kostark · September 15, 2018 14:12 · Sep 15, 2018
diff --git a/dynamic.js b/dynamic.js
@@ -0,0 +1,117 @@
+import React from 'react'
+import Loadable from './loadable'
+
+type ImportedComponent = Promise<null|ElementType>
+
+type ComponentMapping = {[componentName: string]: ImportedComponent}
+
+type NextDynamicOptions = {
+  loader?: ComponentMapping | () => ImportedComponent,
+  loading: ElementType,
+  timeout?: number,
+  delay?: number,
+  ssr?: boolean,
+  render?: (props: any, loaded: {[componentName: string]: ElementType}) => ElementType,
+  modules?: () => ComponentMapping,
+  loadableGenerated?: {
+    webpack?: any,
+    modules?: any
+  }
+}
+
+type LoadableOptions = {
+  loader?: ComponentMapping | () => ImportedComponent,
+  loading: ElementType,
+  timeout?: number,
+  delay?: number,
+  render?: (props: any, loaded: {[componentName: string]: ElementType}) => ElementType,
+  webpack?: any,
+  modules?: any
+}
+
+const isServerSide = typeof window === 'undefined'
+
+export function noSSR (LoadableInitializer: (loadableOptions: LoadableOptions) => ElementType, loadableOptions: LoadableOptions) {
+  // Removing webpack and modules means react-loadable won't try preloading
+  delete loadableOptions.webpack
+  delete loadableOptions.modules
+
+  // This check is neccesary to prevent react-loadable from initializing on the server
+  if (!isServerSide) {
+    return LoadableInitializer(loadableOptions)
+  }
+
+  // This will only be rendered on the server side
+  return () => <loadableOptions.loading error={null} isLoading pastDelay={false} timedOut={false} />
+}
+
+function DefaultLoading () {
+  return <p>loading...</p>
+}
+
+export default function dynamic (dynamicOptions: any, options: NextDynamicOptions) {
+  let loadableFn = Loadable
+  let loadableOptions: NextDynamicOptions = {
+    // A loading component is not required, so we default it
+    loading: ({error, isLoading}) => {
+      if (process.env.NODE_ENV === 'development') {
+        if (isLoading) {
+          return <DefaultLoading />
+        }
+        if (error) {
+          return <p>{error.message}<br />{error.stack}</p>
+        }
+      }
+
+      return <DefaultLoading />
+    }
+  }
+
+  // Support for direct import(), eg: dynamic(import('../hello-world'))
+  if (typeof dynamicOptions.then === 'function') {
+    loadableOptions.loader = () => dynamicOptions
+  // Support for having first argument being options, eg: dynamic({loader: import('../hello-world')})
+  } else if (typeof dynamicOptions === 'object') {
+    loadableOptions = {...loadableOptions, ...dynamicOptions}
+  }
+
+  // Support for passing options, eg: dynamic(import('../hello-world'), {loading: () => <p>Loading something</p>})
+  loadableOptions = {...loadableOptions, ...options}
+
+  // Support for `render` when using a mapping, eg: `dynamic({ modules: () => {return {HelloWorld: import('../hello-world')}, render(props, loaded) {} } })
+  if (dynamicOptions.render) {
+    loadableOptions.render = (loaded, props) => dynamicOptions.render(props, loaded)
+  }
+  // Support for `modules` when using a mapping, eg: `dynamic({ modules: () => {return {HelloWorld: import('../hello-world')}, render(props, loaded) {} } })
+  if (dynamicOptions.modules) {
+    loadableFn = Loadable.Map
+    const loadModules = {}
+    const modules = dynamicOptions.modules()
+    Object.keys(modules).forEach(key => {
+      const value = modules[key]
+      if (typeof value.then === 'function') {
+        loadModules[key] = () => value.then(mod => mod.default || mod)
+        return
+      }
+      loadModules[key] = value
+    })
+    loadableOptions.loader = loadModules
+  }
+
+  // coming from build/babel/plugins/react-loadable-plugin.js
+  if (loadableOptions.loadableGenerated) {
+    loadableOptions = {...loadableOptions, ...loadableOptions.loadableGenerated}
+    delete loadableOptions.loadableGenerated
+  }
+
+  // support for disabling server side rendering, eg: dynamic(import('../hello-world'), {ssr: false})
+  if (typeof loadableOptions.ssr === 'boolean') {
+    if (!loadableOptions.ssr) {
+      delete loadableOptions.ssr
+      return noSSR(loadableFn, loadableOptions)
+    }
+    delete loadableOptions.ssr
+  }
+
+  return loadableFn(loadableOptions)
+}