do not activate widgets if their scripts are not loaded

Author: Andrew Telnov (DevExpress)

src/icheck.js

@@ -2,7 +2,10 @@ function init(Survey) {
     var widget = {
         className: "iradio_square-blue",
         name: "icheck",
-        isFit : function(question) {  var t = question.getType(); return t === 'radiogroup' || t === 'checkbox' || t === 'matrix'; },
+        isFit : function(question) {  
+            if(typeof iCheck == undefined && typeof _iCheck == undefined) return false;
+            var t = question.getType(); return t === 'radiogroup' || t === 'checkbox' || t === 'matrix'; 
+        },
         isDefaultRender: true,
         afterRender: function(question, el) {
             var rootWidget = this;

src/inputmask.js

@@ -8,6 +8,7 @@ function init(Survey) {
         numericPrefix: '$',
         numericPlaceholder: '0',
         isFit : function(question) { 
+            if(typeof Inputmask == undefined) return false;
             if(question.getType() == "multipletext") return true;
             return question.getType() == "text" && (question.inputMask != "none" || question.inputFormat);
         },

src/select2.js

@@ -5,7 +5,7 @@ function init(Survey) {
         htmlTemplate: "<select style='width: 100%;'></select>",
         isFit : function(question) {
             if(widget.activatedBy == "property") return question["renderAs"] === 'select2' && question.getType() === 'dropdown'; 
-            if(widget.activatedBy == "type") return question.getType() === 'dropdown'; 
+            if(widget.activatedBy == "type") return  typeof Select2 !== undefined && question.getType() === 'dropdown'; 
             if(widget.activatedBy == "customtype") return question.getType() === 'select2';
             return false;
         },