Angular Directive: Enabling Form Validation for Submit Button Directive

Question

Angular Directive: Enabling Form Validation for Submit Button Directive

Managing validations for multiple forms in my project has been quite challenging. Each form requires specific validation expressions, along with a loading element which complicates the reuse of buttons. To tackle this issue, I thought of utilizing a directive instead. However, when passing the expressions through attributes, they do not update or validate as expected when users input data - essentially behaving like static strings rather than dynamic expressions.

My goal is to achieve something similar to this:

<submit-button label="My Label" validate="!myForm.$valid"></submit-button>

This should translate to:

<button ng-disabled="!myForm.$valid">My Label</button>

For reference, here's a basic isolated template on jsfiddle showcasing my progress so far: https://jsfiddle.net/lucasbittar/8m992bet/3/

Any guidance or assistance would be greatly appreciated!

javascript angularjs validation angularjs-directive

Answer 1

Answer №1

To easily accomplish this in the specified Angular version, you can make use of a two-way attribute binding on your directive. Simply bind the validate attribute or scope property to your expression and then reference it in the ngDisabled directive.

It is important to remember that directives like ngDisabled (and other ng-prefixed ones, if I recall correctly) work directly with expressions, so avoid using double brackets for interpolation.

Your directive code will look something like this:

function submitButton () {
  var submit = {
    restrict: 'E',
    require: ['^form'],
    template: '<button ng-disabled="validate">{{ label }}</button>',
    scope: {
      validate: '='
    },
    link: link
  }
  return submit;

  function link (scope, el, attr, formCtrl) {
    scope.label = attr.label;
  }
}

You can test out the functionality by following this fiddle link: https://jsfiddle.net/8m992bet/6/

Keep in mind that if desired, you could achieve similar results by utilizing an inherited scope in your directive along with scope.$watch, but opting for a two-way binding approach is simpler.

Additionally, note that in Angular 1.5 you have the option to use one-way binding on a directive using < instead of =.

Answer 2

To easily accomplish this in the specified Angular version, you can make use of a two-way attribute binding on your directive. Simply bind the validate attribute or scope property to your expression and then reference it in the ngDisabled directive.

It is important to remember that directives like ngDisabled (and other ng-prefixed ones, if I recall correctly) work directly with expressions, so avoid using double brackets for interpolation.

Your directive code will look something like this:

function submitButton () {
  var submit = {
    restrict: 'E',
    require: ['^form'],
    template: '<button ng-disabled="validate">{{ label }}</button>',
    scope: {
      validate: '='
    },
    link: link
  }
  return submit;

  function link (scope, el, attr, formCtrl) {
    scope.label = attr.label;
  }
}

You can test out the functionality by following this fiddle link: https://jsfiddle.net/8m992bet/6/

Keep in mind that if desired, you could achieve similar results by utilizing an inherited scope in your directive along with scope.$watch, but opting for a two-way binding approach is simpler.

Additionally, note that in Angular 1.5 you have the option to use one-way binding on a directive using < instead of =.

Angular Directive: Enabling Form Validation for Submit Button Directive

Answer №1

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