From ed28f808b26f515299dc1160914a2ff4fcd27cee Mon Sep 17 00:00:00 2001
From: neverland <chenjiahan@youzan.com>
Date: Sat, 28 Mar 2020 16:19:25 +0800
Subject: [PATCH] feat(NavBar): add placeholder prop (#5938)

---
 src/nav-bar/README.md                         |   5 +-
 src/nav-bar/README.zh-CN.md                   |   9 +-
 src/nav-bar/demo/index.vue                    |  13 ++-
 src/nav-bar/index.js                          | 103 ++++++++++++++++++
 src/nav-bar/index.tsx                         |  95 ----------------
 .../test/__snapshots__/demo.spec.js.snap      |   2 +-
 .../test/__snapshots__/index.spec.js.snap     |  10 ++
 src/nav-bar/test/index.spec.js                |  33 ++++++
 8 files changed, 166 insertions(+), 104 deletions(-)
 create mode 100644 src/nav-bar/index.js
 delete mode 100644 src/nav-bar/index.tsx

diff --git a/src/nav-bar/README.md b/src/nav-bar/README.md
index ec1b0a071..2dbbb06e6 100644
--- a/src/nav-bar/README.md
+++ b/src/nav-bar/README.md
@@ -39,7 +39,7 @@ export default {
 }
 ```
 
-### Advanced Usage
+### Use Slot
 
 ```html
 <van-nav-bar title="Title" left-text="Back" left-arrow>
@@ -59,8 +59,9 @@ export default {
 | left-text | Left Text | *string* | `''` |
 | right-text | Right Text | *string* | `''` |
 | left-arrow | Whether to show left arrow | *boolean* | `false` |
-| fixed | Whether to fixed top | *boolean* | `false` |
 | border | Whether to show bottom border | *boolean* | `true` |
+| fixed | Whether to fixed top | *boolean* | `false` |
+| placeholder `v2.6.0` | Whether to generage a placeholder element when fixed | *boolean* | `false` |
 | z-index | Z-index | *number \| string* | `1` |
 
 ### Slots
diff --git a/src/nav-bar/README.zh-CN.md b/src/nav-bar/README.zh-CN.md
index 1825ec6a2..2a129b318 100644
--- a/src/nav-bar/README.zh-CN.md
+++ b/src/nav-bar/README.zh-CN.md
@@ -39,14 +39,14 @@ export default {
 }
 ```
 
-### 高级用法
+### 使用插槽
 
-通过插槽定制内容
+通过插槽自定义导航栏两侧的内容
 
