To achieve this requirement, we will be using two Chatter objects viz. Feed Item and Feed Comment. ‘Feed Item’ records are the posts created by a User and the ‘Feed Comment’ records are the comments on that post.

In other words, our requirement is to insert a random ‘Feed Comment’ record, whenever a ‘Feed Item’ record is inserted.

The Trigger should be written with the following flow:

1. Define the Trigger
2. Create a list for DML (last step)
3. Create a List of ‘Strings’/ Comments
4. Get a Random comment from the List in Step 3
5. Iterate through each Feed Item record in the List from Step 2. and add the random comment.
6. DML to insert List of newly created records

Now lets go through each step once again and write its respective code.

trigger randomChatterComment on FeedItem (after insert) {

    //Create a list to hold the list of Feed Comment records being inserted
    List<FeedComment> List2insert = New list<FeedComment>();

//Create a list of Strings
    List<String> commentList = New List<String>{
        'Congratulations and BRAVO!',
            'This calls for celebrating! Congratulations!',
            'You did it! So proud of you!',
            'I knew it was only a matter of time. Well done!',
            'Congratulations on your well-deserved success.',
            'Heartfelt congratulations to you.',
            'Warmest congratulations on your achievement.',
            'Congratulations and best wishes for your next adventure!',
            'So pleased to see you accomplishing great things.',
            'Feeling so much joy for you today. What an impressive achievement!',
            'You’ve worked so hard for this. Congrats!',
            'This is awesome! You’re awesome! Way to go!',
            'Here’s to your streak! Keep it up!',
            'Sincere congratulations on your hard-earned success',
            'You are proof that good things come to those who are willing to sacrifice to reach a worthwhile goal. Words can’t express how proud I am!',
            'You have the creativity and determination to do whatever you can dream. I hope you feel proud today and confident in your ability to rise to your next challenge.',
            'Celebrating the dedication you’ve shown on the way to this achievement. You’ve earned every bit of the success you’re enjoying.',
            'Congrats!!!'           
            };

//Get a random number which is less than the size of the above list
   Integer i = (Math.random()* (commentList.size() -1)).intvalue();

    //iterate through each feed item record and add the comments
    For (FeedItem FIR:Trigger.new) { 
        //check if the post contains the word "Success"
        If (FIR.Body.contains('success')) {
            FeedComment FC = New FeedComment(); 
            FC.CommentBody = commentList.get(i);//add a random comment from the comment list using the random number generated earlier
            FC.FeedItemID = FIR.id;
            FC.CreatedById = '005f4000002NG0g'; //ID of user who will be commenting
            List2insert.add(fc); //add to final list of comments that needs to be inserted
        }
    }

Insert List2insert; // insert the final list of comments

The complete trigger to post a random chatter comment will be as follows:

trigger randomChatterComment on FeedItem (after insert) {
    
    //Create a list to hold the list of Feed Comment records being inserted
    List<FeedComment> List2insert = New list<FeedComment>();
    
    //Create a list of comments
    List<String> commentList = New List<String>{
        'Congratulations and BRAVO!',
            'This calls for celebrating! Congratulations!',
            'You did it! So proud of you!',
            'I knew it was only a matter of time. Well done!',
            'Congratulations on your well-deserved success.',
            'Heartfelt congratulations to you.',
            'Warmest congratulations on your achievement.',
            'Congratulations and best wishes for your next adventure!',
            'So pleased to see you accomplishing great things.',
            'Feeling so much joy for you today. What an impressive achievement!',
            'You’ve worked so hard for this. Congrats!',
            'This is awesome! You’re awesome! Way to go!',
            'Here’s to your streak! Keep it up!',
            'Sincere congratulations on your hard-earned success',
            'You are proof that good things come to those who are willing to sacrifice to reach a worthwhile goal. Words can’t express how proud I am!',
            'You have the creativity and determination to do whatever you can dream. I hope you feel proud today and confident in your ability to rise to your next challenge.',
            'Celebrating the dedication you’ve shown on the way to this achievement. You’ve earned every bit of the success you’re enjoying.',
            'Congrats!!!'           
            };
                //Get a random number which is less than the size of the above list
                Integer i = (Math.random()* (commentList.size() -1)).intvalue();
    
