AngularJS Filter REST JSON in Controller - json

Question

I need to output a count of items from JSON by category (using .length I believe), and would like to manage this in a controller so I can place it to scope anywhere I want. How can I filter REST JSON in a controller?
My sample JSON is as follows:
[
{
"id": "66D5069C-DC67-46FC-8A51-1F15A94216D4",
"articletitle": "artilce1",
"articlecategoryid": 1,
"articlesummary": "article 1 summary. "
},
{
"id": "66D5069C-DC67-46FC-8A51-1F15A94216D5",
"articletitle": "artilce2",
"articlecategoryid": 2,
"articlesummary": "article 2 summary. "
},
{
"id": "66D5069C-DC67-46FC-8A51-1F15A94216D6",
"articletitle": "artilce3",
"articlecategoryid": 3,
"articlesummary": "article 3 summary. "
},
{
"id": "66D5069C-DC67-46FC-8A51-1F15A94216D7",
"articletitle": "artilce4",
"articlecategoryid": 1,
"articlesummary": "article 3 summary. "
},
]
My Resource is as follows:
// Articles by ID
pfcServices.factory('pfcArticles', ['$resource', function ($resource) {
return $resource('https://myrestcall.net/tables/articles', {},
{
'update': { method:'PATCH'}
});
}]);
My Controller is as follows:
// Count number of total articles
pfcControllers.controller('pfcArticleCountCtrl', ['$scope', 'pfcArticles', function ($scope, pfcArticles) {
$scope.articlecount = pfcArticles.query();
I believe I would need to add something to the controller (ex. $scope.cat1 = filter(my logic to get my category here), but am a little lost on how to query this so I have a count of items per category.

Answer 1

Build a filter like this.
angular.module('FilterModule', [])
.filter( 'cat1', function() {
return function(yourJSON) {
var count = 0;
yourJSON.forEach(function(item) {
switch(item.articlecategoryid) {
case 1:
count++;
break;
default:
console.log('item is not of category 1');
}
});
return count;
};
});
Inject the $filter service and fetch the cat1 filter. Now you can use it as $scope.cat1 = $filter('cat1')(yourJSON);