 ```html
 <van-nav-bar title="标题" left-text="返回" left-arrow>
   <template #right>
-    <van-icon name="search"/> 
+    <van-icon name="search" size="18" /> 
   </template>
 </van-nav-bar>
 ```
@@ -61,8 +61,9 @@ export default {
 | left-text | 左侧文案 | *string* | `''` |
 | right-text | 右侧文案 | *string* | `''` |
 | left-arrow | 是否显示左侧箭头 | *boolean* | `false` |
-| fixed | 是否固定在顶部 | *boolean* | `false` |
 | border | 是否显示下边框 | *boolean* | `true` |
+| fixed | 是否固定在顶部 | *boolean* | `false` |
+| placeholder `v2.6.0` | 固定在顶部时，是否在标签位置生成一个等高的占位元素 | *boolean* | `false` |
 | z-index | 元素 z-index | *number \| string* | `1` |
 
 ### Slots
diff --git a/src/nav-bar/demo/index.vue b/src/nav-bar/demo/index.vue
index 9b6b85c4f..cededbc20 100644
--- a/src/nav-bar/demo/index.vue
+++ b/src/nav-bar/demo/index.vue
@@ -11,10 +11,10 @@
       />
     </demo-block>
 
-    <demo-block :title="t('advancedUsage')">
+    <demo-block :title="t('useSlot')">
       <van-nav-bar :title="t('title')" :left-text="t('back')" left-arrow>
         <template #right>
-          <van-icon name="search" />
+          <van-icon name="search" size="18" />
         </template>
       </van-nav-bar>
     </demo-block>
@@ -23,6 +23,15 @@
 
 <script>
 export default {
+  i18n: {
+    'zh-CN': {
+      useSlot: '使用插槽',
+    },
+    'en-US': {
+      useSlot: 'Use Slot',
+    },
+  },
+
   methods: {
     onClickLeft() {
       this.$toast(this.t('back'));
diff --git a/src/nav-bar/index.js b/src/nav-bar/index.js
new file mode 100644
index 000000000..ab3ec7045
--- /dev/null
+++ b/src/nav-bar/index.js
@@ -0,0 +1,103 @@
+// Utils
+import { createNamespace } from '../utils';
+import { BORDER_BOTTOM } from '../utils/constant';
+
+// Components
+import Icon from '../icon';
+
+const [createComponent, bem] = createNamespace('nav-bar');
+
+export default createComponent({
+  props: {
+    title: String,
+    fixed: Boolean,
+    zIndex: [Number, String],
+    leftText: String,
+    rightText: String,
+    leftArrow: Boolean,
+    placeholder: Boolean,
+    border: {
+      type: Boolean,
+      default: true,
+    },
+  },
+
+  data() {
+    return {
+      height: null,
+    };
+  },
+
+  mounted() {
+    if (this.placeholder && this.fixed) {
+      this.height = this.$refs.navBar.getBoundingClientRect().height;
+    }
+  },
+
+  methods: {
+    genLeft() {
+      const leftSlot = this.slots('left');
+
+      if (leftSlot) {
+        return leftSlot;
+      }
+
+      return [
+        this.leftArrow && <Icon class={bem('arrow')} name="arrow-left" />,
+        this.leftText && <span class={bem('text')}>{this.leftText}</span>,
+      ];
+    },
+
+    genRight() {
+      const rightSlot = this.slots('right');
+
+      if (rightSlot) {
+        return rightSlot;
+      }
+
+      if (this.rightText) {
+        return <span class={bem('text')}>{this.rightText}</span>;
+      }
+    },
+
+    genNavBar() {
+      return (
+        <div
+          ref="navBar"
+          style={{ zIndex: this.zIndex }}
+          class={[bem({ fixed: this.fixed }), { [BORDER_BOTTOM]: this.border }]}
+        >
+          <div class={bem('left')} onClick={this.onClickLeft}>
+            {this.genLeft()}
+          </div>
+          <div class={[bem('title'), 'van-ellipsis']}>
+            {this.slots('title') || this.title}
+          </div>
+          <div class={bem('right')} onClick={this.onClickRight}>
+            {this.genRight()}
+          </div>
+        </div>
+      );
+    },
+
+    onClickLeft(event) {
+      this.$emit('click-left', event);
+    },
+
+    onClickRight(event) {
+      this.$emit('click-right', event);
+    },
+  },
+
+  render() {
+    if (this.placeholder && this.fixed) {
+      return (
+        <div class={bem('placeholder')} style={{ height: `${this.height}px` }}>
+          {this.genNavBar()}
+        </div>
+      );
+    }
+
+    return this.genNavBar();
+  },
+});
diff --git a/src/nav-bar/index.tsx b/src/nav-bar/index.tsx
deleted file mode 100644
index 086e229d0..000000000
--- a/src/nav-bar/index.tsx
+++ /dev/null
@@ -1,95 +0,0 @@
-// Utils
-import { createNamespace, noop } from '../utils';
-import { inherit } from '../utils/functional';
-import { BORDER_BOTTOM } from '../utils/constant';
-
-// Components
-import Icon from '../icon';
-
-// Types
-import { CreateElement, RenderContext } from 'vue/types';
-import { ScopedSlot, DefaultSlots } from '../utils/types';
-
-export type NavBarProps = {
