Change Field STatus - google-app-maker

Question

I have a button in a google-app-maker page, it's function is to sending Invoice by email. So once this button clicked, it will do two function.
1. Sending invoice by email.
2. Change status of EmailStatus to 'YES'.
/* var widgets = widget.parent.descendants; */
var to = "webmaster#myemail.com";
var subject = "Prepare Invoice : " + widget.datasource.item.Client_Name;
var msg = "Please Prepare Invoice for " + "\n\nClient Name : " +
widget.datasource.item.Client_Name + "\n\nService : " +
widget.datasource.item.Service + "\n\nCase : " +
widget.datasource.item.Subjects + "\n\nScope :" +
widget.datasource.item.Scope + "\n\nSubject : " +
widget.datasource.item.Subjects + "\n\nStart :" +
widget.datasource.item.Start + "\n\nInterim : " +
widget.datasource.item.Interim + "\n\nStatus :" +
widget.datasource.item.Statusx + "\n\nCA : " +
widget.datasource.item.Client_Ref + "\n\nBilling : " +
widget.datasource.item.Billing + "\n\nFee VS : " +
widget.datasource.item.Fee_VS + "\n\nFee VI" +
widget.datasource.item.Fee_VI + "\n\nNotes : " +
widget.datasource.item.Notes + "\n\nPrep Invoice : " +
widget.datasource.item.Prep_Invoice + "\n\nInvoiced : " +
widget.datasource.item.Prep_Invoice + "\n\nInvoice Number : " +
widget.datasource.item.Invoice_Number;
SendEmail(to, subject, msg);
widget.datasource.modes.create.item.EmailStatus = 'YES';
There's no problem with sending email, but for EmailStatus change to field have problem. It can not change value from NULL to 'YES'. Do you have any idea how to solved it ?
Thanks

Answer 1

Here is a scenario how to handle this assuming that your EmailStatus is just field in the same model/datasource as where you have all of your invoice information.
Delete this line of code:
widget.datasource.modes.create.item.EmailStatus = 'YES';
Change this line of code:
SendEmail(to, subject, message);
to:
SendEmail(to, subject, message, widget.datasource.item);
Change your client send email function to this:
function SendEmail(to, subject, message, item) {
google.script.run
.withSuccessHandler(function() {
item.EmailStatus = 'YES';
})
.withFailureHandler(function(error) {
//include a failure message popup or something here
})
.ServerSendEmailFunction(to, subject, message);
}
Hope this helps and solves your problem.

Answer 2

Is "EmailStatus" a field in the datasource of the widget, or is it a field in a different datasource? If it is actually a field in a different datasource/model, then you have to specify which record in that other datasource you want to connect to (in this case, the record called "Yes").
I'd recommend creating another server script function to set the status to "Yes" - here's the instructions for doing that: https://developers.google.com/appmaker/models/relations#server_script
Then call this new function in your success handler for the SendEmail function.