refact: rewrite dynamic util, Close #1256

packages/dva-example-user-dashboard/package.json

@@ -32,6 +32,6 @@
     "expect": "^1.20.2",
     "husky": "^0.13.0",
     "redbox-react": "^1.3.2",
-    "roadhog": "^1.2.0"
+    "roadhog": "^1.2.2"
   }
 }

packages/dva/src/dynamic.js

@@ -1,4 +1,4 @@
-import { asyncComponent } from 'react-async-component';
+import React, { Component } from 'react';
 
 const cached = {};
 function registerModel(app, model) {
@@ -8,6 +8,42 @@ function registerModel(app, model) {
   }
 }
 
+function asyncComponent(config) {
+  const { resolve } = config;
+
+  return class DynamicComponent extends Component {
+    constructor(...args) {
+      super(...args);
+      this.LoadingComponent =
+        config.LoadingComponent || (() => <p>loading...</p>);
+      this.load();
+    }
+
+    componentDidMount() {
+      this.mounted = true;
+    }
+
+    load() {
+      resolve().then(m => {
+        const AsyncComponent = m.default || m;
+        if (this.mounted) {
+          this.setState({ AsyncComponent });
+        } else {
+          this.state.AsyncComponent = AsyncComponent; // eslint-disable-line
+        }
+      });
+    }
+
+    render() {
+      const { AsyncComponent } = this.state;
+      const { LoadingComponent } = this;
+      if (AsyncComponent) return <AsyncComponent {...this.props} />;
+
+      return <LoadingComponent {...this.props} />;
+    }
+  };
+}
+
 export default function dynamic(config) {
   const { app, models: resolveModels, component: resolveComponent } = config;
   return asyncComponent({