argument of Controller.bind() must be a HTMLElement

Author: peter-gribanov

README.md

@@ -82,7 +82,7 @@ Find the controls in element and children elements and binding it.
 
 #### Arguments
 
-1. `element` (**?HTMLElement**) HTMLElement for binding. The `BODY` element as a default.
+1. `element` (**HTMLElement**) HTMLElement for binding.
 
 #### Returns
 
@@ -97,7 +97,7 @@ controller:
 Controller.registerControl('form-date', element => $(element).datepicker({dateFormat: 'yy-mm-dd'}));
 
 document.addEventListener('DOMContentLoaded', function() {
-  Controller.bind(); // bind datepicker control
+  Controller.bind(document.getElementsByTagName('body')[0]); // find input and bind datepicker control to it
 });
 ```
 
@@ -196,7 +196,7 @@ Controller.registerControls({
     'form-date': element => $(element).datepicker({dateFormat: 'yy-mm-dd'}),
     'append': element => new AppendControl(element),
 });
-Controller.bind();
+Controller.bind(document.getElementsByTagName('body')[0]);
 ```
 
 Use in HTML:

src/controller.js

@@ -68,6 +68,10 @@
      * @returns {boolean}
      */
     static singleBind(element) {
+      if (!(element instanceof HTMLElement)) {
+        throw new Error(`The element to be binding must be instance of HTMLElement, now it is "${typeof element}".`);
+      }
+
       if (!element.getAttribute('data-control')) {
         return false;
       }
@@ -89,11 +93,13 @@
 
     /**
      * Find the controls in element and children elements and binding it.
-     * @param {?HTMLElement} [element=null]
+     * @param {HTMLElement} element
      * @returns {boolean}
      */
     static bind(element) {
-      element = element || document.getElementsByTagName('body')[0];
+      if (!(element instanceof HTMLElement)) {
+        throw new Error(`The element to be binding must be instance of HTMLElement, now it is "${typeof element}".`);
+      }
 
       let binded = Controller.singleBind(element);