    //iterate through each feed item record and add the comments
    For (FeedItem FIR:trigger.new) { 
        //check if the post contains the word "Success"
        If (FIR.Body.contains('success')) {
            FeedComment FC = New FeedComment(); 
            FC.CommentBody = commentList.get(i);//add a random comment from the comment list using the random number generated earlier
            FC.FeedItemID = FIR.id;
            FC.CreatedById = '005f4000002NG0g'; //ID of user who will be commenting
            List2insert.add(fc); //add to final list of comments that needs to be inserted
        }
    }
    Insert List2insert; // insert the final list of comments
    
}

This post is dedicated to learning Salesforce triggers with examples and scenarios by dissecting them line by line. All triggers will be written with plenty of comments and explanations so that its easier for us to understand and implement.

• Write Your First Hello World Salesforce Apex Trigger – Triggers for Beginners

The “Hello World” program is the simplest program used to illustrate the basic syntax of a programming language. The program outputs “Hello World” and is traditionally the first program written by all beginner developers. Our Hello World trigger’s requirement is: When a Lead is updated, update the lead’s first name to ‘Hello’ and the last name to ‘World’

• Trigger to Change the Stage when an Opportunity is created

Every time an Opportunity is created (and the user selects any Stage), the Opportunity Stage should change and default to Prospecting.

• Trigger to create a task when an Opportunity is updated

When an Opportunity is updated, a new Task should be created and assigned to the Opportunity Owner. The status of the task should be “In Progress”

• Trigger to create a roll-up summary of Contact’s fields on Accounts

On each Account, the Total Salary custom field should hold the sum of Salaries from its associated Contacts. The trigger should work whenever a Contact’s Salary is updated, New Contact is Created or when an existing Contact is deleted.

• Trigger to Prevent Duplicate Contacts

When a Contact is being created and if a record with the same Email Id or Phone number exists, the trigger should throw an error and the User should not be allowed to create the Duplicate Contact

• Trigger to Post Automated Random Chatter Comment

When a user posts to chatter and if the user’s post contains the term “Success”, an automated comment should be posted. This comment should be randomly selected from a list of comments; And should be posted as a specific user.

Please support this post by linking it from your website/blog
http://www.syedtaha.com/salesforce-apex-triggers/learn-salesforce-triggers-with-examples-and-scenarios/1072/

Here is a simple tool that converts the Salesforce 15 character Ids to 18 character Ids.

This conversion of Salesforce ids from 15 character to 18 characters is done on the local machine and is safe to use.The Salesforce 15 to 18 char Id conversion tool calls Javascript from the footer of the page hence transmits no data to the server.

Enter the 15 character Salesforce Ids in the input text box (one per line) and click on the convert button to get the 18 character Salesforce Ids.

 
Input 15 character Salesforce Ids – one per line

 
Click to Convert Salesforce 15 digit Ids tp 18 digits
 
Output: 18 character Salesforce Ids

Requirement:

1. The Account object has a field named Total Salary with the API name total_salary__c
2. The Contact object has a field named Salary with the API name salary__c
3. On each Account, the Total Salary field should hold the sum of Salaries from its associated Contacts. The trigger should work whenever a Contact’s Salary is updated, New Contact is Created or when an existing Contact is deleted.

