I have an angular directive which is initialized like so:
<conversation style="height:300px" type="convo" type-id="{{some_prop}}"></conversation>
I'd like it to be smart enough to refresh the directive when $scope.some_prop changes, as that implies it should show completely different content.
I have tested it as it is and nothing happens, the linking function doesn't even get called when $scope.some_prop changes. Is there a way to make this happen ?
This question is related to
javascript
angularjs
angularjs-directive
angularjs-scope
I hope this will help reloading/refreshing directive on value from parent scope
<html>
<head>
<!-- version 1.4.5 -->
<script src="angular.js"></script>
</head>
<body ng-app="app" ng-controller="Ctrl">
<my-test reload-on="update"></my-test><br>
<button ng-click="update = update+1;">update {{update}}</button>
</body>
<script>
var app = angular.module('app', [])
app.controller('Ctrl', function($scope) {
$scope.update = 0;
});
app.directive('myTest', function() {
return {
restrict: 'AE',
scope: {
reloadOn: '='
},
controller: function($scope) {
$scope.$watch('reloadOn', function(newVal, oldVal) {
// all directive code here
console.log("Reloaded successfully......" + $scope.reloadOn);
});
},
template: '<span> {{reloadOn}} </span>'
}
});
</script>
</html>
What you're trying to do is to monitor the property of attribute in directive. You can watch the property of attribute changes using $observe() as follows:
angular.module('myApp').directive('conversation', function() {
return {
restrict: 'E',
replace: true,
compile: function(tElement, attr) {
attr.$observe('typeId', function(data) {
console.log("Updated data ", data);
}, true);
}
};
});
Keep in mind that I used the 'compile' function in the directive here because you haven't mentioned if you have any models and whether this is performance sensitive.
If you have models, you need to change the 'compile' function to 'link' or use 'controller' and to monitor the property of a model changes, you should use $watch(), and take of the angular {{}} brackets from the property, example:
<conversation style="height:300px" type="convo" type-id="some_prop"></conversation>
And in the directive:
angular.module('myApp').directive('conversation', function() {
return {
scope: {
typeId: '=',
},
link: function(scope, elm, attr) {
scope.$watch('typeId', function(newValue, oldValue) {
if (newValue !== oldValue) {
// You actions here
console.log("I got the new value! ", newValue);
}
}, true);
}
};
});
angular.module('app').directive('conversation', function() {
return {
restrict: 'E',
link: function ($scope, $elm, $attr) {
$scope.$watch("some_prop", function (newValue, oldValue) {
var typeId = $attr.type-id;
// Your logic.
});
}
};
}
If You're under AngularJS 1.5.3 or newer, You should consider to move to components instead of directives. Those works very similar to directives but with some very useful additional feautures, such as $onChanges(changesObj), one of the lifecycle hook, that will be called whenever one-way bindings are updated.
app.component('conversation ', {
bindings: {
type: '@',
typeId: '='
},
controller: function() {
this.$onChanges = function(changes) {
// check if your specific property has changed
// that because $onChanges is fired whenever each property is changed from you parent ctrl
if(!!changes.typeId){
refreshYourComponent();
}
};
},
templateUrl: 'conversation .html'
});
Here's the docs for deepen into components.
Source: Stackoverflow.com