move class rendering into vdom

src/compiler/codegen.js

@@ -41,9 +41,15 @@ function genData (el, key) {
   if (!el.attrs.length) {
     return '{}'
   }
-  let data = key ? `{key:${ key },` : `{`
-  if (el.attrsMap[':class'] || el.attrsMap['class']) {
-    data += `class: _renderClass(${ el.attrsMap[':class'] }, "${ el.attrsMap['class'] || '' }"),`
+  let data = '{'
+  if (key) {
+    data += `key:${ key },`
+  }
+  if (el.attrsMap[':class']) {
+    data += `class: ${ el.attrsMap[':class'] },`
+  }
+  if (el.attrsMap['class']) {
+    data += `staticClass: "${ el.attrsMap['class'] }"`
   }
   let attrs = `attrs:{`
   let props = `props:{`

src/instance/index.js

@@ -32,17 +32,6 @@ export default class Component {
     this._tree = vtree
   }
 
-  _renderClass (dynamic, cls) {
-    dynamic = dynamic
-      ? typeof dynamic === 'string'
-        ? dynamic
-        : Object.keys(dynamic).filter(key => dynamic[key]).join(' ')
-      : ''
-    return cls
-      ? cls + (dynamic ? ' ' + dynamic : '')
-      : dynamic
-  }
-
   _proxy (key) {
     if (!isReserved(key)) {
       // need to store ref to self here

src/vdom/modules/class.js

@@ -1,8 +1,37 @@
-import { setClass } from '../../util/index'
+import { isArray, setClass } from '../../util/index'
+
+function genClass (data) {
+  if (!data) {
+    return ''
+  }
+  if (typeof data === 'object') {
+    let res = ''
+    for (var key in data) {
+      if (data[key]) res += key + ' '
+    }
+    return res.slice(0, -1)
+  }
+  if (isArray(data)) {
+    let res = ''
+    for (let i = 0, l = data.length; i < l; i++) {
+      if (data[i]) res += genClass(data[i]) + ' '
+    }
+    return res.slice(0, -1)
+  }
+  if (typeof data === 'string') {
+    return data
+  }
+}
 
 function updateClass (oldVnode, vnode) {
-  if (vnode.data.class !== undefined) {
-    setClass(vnode.elm, vnode.data.class || '')
+  let dynamicClass = vnode.data.class
+  let staticClass = vnode.data.staticClass
+  if (staticClass || dynamicClass) {
+    dynamicClass = genClass(dynamicClass)
+    let cls = staticClass
+      ? staticClass + (dynamicClass ? ' ' + dynamicClass : '')
+      : dynamicClass
+    setClass(vnode.elm, cls)
   }
 }