<script>
  export default {
    data() {
      return {
        options2: [{
          label: 'California',
          cities: []
        }, {
          label: 'Florida',
          cities: []
        }],
        props: {
          value: 'label',
          children: 'cities'
        },
        options: [{
          value: 'guide',
          label: 'Guide',
          children: [{
            value: 'disciplines',
            label: 'Disciplines',
            children: [{
              value: 'consistency',
              label: 'Consistency'
            }, {
              value: 'feedback',
              label: 'Feedback'
            }, {
              value: 'efficiency',
              label: 'Efficiency'
            }, {
              value: 'controllability',
              label: 'Controllability'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'side nav',
              label: 'Side Navigation'
            }, {
              value: 'top nav',
              label: 'Top Navigation'
            }]
          }]
        }, {
          value: 'component',
          label: 'Component',
          children: [{
            value: 'basic',
            label: 'Basic',
            children: [{
              value: 'layout',
              label: 'Layout'
            }, {
              value: 'color',
              label: 'Color'
            }, {
              value: 'typography',
              label: 'Typography'
            }, {
              value: 'icon',
              label: 'Icon'
            }, {
              value: 'button',
              label: 'Button'
            }]
          }, {
            value: 'form',
            label: 'Form',
            children: [{
              value: 'radio',
              label: 'Radio'
            }, {
              value: 'checkbox',
              label: 'Checkbox'
            }, {
              value: 'input',
              label: 'Input'
            }, {
              value: 'input-number',
              label: 'InputNumber'
            }, {
              value: 'select',
              label: 'Select'
            }, {
              value: 'cascader',
              label: 'Cascader'
            }, {
              value: 'switch',
              label: 'Switch'
            }, {
              value: 'slider',
              label: 'Slider'
            }, {
              value: 'time-picker',
              label: 'TimePicker'
            }, {
              value: 'date-picker',
              label: 'DatePicker'
            }, {
              value: 'datetime-picker',
              label: 'DateTimePicker'
            }, {
              value: 'upload',
              label: 'Upload'
            }, {
              value: 'rate',
              label: 'Rate'
            }, {
              value: 'form',
              label: 'Form'
            }]
          }, {
            value: 'data',
            label: 'Data',
            children: [{
              value: 'table',
              label: 'Table'
            }, {
              value: 'tag',
              label: 'Tag'
            }, {
              value: 'progress',
              label: 'Progress'
            }, {
              value: 'tree',
              label: 'Tree'
            }, {
              value: 'pagination',
              label: 'Pagination'
            }, {
              value: 'badge',
              label: 'Badge'
            }]
          }, {
            value: 'notice',
            label: 'Notice',
            children: [{
              value: 'alert',
              label: 'Alert'
            }, {
              value: 'loading',
              label: 'Loading'
            }, {
              value: 'message',
              label: 'Message'
            }, {
              value: 'message-box',
              label: 'MessageBox'
            }, {
              value: 'notification',
              label: 'Notification'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'menu',
              label: 'NavMenu'
            }, {
              value: 'tabs',
              label: 'Tabs'
            }, {
              value: 'breadcrumb',
              label: 'Breadcrumb'
            }, {
              value: 'dropdown',
              label: 'Dropdown'
            }, {
              value: 'steps',
              label: 'Steps'
            }]
          }, {
            value: 'others',
            label: 'Others',
            children: [{
              value: 'dialog',
              label: 'Dialog'
            }, {
              value: 'tooltip',
              label: 'Tooltip'
            }, {
              value: 'popover',
              label: 'Popover'
            }, {
              value: 'card',
              label: 'Card'
            }, {
              value: 'carousel',
              label: 'Carousel'
            }, {
              value: 'collapse',
              label: 'Collapse'
            }]
          }]
        }, {
          value: 'resource',
          label: 'Resource',
          children: [{
            value: 'axure',
            label: 'Axure Components'
          }, {
            value: 'sketch',
            label: 'Sketch Templates'
          }, {
            value: 'docs',
            label: 'Design Documentation'
          }]
        }],
        optionsWithDisabled: [],
        selectedOptions: [],
        selectedOptions2: [],
        selectedOptions3: ['component', 'data', 'tag']
      };
    },
    created() {
      this.optionsWithDisabled = JSON.parse(JSON.stringify(this.options));
      this.optionsWithDisabled[0].disabled = true;
    },
    mounted() {
      this.$nextTick(() => {
        const demos = document.querySelectorAll('.source');
        demos[0].style.padding = '0';
        demos[demos.length - 1].style.padding = '0';
      });
    },
    methods: {
      handleItemChange(val) {
        console.log('active item:', val);
        setTimeout(_ => {
          if (val.indexOf('California') > -1 && !this.options2[0].cities.length) {
            this.options2[0].cities = [{
              label: 'Los Angeles'
            }];
          } else if (val.indexOf('Florida') > -1 && !this.options2[1].cities.length) {
            this.options2[1].cities = [{
              label: 'Orlando'
            }];
          }
        }, 300);
      },
      handleChange(value) {
        console.log(value);
      }
    }
  };
</script>

<style>
  .demo-cascader {
    .el-cascader {
      width: 222px;
    }
  }
  .demo-cascader-size {
    .el-cascader {
      vertical-align: top;
      margin-right: 15px;
    }
  }
  .demo-cascader .block {
    padding: 30px 0;
    text-align: center;
    border-right: solid 1px #EFF2F6;
    display: inline-block;
    width: 50%;
    box-sizing: border-box;
    &:last-child {
      border-right: none;
    }
  }
  .demo-cascader .demonstration {
    display: block;
    color: #8492a6;
    font-size: 14px;
    margin-bottom: 20px;
  }
</style>

## Cascader

Si las opciones tienen una estructura jerárquica clara, Cascader puede utilizarse para visualizarlas y seleccionarlas.

