Using object map filtering instead of array filtering in AngularJS

Question

Using object map filtering instead of array filtering in AngularJS

If I have a controller with a $scope property that is an object with other properties rather than an array, how can I properly filter the ng-repeat set in AngularJS?

Check out this JSFiddle example: http://jsfiddle.net/ZfGx4/110/

This is how the controller looks:

function HelloCntl($scope, $filter) {
    $scope.friends = {
        john: {
            name: 'John',
            phone: '555-1276'
        },
        mary: {
            name: 'Mary',
            phone: '800-BIG-MARY'
        },
        mike: {
               name: 'Mike',
               phone: '500-4321'
          },
         adam: {
Name: 'Adam', 
phone:'100-5678'
},
julie:{
name:'Julie',
phone: '900-8765'
}
};
}

And here is the template:

<div ng:app>
 <div ng-controller="HelloCntl">
  <input placeholder="Type to filter" ng-model="query">     
  <ul>
<li ng-repeat="(id, friend) in friends | filter:query">
<Span>{{friend.name}} @ {{friend.phone}}</span>
</li>
</ul>
 </div>
</div>

javascript angularjs

Answer 1

Answer №1

To enhance the efficiency of my code, I decided to switch to using an array as my data structure. Here is an alternative method for filtering your friends object:

angular.module('filters',['utils'])
  .filter('friendFilter', function(utils){

    return function(input, query){
      if(!query) return input;
      var result = [];

      angular.forEach(input, function(friend){
        if(utils.compareStr(friend.name, query) ||
           utils.compareStr(friend.phone, query))
          result.push(friend);          
      });
      return result;
    };
  });

This revised approach allows for a single iteration over the object, comparison by name and phone, and can be invoked like this:

<li ng-repeat="friend in friends | friendFilter:query">

I have defined the compareStr function in another module, although it may not be necessary:

angular.module('utils', [])
  .factory('utils', function(){
    return{
      compareStr: function(stra, strb){
        stra = ("" + stra).toLowerCase();
        strb = ("" + strb).toLowerCase();
        return stra.indexOf(strb) !== -1;
      }
    };
  });

Remember to include the filters module in your application:

angular.module('app',['filters'])

For a complete example, you can visit: http://jsbin.com/acagag/5/edit

Answer 2

To enhance the efficiency of my code, I decided to switch to using an array as my data structure. Here is an alternative method for filtering your friends object:

angular.module('filters',['utils'])
  .filter('friendFilter', function(utils){

    return function(input, query){
      if(!query) return input;
      var result = [];

      angular.forEach(input, function(friend){
        if(utils.compareStr(friend.name, query) ||
           utils.compareStr(friend.phone, query))
          result.push(friend);          
      });
      return result;
    };
  });

This revised approach allows for a single iteration over the object, comparison by name and phone, and can be invoked like this:

<li ng-repeat="friend in friends | friendFilter:query">

I have defined the compareStr function in another module, although it may not be necessary:

angular.module('utils', [])
  .factory('utils', function(){
    return{
      compareStr: function(stra, strb){
        stra = ("" + stra).toLowerCase();
        strb = ("" + strb).toLowerCase();
        return stra.indexOf(strb) !== -1;
      }
    };
  });

Remember to include the filters module in your application:

angular.module('app',['filters'])

For a complete example, you can visit: http://jsbin.com/acagag/5/edit

Answer 3

Answer №2

It seems that the 'filter' function in Angular.js doesn't work directly in this case. Upon examining the code, we can see that the filter function first checks if the input is an array:

function filterFilter() {
  return function(array, expression) {
    if (!(array instanceof Array)) return array;

If the input is not an array, it simply returns the input as is.

One workaround could be converting the data to an array before applying the filter. Here's a suggestion:

In the controller, you can convert the data into an array before using the filter:

$scope.filteredFriends = function() {
    var array = [];
    for(key in $scope.friends) {
        array.push($scope.friends[key]);
    }
    return $filter('filter')(array, $scope.query);
}

And then in the ng-repeat directive:

<li ng-repeat="friend in filteredFriends()">

You can see an example of this approach here: http://jsbin.com/acagag/2/edit

An alternative solution might be creating a custom filter for this specific scenario.

Answer 4

It seems that the 'filter' function in Angular.js doesn't work directly in this case. Upon examining the code, we can see that the filter function first checks if the input is an array:

function filterFilter() {
  return function(array, expression) {
    if (!(array instanceof Array)) return array;

If the input is not an array, it simply returns the input as is.

One workaround could be converting the data to an array before applying the filter. Here's a suggestion:

In the controller, you can convert the data into an array before using the filter:

$scope.filteredFriends = function() {
    var array = [];
    for(key in $scope.friends) {
        array.push($scope.friends[key]);
    }
    return $filter('filter')(array, $scope.query);
}

And then in the ng-repeat directive:

<li ng-repeat="friend in filteredFriends()">

You can see an example of this approach here: http://jsbin.com/acagag/2/edit

An alternative solution might be creating a custom filter for this specific scenario.