Solution:

Let’s write this Trigger in the following flow:

1. Get a List of Accounts that needs to be updated.
2. Get a List of Contacts whose Salaries will be added
3. Create a Map of Accounts and List of associated Contacts
4. Iterate through each Account to update the Total Salary
   1. Iterate through each associated Contact to add the Salaries.
5. Update the final List of Accounts using DML

Here’s the trigger:

trigger CustRollUpSummaryAccount on Contact (after insert,after update, after delete) {
    
    //New List to perform DML on the final List of Accounts
    List<Account> List2Update = New List <Account>();
    
    //New Set of Account Ids that'd be used to get Accounts & Contacts List
    Set<ID> accountIds = New Set <ID>();
    
    //Using Context variables and populating the above Set
    If (trigger.isInsert || trigger.isUpdate) {
        for (contact c1:Trigger.New){
            accountIds.add(c1.AccountId);
        }
    } else If (trigger.isDelete) {
        for (contact c2:Trigger.Old){
            accountIds.add(c2.AccountId);
        }
    }
    
    //List of Accounts in this trigger populated using SOQL
    List <Account> accountList = New List <Account>();
    accountList = [SELECT Id FROM Account WHERE ID IN:accountIds];
    
    //List of Contacts in this trigger populated using SOQL
    List <Contact> contactList = New List <Contact>();
    contactList = [SELECT id,accountid,salary__c FROM Contact WHERE accountid in:accountIds];
    
    //New Map for Accounts and List of its Contacts
    Map<Id,List<Contact>> accConMap = New Map <Id,List<Contact>>();
    
    //Iterate through Contacts and populate the above map
    For (Contact Con:contactList) {        
        If (!accConMap.keyset().contains(con.AccountId)) {
            accConMap.put(con.AccountId, New List<Contact>());
        }
        accConMap.get(con.AccountId).add(con);
    }
    
    //Iterate through accounts 
    For (Account acc:accountList) {
        Double Amount = 0;    
        
        If (accConMap.get(acc.Id) != null && accConMap.get(acc.Id).size() > 0) {
            //Iterate through List of Contacts and add the amounts in the Salary fields
            For (Contact con1:accConMap.get(acc.Id)){
                If (con1.Salary__c != null) {
                    Amount = Amount + con1.Salary__c;
                }
            }    
            
        }
        acc.Total_Salary__c = Amount; //Update the Total Salary field on Account
        List2Update.add(acc); //add account to final update List
        
    }
    update List2Update; //update the final list of Accounts
}

There are times when an Administrator needs to manually setup a users password in Salesforce. Salesforce Administrator’s can reset a User’s password from the User record detail page but Salesforce user interface doesn’t allow an Administrator to setup a specific password. Here is an Awesome Admin Hack to achieved this using the Developer Console or the Workbench.

Let’s discuss each method step by step.

Manually Setup a User’s Password in Salesforce Using the Developer Console.

Step 1. Get the User’s Id from the URL bar on the User’s record detail page.

Step 2. Open Developer Console

Step 3. Open the Execute Anonymous Window from Debug >> Open Execute Anonymous Window OR using the shortcut Ctrl + E

Step 4. Enter the following Apex code. Replace the UserId and Password with the actual values we need.

System.SetPassword('UserId','Password'); //Replace the UserId and Password

Step 5. Click Execute

We successfully manually setup the User’s password using the developer console and an email with the new security token will is emailed to the User.

Manually Setup a User’s Password in Salesforce Using Workbench.

1. Visit Workbench (https://workbench.developerforce.com/login.php) and Login using your Salesforce credentials.
2. Navigate to Utilities >> Password Management
3. Enter the User’s Id and the New Password
4. Click on Change Password

We successfully manually setup the User’s password using Workbench and an email with the new security token will is emailed to the User.

Pro Tip: Creating a User Interface to manually setup a User’s password in Salesforce.

Step 1. Create a New Text Field on the User Object and Name it Password__c

Step 2. Create the following trigger on the User object

trigger setPassword on User (before update) {
    for (User u:Trigger.New) {
        User oldUser = Trigger.OldMap.get(u.id);
        If ((u.Password__c != null) && (oldUser.Password__c != u.Password__c)) {
            System.SetPassword(u.id,u.password__c);
            //Uncomment below line to clear password field
            //u.Password__c = null;
        }    
    }
}

Note: Use validation rules on Password__c to only accept passwords that align with your organization’s password policies.

