Tutor and Tricks

Apex Trigger in Salesforce

What is an Apex trigger?

Trigger is piece of code that is executes before and after a record is Inserted/Updated/Deleted from the force.com database.
Syntax:
Trigger <trigger name> on <Object name> (trigger Events) {
// Implement the Logic here
}

Types of Triggers:
– Before Triggers
– After Triggers

Before Trigger: Before triggers are used to perform the logic on the same object and specifically we cannot use the DML operation (Insert, update, delete) on these triggers.
These triggers are fired before the data is saved into the database.
After Trigger: After triggers are used to perform the logic on the related objects and these triggers are used access the fields values that are created by system (Ex: CreatedBy, LasteModifiedBy , Record Id etc..).

Bulk Triggers:
By default every trigger is a bulk trigger which is used to process the multiple records at a time as a batch. For each batch of 200 records.

Trigger Context Variables:
All the trigger context variables are prefixed with “Trigger.” (Ex: Trigger.isInsert, etc..)
isInsert: Returns true if the trigger was fired due to insert operation.
isUpdate: Returns true if the trigger was fired due to update operation.
isDelete: Returns true if the trigger was fired due to delete operation.
isBefore: Returns true if the trigger was fired before record is saved.
isAfter: Returns true if the trigger was fired after record is saved.
New: Returns a list of new version of sObject records.
Old: Returns a list of old version of sObject records.
NewMap: Returns a map of new version of sObject records. (map is stored in the form of map<id,newRecords>)
OldMap: Returns a map of old version of sObject records. (map is stored in the form of map<id,oldRecords>)
Size: Returns a integer (total number of records invoked due to trigger invocation for the both old and new)
isExecuting: Returns true if the current apex code is a trigger.

The below table is tells what are the events we can use in the new trigger and old trigger

Trigger Event	Trigger.New	Trigger.Old
Before Insert	Yes	No
Before Update	Yes	Yes
Before Delete	No	Yes
Before UnDelete	No	Yes
After Insert	Yes	No
After Update	Yes	Yes
After Delete	No	Yes

Trigger Context Variable considerations:
– Trigger.Old is always readOnly
– We cannot delete trigger.new
– In before triggers, trigger.new can be used to update the fields on the same object.
– In After trigger, we get run time exception is thrown when user try to modify the fields in the same object.

salesforce creating on demand apps

Visualforce

how to hide approve/Reject links in the home page?

We can hide the approve/Reject links, If we want to restrict the user to approve the record from home page.

If we have implemented logic for the approval process (customized approval process) for that we have to override the all the links (Approve links) and buttons in the details page.

How we can restrict the user to approve from home page.

Steps:

Create a StaticResouce “StaticResourceName” upload a JS file. (File extension should be .JS)

var j$ = jQuery.noConflict();

j$(document).ready(function(){

j$(“table.list td.actionColumn”).html(”);

});

go to Setup > Home > Custom Links
create a new link call it “HideApproveLink”
Behaviour = “Execute JavaScript”
Content Source = “Onclick JavaScript”
at the body enter {!REQUIRESCRIPT(“/resource/StaticResourceName”)}
go to Setup > Home > Home Page Components à New
call it “HideApproveLink-Box”
pick type “Links”
click next
pick “HideApprovalLink” we created above à save
got to Setup > Home > Home Page Layouts
add “HideApprovalLink-box” to your layout
Click on home Tab you can see the Approva/Reject links are hidden in the page.

We can create a home page component and written script to hide the links. But from summer ‘15 we don’t have the capability to write the script in home page component.

Disabling the command buttons and Grey out the total vf page on any action

How to disable the command buttons and Grey out the total vf page on any action?

Usually we multiple records creates whenever multiple click on save button on custom save button on VF page. So to overcome this issue we can hide the all buttons once user click on buttons.

VF Page:

<apex:commandButton action=”{!doSave}” id=”saveButton ” value=”save” onclick=”disableAllButtons()”/>

<apex:commandButton action=”{!doCancel}” id=”cancelButton” value=”cancel” onclick=” disableAllButtons()”/>

var j$ = jQuery.noConflict();

function disableAllButtons(){

j$(“[id$= saveButton],[id$= cancelButton]”).hide();

}

function showButtons(){

j$(“[id$= cancelButton],[id$= saveButton]”).show();

}

</Script>

showButtons function is to show the button once the action.
If we can use the same code for the input fields as well which have the action function. So that we can restrict the user to change the field and click the buttons immediately.
Some times we have to restrict the user to modify the fields on that page after click on button or change on any fields of having action function.

So, here we have to grey out the total VF page to restrict the user to change the fields if any action is In-progress.

The below code is to grey out the page. Gering out the backgrouond,status box and all tex boxes in the page.

