fix(options): react to changes of options of Function type (#590)

fixes #589

Author: zuzusik

dist/rzslider.css

@@ -1,7 +1,7 @@
 /*! angularjs-slider - v6.4.0 - 
  (c) Rafal Zajac <[email protected]>, Valentin Hervieu <[email protected]>, Jussi Saarivirta <[email protected]>, Angelin Sirbu <[email protected]> - 
  https://github.com/angular-slider/angularjs-slider - 
- 2017-10-25 */
+ 2017-11-14 */
 /*jslint unparam: true */
 /*global angular: false, console: false, define, module */
 ;(function(root, factory) {
@@ -404,16 +404,15 @@
 
           // Watchers (order is important because in case of simultaneous change,
           // watchers will be called in the same order)
-          this.scope.$watch(
+          this.scope.$watchCollection(
             'rzSliderOptions()',
             function(newValue, oldValue) {
               if (newValue === oldValue) return
               self.applyOptions() // need to be called before synchronizing the values
               self.syncLowValue()
               if (self.range) self.syncHighValue()
               self.resetSlider()
-            },
-            true
+            }
           )
 
           this.scope.$watch('rzSliderModel', function(newValue, oldValue) {

dist/rzslider.js

@@ -408,16 +408,15 @@
 
           // Watchers (order is important because in case of simultaneous change,
           // watchers will be called in the same order)
-          this.scope.$watch(
+          this.scope.$watchCollection(
             'rzSliderOptions()',
             function(newValue, oldValue) {
               if (newValue === oldValue) return
               self.applyOptions() // need to be called before synchronizing the values
               self.syncLowValue()
               if (self.range) self.syncHighValue()
               self.resetSlider()
-            },
-            true
+            }
           )
 
           this.scope.$watch('rzSliderModel', function(newValue, oldValue) {

dist/rzslider.min.css

@@ -1678,5 +1678,30 @@
         expect(helper.slider.maxValue).to.equal(1000)
       })
     })
+
+    describe('reacting to changes - ', function() {
+      beforeEach(function() {
+        var sliderConf = {
+          value: 10,
+          options: {
+            floor: 0,
+            ceil: 100,
+            step: 10,
+            translate: function(val) {
+              return val + '%'
+            }
+          }
+        }
+        helper.createSlider(sliderConf)
+      })
+
+      it('should react to changes of options which are functions', function() {
+        helper.scope.slider.options.translate = function(val) {
+          return val + '$'
+        }
+        helper.scope.$digest()
+        expect(helper.slider.customTrFn(100)).to.equal('100$')
+      })
+    })
   })
 })()