Why Places field on account object is not getting updated in the UI after making callout from trigger using future method?

Question

I have made two custom fields 'Pincode__c' of type text and 'Places__c' of type Long Text Area.I am inserting account record by providing 'Pincode__c' value and want the custom field 'Places__c' to get automatically updated with the value of Name field from the response that we get from API . For that to happen, I am calling future method from trigger and that future method is making the callout to 'https://api.postalpincode.in/pincode/110001'.

Below is the image of data which I used for creation of Account record.

The response from API is of the format as below:

 {
       "Message":"Number of Post office(s) found: 2",
       "Status":"Success",
       "PostOffice":[
          {
             "Name":"Baroda House",
             "Description":"",
             "BranchType":"Sub Post Office",
             "DeliveryStatus":"Non-Delivery",
             "Circle":"New Delhi",
             "District":"Central Delhi",
             "Division":"New Delhi Central",
             "Region":"Delhi",
             "State":"Delhi",
             "Country":"India"
          },
{
        "Name": "Bengali Market",
        "Description": null,
        "BranchType": "Sub Post Office",
        "DeliveryStatus": "Non-Delivery",
        "Circle": "Delhi",
        "District": "Central Delhi",
        "Division": "New Delhi Central",
        "Region": "Delhi",
        "Block": "New Delhi",
        "State": "Delhi",
        "Country": "India",
        "Pincode": "110001"
      }
       ]
    }

Below is the trigger which is internally calling the future method.

trigger Pincode_Trigger on Account (after insert) {
    Map<Id,Account> accMap = Trigger.newMap;
    Set<Id> keys = accMap.keySet();
    FutureCall_Example.invoke(keys);
}


public class FutureCall_Example {
@future(callout=true)
    public static void invoke(Set<Id> accIds)
    {
         List<Account> accounts = [SELECT ID,Places__c,Pincode__c from Account where ID IN:accIds];
         for(Account a : accounts)
            {
            Http p = new HTTP();
            HttpRequest request = new HttpRequest();
            String url = 'https://api.postalpincode.in/pincode/' + a.Pincode__c;
            request.setEndpoint(url);
            request.setMethod('GET');
            HttpResponse response = p.send(request);
            String jsonString = response.getBody();
            System.debug(jsonString);
            System.JSONParser jp = JSON.createParser(jsonString);
                String places='';
            while(jp.nextToken()!=NULL)
                    {
                    if(jp.getText() == 'Name')
                        {
                            jp.nextToken();
                            places = places + ',' + jp.getText();
                            System.debug(places);
                        }
                    }
                a.Places__c = places;
                System.debug(a.Places__c);
               
            }
        
    }
        
}

I am not able to see the 'Places__c' field getting updated on the page layout of Account object, but when I am using system.debug() for that particular account in the code, I am able to see Places__c values. But the value is not visible on Account record page. Below is the image of account record page and debug logs after saving the record and after future method is completed successfully.

We can clearly see on account record page 'Places field has no value while on debug logs we can see the value of the 'Places field.

Answer 1

Because you're not performing DML in your @future method.

@future methods (and all ways of executing code asynchronously) are run in an entirely separate transaction from the transaction that your trigger is run in.

The only time you don't need DML is when you're in a before insert or before update trigger, and modify data on the instance of your record contained in trigger.new or trigger.newmap.

Also, you should look at using JSON.deserialize() or JSON.deserializeUntyped() instead of JSONParser, and handle the deserialization outside of a loop. It's a lot easier to make mistakes with JSONParser. As a brief illustration, your JSON has 2 attributes called "Name". Which one of them is your code using? is it the right one? will it always be the right one?

Answer 2

From the code you pasted it seems like you're never updating the values even though you are assigning them correctly. You should be able to set the values by updating Accounts outside the for(Account a : accounts) loop.

Something similar to this should do the trick:

public class FutureCall_Example {
@future(callout=true)
    public static void invoke(Set<Id> accIds)
    {
         List<Account> accounts = [SELECT ID,Places__c,Pincode__c from Account where ID IN:accIds];
         for(Account a : accounts)
            {
            Http p = new HTTP();
            HttpRequest request = new HttpRequest();
            String url = 'https://api.postalpincode.in/pincode/' + a.Pincode__c;
            request.setEndpoint(url);
            request.setMethod('GET');
            HttpResponse response = p.send(request);
            String jsonString = response.getBody();
            System.debug(jsonString);
            System.JSONParser jp = JSON.createParser(jsonString);
                String places='';
            while(jp.nextToken()!=NULL)
                    {
                    if(jp.getText() == 'Name')
                        {
                            jp.nextToken();
                            places = places + ',' + jp.getText();
                            System.debug(places);
                        }
                    }
                a.Places__c = places;
                System.debug(a.Places__c);
            }
             update accounts;
    }
}