move url filter functionality to service ProductFiltersService

app/assets/javascripts/admin/services/product_filters.js.coffee

@@ -0,0 +1,23 @@
+angular.module("ofn.admin").factory "ProductFiltersService", ($httpParamSerializer) ->
+  new class ProductFiltersService
+    productFilters: ['producerFilter', 'categoryFilter', 'query', 'sorting', 'importDateFilter']
+
+    loadFromUrl: (filters) ->
+      loadedFilters = {}
+      for filter in @productFilters
+        loadedFilters[filter] = if filters[filter] then filters[filter] else ""
+
+      loadedFilters
+
+    generate: (ctrlFilters) ->
+      filters = {}
+      for filter in @productFilters
+        filters[filter] = ctrlFilters[filter] if ctrlFilters[filter]
+
+      filters
+
+    buildUrl: (baseUrl, ctrlFilters) ->
+      filterUrl = $httpParamSerializer(@generate(ctrlFilters))
+      filterUrl = "?#{filterUrl}" if filterUrl isnt ""
+
+      "#{baseUrl}#{filterUrl}"