viewpage1) and another set of users to view another page (for ex:viewpage2).

First of all, create the two visualforce pages viewpage1 and viewpage2

Secondly, create a new visualforce page called "viewpageredir". This page would contain the following code...

Note that i have created this page for the "Account" object. I would use this page to override my Account View button. You can use this code for any object by specifying the name of the object in the standardcontroller attribute.

<apex:page showheader="false" action="{!pageredirect}" standardcontroller="Account" extensions="pageredir">

</apex:page>

The Apex Code would be...

public class pageredir
{

public pageredir(ApexPages.StandardController controller) {

}

public Pagereference pageredirect()
{
if (Userinfo.getUserName() == 'testview1@org.com')
{
Pagereference p = Page.viewpage1;
return p;
} 
else
{
Pagereference p = Page.viewpage2;  
return p;
}  
}      
}

Now, let's see how this works.. As you can see "viewpageredir" has only one tag "<apex:page>" . There is no other content in this page as we are using it only to redirect the user to his specific page.

We, have an action attribute in the page. The action method is called when the page loads. This causes the method "pageredirect" to be called. In this page we check the current user's Username. "Userinfo" can not only get the username but also the ID, ProfileId etc. See the Apex Language reference for the entire list.

Based on the username, we redirect the user to the desired page......

__c

Understanding relationships in Salesforce

3:35 AM

Relationship between objects are created when you create a field of type Look-up... Of course, Salesforce standard objects come with their own built-in relationships.. Let's categorize relationships into two categories...

Standard Relationship
Custom Relationship

We all know how a relationship looks like in the UI, for ex: Account - Contact relationship. You can see that one Account can have many Contacts associated to it . When you create or edit a Contact you will have to select a Account from the look-up dialog to establish a relationship...

Now, that's all what we know.. But at the database level there is much more to be explored..

Standard Relationship

Standard relationships are the one's that come pre-built between Standard objects in Salesforce.

Let's understand the Account-Contact relationship.. In Contact you can find a field called Account.. This field establishes the relationship.. When you view a Contact record you will see the Account Name populated in this field... But guess what, that is not actually stored in the database..

The ID of the Account is stored in the look-up field. Hence, all look-up fields would store the ID.

Here is how the actual database fields are....

AccountId - This stores the ID of the Account.
Account -- This stores the relationship of the Account.

So, here come's the interesting part. By using the "Account" relationship you can access any field of the associated Account.

[Select Account.Name,Account.BillingCity from Contact]

And what more, you can retrieve data from a relationship to a relationship as well...

[Select Account.Name,Account.BillingCity,Account.Owner.Name from Contact]

So, they can be multi-level....

What's the advantage??

The better you understand relationships, the better you can construct complex nested queries and try to minimize the number of queries used.

Custom Relationship:

This is same as the standard relationship except that the naming convention has some differences...

THE __c and __r :

In our same example, if we create a custom Account look-up field on Contact and name it as CustomAccount... then accessing the relationship is as follows...

CustomAccount__c --> Equivalent of AccountId, holds the ID of the Account.

CustomAccount__r --> Equivalent of Account, holds the relationship

Our example query will modify as below..

[Select CustomAccount__r.Name,CustomAccount__r.BillingCity,CustomAccount__r.Owner.Name from Contact]

Wondering how i came to know about this and where will you find more details on this????

Go to Setup--> Develop --> API and click on "Generate Enterprise WSDL"

The WSDL shows the actual way data is stored, the actual field names, the actual relationships etc...

Getter and setter methods - What are they??

9:18 AM

Well, once you start using a controller or an extension you will get used to these words...

So, it is good that we understand what these methods really do..

Getter and setter methods are used to pass data from your visualforce page to your controller and vice versa..

Let's take a very simple scenario... Let's assume you want to display a textbox in your visualforce page.. When the user enters some value in this textbox and clicks on a button you want the value entered by the user in your Apex class (ie. basically your controller or extension)

So go ahead and create a simple visualforce page.. the code for this would be

<apex:page controller="simplegetset">
  <apex:form>
    <apex:outputlabel value="Enter your name here"/>
       <apex:inputtext value="{!userinput}"/>          
  </apex:form>    
</apex:page>

The Apex code for this page would be...

public class simplegetset
{
    public String userinput{get; set;}
}

Now, the variable "userinput" in your Apex class will store the value entered by the user....

Let's analyze the methods now...

Get

The "get" method is used to pass data from your Apex code to your Visualforce page.. In our example we are not passing any value.. hence, when your page loads initially the textbox will have a empty value...

So, lets modify our code and pass a default value to the textbox.. Change the Apex code as follows..

public class simplegetset
{  
    public String userinput;
    public String getuserinput(){return 'John';}
   
    public void setuserinput(String userinput)
    {
        this.userinput = userinput;
    }   
}

You can now see that your page loads with a value 'John'...

Set

The "set" method is used to pass values from your visualforce page to the controller... In our example the variable "userinput" will be storing the value entered in the textbox..

Now modify your VF page as below..

<apex:page controller="simplegetset">
  <apex:form>
    <apex:outputlabel value="Enter your name here"/>
       <apex:inputtext value="{!userinput}">
           <apex:actionsupport event="onclick" rerender="display" />
       </apex:inputtext>                   
    <apex:outputpanel id="display">
        <apex:outputtext value="The name entered is {!userinput}"/>
    </apex:outputpanel>                   
  </apex:form>    
</apex:page>

The Apex code would be...

public class simplegetset
{
    public String userinput{get; set;}
}

In this example what happens is.. the variable "userinput" stores the value entered in visualforce page and passes it to the Apex code.. hence you are able to see the entered value in the visualforce page..

I guess you might understand what i am saying.. to make things simple now use the same visualforce page.. but modify the Apex code as below..

public class simplegetset
{  
    public String userinput;
    public String getuserinput(){return 'John';}
   
    public void setuserinput(String userinput)
    {
        this.userinput = userinput;
    }   
}

Now, whatever value you enter the page always displays "The name entered is John".... This is because your get method always returns 'John'... but still your set method will store the value you entered in the variable "userinput"....

Hope i did not confuse...

Overriding Standard buttons with Visualforce Page and redirecting based on User

Understanding relationships in Salesforce

Getter and setter methods - What are they??

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