故意在$ http发布请求中调用错误

Question

I'm using Angular to send a post request with the $http service. I am doing all of the data validation of the form in Angular prior to sending the post request. However, there is one validation I am doing in PHP of whether the user already exists in the database. How do I purposefully invoke an error (in the php file) so that the Angular error callback is triggered instead of the success callback? Should I purposefully throw an exception?

IF the intent is to throw an exception, does the exception message get passed into the data parameter for the Angular error callback function?

Answer 1

Based on the comments to my question, I just did the following to my code:

if (duplicateUsers($username) > 0) {
  return http_response_code(400); // successfully generated an error in 
                                  // the $http AngularJS servicces
} else {
  // other code
}