Salesforce and Namespaces

Instead of dumping you people with the technical definition of what namespace is, I would like to show you a simple example

I am pretty sure you are aware of test methods in salesforce Test.StartTest() and Test.StopTest()

Lets say you created a class with name Test and method with the name StartTest

public class Test{
public void StartTest(String s){

}
}

Now lets try running a test class

Test.StartTest() will give you an error but System.Test.StartTest() runs successfully. Why?

That mystery behind this is apart from the organization namespace that each Salesforce organization have, there is a namespace called System that is commonly available to all the salesforce organizations.

In this example the compiler checks if there is a class called Test in your organization namespace. Next if looks for Test in System namespace. What we did here was we accidentally overrided System namespace class.

Now I will give you the technical definition of Namespace. “A namespace is an abstract container or environment created to hold a logical grouping of unique identifiers or symbols”.

Credit Card Validation in Apex

There are requests from my blog readers asking for Credit Card Validation logic using Apex. I did some reasearch on credit card validation and found this algorithm called Luhn Algorithm which uses a simple checksum formula to validate a variety of Credit Card Numbers.

Lunh’s Algorithm

Here is the code I wrote for Credit Card Number as String input. You can also use this for Integer input with simple tweaks.

Credit Card Validation using Apex

public boolean CCValidation(String CCNumber){
Integer sum = 0;
Integer len = CCNumber.length();
for(Integer i=len-1;i>=0;i--){
Integer num = Integer.ValueOf(CCNumber.substring(i,i+1));
if ( math.mod(i , 2) == math.mod(len, 2) )
{
Integer n = num * 2;
sum += (n / 10) + ( math.mod(n, 10));
}
else{
sum += num;
}
}
return ( math.mod( sum, 10) == 0 );
}

SOQL and Relationship Queries last part

Relationship Queries Part 1
Relationship Queries Part 2

Date Functions

SOQL has a list of functions that deal with dates which makes your life a lot easier.

1) CALENDAR functions: CALENDAR_MONTH, CALENDAR_QUARTER, CALENDAR_YEAR
2) DAYDAY : DAY_IN_MONTH, DAY_IN_WEEK, DAY_IN_YEAR, DAY_ONLY
3) FISCAL: FISCAL_MONTH, FISCAL_QUARTER, FISCAL_YEAR
4) HOUR function: HOUR_IN_DAY
5) WEEK function: WEEK_IN_MONTH, WEEK_IN_YEAR

SELECT Title FROM Position__c WHERE CALENDAR_MONTH(Date_Closed__c) = 2

 
Aggregate Results with GROUP BY and HAVING

GROUP BY

GROUP BY is used in conjunction with aggregate functions to group the result-set by one or more columns.

SELECT Position__r.Department__c deptname, COUNT(id) total FROM Job_Application__c GROUP BY Position__r.Department__c

As you can see this query displayed number of Job Applications grouped by Department.

This example would make it more clear.

List aggrs = [SELECT Position__r.Department__c deptname, COUNT(id) total FROM Job_Application__c
GROUP BY Position__r.Department__c];
for (AggregateResult ja : aggrs){
System.debug(ja.get('dept') + ' | ' + ja.get('total'));
}

 
HAVING

You can use HAVING clause along with GROUP BY clause to filter the results returned by aggregate functions. A HAVING clause is similar to WHERE clause. The difference is you can include aggregate functions in a HAVING clause, but not in WHERE clause.

Lets use the above example again

SELECT Position__r.Department__c deptname, COUNT(id) total FROM Job_Application__c GROUP BY Position__r.Department__c HAVING COUNT(id)>1

This would return Job Applications GROUP BY Department for which there are more than one Job Applications.

Relationship Queries in SOQL

Relationship queries helps you extract data from Salesforce database with minimum possible number of queries. Let me give you simple examples of all kinds of relationship queries you can write.
 
Basic Child to Parent

Select Id, Name, Account.Name From Contact

Account is the name of relationship thats defined by AccountId lookup field on contact object.

Expanded Child to Parent

Select Id, Name, Account.Parent.Name From Contact

This will retrieve the name of the parent account of the account associated with the contact

Basic Parent to Child

Select Id, Name (Select Name From Contacts) From Account

You know what this will return.

Combined Child to Parent and Parent to Child

Select Id, Name, Account.Name (Select Quantity, UnitPrice, TotalPrice, PricebookEntry.Name, PricebookEntry.Product2.Family From OpportunityLineItems) From Opportunity

VisualForce Email Template

VisualForce email templates came as a part of winte ’09 release which leverages on VisualForce technology to provide underlying framework for email templates.

You need to know three tags to create VisualForce email template

1) <messaging:emailTemplate> – in which you specify recipient type, relatedToType, subject and email address that they can reply back to.

2) <messaging:htmlEmailBody> – in which you define the html content you want to show in your Email.

3) <messaging:plainTextEmailBody> – in which you include the text version of your Email.

Let me show you a simple example of how to create a VisualForce email template. We are going to create an email template which sends email about contacts that are related to an account.

The first step is to create an email template by going to Setup -> Administration Setup -> Communication Templates -> Email Templates -> New Template


<messaging:emailTemplate subject="Contact Information for Account: {!relatedTo.name}" recipientType="Contact" relatedToType="Account" replyTo="sivateja.s@gmail.com">
<messaging:htmlEmailBody >
<html>
<body>
<p> Dear {!recipient.name},</p>
<p> Below is the list of contacts related to your account: {!relatedTo.name}.</p>
<table border="0">
<tr>
<th> Action </th>
<th> Contact Name </th>
<th> Contact Email </th>
</tr>
<apex:repeat var="con" value="{!relatedTo.Contacts}">
<tr>
<td> <a href="na7.salesforce.com/{con.id}"> View </a>
<a href="na7.salesforce.com/{con.id}/e"> Edit </a> </td>
<td> {!con.Name} </td>
<td> {!con.Email} </td>
</tr>
</apex:repeat>
</table>
</body>
</html>
</messaging:htmlEmailBody>
<messaging:plainTextEmailBody >
Dear {!recipient.name},

Below is the list of Contacts related to Account: {!relatedTo.name}.

[Contact Name] - [Contact Email]
<apex:repeat var="cont" value="{!relatedTo.Contacts">
[cont.Name]  -  [cont.Email]
</apex:repeat>

For more detailed information login to http://www.salesforce.com
</messaging:plainTextEmailBody>
</messaging:emailTemplate>

 

Last step is to test and verify merge fields. Click Send Test and Verify Merge Fields button to verify merge fields.