<apex:commandButton action=”{!doSave}” id=”saveButton ” value=”save” onclick=”disableAllButtons()”/>

<apex:commandButton action=”{!doCancel}” id=”cancelButton” value=”cancel” onclick=” disableAllButtons()”/>

“Processing…….” </div>

var j$ = jQuery.noConflict();

function disableAllButtons(){

j$(“[id$= saveButton],[id$= cancelButton]”).hide();

j$(“# processingSimbol “).show();

j$(“[id$=formId]”).append(j$(“<div>”,{“id”:”blurybackground”})

,j$(“<div>”,{“id”:”statusBox”})

.append(

j$(“<img>”,{“src”:”/img/loading32.gif”}),

j$(“<div>”,{“id”:”textBox”}).text(“{!$Label.MDF_Status_Processing}”)));

}

function showButtons(){

j$(“[id$= cancelButton],[id$= saveButton]”).show();

j$(“#blurybackground, #statusBox”).remove();

if(globalFocus != null){

globalFocus.focus();

if(globalFocus.attr(‘class’).indexOf(‘amountInput’)!=-1){

var focusId = globalFocus.attr(‘id’).split(‘:’).join(‘\\\\:’);

setTimeout(function(){

j$(“#”+focusId).focus();

},300);

}

</Script>

<style>

#blurybackground {

z-index:1000;

//bottom:0;

position:absolute;

left:0px;

top:0px;

width:100%;

height:100%;

text-align:center;

vertical-align: middle;

background-color: #222;

opacity:0.6;

filter:alpha(opacity=60);

}

#statusBox {

// for Modzilla

-moz-background-clip:border;

-moz-background-inline-policy:continuous;

-moz-background-origin:padding;

-moz-border-radius-bottomleft:5px;

-moz-border-radius-bottomright:5px;

-moz-border-radius-topleft:5px;

-moz-border-radius-topright:5px;

-moz-box-shadow:1px 6px 5px #888888;

-webkit-border-bottom-left-radius:5px;

-webkit-border-bottom-right-radius:5px;

-webkit-border-top-left-radius:5px;

-webkit-border-top-right-radius:5px;

-webkit-box-shadow:1px 6px 5px #888888;

box-shadow: 1px 6px 5px #888888;

z-index:1000;

background:#FFFFFF none repeat scroll 0 0;

height:42px;

width:150px;

left:45%;

top:35%;

padding-left:15px;

padding-top:11px;

position:absolute;

vertical-align:middle;

}

#textBox {

margin-left:40px;

margin-top:-20px;

font-weight:bold;

font-size:14px;

}

</style>

Visualforce page to add multiple records

Adding multiple records:

Generally by using standard salesforce tab you can enter only one record at a time form UI. I don’t want to enter single record at a time. I want to enter multiple records at time. How can we achieve this? We can achieve this by using simple visual force page.

Example: I want to enter multiple accounts in single save. See the below visualforce page.

Visualforce page:

<apex:page Controller=”AddmultipleAccountsController”>
<apex:form >
<apex:pageBlock >
<apex:pageBlockTable value=”{!listAccount}” var=”acc”>
<apex:column headerValue=”Account Name”>
<apex:inputField value=”{!acc.Name}”/>
</apex:column>
<apex:column headerValue=”Account Number”>
<apex:inputField value=”{!acc.AccountNumber}”/>
</apex:column>
<apex:column headerValue=”Account Type”>
<apex:inputField value=”{!acc.Type}”/>
</apex:column>
<apex:column headerValue=”Industry”>
<apex:inputField value=”{!acc.Industry}”/>
</apex:column>
</apex:pageBlockTable>
<apex:pageBlockButtons >
<apex:commandButton value=”Add Accounts Row” action=”{!addAccount}”/>
<apex:commandButton value=”Save Accounts” action=”{!saveAccount}”/>
</apex:pageBlockButtons>
</apex:pageBlock>
</apex:form>
</apex:page>

Controller related to above page:

public class AddmultipleAccountsController {
Account account = new Account();
public list<Account> listAccount{ get; set; }

public AddmultipleAccountsController()
{
listAccount=new list<Account>();
listAccount.add(account);
}

Public void addAccount()
{
Account acc = new Account();
listAccount.add(acc);
}
public PageReference saveAccount() {
for(Integer i=0; i<listAccount.size(); i++)
{
insert listAccount;
}
return Page.Allaccountssaved;
}
}

Visualforce page Allaccountssaved( using this page above controller):

<apex:page sidebar=”false” showHeader=”true”>
<center><h3>Congrtas your accounts are successfully saved!!</h3></center>
</apex:page>

Output of above example:

Here Add Account row is used to enter one more account and Save Account is used to save all account records you entered. See below screen, you can understand functionality of Add Account Row button.