-  title?: string;
-  fixed?: boolean;
-  zIndex: number;
-  border: boolean;
-  leftText?: string;
-  rightText?: string;
-  leftArrow?: boolean;
-};
-
-export type NavBarSlots = DefaultSlots & {
-  left?: ScopedSlot;
-  title?: ScopedSlot;
-  right?: ScopedSlot;
-};
-
-export type NavBarEvents = {
-  'click-left'?(event: Event): void;
-  'click-right'?(event: Event): void;
-};
-
-const [createComponent, bem] = createNamespace('nav-bar');
-
-function NavBar(
-  h: CreateElement,
-  props: NavBarProps,
-  slots: NavBarSlots,
-  ctx: RenderContext<NavBarProps>
-) {
-  function LeftPart() {
-    if (slots.left) {
-      return slots.left();
-    }
-
-    return [
-      props.leftArrow && <Icon class={bem('arrow')} name="arrow-left" />,
-      props.leftText && <span class={bem('text')}>{props.leftText}</span>,
-    ];
-  }
-
-  function RightPart() {
-    if (slots.right) {
-      return slots.right();
-    }
-
-    if (props.rightText) {
-      return <span class={bem('text')}>{props.rightText}</span>;
-    }
-  }
-
-  return (
-    <div
-      style={{ zIndex: props.zIndex }}
-      class={[bem({ fixed: props.fixed }), { [BORDER_BOTTOM]: props.border }]}
-      {...inherit(ctx)}
-    >
-      <div class={bem('left')} onClick={ctx.listeners['click-left'] || noop}>
-        {LeftPart()}
-      </div>
-      <div class={[bem('title'), 'van-ellipsis']}>
-        {slots.title ? slots.title() : props.title}
-      </div>
-      <div class={bem('right')} onClick={ctx.listeners['click-right'] || noop}>
-        {RightPart()}
-      </div>
-    </div>
-  );
-}
-
-NavBar.props = {
-  title: String,
-  fixed: Boolean,
-  zIndex: [Number, String],
-  leftText: String,
-  rightText: String,
-  leftArrow: Boolean,
-  border: {
-    type: Boolean,
-    default: true,
-  },
-};
-
-export default createComponent<NavBarProps, NavBarEvents>(NavBar);
diff --git a/src/nav-bar/test/__snapshots__/demo.spec.js.snap b/src/nav-bar/test/__snapshots__/demo.spec.js.snap
index 5e435b9cb..bcd8a6ba2 100644
--- a/src/nav-bar/test/__snapshots__/demo.spec.js.snap
+++ b/src/nav-bar/test/__snapshots__/demo.spec.js.snap
@@ -15,7 +15,7 @@ exports[`renders demo correctly 1`] = `
       <div class="van-nav-bar__left"><i class="van-icon van-icon-arrow-left van-nav-bar__arrow">
           <!----></i><span class="van-nav-bar__text">返回</span></div>
       <div class="van-nav-bar__title van-ellipsis">标题</div>
-      <div class="van-nav-bar__right"><i class="van-icon van-icon-search">
+      <div class="van-nav-bar__right"><i class="van-icon van-icon-search" style="font-size: 18px;">
           <!----></i></div>
     </div>
   </div>
diff --git a/src/nav-bar/test/__snapshots__/index.spec.js.snap b/src/nav-bar/test/__snapshots__/index.spec.js.snap
index 2f5067a45..fc8476fd7 100644
--- a/src/nav-bar/test/__snapshots__/index.spec.js.snap
+++ b/src/nav-bar/test/__snapshots__/index.spec.js.snap
@@ -1,5 +1,15 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`placeholder prop 1`] = `
+<div class="van-nav-bar__placeholder" style="height: 0px;">
+  <div class="van-nav-bar van-nav-bar--fixed van-hairline--bottom">
+    <div class="van-nav-bar__left"></div>
+    <div class="van-nav-bar__title van-ellipsis"></div>
+    <div class="van-nav-bar__right"></div>
+  </div>
+</div>
+`;
+
 exports[`render left & right slot 1`] = `
 <div class="van-nav-bar van-hairline--bottom">
   <div class="van-nav-bar__left">Custom Left</div>
diff --git a/src/nav-bar/test/index.spec.js b/src/nav-bar/test/index.spec.js
index 042d04ffe..99aab1a7c 100644
--- a/src/nav-bar/test/index.spec.js
+++ b/src/nav-bar/test/index.spec.js
@@ -21,3 +21,36 @@ test('render title slot', () => {
 
   expect(wrapper).toMatchSnapshot();
 });
+
+test('placeholder prop', () => {
+  const wrapper = mount(NavBar, {
+    propsData: {
+      fixed: true,
+      placeholder: true,
+    },
+  });
+
+  expect(wrapper).toMatchSnapshot();
+});
+
+test('click-left event', () => {
+  const wrapper = mount(NavBar, {
+    propsData: {
+      leftText: 'left',
+    },
+  });
+
+  wrapper.find('.van-nav-bar__left').trigger('click');
+  expect(wrapper.emitted('click-left')).toBeTruthy();
+});
+
+test('click-right event', () => {
+  const wrapper = mount(NavBar, {
+    propsData: {
+      rightText: 'right',
+    },
+  });
+
+  wrapper.find('.van-nav-bar__right').trigger('click');
+  expect(wrapper.emitted('click-right')).toBeTruthy();
+});