Optionally disable wrappedInstance ref

Stateless components cannot use refs, so this adds the withRef option
(enabled by default for compatibility) which enables or disables passing
the wrappedInstance ref to the wrapped component. Addresses issue #30.
Inspired by reduxjs/react-redux@2d3d0be

Author: Aesthetikx

README.md

@@ -54,6 +54,8 @@ or as an [ES7 class decorator](https://github.com/wycats/javascript-decorators)
     -   `options.className` **[string](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)=** Control the class name set on the wrapper `<div>`
     -   `options.elementResize` **[boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)=** Set true to watch the wrapper `div` for changes in
         size which are not a result of window resizing - e.g. changes to the flexbox and other layout. (optional, default `false`)
+    -   `options.withRef` **[boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)=** Set true to enable accessing the wrapped instance with
+        [getWrappedInstance()](https://github.com/digidem/react-dimensions#getwrappedinstance). Disable this when wrapping stateless components, as they cannot use `refs`. (optional, default `true`)
 
 **Examples**
 

index.jsx

@@ -77,7 +77,8 @@ module.exports = function Dimensions ({
     getDimensions = defaultGetDimensions,
     debounce = 0,
     debounceOpts = {},
-    elementResize = false
+    elementResize = false,
+    withRef = true
   } = {}) {
   return (ComposedComponent) => {
     return class DimensionsHOC extends React.Component {
@@ -152,6 +153,9 @@ module.exports = function Dimensions ({
        * @return {object} The rendered React component
        **/
       getWrappedInstance () {
+        if (!withRef) {
+          console.warn('You need to enable the `withRef` option to access the wrapped instance')
+        }
         return this.refs.wrappedInstance
       }
 
@@ -166,14 +170,15 @@ module.exports = function Dimensions ({
           height: 0,
           width: 0
         }
+        const ref = withRef ? 'wrappedInstance' : null
         return (
           <div style={wrapperStyle} ref='wrapper'>
             {(containerWidth || containerHeight) &&
               <ComposedComponent
                 {...this.state}
                 {...this.props}
                 updateDimensions={this.updateDimensions}
-                ref='wrappedInstance'
+                ref={ref}
               />
             }
           </div>