Accessing variable from controller to service | Angular 1.5

Question

I want to access a variable from my controller so I can use it in my service! I thought that if I made the variable global I could access it in my service, but it's not working out hehe. The variable is shops btw!

Here is where I'm creating the variable:

    $scope.$on('$ionicView.enter', function (e) {
    ecommercer.getData().then(function (s) {
        $scope.shops = s.vendors
        $scope.categories = s.categories

        $ionicScrollDelegate.resize()

        if ($stateParams.id && $stateParams.id.length > 1) {
            $ionicTabsDelegate.showBar(false)
            ecommercer.saveShopById($stateParams.id)
            $state.go('tab.ecommerce.shop')
        }
    })
})

Here (the same file) is where I'm using my variable:

    $scope.$watch('selectedCategory.name', function (newval, oldval) {

        if ($scope.selectedCategory.name != undefined) {
            $scope.shops = ecommercer.filterByCategory(newval.id)

        } else {
            $scope.shops = ecommercer.filterByCategory(null)
        }

    })

Here is where I create the same variable in my service file:

app.service('ecommercer', function (eapi, $q, storage, $http, endpointHandler, $state, $rootScope, $filter) {
var products, categories, vendors, shops

Finally, here is when I'm trying to use it in my service:

function filterByCategory(categoryid, shops) {
    if (!categoryid) return shops
    console.log(shops);

    var newlist = []
    for (var s in shops) {
        if (shops[s].category.split(',').length > 0) {
            for (var c in shops[s].category.split(',')) {
                if (shops[s].category.split(',')[c] == categoryid) {
                    newlist.push(shops[s])
                }
            }
        }
    } 
    return newlist
}

Answer 1

Your controller is actually just the glue between your view and singleton services... They are (re)created and detroyed throughout your applications lifecycle - services are created once (singletons - and reused after creation when injected).

Therefor you should turn your approach around, instead of holding your variable you want to share accross your application (controller / service) inside your controller - on the $scopeobject - you should create it inside your singleton service ecommercer.

Through the getter / setter principle you can update / retrieve the variable shops inside your singleton service ecommercer.

See following rough example to illustrate on how you should change your approach.

CONTROLLER & SERVICE

angular
  .module('app', [])
  .controller('MainController', MainController)
  .service('ecommercer', ecommercer)

function ecommercer() {
  var shops;

  return {
    setShops: setShops,
    getShops: getShops
  }

  function setShops(shops) {
    this.shops = shops;
  }

  function getShops(shops) {
    return this.shops;
  }

}


function MainController(ecommercer) {
  var vm = this;
  this.setShops = setShops;

  function setShops() {
    ecommercer.setShops([{
      id: 1,
      name: 'test shop 1'
    }, {
      id: 2,
      name: 'test shop 2'
    }]);
    vm.shops = ecommercer.getShops();
  }

}

VIEW

<div ng-app="app" ng-controller="MainController as vm">
  <div ng-click="vm.setShops()">
    Set shops
  </div>
  <div>
    {{vm.shops}}
  </div>
</div>

https://jsfiddle.net/DaanDeSmedt/j5uqaxgy/