## Tabs

Divide data collections which are related yet belong to different types.

### Basic usage

Basic and concise tabs.

:::demo Tabs provide a selective card functionality. By default the first tab is selected as active, and you can activate any tab by setting the `value` attribute.

```html
<template>
  <el-tabs v-model="activeName" @tab-click="handleClick">
    <el-tab-pane label="User" name="first">User</el-tab-pane>
    <el-tab-pane label="Config" name="second">Config</el-tab-pane>
    <el-tab-pane label="Role" name="third">Role</el-tab-pane>
    <el-tab-pane label="Task" name="fourth">Task</el-tab-pane>
  </el-tabs>
</template>
<script>
  export default {
    data() {
      return {
        activeName: 'first',
      }
    },
    methods: {
      handleClick(tab, event) {
        console.log(tab, event)
      },
    },
  }
</script>
```

:::

### Card Style

Tabs styled as cards.

:::demo Set `type` to `card` can get a card-styled tab.

```html
<template>
  <el-tabs type="card" @tab-click="handleClick">
    <el-tab-pane label="User">User</el-tab-pane>
    <el-tab-pane label="Config">Config</el-tab-pane>
    <el-tab-pane label="Role">Role</el-tab-pane>
    <el-tab-pane label="Task">Task</el-tab-pane>
  </el-tabs>
</template>
<script>
  export default {
    data() {
      return {
        activeName: 'first',
      }
    },
    methods: {
      handleClick(tab, event) {
        console.log(tab, event)
      },
    },
  }
</script>
```

:::

### Border card

Border card tabs.

:::demo Set `type` to `border-card`.

```html
<el-tabs type="border-card">
  <el-tab-pane label="User">User</el-tab-pane>
  <el-tab-pane label="Config">Config</el-tab-pane>
  <el-tab-pane label="Role">Role</el-tab-pane>
  <el-tab-pane label="Task">Task</el-tab-pane>
</el-tabs>
```

:::

### Tab position

You can use `tab-position` attribute to set the tab's position.

:::demo You can choose from four directions: `tabPosition="left|right|top|bottom"`

```html
<template>
  <el-radio-group v-model="tabPosition" style="margin-bottom: 30px;">
    <el-radio-button label="top">top</el-radio-button>
    <el-radio-button label="right">right</el-radio-button>
    <el-radio-button label="bottom">bottom</el-radio-button>
    <el-radio-button label="left">left</el-radio-button>
  </el-radio-group>

  <el-tabs :tab-position="tabPosition" style="height: 200px;">
    <el-tab-pane label="User">User</el-tab-pane>
    <el-tab-pane label="Config">Config</el-tab-pane>
    <el-tab-pane label="Role">Role</el-tab-pane>
    <el-tab-pane label="Task">Task</el-tab-pane>
  </el-tabs>
</template>
<script>
  export default {
    data() {
      return {
        tabPosition: 'left',
      }
    },
  }
</script>
```

:::

### Custom Tab

You can use named slot to customize the tab label content.

:::demo

```html
<el-tabs type="border-card">
  <el-tab-pane>
    <template #label>
      <span><i class="el-icon-date"></i> Route</span>
    </template>
    Route
  </el-tab-pane>
  <el-tab-pane label="Config">Config</el-tab-pane>
  <el-tab-pane label="Role">Role</el-tab-pane>
  <el-tab-pane label="Task">Task</el-tab-pane>
</el-tabs>
```

:::

### Add & close tab

Only card type Tabs support addable & closeable.

:::demo

```html
<el-tabs
  v-model="editableTabsValue"
  type="card"
  editable
  @edit="handleTabsEdit"
>
  <el-tab-pane
    v-for="(item, index) in editableTabs"
    :key="item.name"
    :label="item.title"
    :name="item.name"
  >
    {{item.content}}
  </el-tab-pane>
</el-tabs>
<script>
  export default {
    data() {
      return {
        editableTabsValue: '2',
        editableTabs: [
          {
            title: 'Tab 1',
            name: '1',
            content: 'Tab 1 content',
          },
          {
            title: 'Tab 2',
            name: '2',
            content: 'Tab 2 content',
          },
        ],
        tabIndex: 2,
      }
    },
    methods: {
      handleTabsEdit(targetName, action) {
        if (action === 'add') {
          let newTabName = ++this.tabIndex + ''
          this.editableTabs.push({
            title: 'New Tab',
            name: newTabName,
            content: 'New Tab content',
          })
          this.editableTabsValue = newTabName
        }
        if (action === 'remove') {
          let tabs = this.editableTabs
          let activeName = this.editableTabsValue
          if (activeName === targetName) {
            tabs.forEach((tab, index) => {
              if (tab.name === targetName) {
                let nextTab = tabs[index + 1] || tabs[index - 1]
                if (nextTab) {
                  activeName = nextTab.name
                }
              }
            })
          }

          this.editableTabsValue = activeName
          this.editableTabs = tabs.filter((tab) => tab.name !== targetName)
        }
      },
    },
  }
</script>
```

