Angularfire remove items by checkbox - angularjs

Question

I am using Angularfire and I'd like to remove the items by checkbox.
And there is a button that can do the "checkAll" and another do the "uncheckAll"
HTML
<div ng-app="app" ng-controller="Ctrl">
<li ng-repeat="item in newslist">
<input type="checkbox"> {{item.newsTitle}}
</li>
<br>
<button ng-click="checkAll()">check all</button>
<button ng-click="uncheckAll()">uncheck all</button>
<button ng-click="newslist.$remove(item)">Remove</button>
</div>
JS
var app = angular.module("app", ["firebase"]);
app.value('newsURL', 'https://XXX.firebaseio.com/XXX/');
app.factory('newsFactory', function($firebase, newsURL) {
return $firebase(new Firebase(newsURL)).$asArray();
});
app.controller('Ctrl', function($scope, $firebase, newsFactory) {
$scope.newslist = newsFactory;
$scope.checkAll = function() {
};
$scope.uncheckAll = function() {
};
});
plunker here
I don't know how to remove the items by checkbox or how to make the "checkAll" button work.
I will be appreciate if someone could tell me your answer.

Answer 1

Here is function you would need to check/uncheck and for removing items:
$scope.checkAll = function() {
$scope.newslist.forEach(function(el) {
el.checked = true;
$scope.newslist.$save(el);
});
};
$scope.uncheckAll = function() {
$scope.newslist.forEach(function(el) {
el.checked = false;
$scope.newslist.$save(el);
});
}
$scope.remove = function() {
$scope.newslist.forEach(function(item) {
if (item.checked) {
$scope.newslist.$remove(item);
}
});
};
Demo: http://plnkr.co/edit/GsGVsGGjNwW4i1kTOuko?p=preview
I added checked property for ngModel directive.
HTML becomes:
<li ng-repeat="item in newslist">
<input type="checkbox" ng-model="item.checked">{{item.newsTitle}}
</li>
<button ng-click="checkAll()">check all</button>
<button ng-click="uncheckAll()">uncheck all</button>
<button ng-click="remove()">Remove</button>