How do I pass multiple attributes into an Angular.js attribute directive?
I have an attribute directive restricted as follows:
restrict: "A"
I need to pass in two attributes; a number and a function/callback, accessing them within the directive using the attrs
object.
If the directive was an element directive, restricted with "E"
I could to this:
<example-directive example-number="99" example-function="exampleCallback()">
However, for reasons I won't go into I need the directive to be an attribute directive.
How do I pass multiple attributes into an attribute directive?
Solution 1:
The directive can access any attribute that is defined on the same element, even if the directive itself is not the element.
Template:
<div example-directive example-number="99" example-function="exampleCallback()"></div>
Directive:
app.directive('exampleDirective ', function () {
return {
restrict: 'A', // 'A' is the default, so you could remove this line
scope: {
callback : '&exampleFunction',
},
link: function (scope, element, attrs) {
var num = scope.$eval(attrs.exampleNumber);
console.log('number=',num);
scope.callback(); // calls exampleCallback()
}
};
});
fiddle
If the value of attribute example-number
will be hard-coded, I suggest using $eval
once, and storing the value. Variable num
will have the correct type (a number).
Solution 2:
You do it exactly the same way as you would with an element directive. You will have them in the attrs object, my sample has them two-way binding via the isolate scope but that's not required. If you're using an isolated scope you can access the attributes with scope.$eval(attrs.sample)
or simply scope.sample, but they may not be defined at linking depending on your situation.
app.directive('sample', function () {
return {
restrict: 'A',
scope: {
'sample' : '=',
'another' : '='
},
link: function (scope, element, attrs) {
console.log(attrs);
scope.$watch('sample', function (newVal) {
console.log('sample', newVal);
});
scope.$watch('another', function (newVal) {
console.log('another', newVal);
});
}
};
});
used as:
<input type="text" ng-model="name" placeholder="Enter a name here">
<input type="text" ng-model="something" placeholder="Enter something here">
<div sample="name" another="something"></div>
Solution 3:
You could pass an object as attribute and read it into the directive like this:
<div my-directive="{id:123,name:'teo',salary:1000,color:red}"></div>
app.directive('myDirective', function () {
return {
link: function (scope, element, attrs) {
//convert the attributes to object and get its properties
var attributes = scope.$eval(attrs.myDirective);
console.log('id:'+attributes.id);
console.log('id:'+attributes.name);
}
};
});
Solution 4:
This worked for me and I think is more HTML5 compliant. You should change your html to use 'data-' prefix
<div data-example-directive data-number="99"></div>
And within the directive read the variable's value:
scope: {
number : "=",
....
},