AngularJS toArray Filter
Although AngularJS 1.x supports iterating over an object (keys and values), it is
not the preferred way of doing things. Moreover, filters like filter and orderBy
just don't work with objects; they are designed to work with arrays.
This filter can convert your objects into stable arrays that can then be filtered and sorted using the standard AngularJS filters.
Get It
The easiest way to install is using bower:
bower install --save angular-toArrayFilter
Alternatively you can download from the GitHub project: https://github.com/petebacondarwin/angular-toArrayFilter
Load It
Load the toArrayFilter.js file into your web app after loading angular.js
<html>
...
<head>
...
<script src="angular.js"></script>
<script src="bower_components/angular-toArrayFilter/toArrayFilter.js"></script>
...
</head>
...
</html>Use It
Make sure that your AngularJS application references the angular-toArrayFilter module:
angular.module('myApp', ['angular-toArrayFilter']);
Now if you have an object that you wish to repeat over, just slip the toArray filter in
before you try sorting or filtering:
<div ng-repeat="item in itemObj | toArray | orderBy : 'someProp'">
{{ item.$key }} - {{ item.someProp }}
</div>How it works
The filter iterates over the object's keys and creates an array containing the value of each
property. By default, the filter also attaches a new property $key to the value containing
the original key that was used in the object we are iterating over to reference the property.
Not adding the $key property
If you don't want the $key property to be attached to each of the property values, you simply
put an additional parameter on the toArray filter:
<div ng-repeat="item in itemObj | toArray : false | orderBy : 'someProp'">
{{ item.someProp }} (no $key available now)
</div>
Using $key with non-objects
Non-objects such as strings and numbers cannot have a new $key property attached to them.
If the object properties you are iterating over are not objects then you must either disable
the $key property or the filter will replace the non-object with a new object of the form:
{ $key: key, $value: value }.
Caveats
There are always issues when trying to iterate over properties in JavaScript and the toArray
filter has its own set of things to be aware of when using it:
- It only works with plain Objects - don't try to filter arrays and strings with it.
- If you don't disable it, the filter will modify each property value with a new
$keyproperty. - This filter is not compatible with IE8. (It uses
Object.keysandObject.definePropertywhich don't work well or at all in Internet Explorer 8 (IE8).
Example
Here is a fuller example of using the toArray filter on an object, to allow sorting and filtering
by a date property on each property of the original object. It also demonstrates how you can easily
update the original object and the array will stay in sync.
Check out the Live Demo
index.html:
<div ng-app="app">
<div ng:controller="Main">
<div ng:repeat="item in items | toArray | orderBy: 'date'">
{{item.$key}}: {{item.date | date}}
<button ng-click="remove(item)">Remove</button>
</div>
<button ng-click="add()">Add</button>
</div>
</div>app.js
angular.module('app', [])
.controller('Main', function Main($scope) {
$scope.nextKey = 4;
$scope.items = {
0: {date: new Date('12/23/2013')},
1: {date: new Date('12/23/2011')},
2: {date: new Date('12/23/2010')},
3: {date: new Date('12/23/2015')}
};
$scope.remove = function(item) {
delete $scope.items[item.$key];
};
$scope.add = function() {
$scope.items[$scope.nextKey] = { date: new Date() };
$scope.nextKey += 1;
};
});