Here’s how the trigger looks in the developer console (image)

Step 3. Now visit the User’s record detail page and enter the new password in the Password field that we created and click Save.

The User’s password will be changed and an email with the new security token will be emailed to the User.

Update: To send the new password to the user by email, the trigger will be:

trigger CPTsetPassword on User (before update) {
    List <String> toAddresses = New List <String>();
    for (User u:Trigger.New) {
        User oldUser = Trigger.OldMap.get(u.id);
        If ((u.Password__c != null) && (oldUser.Password__c != u.Password__c)) {
            System.SetPassword(u.id,u.password__c);
            toAddresses.add(u.Email);
            //Uncomment below line to clear password field after reset
            //u.Password__c = null;   
            
            //Sending the users new password by email
            Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
            mail.setToAddresses(toAddresses);
            mail.setSubject('Salesforce Password Reset');
            mail.setPlaintextBody('Your password was reset by the Administrator and the new Password is ' + u.Password__c);
            Messaging.sendEmail(new Messaging.SingleEmailMessage[] {mail});         
        }    
    } 
}

Scenario:

While creating an Event or Task in Salesforce, the “Reminder” Checkbox is checked by default for all users. The reminders have piled up and making it difficult to keep track of the important events and tasks. The Sales team wants you to uncheck the “Set default event reminders to” Checkbox for all users.

This setting is found in:
My Settings >> Calendar and Reminders >> Activity Reminders >> ‘Set default event reminders to’

Solution:

This can be achieved by updating the User Object using Apex Code or the Data Loader

Executing Apex Code Method

A simple Apex code snipped can help us in unchecking “Set default event reminders to” Checkbox for multiple users. We will be using the Developer Console’s Execute Anonymous Window to run the Apex code.

To “Set default event reminders to” Checkbox to Unchecked, our Apex code will perform the following steps:

1. Step 1: Create a List to hold Users that need an update to their settings.
2. Step 2: Find all Active Users whose ‘Activity Reminder Checkbox’ is ‘Checked’ and add them to the above list.
3. Step 3: Iterate through each user in the above list and Uncheck the Activity Reminder Checkbox
4. Step 4: Create a final list to update to reduce the DML statements

// Create a list of Users whose setting needs to be changed
List <User> userList = New List <User>();

//SOQL to add all users to the above list
userList = [
    SELECT Id, UserPreferencesEventRemindersCheckboxDefault
    FROM User
    WHERE UserPreferencesEventRemindersCheckboxDefault = True AND ISACTIVE = True];

// Iterate through each user and update the setting
For (User u:userList) {
    u.UserPreferencesEventRemindersCheckboxDefault = False;
    userList2update.add(u);  //Add user to the final list to update
}

//Create a final list of Users to perform DML
List <User> userList2Update = New List <User>();


update userList2Update;  //Update the final List

Here’s the complete code to uncheck the “Set Default Reminders to” or any other user setting in Salesforce.

//Create a final list of Users to perform DML
List <User> userList2Update = New List <User>();
// Create a list of Users whose setting needs to be changed
List <User> userList = New List <User>();

//SOQL to add all users to the above list
userList = [
    SELECT Id, UserPreferencesEventRemindersCheckboxDefault
    FROM User
    WHERE UserPreferencesEventRemindersCheckboxDefault = True AND ISACTIVE = True];

// Iterate through each user and update the setting
For (User u:userList) {
    u.UserPreferencesEventRemindersCheckboxDefault = False;
    userList2update.add(u);  //Add user to the final list to update
}

update userList2Update;  //Update the final List

Now that we have the Apex Code, lets head to the Developer Console and execute this code from the Anonymous Window (Ctrl + E)

For the Data Loader method, please visit the Salesforce Help Article
https://help.salesforce.com/articleView?id=000004609&language=en_US&type=1

For a complete list of fields on the User Object, please visit the Developer Guide
https://developer.salesforce.com/docs/atlas.en-us.api.meta/api/sforce_api_objects_user.htm

Requirement: Write a Salesforce Apex Trigger to change the Stage/default the stage to ‘Prospecting’ when an Opportunity is created. In other words, when an Opportunity is created by selecting any Stage, the Stage should default back to Prospecting.

