Select: add collapse-tags

examples/docs/en-US/select.md

@@ -101,6 +101,7 @@
         value8: '',
         value9: [],
         value10: [],
+        value11: [],
         loading: false,
         states: ["Alabama", "Alaska", "Arizona", "Arkansas", "California", "Colorado", "Connecticut", "Delaware", "Florida", "Georgia", "Hawaii", "Idaho", "Illinois", "Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana", "Maine", "Maryland", "Massachusetts", "Michigan", "Minnesota", "Mississippi", "Missouri", "Montana", "Nebraska", "Nevada", "New Hampshire", "New Jersey", "New Mexico", "New York", "North Carolina", "North Dakota", "Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island", "South Carolina", "South Dakota", "Tennessee", "Texas", "Utah", "Vermont", "Virginia", "Washington", "West Virginia", "Wisconsin", "Wyoming"]
       };
@@ -320,7 +321,7 @@ You can clear Select using a clear icon.
 
 Multiple select uses tags to display selected options.
 
-:::demo Set `multiple` attribute for `el-select` to enable multiple mode. In this case, the value of `v-model` will be an array of selected options.
+:::demo Set `multiple` attribute for `el-select` to enable multiple mode. In this case, the value of `v-model` will be an array of selected options. By default the selected options will be displayed as Tags. You can collapse them to a text by using `collapse-tags` attribute.
 ```html
 <template>
   <el-select v-model="value5" multiple placeholder="Select">
@@ -331,6 +332,20 @@ Multiple select uses tags to display selected options.
       :value="item.value">
     </el-option>
   </el-select>
+  
+  <el-select
+    v-model="value11"
+    multiple
+    collapse-tags
+    style="margin-left: 20px;"
+    placeholder="Select">
+    <el-option
+      v-for="item in options"
+      :key="item.value"
+      :label="item.label"
+      :value="item.value">
+    </el-option>
+  </el-select>
 </template>
 
 <script>
@@ -650,6 +665,7 @@ If the binding value of Select is an object, make sure to assign `value-key` as
 | value-key | unique identity key name for value, required when value is an object | string | — | value |
 | size | size of Input | string | large/small/mini | — |
 | clearable | whether single select can be cleared | boolean | — | false |
+| collapse-tags | whether to collapse tags to a text when multiple selecting | boolean | — | false |
 | multiple-limit | maximum number of options user can select when `multiple` is `true`. No limit when set to 0 | number | — | 0 |
 | name | the name attribute of select input | string | — | — |
 | placeholder | placeholder | string | — | Select |

examples/docs/zh-CN/select.md

@@ -101,6 +101,7 @@
         value8: '',
         value9: '',
         value10: [],
+        value11: [],
         loading: false,
         states: ["Alabama", "Alaska", "Arizona", "Arkansas", "California", "Colorado", "Connecticut", "Delaware", "Florida", "Georgia", "Hawaii", "Idaho", "Illinois", "Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana", "Maine", "Maryland", "Massachusetts", "Michigan", "Minnesota", "Mississippi", "Missouri", "Montana", "Nebraska", "Nevada", "New Hampshire", "New Jersey", "New Mexico", "New York", "North Carolina", "North Dakota", "Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island", "South Carolina", "South Dakota", "Tennessee", "Texas", "Utah", "Vermont", "Virginia", "Washington", "West Virginia", "Wisconsin", "Wyoming"]
       };
@@ -319,7 +320,7 @@
 
 适用性较广的基础多选，用 Tag 展示已选项
 
-:::demo 为`el-select`设置`multiple`属性即可启用多选，此时`v-model`的值为当前选中值所组成的数组
+:::demo 为`el-select`设置`multiple`属性即可启用多选，此时`v-model`的值为当前选中值所组成的数组。默认情况下选中值会以 Tag 的形式展现，你也可以设置`collapse-tags`属性将它们合并为一段文字。
 ```html
 <template>
   <el-select v-model="value5" multiple placeholder="请选择">
@@ -330,6 +331,20 @@
       :value="item.value">
     </el-option>
   </el-select>
+
+  <el-select
+    v-model="value11"
+    multiple
+    collapse-tags
+    style="margin-left: 20px;"
+    placeholder="请选择">
+    <el-option
+        v-for="item in options"
+        :key="item.value"
+        :label="item.label"
+        :value="item.value">
+    </el-option>
+  </el-select>
 </template>
 
 <script>
@@ -645,6 +660,7 @@
 | value-key | 作为 value 唯一标识的键名，绑定值为对象类型时必填 | string | — | value |
 | size | 输入框尺寸 | string | large/small/mini | — |
 | clearable | 单选时是否可以清空选项 | boolean | — | false |
+| collapse-tags | 多选时是否将选中值按文字的形式展示 | boolean | — | false |
 | multiple-limit | 多选时用户最多可以选择的项目数，为 0 则不限制 | number | — | 0 |
 | name | select input 的 name 属性 | string | — | — |
 | placeholder | 占位符 | string | — | 请选择 |

packages/select/src/select.vue

@@ -9,7 +9,12 @@
       @click.stop="toggleMenu"
       ref="tags"
       :style="{ 'max-width': inputWidth - 32 + 'px' }">
-      <transition-group @after-leave="resetInputHeight">
+      <span
+        class="el-select__multiple-text"
+        v-if="collapseTags">
+        {{ multipleText }}
+      </span>
+      <transition-group @after-leave="resetInputHeight" v-if="!collapseTags">
         <el-tag
           v-for="item in selected"
           :key="getValueKey(item)"
@@ -184,6 +189,14 @@
 
       selectSize() {
         return this.size || this._elFormItemSize || (this.$ELEMENT || {}).size;
+      },
+
+      multipleText() {
+        const selected = this.selected;
+        if (!selected || !selected.length) return '';
+        const length = selected.length;
+        const countText = length > 1 ? `(+${ selected.length - 1 })` : '';
+        return `${ selected[0].currentLabel } ${ countText }`;
       }
     },
 
@@ -232,7 +245,8 @@
       valueKey: {
         type: String,
         default: 'value'
-      }
+      },
+      collapseTags: Boolean
     },
 
     data() {
@@ -535,6 +549,7 @@
       },
 
       resetInputHeight() {
+        if (this.collapseTags) return;
         this.$nextTick(() => {
           if (!this.$refs.reference) return;
           let inputChildNodes = this.$refs.reference.$el.childNodes;

packages/theme-chalk/src/select.scss

 @import "mixins/mixins";
+@import "mixins/utils";
 @import "common/var";
 @import "select-dropdown";
 @import "input";
@@ -88,6 +89,14 @@
     }
   }
 
+  @include e(multiple-text) {
+    margin-left: 15px;
+    color: $--input-color;
+    font-size: $--font-size-base;
+    display: block;
+    @include utils-ellipsis;
+  }
+
   @include e(close) {
     cursor: pointer;
     position: absolute;