(Proposal) bh-submit directive submission

[sfount]

The bh-submit directive currently stops all propagation (does not call the submit method) if the form.$invalid flag is set.

The goal of this issue is to find a way to allow controllers to perform tasks if the form is invalid, often revolving around informing the user. For example:

• Display a danger notification
• Handle an unrelated error
• Scroll to the invalid form element

One suggestion for how this could be achieved is to remove the $invalid check from the bh-submit directive - this will always call the submission method and the directive can no longer assume a Promise will be returned.

One way of accomidating this is to check if the required method (finally) is returned in the function call - if not the loading state should simply be reverted.

For example:

FormController.$toggleLoading();

let response = $scope.submit();

if (response.finally) { 
  // attach method to clean up loading state 
  response.finally(() => FromController.$toggleLoading());
} else { 
  // method either did not return or quit early - retract loading state
  FormController.$toggleLoading();
}

Disadvantages:

• If the controller forgets to return a promise to the loading directive it will simple toggle loading off. This is a programmer mistake but may not be easy to catch

@IMA-WorldHealth/local-contributors This will change the way the submission directive works so should first be approved.