[new feature] Toast: add className prop (#2680)

packages/toast/Toast.js

@@ -10,6 +10,7 @@ export default sfc({
   mixins: [Popup],
 
   props: {
+    className: String,
     forbidClick: Boolean,
     message: [String, Number],
     type: {
@@ -89,7 +90,7 @@ export default sfc({
 
     return (
       <transition name="van-fade">
-        <div vShow={this.value} class={bem([style, this.position])}>
+        <div vShow={this.value} class={[bem([style, this.position]), this.className]}>
           {Content()}
         </div>
       </transition>

packages/toast/en-US.md

@@ -104,4 +104,5 @@ toast2.clear();
 | mask | Whether to show mask | `Boolean` | `false` |
 | forbidClick | Whether to forbid click background | `Boolean` | `false` |
 | loadingType | Loading icon type, can be set to `spinner` | `String` | `circular` |
-| duration | Toast duration(ms), won't disappear if value is 0 | `Number` | `3000` |
+| duration | Toast duration(ms), won't disappear if value is 0 | `Number` | `3000` |
+| className | Custom className | `String | Array | Object` | - |

packages/toast/index.js

@@ -8,6 +8,7 @@ const defaultOptions = {
   message: '',
   value: true,
   duration: 3000,
+  className: '',
   position: 'middle',
   loadingType: 'circular',
   forbidClick: false,