Find out programmatically if a field can be tracked

Question

I've grappled with this one for a long time, and I am almost sure it's a gap in the platform. The problem I have is that I need a way to find out all the fields that can be tracked. That is to say, all of the fields that would be visible in the setup menu if you went to an object and tried to track fields.

The metadata api seemed to be a logical contender for this purpose. And it was! It was working swimmingly for standard objects. Even standard objects with custom fields were a-ok. However, if you read (or retrieve) the CustomObject metadata for a custom object OR the CustomField metadata from a field on a custom object, the trackHistory value does not come back or comes back as null.

So for standard objects, I am able to tell the total amount of trackable fields by reading metadata for all the fields on the object, and noticing which values come back as true or false rather than null.

But since I am not able to get the trackHistory value back from fields on custom objects, I can't tell which fields on the custom objects can be tracked.

I am able to tell which fields ARE tracked on the custom objects by heading to the FieldDefinition Tooling API table. There is a field on that table titled IsFieldHistoryTracked. That field actually tells you if the field is tracked or not (contrary to the docs, which SAY that it is supposed to show if "the field’s history can be tracked", but i digress).

HOWEVER, just knowing that the field is tracked is not enough, as all of the fields that can or cannot be tracked have a true / false value in this field.

So, does anyone know of a way out of this for me? Is there any real way to figure out which fields can and can not be tracked programmatically? Do I have to scrape the menu screen (60% joking).

Any and all help is much appreciated.

Answer 1

Fields that are tracked using the Metadata API

Using Workbench, I used this package:

<?xml version="1.0" encoding="UTF-8"?>
<Package xmlns="http://soap.sforce.com/2006/04/metadata">
    <types>
        <members>SuperOrder__c</members>
        <name>CustomObject</name>
    </types>
    <version>46.0</version>
</Package>

where SuperOrder__c is a custom object in my org

and in the retrieved zip file, I get:

...
<fields>
        <fullName>Cancelled_Order_Count__c</fullName>
        <description>calculated by dlrs</description>
        <externalId>false</externalId>
        <inlineHelpText># of child Orders where Status = Cancelled</inlineHelpText>
        <label>Cancelled Order Count</label>
        <precision>18</precision>
        <required>false</required>
        <scale>0</scale>
        <trackHistory>true</trackHistory>  <-- LOOK HERE!
        <trackTrending>false</trackTrending>
        <type>Number</type>
        <unique>false</unique>
    </fields>
...

Now, if your version of the fflib Metadata API wrapper is too old (the current version on GitHub is V42.0), you may need to patch the installed version using the How to create your own MetadataService.cls instructions

Fields that are trackable

• The Metadata API will return fields that are not trackable with <trackHistory>false</trackHistory>
• But a trackable field that is not tracked will also return <trackHistory>false</trackHistory>

So, how to differentiate?

• If the custom field is a Formula, by definition, it is not trackable then the metadata will include <formula>...</formula>

In addition, from the doc:

You can’t track the following fields:

• Formula, roll-up summary, or auto-number fields
• Created By and Last Modified By
• Fields that have the AI Prediction checkbox selected
• Expected Revenue field on opportunities
• Master Solution Title or the Master Solution Details fields on solutions; these fields display only for translated solutions in organizations with multilingual solutions enable

Answer 2

So along with @Prudhvi Konda, I came to the conclusion that the best solution would be to deduce the custom fields by which fields can be tracked or not.

So my final method to find out which fields were trackable was split into 2 approaches: Standard fields and Custom fields.

Standard Fields Use the Metadata API to read the CustomField metadata for all standard fields. Record which fields have a trackHistory value of true or false. Those are all the trackable standard fields (and their tracked values).

Custom Fields Use the FieldDefinition Tooling API object to check all fields on Custom objects. You are looking for any field from a custom object that meets the following criteria:

• Data Type is not a formula, auto number, or roll up summary
• Field API name is not in this list: 'Id', 'IsDeleted', 'CreatedDate', 'CreatedById', 'LastModifiedDate', 'LastModifiedById', 'SystemModstamp', 'UserRecordAccessId', 'RecordVisibilityId'

After you have filtered out fields that meet the above criteria, you can check the IsFieldHistoryTracked value to find out if the field is tracked or not

Combining these two data sets gives you the most complete programmatic picture you can paint of trackable fields in a general org.