Merge pull request #161 from 1921622004/master

修复render返回数组的问题

packages/omi/examples/render-array/main.js

@@ -2,16 +2,27 @@ import { tag, render, WeElement } from '../../src/omi'
 
 @tag('hello-element')
 class HelloElement extends WeElement {
-  render() {
-    return [<div>Hello</div>, <div>Element</div>]
+  render(props) {
+    const { count } = props
+    return [<div>Hello</div>, <div>Element</div>,<div>{count}</div>]
   }
 }
 
 @tag('my-app')
 class MyApp extends WeElement {
+  data = {
+    count: 1
+  }
   render() {
     return [<hello-element />, <hello-element />, <div>abc</div>]
   }
+
+  installed() {
+    setInterval(() => {
+      this.data.count++
+      this.update()
+    })
+  }
 }
 
 render(<my-app />, 'body')

packages/omi/src/we-element.js

@@ -28,7 +28,18 @@ export default class WeElement extends HTMLElement {
     }
 
     this.install()
-    const shadowRoot = this.attachShadow({ mode: 'open' })
+    var shadowRoot
+    if (!this.shadowRoot) {
+      shadowRoot = this.attachShadow({
+        mode: 'open'
+      })
+    } else {
+      shadowRoot = this.shadowRoot
+      var fc
+      while (fc = shadowRoot.firstChild) {
+        shadowRoot.removeChild(fc)
+      }
+    }
 
     this.css && shadowRoot.appendChild(cssToDom(this.css()))
     this.beforeRender()