Add an example with custom loading component.

examples/with-dynamic-import/components/hello.js

@@ -1,3 +0,0 @@
-export default () => (
-  <p>Hello World (imported dynamiclly) </p>
-)

examples/with-dynamic-import/components/hello1.js

@@ -0,0 +1,3 @@
+export default () => (
+  <p>Hello World 1 (imported dynamiclly) </p>
+)

examples/with-dynamic-import/components/hello2.js

@@ -0,0 +1,3 @@
+export default () => (
+  <p>Hello World 2 (imported dynamiclly) </p>
+)

examples/with-dynamic-import/pages/index.js

@@ -3,12 +3,19 @@ import Header from '../components/Header'
 import Counter from '../components/Counter'
 import dynamic from 'next/dynamic'
 
-const DynamicComponent = dynamic(import('../components/hello'))
+const DynamicComponent = dynamic(import('../components/hello1'))
+const DynamicComponentWithCustomLoading = dynamic(
+  import('../components/hello2'),
+  {
+    loading: () => (<p>...</p>)
+  }
+)
 
 export default () => (
   <div>
     <Header />
     <DynamicComponent />
+    <DynamicComponentWithCustomLoading />
     <p>HOME PAGE is here!</p>
     <Counter />
   </div>

lib/dynamic.js

@@ -2,10 +2,11 @@ import React from 'react'
 
 let currentChunks = []
 
-export default function dynamicComponent (promise, Loading = () => (<p>Loading...</p>)) {
+export default function dynamicComponent (promise, options = {}) {
   return class Comp extends React.Component {
     constructor (...args) {
       super(...args)
+      this.LoadingComponent = options.loading ? options.loading : () => (<p>loading...</p>)
       this.state = { AsyncComponent: null }
       this.isServer = typeof window === 'undefined'
       this.loadComponent()
@@ -30,7 +31,8 @@ export default function dynamicComponent (promise, Loading = () => (<p>Loading..
 
     render () {
       const { AsyncComponent } = this.state
-      if (!AsyncComponent) return (<Loading {...this.props} />)
+      const { LoadingComponent } = this
+      if (!AsyncComponent) return (<LoadingComponent {...this.props} />)
 
       return <AsyncComponent {...this.props} />
     }