I have a custom subtab created. how do I populate data into this subtab?

AI generated answer (using internal Slack threads):

To populate data into a custom subtab, you need to create a sublist on that subtab. Here are the steps: 1. Create your subtab on the parent record. 2. Add your custom record as a sublist on the subtab. Here is a sample code snippet that demonstrates how to create a subtab and sublist:

javascript
var subtab = form.addTab({
    id: 'custpage_mysubtab',
    label: 'My Subtab'
});

var sublist = form.addSublist({
    id: 'custpage_mysublist',
    type: serverWidget.SublistType.LIST,
    label: 'My Sublist',
    tab: 'custpage_mysubtab'
});

After creating the subtab and sublist, you can add fields to the sublist and populate them with data. Here is how you can add a field to the sublist:

javascript
sublist.addField({
    id: 'custpage_myfield',
    type: serverWidget.FieldType.TEXT,
    label: 'My Field'
});

And here is how you can populate the field with data:

javascript
record.setSublistValue({
    sublistId: 'custpage_mysublist',
    fieldId: 'custpage_myfield',
    line: 0,
    value: 'My Value'
});

Remember to load the record in edit mode before setting sublist values and save the record after setting all values. For more information, you can refer to the NetSuite Help Center articles on Custom Child Record Sublist Creation with SuiteScript and SuiteScript 2.x Custom Forms. ****** Disclaimer: This response was generated by an artificial intelligence assistant based on previous conversations from multiple Slack channels, and may contain inaccuracies or mistakes. ******