Answer 5

Answer №3

I encountered a similar issue but managed to find a solution by developing my own custom filter that works with a map, while leveraging the existing filter functionality for the actual matching process.

My unique filter iterates through the map and for each element, it calls the built-in filter. However, since the filter only accepts an array, I wrap each element in an array of length 1 (like [data] below). The match is considered successful if the output-array's length remains 1.

.filter('mapFilter', function($filter) {
  var filter = $filter('filter');

  return function(map, expression, comparator) {
    if (!expression) return map;

    var result = {};
    angular.forEach(map, function(data, index) {
      if (filter([data], expression, comparator).length)
        result[index] = data;          
    });

    return result;
  }
})

This approach may sacrifice some efficiency as the built-in filter needs to be invoked multiple times for each element in the map. Despite this, even with a map containing 500 elements, the filtering process remains almost instantaneous in my case.

Answer 6

I encountered a similar issue but managed to find a solution by developing my own custom filter that works with a map, while leveraging the existing filter functionality for the actual matching process.

My unique filter iterates through the map and for each element, it calls the built-in filter. However, since the filter only accepts an array, I wrap each element in an array of length 1 (like [data] below). The match is considered successful if the output-array's length remains 1.

.filter('mapFilter', function($filter) {
  var filter = $filter('filter');

  return function(map, expression, comparator) {
    if (!expression) return map;

    var result = {};
    angular.forEach(map, function(data, index) {
      if (filter([data], expression, comparator).length)
        result[index] = data;          
    });

    return result;
  }
})

This approach may sacrifice some efficiency as the built-in filter needs to be invoked multiple times for each element in the map. Despite this, even with a map containing 500 elements, the filtering process remains almost instantaneous in my case.

Answer 7

Answer №4

I recently created a demonstration on how to avoid converting your object into an array. In my opinion, this provides a more accurate solution to the question.

Like many others, I encountered difficulties when trying to search within an object.

http://jsbin.com/acagag/223/edit

angular.module('filters',['utils'])
  .filter('friendFilter', function(utils){

    return function(input, query){
      if(!query) return input;
      var result = {};

      angular.forEach(input, function(friendData, friend){
        if(utils.compareStr(friend, query) ||
           utils.compareStr(friendData.phone, query))
          result[friend] = friendData;          
      });
      return result;
    };
  });

Instead of returning an array, simply return an object.

I hope this explanation proves helpful to someone out there!

Answer 8

I recently created a demonstration on how to avoid converting your object into an array. In my opinion, this provides a more accurate solution to the question.

Like many others, I encountered difficulties when trying to search within an object.

http://jsbin.com/acagag/223/edit

angular.module('filters',['utils'])
  .filter('friendFilter', function(utils){

    return function(input, query){
      if(!query) return input;
      var result = {};

      angular.forEach(input, function(friendData, friend){
        if(utils.compareStr(friend, query) ||
           utils.compareStr(friendData.phone, query))
          result[friend] = friendData;          
      });
      return result;
    };
  });

Instead of returning an array, simply return an object.

I hope this explanation proves helpful to someone out there!

Answer 9

Answer №5

This may not be the most efficient solution, but if you're looking for a quick and easy fix:

<li ng-repeat="(id, friend) in friends | filter:query" ng-hide="id !== query.id">
  <span>{{friend.name}} @ {{friend.phone}}</span>
</li>

Alternatively, you could use ng-if instead of ng-hide

Answer 10

This may not be the most efficient solution, but if you're looking for a quick and easy fix:

<li ng-repeat="(id, friend) in friends | filter:query" ng-hide="id !== query.id">
  <span>{{friend.name}} @ {{friend.phone}}</span>
</li>

Alternatively, you could use ng-if instead of ng-hide

Answer 11

Answer №6

Instead of relying on a filter, you have the option to :

$http.get('api/users').then(function(response){
    angular.forEach(response.data, function(user){
        users.push(user);
    });
    $scope.users = users;
});

You can then include the following code snippet in your template:

<input type="text" ng-model="searchQuery" placeholder="Search user"/>

<li ng-repeat="user in users | filter:searchQuery">
    {{ user.name }}
</li>

Answer 12

Instead of relying on a filter, you have the option to :

$http.get('api/users').then(function(response){
    angular.forEach(response.data, function(user){
        users.push(user);
    });
    $scope.users = users;
});

You can then include the following code snippet in your template:

<input type="text" ng-model="searchQuery" placeholder="Search user"/>

<li ng-repeat="user in users | filter:searchQuery">
    {{ user.name }}
</li>

Using object map filtering instead of array filtering in AngularJS

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

Answer №6

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