add nouislider widget

Author: Andrew Telnov (DevExpress)

src/nouislider.js

@@ -0,0 +1,51 @@
+import "./surveyjs_importer.js";
+
+var widget = {
+    name: "nouislider",
+    isFit : function(question) { return question.getType() === 'nouislider'; },
+    htmlTemplate: "<div></div>",
+    activatedByChanged: function(activatedBy) {
+        Survey.JsonObject.metaData.addClass("nouislider", [], null, "empty");
+        Survey.JsonObject.metaData.addProperties("nouislider", [{name: "rangeMin:number", default: 0}, {name: "rangeMax:number", default: 100},
+        {name: "defaultRangeMin:number", default: 30}, {name: "defaultRangeMax:number", default: 70}]);
+    },
+    afterRender: function(question, el) {
+        var startValue = question.value;
+        if(!startValue || startValue.length != 2) {
+            startValue = [question.defaultRangeMin, question.defaultRangeMax];
+        }
+        if(startValue[0] < question.rangeMin) startValue[0] = question.rangeMin;
+        if(startValue[0] > question.rangeMax) startValue[0] = question.rangeMax;
+        if(startValue[1] < startValue[0]) startValue[1] = startValue[0];
+        if(startValue[1] > question.rangeMax) startValue[1] = question.rangeMax;
+        question.value = startValue;
+
+        var slider = noUiSlider.create(el, {
+        	start: startValue,
+        	connect: true,
+            pips: {
+                mode: 'steps',
+                stepped: true,
+                density: 4
+            },
+        	range: {
+        		'min': question.rangeMin,
+        		'max': question.rangeMax
+        	}
+        });
+        slider.on('set', function(){
+        	question.value = slider.get();
+        }); 
+        var updateValueHandler = function() {
+            slider.set(question.value);
+        };
+        question.noUiSlider = slider;
+        question.valueChangedCallback = updateValueHandler;
+    },
+    willUnmount: function(question, el) {
+        question.noUiSlider.destroy(); 
+        question.noUiSlider = null;
+    } 
+}
+
+Survey.CustomWidgetCollection.Instance.addCustomWidget(widget, "customtype");