AngularJS checkbox filter
I would like to filter the results.
There is a list of wines, my wish is when no checkbox is checked, the entire list of wine is displayed.
- when only 1 checkbox is checked is displayed the related category
- when more than one checkbox are checked the related categories are displayed
I'm a newbie to AngularJS, I tried with ng-model wihout success, here is the code without ng-model associated to the function:
<html ng-app="exampleApp">
<head>
<title></title>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.3.0-beta.10/angular.min.js"></script>
<script>
angular.module("exampleApp", [])
.controller("defaultCtrl", function ($scope) {
$scope.wines = [
{ name: "Wine A", category: "red" },
{ name: "Wine B", category: "red" },
{ name: "wine C", category: "white" },
{ name: "Wine D", category: "red" },
{ name: "Wine E", category: "red" },
{ name: "wine F", category: "white" },
{ name: "wine G", category: "champagne"},
{ name: "wine H", category: "champagne" }
];
$scope.selectItems = function (item) {
return item.category == "red";
};
$scope.selectItems = function (item) {
return item.category == "white";
};
$scope.selectItems = function (item) {
return item.category == "champagne";
};
});
</script>
</head>
<body ng-controller="defaultCtrl">
<h4>red: <input type="checkbox"></h4>
<h4>white: <input type="checkbox"></h4>
<h4>champagne: <input type="checkbox"></h4>
<div ng-repeat="w in wines | filter:selectItems">
{{w.name}}
{{w.category}}
</div>
</body>
</html>
How to use ng-model or ng-change to associate a function to each checkbox button to have a real time filtering model??
Answer
There are several implementations possible. Here's one:
Have a
$scope.filter = {}object to hold the state of each filter. E.g.{red: true, white: false...}.Associate each checkbox with the corresponding property using
ng-model. E.g.:input type="checkbox" ng-model="filter['red']" />.Have a function (e.g.
$scope.filterByCategory(wine)) that decides if a wine should be displayed or not (based on the$scope.filterobject).Use that function to filter the items based on their category. E.g.
<div ng-repeat="wine in wines | filter:filterByCategory">
The filterByCategory function could be implemented like this:
function filterByCategory(wine) {
// Display the wine if
var displayWine =
// the wine's category checkbox is checked (`filter[category]` is true)
$scope.filter[wine.category] || // or
// no checkbox is checked (all `filter[...]` are false)
noFilter($scope.filter);
return displayWine;
};
where noFilter() is a function that checks if there is any filter activated (and returns true if there is none):
function noFilter(filterObj) {
return Object.
keys(filterObj).
every(function (key) { return !filterObj[key]; });
}
See, also, this short demo.
UPDATE:
I created a modified version, which supports multiple filters (not just filtering by category).
Basically, it dynamically detects the available properties (based on the first wine element), adds controls (groups of check-boxes) for applying filters based on each property and features a custom filter function that:
- Filters each
wineitem, based on every property. - If a property has no filter applied (i.e. no check-box checked), it is ignored.
- If a property has check-boxes checked, it is used for filtering out
wineitems (see above). - There is code for applying multiple filters using AND (i.e. all properties must match) or OR (at least one property must match).
See, also, this updated demo.