Lets start by revisiting the Salesforce Apex Trigger Syntax:

trigger *triggerName* on *Object* (*before/after event*) {
    for (*Object* *Variable* : Trigger.New)      
        **Trigger Actions & Code Block**
}

We will write the trigger in the following three Steps:

1. Define the trigger
2. Build a ‘For Each’ loop to iterate through each record
3. Update the Stage

Now lets write each Step for this trigger.

//Defining the Trigger - Trigger Name, Object and Events.
trigger DefaultStageProspecting on Opportunity (before insert) {

    //For each Opportunity record being updated, assign the variable 'Opp' to it.
    for ( Opportunity Opp :Trigger.New) {

// Update the Stage to 'Prospecting'    
    Opp.StageName = 'Prospecting';

    }
}

The complete Trigger to change the Stage when Opportunity is Created would be:

//Defining the Trigger - Trigger Name, Object and Events.
trigger DefaultStageProspecting on Opportunity (before insert) {

    //For each Opportunity record being updated, assign the variable 'Opp' to it.
    for ( Opportunity Opp :Trigger.New) {
    
	// Update the Stage to 'Prospecting'    
    Opp.StageName = 'Prospecting';

    }
}

This is how the Trigger looks in the Developer Console (Image)

Requirement: Write a Salesforce Apex Trigger to create a Task when an Opportunity is updated. The task should be assigned to the Opportunity owner and the status of the task should be “In Progress”.

The Salesforce Apex Trigger Sytax is as follows:

trigger *triggerName* on *Object* (*before/after event*) {
    for (*Object* *Variable* : Trigger.New)      
        **Trigger Actions & Code Block**
}

Now lets write our trigger with the following steps.

1.  Define the trigger
2.  Iterate through each opportunity
3.  Create a Task
4.  Assign values to the Task

trigger createTaskOnOpp on Opportunity (before update) {

for (Opportunity Opp :Trigger.New) {

Task t = new Task();

	t.WhatID = Opp.Id;
	t.Ownerid = opp.Ownerid;
	t.subject = 'This is the Subject';
	t.Status = 'In Progress';
	t.Description = 'This is the Description';
	insert t;
	}
}

The complete Salesforce Apex Trigger to create a Task when an Opportunity is updated would be:

////define the trigger name, object and events
trigger createTaskOnOpp on Opportunity (before update) {
    //Iterate through each opportunity and assign it the variable Opp
    for (Opportunity Opp :Trigger.New) {
	//Create a new task and assign it the variable t
        Task t = new Task();
        // Assign Values to the task t
        t.WhatID          = Opp.Id;
        t.Ownerid         = opp.Ownerid;
        t.subject 	  = 'This is the Subject';
        t.Status	  = 'In Progress';
        t.Description     = 'This is the Description';
        insert t;
    }
}

This is how the trigger looks in the developer console (image)

The “Hello World” program is the simplest program used to illustrate the basic syntax of a programming language. The program outputs “Hello World” and is traditionally the first program written by all beginner developers.

Let’s write our first “Hello World” Salesforce Apex trigger which will update a Lead with “Hello” as the first name and “World” as the last name.

Requirement:
When a Lead is updated, update the lead’s first name to ‘Hello’ and last name to ‘World’

Lets write the trigger in the “Developer Console”. To access the developer console, click the drop down on your Name (on the top right), and then click on Developer Console.

Once the developer console is open, click on File >> Open >> Apex Trigger. Now we are ready to write our first trigger.

