[new feature] Uploader: support multiple files (#480)

packages/uploader/index.vue

@@ -7,7 +7,7 @@
       class="van-uploader__input"
       v-bind="$attrs"
       :disabled="disabled"
-      @change="onValueChange"
+      @change="onChange"
     />
   </div>
 </template>
@@ -29,30 +29,52 @@ export default create({
   },
 
   methods: {
-    onValueChange(event) {
-      if (this.disabled) {
+    onChange(event) {
+      let { files } = event.target;
+      if (this.disabled || !files.length) {
         return;
       }
 
-      const file = event.target.files[0];
-      if (!file || (this.beforeRead && !this.beforeRead(file))) {
+      files = files.length === 1 ? files[0] : [].slice.call(files, 0);
+      if (!files || (this.beforeRead && !this.beforeRead(files))) {
         return;
       }
 
-      const reader = new FileReader();
-      reader.onload = (e) => {
-        this.afterRead && this.afterRead({
-          file,
-          content: e.target.result
+      if (Array.isArray(files)) {
+        Promise.all(files.map(this.readFile)).then(contents => {
+          this.onAfterRead(
+            files.map((file, index) => ({
+              file: files[index],
+              content: contents[index]
+            }))
+          );
+        });
+      } else {
+        this.readFile(files).then(content => {
+          this.onAfterRead({ file: files, content });
         });
-        this.$refs.input && (this.$refs.input.value = '');
-      };
-
-      if (this.resultType === 'dataUrl') {
-        reader.readAsDataURL(file);
-      } else if (this.resultType === 'text') {
-        reader.readAsText(file);
       }
+    },
+
+    readFile(file) {
+      return new Promise(resolve => {
+        const reader = new FileReader();
+
+        reader.onload = event => {
+          resolve(event.target.result);
+        };
+
+        if (this.resultType === 'dataUrl') {
+          reader.readAsDataURL(file);
+        } else if (this.resultType === 'text') {
+          reader.readAsText(file);
+        }
+      });
+    },
+
+    onAfterRead(file) {
+      this.afterRead && this.afterRead(file);
+      this.$refs.input && (this.$refs.input.value = '');
     }
   }
 });