AngularJS : ng-model binding not updating when changed with jQuery

问题

This is my HTML:

<input id=\"selectedDueDate\" type=\"text\" ng-model=\"selectedDate\" />

When I type into the box, the model is updated via the 2-way-binding mechanism. Sweet.

However when I do this via JQuery...

$(\'#selectedDueDate\').val(dateText);

It doesn\'t update the model. Why?

回答1:

Angular doesn't know about that change. For this you should call $scope.$digest() or make the change inside of $scope.$apply():

$scope.$apply(function() { 
   // every changes goes here
   $('#selectedDueDate').val(dateText); 
});

See this to better understand dirty-checking

UPDATE: Here is an example

回答2:

Just use;

$('#selectedDueDate').val(dateText).trigger('input');

回答3:

I have found that if you don't put the variable directly against the scope it updates more reliably.

Try using some "dateObj.selectedDate" and in the controller add the selectedDate to a dateObj object as so:

$scope.dateObj = {selectedDate: new Date()}

This worked for me.

回答4:

Try this

var selectedDueDateField = document.getElementById("selectedDueDate");
var element = angular.element(selectedDueDateField);
element.val('new value here');
element.triggerHandler('input');

回答5:

Just run the following line at the end of your function:

$scope.$apply()

回答6:

Whatever happens outside the Scope of Angular, Angular will never know that.

Digest cycle put the changes from the model -> controller and then from controller -> model.

If you need to see the latest Model, you need to trigger the digest cycle

But there is a chance of a digest cycle in progress, so we need to check and init the cycle.

Preferably, always perform a safe apply.

       $scope.safeApply = function(fn) {
            if (this.$root) {
                var phase = this.$root.$$phase;
                if (phase == '$apply' || phase == '$digest') {
                    if (fn && (typeof (fn) === 'function')) {
                        fn();
                    }
                } else {
                    this.$apply(fn);
                }
            }
        };


      $scope.safeApply(function(){
          // your function here.
      });

回答7:

AngularJS pass string, numbers and booleans by value while it passes arrays and objects by reference. So you can create an empty object and make your date a property of that object. In that way angular will detect model changes.

In controller

app.module('yourModule').controller('yourController',function($scope){
$scope.vm={selectedDate:''}
});

In html

<div ng-controller="yourController">
<input id="selectedDueDate" type="text" ng-model="vm.selectedDate" />
</div>

回答8:

You have to trigger the change event of the input element because ng-model listens to input events and the scope will be updated. However, the regular jQuery trigger didn't work for me. But here is what works like a charm

$("#myInput")[0].dispatchEvent(new Event("input", { bubbles: true })); //Works

Following didn't work

$("#myInput").trigger("change"); // Did't work for me

You can read more about creating and dispatching synthetic events.

回答9:

I've written this little plugin for jQuery which will make all calls to .val(value) update the angular element if present:

(function($, ng) {
  'use strict';

  var $val = $.fn.val; // save original jQuery function

  // override jQuery function
  $.fn.val = function (value) {
    // if getter, just return original
    if (!arguments.length) {
      return $val.call(this);
    }

    // get result of original function
    var result = $val.call(this, value);

    // trigger angular input (this[0] is the DOM object)
    ng.element(this[0]).triggerHandler('input');

    // return the original result
    return result; 
  }
})(window.jQuery, window.angular);

Just pop this script in after jQuery and angular.js and val(value) updates should now play nice.

Minified version:

!function(n,t){"use strict";var r=n.fn.val;n.fn.val=function(n){if(!arguments.length)return r.call(this);var e=r.call(this,n);return t.element(this[0]).triggerHandler("input"),e}}(window.jQuery,window.angular);

Example:

// the function
(function($, ng) {
  'use strict';
  
  var $val = $.fn.val;
  
  $.fn.val = function (value) {
    if (!arguments.length) {
      return $val.call(this);
    }
    
    var result = $val.call(this, value);
    
    ng.element(this[0]).triggerHandler('input');
    
    return result;
    
  }
})(window.jQuery, window.angular);

(function(ng){ 
  ng.module('example', [])
    .controller('ExampleController', function($scope) {
      $scope.output = "output";
      
      $scope.change = function() {
        $scope.output = "" + $scope.input;
      }
    });
})(window.angular);

(function($){  
  $(function() {
    var button = $('#button');
  
    if (button.length)
      console.log('hello, button');
    
    button.click(function() {
      var input = $('#input');
      
      var value = parseInt(input.val());
      value = isNaN(value) ? 0 : value;
      
      input.val(value + 1);
    });
  });
})(window.jQuery);

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div ng-app="example" ng-controller="ExampleController">
  <input type="number" id="input" ng-model="input" ng-change="change()" />
  <span>{{output}}</span>
  <button id="button">+</button>
</div>

This answer was copied verbatim from my answer to another similar question.

回答10:

Just use:

$('#selectedDueDate').val(dateText).trigger('input');

instead of:

$('#selectedDueDate').val(dateText);

来源：https://stackoverflow.com/questions/11873627/angularjs-ng-model-binding-not-updating-when-changed-with-jquery

标签

javascript

jquery

angularjs

data-binding

angular-ngmodel