google app maker link fields of related records - scripting

Question

I am attempting to set a field in one data model to equal to a field in a related data model. I've considered setting up an event to set the field equal to the other but do not know what the best trigger for this event would be and do not know the code that would be required.
Additionally, perhaps an event is not needed and there is some more fundamental/basic way to establish this field connection between related models.
Example: People Model has Companies Model as a related model. When adding a new People record, selecting the related Companies record would mean that the "Industry" field in the People record would be equal to the "Industry" field in the related Companies record.
Thank you!

Answer 1

You can execute a callback function after the People record is created. The callback function would change the Industry field value of the related Companies record to match the same value of the People record. Something like this (GIF). Notice that I am updating the Companies Industry value while creating a People record.
Here's the code on a Client Script:
var pgPeople = app.pages.PeopleCompanies;
var pgPeopleDesc = pgPeople.descendants;
function updateRelatedRecordField(){
var peopleDatasource = app.datasources.People;
peopleDatasource.createItem(function(record){
var industry = record.Industry;
record.Companies.Industry = industry;
});
}
You need to replace the default onClick function on the Form widget button with your function updateRelatedRecordField();
Read more here.