[Improvement] Field: support autosize maxHeight & minHeight (#718)

docs/demos/views/field.vue

@@ -53,7 +53,7 @@
           type="textarea"
           :placeholder="$t('messagePlaceholder')"
           rows="1"
-          autosize
+          :autosize="{ maxHeight: 100, minHeight: 40 }"
         />
       </van-cell-group>
     </demo-block>

docs/markdown/en-US/field.md

@@ -99,7 +99,7 @@ Filed support all native properties of input tag，such as `maxlength`、`placeh
 | disabled | Disable field | `Boolean` | `false` | - |
 | error | Whether to show error info | `Boolean` | `false` | - |
 | error-message | Error message | `String` | `''` | - |
-| autosize | Textarea auto resize | `Boolean` | `false` | - |
+| autosize | Textarea auto resize，can accpet an object, e.g. { maxHeight: 100, minHeight: 50 } | `Boolean | Object` | `false` | - |
 | icon | Right side Icon name | `String` | - | - |
 
 ### Event

docs/markdown/zh-CN/field.md

@@ -101,7 +101,7 @@ Filed 默认支持 Input 标签所有的原生属性，比如 `maxlength`、`pla
 | disabled | 是否禁用输入框 | `Boolean` | `false` | - |
 | error | 输入框是否有错误 | `Boolean` | `false` | - |
 | error-message | 输入框底部错误提示文案 | `String` | `''` | - |
-| autosize | 高度自适应(仅支持textarea) | `Boolean` | `false` | - |
+| autosize | 自适应内容高度，只对 textarea 有效，可传入对象，如 { maxHeight: 100, minHeight: 50 }，单位为 px | `Boolean | Object` | `false` | - |
 | icon | 输入框尾部图标 | `String` | - |  Icon 组件支持的类型 |
 
 ### Event

packages/field/index.vue

@@ -49,7 +49,7 @@
 </template>
 
 <script>
-import { create } from '../utils';
+import { create, isObj } from '../utils';
 
 export default create({
   name: 'field',
@@ -67,7 +67,7 @@ export default create({
     error: Boolean,
     border: Boolean,
     required: Boolean,
-    autosize: Boolean,
+    autosize: [Boolean, Object],
     errorMessage: String,
     onIconClick: {
       type: Function,
@@ -77,21 +77,12 @@ export default create({
 
   watch: {
     value() {
-      if (this.autosize && this.type === 'textarea') {
-        this.$nextTick(this.adjustSize);
-      }
+      this.$nextTick(this.adjustSize);
     }
   },
 
   mounted() {
-    if (this.autosize && this.type === 'textarea') {
-      const el = this.$refs.textarea;
-      const scrollHeight = el.scrollHeight;
-      if (scrollHeight !== 0) {
-        el.style.height = scrollHeight + 'px';
-      }
-      el.style.overflowY = 'hidden';
-    }
+    this.$nextTick(this.adjustSize);
   },
 
   computed: {
@@ -131,9 +122,25 @@ export default create({
     },
 
     adjustSize() {
+      if (!(this.type === 'textarea' && this.autosize)) {
+        return;
+      }
+
       const el = this.$refs.textarea;
       el.style.height = 'auto';
-      el.style.height = el.scrollHeight + 'px';
+
+      let height = el.scrollHeight;
+      if (isObj(this.autosize)) {
+        const { maxHeight, minHeight } = this.autosize;
+        if (maxHeight) {
+          height = Math.min(height, maxHeight);
+        }
+        if (minHeight) {
+          height = Math.max(height, minHeight);
+        }
+      }
+
+      el.style.height = height + 'px';
     }
   }
 });

test/specs/field.spec.js

@@ -66,23 +66,26 @@ describe('Field', () => {
     });
   });
 
-  it('create a textarea field', () => {
+  it('create a textarea field', (done) => {
     wrapper = mount(Field, {
       propsData: {
         type: 'textarea',
-        autosize: false
+        autosize: true
       }
     });
 
-    expect(wrapper.hasClass('van-field')).to.be.true;
-    expect(wrapper.hasClass('van-field--has-textarea')).to.be.true;
+    setTimeout(() => {
+      expect(wrapper.hasClass('van-field')).to.be.true;
+      expect(wrapper.hasClass('van-field--has-textarea')).to.be.true;
+      done();
+    }, 50);
   });
 
   it('create a autosize textarea field', (done) => {
     wrapper = mount(Field, {
       propsData: {
         type: 'textarea',
-        autosize: true
+        autosize: {}
       }
     });
 
@@ -98,15 +101,49 @@ describe('Field', () => {
     const textAreaDiff = (parseInt(textareaElement.style.paddingBottom, 10) +
           parseInt(textareaElement.style.paddingTop, 10)) || 0;
 
-    textareaElement.value = 'test';
+    const longText = 'testtesttesttesttesttesttest';
+    textareaElement.value = longText;
     textarea.trigger('input');
 
     wrapper.update();
     setTimeout(() => {
-      expect(wrapper.find('.van-field__control')[0].element.value).to.equal('test');
+      expect(wrapper.find('.van-field__control')[0].element.value).to.equal(longText);
       expect(textareaElement.style.height).to.equal((textareaElement.scrollHeight - textAreaDiff) + 'px');
       done();
-    }, 500);
+    }, 50);
+  });
+
+  it('autosize object', (done) => {
+    wrapper = mount(Field, {
+      propsData: {
+        type: 'textarea',
+        autosize: {
+          maxHeight: 100,
+          minHeight: 50
+        }
+      }
+    });
+
+    wrapper.vm.$on('input', val => {
+      wrapper.vm.value = val;
+    });
+
+    expect(wrapper.hasClass('van-field')).to.be.true;
+    expect(wrapper.hasClass('van-field--autosize')).to.be.true;
+
+    const textarea = wrapper.find('.van-field__control')[0];
+    const textareaElement = textarea.element;
+
+    const longText = 'testtesttesttesttesttesttest';
+    textareaElement.value = longText;
+    textarea.trigger('input');
+
+    wrapper.update();
+    setTimeout(() => {
+      expect(wrapper.find('.van-field__control')[0].element.value).to.equal(longText);
+      expect(textareaElement.style.height).to.equal(('50px'));
+      done();
+    }, 50);
   });
 
   it('show icon when has value and icon props', () => {