The Trigger Syntax:
Every trigger is defined by using the following syntax:

  trigger *triggerName* on *Object* (*before/after event*) {
       for (*Object* *Variable* : Trigger.New)
       **Trigger Actions & Code Block**
  }

Here is what the terms in the syntax mean:

• ‘triggerName’ is the name of the trigger which describes it.
• ‘Object’ is the name of the Object on which the trigger is created
• ‘before/after event’ are a comma separated list of events like insert, update, delete
• ‘Trigger.New’ is a list of sObject records
• ‘Variable’ denote a piece of memory that can contain a data value. Descriptive text is used as variables.

Lets get back to our requirement and based on the above syntax, write our ‘Hello World’ Salesforce Apex trigger.
Remember, when a Lead is updated, the first name should be updated to “Hello” and the Last Name to “World“.

We will be using comments to describe the lines of code in our trigger. But what are comments? Comments are used to describe code and are ignored by the parser – meaning the comments are NOT treated as code and will not run.
Single line comments are preceded by // and multi line comments are wrapped in /* and */

Now here comes the trigger:

// Name of the trigger is HelloWorld, It is on the Lead Object and It will run before the lead is updated (event).
trigger HelloWorld on Lead (before update) {
        //for every lead record, denoted by variable ld,in the list that is being updated
        for (lead ld : Trigger.new) {
             // add the first name as 'Hello'
             ld.FirstName = 'Hello';
             // add the last name as 'World'
             ld.LastName = 'World';
         }
}

This is how it looks in the developer console.

Exercise to get used to the syntax and the basic trigger for beginners:

Write a trigger to update the first name of the contact as Taha and the last name as Syed and the Phone number as 000-111-9999

The requirement is:

When a Contact is being created, if a record with the same Email or Phone number exists, the trigger should throw an error and the user should not be allowed to create the duplicate Contact.

To achieve this, we will write a trigger with the following flow:

1. Define the Trigger
2. Create Sets to store the ‘Email Ids’ and ‘Phone Numbers’ of all the records that are being created
3. Iterate through each record that is being created, and add their ‘Email Ids’ and ‘Phone Numbers’ to the Sets.
4. Create a List to store the ‘Email Ids’ and ‘Phone Numbers’ of existing records that match the records being created.
5. Populate the above List with of existing records whose email id or phone number matches the ones being created.
6. Iterate through each record being created and display and error if the record already exists.

Now lets go through each step once again and write its respective code.

trigger PreventDuplicateContacts on Contact (before insert) {

}

Set <String> emailSet = new Set<String>();
Set <String> phoneSet = new Set<String>();

for (contact con:trigger.new) {
     emailSet.add(con.email);
     phoneSet.add(con.phone);
}

// New list to store the found email or phone numbers
List <Contact> contactList = new List<Contact>();

contactList = [SELECT email,phone FROM Contact WHERE email IN :emailSet OR phone IN :phoneSet];

for (contact con:trigger.new) {
     If(contactList.size() > 0) {
     con.email.adderror( 'Duplicate Contact Found. Use Existing Contact.' ); // Displaying the error
     }
}

The complete trigger to prevent duplicate contacts by matching email or phone number and displaying the error on the email field would be:

trigger PreventDuplicateContacts on Contact (before insert) {
    
    // Set to store email ids
    Set <String> emailSet = new Set<String>(); 
    // Set to store phone numbers
    Set <String> phoneSet = new Set<String>(); 
    
    // Iterate through each Contact and add their email and phone number to their respective Sets
    for (contact con:trigger.new) {
        emailSet.add(con.email);
        phoneSet.add(con.phone);
    }

    // New list to store the found email or phone numbers
    List <Contact> contactList = new List<Contact>();

    // Populating the list using SOQL
    contactlist = [SELECT email,phone FROM Contact WHERE email IN :emailSet OR phone IN :phoneSet];

    // Iterating through each Contact record to see if the same email or phone was found
    for (contact con:trigger.new) {
        If (contactList.size() > 0) {
            // Displaying the error
            con.email.adderror( 'Duplicate Contact Found. Use Existing Contact.' );
        }
    }

}

Here is how the Trigger to Prevent Duplicate Contacts looks in the Salesforce Developer Console (image)