AngularJS - Server side validation and client side forms

Question

I am trying to understand how to do the following things:

What is the accepted way of declaring a form. My understanding is you just declare the form in HTML, and ad

Answer 1

As variant

// ES6 form controller class

class FormCtrl {
 constructor($scope, SomeApiService) {
   this.$scope = $scope;
   this.someApiService = SomeApiService;
   this.formData = {};
 }

 submit(form) {
   if (form.$valid) {
     this.someApiService
         .save(this.formData)
         .then(() => {
           // handle success

           // reset form
           form.$setPristine();
           form.$setUntouched();

           // clear data
           this.formData = {};
         })
         .catch((result) => {
           // handle error
           if (result.status === 400) {
             this.handleServerValidationErrors(form, result.data && result.data.errors)
           } else {// TODO: handle other errors}
         })
   }
 }

 handleServerValidationErrors(form, errors) {
  // form field to model map
  // add fields with input name different from name in model
  // example: <input type="text" name="bCategory" ng-model="user.categoryId"/>
  var map = {
    categoryId: 'bCategory',
    // other
  };

  if (errors && errors.length) {
    // handle form fields errors separately
    angular.forEach(errors, (error) => {
      let formFieldName = map[error.field] || error.field;
      let formField = form[formFieldName];
      let formFieldWatcher;

      if (formField) {
        // tell the form that field is invalid
        formField.$setValidity('server', false);

        // waits for any changes on the input
        // and when they happen it invalidates the server error.
        formFieldWatcher = this.$scope.$watch(() => formField.$viewValue, (newValue, oldValue) => {
          if (newValue === oldValue) {
            return;
          }

          // clean up the server error
          formField.$setValidity('server', true);

          // clean up form field watcher
          if (formFieldWatcher) {
            formFieldWatcher();
            formFieldWatcher = null;
          }
        });
      }
    });

  } else {
    // TODO: handle form validation
    alert('Invalid form data');
  }
}

Answer 2

As of July 2014, AngularJS 1.3 has added new form validation features. This includes ngMessages and asyncValidators so you can now fire server side validation per field prior to submitting the form.

Angular 1.3 Form validation tutorial :

• Taming forms in Angular 1.3
• Video | Repo | Demo

References:

• ngMessages directive
• ngModel.NgModelController