create user in trigger of contact

Question

Please help me as I am new to salesforce. i want to create a user record when a contact is inserted. Not all contact but contact which are being converted from lead. i have created a custom checkbox field on contact 'ConvertedFromContact__c' which is mapped to lead custom field. this is to check if contact being converted from lead. but in trigger how to create a user. (need to assign profile and licence)
below is the code written by me

trigger createUserFromLead on Contact (after insert) {

    List<User> userList = new List<User>();

    for(Contact c: Trigger.New){
        if(c.ConvertedFromContact__c == checked){
            User u = new user();

        }
    }
}

Answer 1

You can try below code.

Step 1- A trigger on Contact Object, which will get executed after inserting a Contact Record.

Step 2 - Fetch only those contact where ConvertedFromContact__c is true and pass those contactIds to future method of Handler class.

Step 3 - We are creating a method which is defined as future, as we are working on Setup(User) and Non Setup(Contact) object. Future method will be invoke asynchronously to create a User records for related Contacts.

// Trigger Code

trigger createUserFromLead on Contact (after insert) {

    List<User> userList = new List<User>();
    Set<Id> contactIds = new Set<Id>();
    for(Contact c: Trigger.New){
       if(c.ConvertedFromContact__c){
            contactIds.add(c.id);
        }
    }

    if(contactIds.size() > 0){
        CreateUserHandler.createUserFromContact(contactIds);
    }
}

// Handler Code

public with sharing class CreateUserHandler {

@future
public static void createUserFromContact(Set<Id> contactIds)
{
    List<User> userList = new List<User>();
    List<Profile> profileList = [Select Id from Profile where Name=: 'System Administrator' limit 1];
    List<UserRole> roleList = [Select Id from UserRole where Name=: 'CEO' limit 1];
    for(Contact contactObj : [Select Id, Name, Email,Username__c from Contact where Id IN: contactIds limit 50000]){
        User uObj = new User();
        uObj.Username = contactObj.Username__c;
        uObj.Email = contactObj.Email;
        uObj.Alias = contactObj.Name;
        uObj.UserRoleId = roleList[0].Id;
        uObj.ProfileId = profileList[0].Id;
        uObj.IsActive = true; 
        uObj.TimeZoneSidKey = 'GMT';
        uObj.LanguageLocaleKey = 'en_US';
        uObj.EmailEncodingKey = 'UTF-8';
        uObj.LocaleSidKey = 'en_US';
        uObj.ContactId = contactObj.Id;
        userList.add(uObj);
    }
    try{
           insert userList;  // insert the user record
    }catch(Exception e){
          // Catch Exception
     }
}

}

References for Future Method in Salesforce

Answer 2

Try this,

ProfileID = [Select Id From Profile where (condition) Limit 1].Id;
User u = new user();
u.contactId = contact.Id;
u.LastName = 'Test lastname';
u.Email = '[email protected]';
u.Alias = 'Talias';
u.Username = '[email protected]';
u.CommunityNickname = 'test12';
u.LocaleSidKey = 'en_US';
u.TimeZoneSidKey = 'GMT';
u.ProfileID = ProfileID;
u.LanguageLocaleKey = 'en_US';
u.EmailEncodingKey = 'UTF-8';
insert u;