:::

### Customized trigger button of new tab

:::demo

```html
<div style="margin-bottom: 20px;">
  <el-button size="small" @click="addTab(editableTabsValue)">
    add tab
  </el-button>
</div>
<el-tabs
  v-model="editableTabsValue"
  type="card"
  closable
  @tab-remove="removeTab"
>
  <el-tab-pane
    v-for="(item, index) in editableTabs"
    :key="item.name"
    :label="item.title"
    :name="item.name"
  >
    {{item.content}}
  </el-tab-pane>
</el-tabs>
<script>
  export default {
    data() {
      return {
        editableTabsValue: '2',
        editableTabs: [
          {
            title: 'Tab 1',
            name: '1',
            content: 'Tab 1 content',
          },
          {
            title: 'Tab 2',
            name: '2',
            content: 'Tab 2 content',
          },
        ],
        tabIndex: 2,
      }
    },
    methods: {
      addTab(targetName) {
        let newTabName = ++this.tabIndex + ''
        this.editableTabs.push({
          title: 'New Tab',
          name: newTabName,
          content: 'New Tab content',
        })
        this.editableTabsValue = newTabName
      },
      removeTab(targetName) {
        let tabs = this.editableTabs
        let activeName = this.editableTabsValue
        if (activeName === targetName) {
          tabs.forEach((tab, index) => {
            if (tab.name === targetName) {
              let nextTab = tabs[index + 1] || tabs[index - 1]
              if (nextTab) {
                activeName = nextTab.name
              }
            }
          })
        }

        this.editableTabsValue = activeName
        this.editableTabs = tabs.filter((tab) => tab.name !== targetName)
      },
    },
  }
</script>
```

:::

### Tabs Attributes

| Attribute             | Description                                                                                                                             | Type                                | Accepted Values       | Default           |
| --------------------- | --------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------- | --------------------- | ----------------- |
| model-value / v-model | binding value, name of the selected tab                                                                                                 | string                              | —                     | name of first tab |
| type                  | type of Tab                                                                                                                             | string                              | card/border-card      | —                 |
| closable              | whether Tab is closable                                                                                                                 | boolean                             | —                     | false             |
| addable               | whether Tab is addable                                                                                                                  | boolean                             | —                     | false             |
| editable              | whether Tab is addable and closable                                                                                                     | boolean                             | —                     | false             |
| tab-position          | position of tabs                                                                                                                        | string                              | top/right/bottom/left | top               |
| stretch               | whether width of tab automatically fits its container                                                                                   | boolean                             | -                     | false             |
| before-leave          | hook function before switching tab. If `false` is returned or a `Promise` is returned and then is rejected, switching will be prevented | Function(activeName, oldActiveName) | —                     | —                 |

### Tabs Events

| Event Name | Description                                           | Parameters              |
| ---------- | ----------------------------------------------------- | ----------------------- |
| tab-click  | triggers when a tab is clicked                        | clicked tab             |
| tab-remove | triggers when tab-remove button is clicked            | name of the removed tab |
| tab-add    | triggers when tab-add button is clicked               | —                       |
| edit       | triggers when tab-add button or tab-remove is clicked | (targetName, action)    |

### Tab-pane Attributes

| Attribute | Description                                                                          | Type    | Accepted Values | Default                                                                        |
| --------- | ------------------------------------------------------------------------------------ | ------- | --------------- | ------------------------------------------------------------------------------ |
| label     | title of the tab                                                                     | string  | —               | —                                                                              |
| disabled  | whether Tab is disabled                                                              | boolean | —               | false                                                                          |
| name      | identifier corresponding to the name of Tabs, representing the alias of the tab-pane | string  | —               | ordinal number of the tab-pane in the sequence, e.g. the first tab-pane is '1' |
| closable  | whether Tab is closable                                                              | boolean | —               | false                                                                          |
| lazy      | whether Tab is lazily rendered                                                       | boolean | —               | false                                                                          |

### Tab-pane Slots

| Name  | Description        |
| ----- | ------------------ |
| -     | Tab-pane's content |
| label | Tab-pane's label   |