How can I add a new value to a picklist using APEX?

Question

I have queries pulling all of the information correctly but what I can't seem to find was a way to add new options to a picklist using APEX.

I currently have

Package__c.Products__c.add(new Schema.PicklistEntry(products[j].Name));

Package__c is my custom object, and Products__c is the picklist. products[j] is pulling a list of products pulled from our products page.

And I've tried adding it as a select option, or even casting the variable type.

And this information has to go to the actual picklist within a custom object, and not within a visual force page or anything like that.

Answer 1

The way to do this is using the Apex MetaData API wrapper as provided by esteemed SFSE colleague Andrew Fawcett here

1. Running user needs to have Customize Application privilege so you really want this to be an admin type user
2. Read the examples in the GIT package carefully - there is one for picklists. You need to read the CustomField from the MetaData API first then update, otherwise you'll smash all the existing picklist entries.

The relevant example in the package's MetadataServiceExamples.cls file is here:

public static void updatePicklist()
{
    MetadataService.MetadataPort service = createService();             

    // Read Custom Field
    MetadataService.CustomField customField = 
        (MetadataService.CustomField) service.readMetadata('CustomField', 
            new String[] { 'Lead.picklist__c' }).getRecords()[0];       

    // Add pick list values
    metadataservice.PicklistValue two = new metadataservice.PicklistValue();
    two.fullName= 'second';
    two.default_x=false;
    metadataservice.PicklistValue three = new metadataservice.PicklistValue();
    three.fullName= 'third';
    three.default_x=false;
    customField.picklist.picklistValues.add(two);
    customField.picklist.picklistValues.add(three);     

    // Update Custom Field
    handleSaveResults(
        service.updateMetadata(
            new MetadataService.Metadata[] { customField })[0]);        
}

Answer 2

@cropredy answer is correct. But there are some changes in MetadataService class. So code given in above answer will not work. Below code will work with latest version of mdapi GitHub repo.

MetadataService.MetadataPort service = createService(); 

MetadataService.CustomField picklistField =(List<MetadataService.CustomField>) service.readMetadata('CustomField', 'Lead.picklist__c').getRecords();
        
metadataservice.CustomValue two = new metadataservice.CustomValue();
two.fullName= 'second';
two.default_x=false;  

picklistField.valueSet.valueSetDefinition.value.add(two);

MetadataService.SaveResult result = service.updateMetadata( new MetadataService.Metadata[] { picklistField })[0];

In place of PicklistValue we have to use ValueSet. Also we need to make little change in MetadataService Class. We have to replace ValueSet virtual class in Metadatservice with

public class ValueSet {
        public String controllingField;
        public Boolean restricted;
        public MetadataService.ValueSetValuesDefinition valueSetDefinition;
        public String valueSetName;
        public MetadataService.ValueSettings[] valueSettings;
        private String[] controllingField_type_info = new String[]{'controllingField',SOAP_M_URI,null,'0','1','false'};
        private String[] restricted_type_info = new String[]{'restricted',SOAP_M_URI,null,'0','1','false'};
        private String[] valueSetDefinition_type_info = new String[]{'valueSetDefinition',SOAP_M_URI,null,'0','1','false'};
        private String[] valueSetName_type_info = new String[]{'valueSetName',SOAP_M_URI,null,'0','1','false'};
        private String[] valueSettings_type_info = new String[]{'valueSettings',SOAP_M_URI,null,'0','-1','false'};
        private String[] apex_schema_type_info = new String[]{SOAP_M_URI,'true','false'};
        private String[] field_order_type_info = new String[]{'controllingField','restricted','valueSetDefinition','valueSetName','valueSettings'};
    }

Also Check URL in your metadataPort.endpoint_x. It should be

public String endpoint_x = URL.getSalesforceBaseUrl().toExternalForm() + '/services/Soap/m/42.0';

Answer 3

The above given solutions works perfectly using Apex Metadata Service (https://andyinthecloud.com/2013/10/27/introduction-to-calling-the-metadata-api-from-apex/); but it requires to import all code for even a small requirement. After, release of Tooling API, I find it lifesaver for such implementation without importing and managing too much code. We just need to make a callout using Tooling API.

Full detail article is here: https://sfdcian.com/update-picklist-value-and-add-it-in-record-type-using-apex-salesforce/

PATCH
/services/data/v41.0/tooling/sobjects/CustomField
Body: <as given at below URL>

Here is JSON Body that has to be sent as request body in this callout: https://github.com/ayub-ansari/Create-Picklist-Field-Using-Apex/blob/master/FirstHTTPRequestToUpdatePicklistField

Answer 4

Based on your comments, what you really want is a Junction object to Create a Many-To-Many Relationship between Product and your Package Deal object. I might call it something like Package Deal Line Item.