How to iterate through JavaScript maps using ng-repeat in angularjs?

Question

I try to use JavaScript Maps in the ng-repeat angular directive while searching, I found that this can be done as follows:

<ul ng-controller="MyCtrl"> <li ng-repeat='(key, value) in {"First Name":"John", "Last Name":"Smith"}'> <span>Key: {{key}}, value: {{value}}</span> </li> </ul> 

but this only works with regular JSON objects, when I create a real map as follows, it does not work.

I have this controller, for example

 function MyCtrl($scope) { $scope.items = new map(); $scope.items.set('adam',{'age':10,'fav':'doogie'}); $scope.items.set('amalie',{'age':12}); } 

and this html code

 <ul> <li ng-repeat='(key, value) in items'> <span>Key: {{key}}, value: {{value}}</span> </li> </ul> 

Answer 1

since ng-repeat does not support Map iteration, you can use the custom fromMap filter as shown below

 angular.module('app', []).filter('fromMap', function() { return function(input) { var out = {}; input.forEach((v, k) => out[k] = v); return out; }; }).controller('ctrl',function ($scope) { $scope.items = new Map(); $scope.items.set('adam',{'age':10,'fav':'doogie'}); $scope.items.set('amalie',{'age':12}); $scope.logAdamAge = function() { console.log($scope.items.get("adam").age) }; }); 

 <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script> <div ng-app="app" ng-controller="ctrl"> <div>with Map</div> <ul> <li ng-repeat="(key, value) in items | fromMap"> <div>{{key}}</div> <div ng-repeat="(k, v) in value">{{k}}: <input ng-model="value[k]" /></div> </li> </ul> <pre>{{items | fromMap}}</pre> <button ng-click="logAdamAge()">log Adam age from Map</button> </div> 

Answer 2

this will not work because javascript Map is an iterable object (you can iterate only through entries iterator, each time calling next () and not directly supported by angular ng-repeat .

what can you do if you have existing code to convert an iterable object (map) into a simple array

 $scope.itemsToArray = Array.from($scope.items.entries()); 

this will make your iterative object an array, at this point you can execute the loop in the standard way

 <ul> <li ng-repeat='item in itemsToArray'> <span>Key: {{item[0]}}, value: {{item[1]}}</span> </li> </ul> 

working plnkr here

Answer 3

Although I like the Jag answer , I created a more extensive snippet with different implementations to achieve the same thing, and I extracted most of the ES6 arrow functions and distributed the operator to implement the filter as a one-line: .filter('fromMap', () => mapObject => [...mapObject])

One setting of the observer and even incomprehensible to this observer.

Here's how you can implement ng-repeat in objects of the Map class:

 angular.module('ui.bootstrap.demo', ['ngAnimate', 'ngSanitize', 'ui.bootstrap']); angular.module('ui.bootstrap.demo') .filter('fromMap', () => mapObject => [...mapObject]) .controller('myCtrl', function($scope, $log) { $scope.myMap = new Map([ ['key1', 'value1'], ['key2', 'value2'], ['key3', 'value3'], ['key4', 'value4'], ]); const unsuscribeWatcher1 = $scope.$watch(() => $scope.myMap.size, (newVal, oldVal) => { if (newVal !== oldVal) { //Splicing and pushing keeps the reference to the Array instead of reassigning. $scope.myLoopedMap.splice(0); $scope.myLoopedMap.push(...[...$scope.mySet].filter(k => $scope.myMap.has(k)).map(k => $scope.myMap.get(k))) $scope.myArrFromMap.splice(0); $scope.myArrFromMap.push(...[...$scope.myMap]) } }) const unsuscribeWatcher2 = $scope.$watch(() => $scope.mySet.size, (newVal, oldVal) => { if (newVal !== oldVal) { $scope.myLoopedMap.splice(0); $scope.myLoopedMap.push([...$scope.mySet].filter(k => $scope.myMap.has(k)).map(k => $scope.myMap.get(k))); } }) $scope.mySet = new Set(['key1', 'key3']); $scope.mySet.add('not in the Map') $scope.mySet.add('key7') $scope.myKeys = ['key1', 'key3']; $scope.myArr = [ ['key1', 'value1'], ['key2', 'value2'], ['key3', 'value3'], ['key4', 'value4'], ]; $scope.myArrFromMap = [...$scope.myMap] $scope.myLoopedMap = [...$scope.mySet].filter(k => $scope.myMap.has(k)).map(k => $scope.myMap.get(k)) $scope.myLoopedMap2 = [...$scope.myKeys].reduce((acc, k) => { return $scope.myMap.has(k) ? acc.concat($scope.myMap.get(k)) : acc; }, []) // added to the map later setTimeout(() => { $scope.$apply(() => { // this will be updated as we are watching the Map $scope.myMap.set('key7', 'value7') }) setTimeout(() => { unsuscribeWatcher1(); // this breaks the watching of the Map $scope.$apply(() => { // this will not be updated as the watcher is not working anymore $scope.myMap.set('key8', 'value8') }) }, 3000) }, 3000) }); 

 <!doctype html> <html ng-app="ui.bootstrap.demo"> <head> <script src="//ajax.googleapis.com/ajax/libs/angularjs/1.6.1/angular.js"></script> <script src="//ajax.googleapis.com/ajax/libs/angularjs/1.6.1/angular-animate.js"></script> <script src="//ajax.googleapis.com/ajax/libs/angularjs/1.6.1/angular-sanitize.js"></script> <script src="//angular-ui.imtqy.com/bootstrap/ui-bootstrap-tpls-2.5.0.js"></script> <script src="example.js"></script> </head> <body> <div ng-controller="myCtrl"> <h3>Some test data data</h3> <div>Get 'key1'======> {{myMap.get('key1')}}</div> <div>Arr ==========> {{myArr}}</div> <div>filtered ======> {{myMap | fromMap}}</div> <div>myArrFromMap=> {{myArrFromMap}}</div> <div>myLoopedMap==> {{myLoopedMap}}</div> <div>myLoopedMap2=> {{myLoopedMap2}}</div> <h3>ng repeat in myLoopedMap</h3> <div ng-repeat="item in myLoopedMap"> Item:`{{item}}` </div> <h3>ng repeat in myArrFromMap</h3> <div ng-repeat="(index, value) in myArrFromMap"> value[0]:`{{value[0]}}`, value[1]:`{{value[1]}}`, index: `{{index}}` </div> </div> </body> </html> 

And the corresponding Plnkr