Salesforce passing values to Multipicklist based on another object - salesforce

Question

long time no see, quick question about multipicklist in Apex.
Here is the condition:
1. Two standard objects: Task and Account, task is linked to account.
2. The subject field in the task contains three values: A, B, C.
3. Also, there is a field (Multipicklist)in the account contains the same values A, B, C
Every time I will create a task under a certain account, If I input subject with A, I hope the field in the account can be updated with A;
Then if I create a task with subject B, the field in the account should be (A;B)
So, here is my code:
if(IsSC && t.Status == PickListValuesStandard.Task_Completed){
Account student = new Account(Id = t.WhatId);
student.LatestCompletedActivity__pc = t.Subject;
student.LatestCompletedActivityDate__pc = t.ActivityDate;
if(t.Subject.contains('Post OC Call')){
student.Center_TouchPoints__c += (';Post OC Call');
}
if(t.Subject.contains('Third Week Call')){
student.Center_TouchPoints__c += (';Third Week Call');
}
update student;
}
The bolded part I attached above should be working like I described, Unfortunately, it didn't.
Can anyone help me understand the scenario? How can I achieve this?
Thanks in advance,

Answer 1

I just realized what a big mistake I've made, here is the thought, if I wanna update the multipicklist in the account, first thing first, I need to check whether it's null or not. Here is the update:
if(IsSC && t.Status == PickListValuesStandard.Task_Completed){
//Account student = new Account(Id = t.WhatId);
Account student = [select Center_TouchPoints__c from Account where Id=:t.WhatId];
student.LatestCompletedActivity__pc = t.Subject;
student.LatestCompletedActivityDate__pc = t.ActivityDate;
if(student.Center_TouchPoints__c==null){
if(t.Subject.contains('Post OC Call')){
student.Center_TouchPoints__c = 'Post OC Call;';
}
if(t.Subject.contains('Third Week Call')){
student.Center_TouchPoints__c = 'Third Week Call;';
}
}else if(student.Center_TouchPoints__c.contains ('Post OC Call') && t.Subject.contains('Third Week Call')){
student.Center_TouchPoints__c += ';Third Week Call';
}
update student;
}
However, if anyone of you has any better idea, please shoot me!

Answer 2

One way that might make this a bit more flexible is to loop through all the available values in the picklist and see if the task's subject contains that picklist value and if it does add that to the selected picklist values. This is assuming the name or label of the picklist entries match the values entered into the subject of the task. This way you will be able to add different entries or change the picklist values without changing the code. Here is an example of getting and looping through all picklist values
here's how I think that would look...
if(IsSC && t.Status == PickListValuesStandard.Task_Completed){
Account student = [select Center_TouchPoints__c from Account where Id=:t.WhatId];
student.LatestCompletedActivity__pc = t.Subject;
student.LatestCompletedActivityDate__pc = t.ActivityDate;
Schema.DescribeFieldResult fieldDescribe = account.Center_TouchPoints__c.getDescribe();
//retrieves picklist values
List<Schema.PicklistEntry> picklistVals = fieldResult.getPicklistValues();
String picklistString = '';
for(Schema.PicklistEntry plv : picklistVals){ //Loop through picklist values
if(t.subject.contains(plv.getValue()) && !student.Center_TouchPoints__c.contains(plv.getValue())) {
//If if this picklist value is in the subject and it hasn't been selected already add it.
picklistString += (plv.getValue() + '; ');
}
}
if(student.Center_TouchPoints__c == null)
student.Center_TouchPoints__c = picklistString.substring(1);
else
student.Center_TouchPoints__c += (';' + picklistString);
update student;
}
Hope this helps!