### Uso básico

Existen dos maneras de expandir los elementos hijo de la opción.

:::demo Al asignar al atributo `options` un array de opciones, se genera un Cascader. El atributo `expand-trigger` define cómo se expanden las opciones hijo. Este ejemplo también muestra el evento `change` , cuyo parámetro es el valor de Cascader, un array formado por los valores de cada nivel seleccionado.

```html
<div class="block">
  <span class="demonstration">Child options expand when clicked (default)</span>
  <el-cascader
    :options="options"
    v-model="selectedOptions"
    @change="handleChange">
  </el-cascader>
</div>
<div class="block">
  <span class="demonstration">Child options expand when hovered</span>
  <el-cascader
    expand-trigger="hover"
    :options="options"
    v-model="selectedOptions2"
    @change="handleChange">
  </el-cascader>
</div>

<script>
  export default {
    data() {
      return {
        options: [{
          value: 'guide',
          label: 'Guide',
          children: [{
            value: 'disciplines',
            label: 'Disciplines',
            children: [{
              value: 'consistency',
              label: 'Consistency'
            }, {
              value: 'feedback',
              label: 'Feedback'
            }, {
              value: 'efficiency',
              label: 'Efficiency'
            }, {
              value: 'controllability',
              label: 'Controllability'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'side nav',
              label: 'Side Navigation'
            }, {
              value: 'top nav',
              label: 'Top Navigation'
            }]
          }]
        }, {
          value: 'component',
          label: 'Component',
          children: [{
            value: 'basic',
            label: 'Basic',
            children: [{
              value: 'layout',
              label: 'Layout'
            }, {
              value: 'color',
              label: 'Color'
            }, {
              value: 'typography',
              label: 'Typography'
            }, {
              value: 'icon',
              label: 'Icon'
            }, {
              value: 'button',
              label: 'Button'
            }]
          }, {
            value: 'form',
            label: 'Form',
            children: [{
              value: 'radio',
              label: 'Radio'
            }, {
              value: 'checkbox',
              label: 'Checkbox'
            }, {
              value: 'input',
              label: 'Input'
            }, {
              value: 'input-number',
              label: 'InputNumber'
            }, {
              value: 'select',
              label: 'Select'
            }, {
              value: 'cascader',
              label: 'Cascader'
            }, {
              value: 'switch',
              label: 'Switch'
            }, {
              value: 'slider',
              label: 'Slider'
            }, {
              value: 'time-picker',
              label: 'TimePicker'
            }, {
              value: 'date-picker',
              label: 'DatePicker'
            }, {
              value: 'datetime-picker',
              label: 'DateTimePicker'
            }, {
              value: 'upload',
              label: 'Upload'
            }, {
              value: 'rate',
              label: 'Rate'
            }, {
              value: 'form',
              label: 'Form'
            }]
          }, {
            value: 'data',
            label: 'Data',
            children: [{
              value: 'table',
              label: 'Table'
            }, {
              value: 'tag',
              label: 'Tag'
            }, {
              value: 'progress',
              label: 'Progress'
            }, {
              value: 'tree',
              label: 'Tree'
            }, {
              value: 'pagination',
              label: 'Pagination'
            }, {
              value: 'badge',
              label: 'Badge'
            }]
          }, {
            value: 'notice',
            label: 'Notice',
            children: [{
              value: 'alert',
              label: 'Alert'
            }, {
              value: 'loading',
              label: 'Loading'
            }, {
              value: 'message',
              label: 'Message'
            }, {
              value: 'message-box',
              label: 'MessageBox'
            }, {
              value: 'notification',
              label: 'Notification'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'menu',
              label: 'NavMenu'
            }, {
              value: 'tabs',
              label: 'Tabs'
            }, {
              value: 'breadcrumb',
              label: 'Breadcrumb'
            }, {
              value: 'dropdown',
              label: 'Dropdown'
            }, {
              value: 'steps',
              label: 'Steps'
            }]
          }, {
            value: 'others',
            label: 'Others',
            children: [{
              value: 'dialog',
              label: 'Dialog'
            }, {
              value: 'tooltip',
              label: 'Tooltip'
            }, {
              value: 'popover',
              label: 'Popover'
            }, {
              value: 'card',
              label: 'Card'
            }, {
              value: 'carousel',
              label: 'Carousel'
            }, {
              value: 'collapse',
              label: 'Collapse'
            }]
          }]
        }, {
          value: 'resource',
          label: 'Resource',
          children: [{
            value: 'axure',
            label: 'Axure Components'
          }, {
            value: 'sketch',
            label: 'Sketch Templates'
          }, {
            value: 'docs',
            label: 'Design Documentation'
          }]
        }],
        selectedOptions: [],
        selectedOptions2: []
      };
    },
    methods: {
      handleChange(value) {
        console.log(value);
      }
    }
  };
</script>
```
:::

### Opcion Disabled

Para desactivar una opción configure un campo `disabled` en el objeto de opción.

:::demo En este ejemplo, el primer elemento del array `options` tiene un campo  `disabled: true` , por lo que está desactivado. Por defecto, Cascader verifica el campo `disabled` en cada objeto de opción; si está utilizando otro nombre de campo para indicar si una opción está deshabilitada, puede asignarla en el atributo `props` (consulte la tabla API a continuación para obtener más detalles). Y por supuesto, el valor de `value`, `label` y `children` también se pueden personalizar de la misma manera.

```html
<el-cascader
  :options="optionsWithDisabled"
></el-cascader>
<script>
  export default {
    data() {
      return {
        optionsWithDisabled: [{
          value: 'guide',
          label: 'Guide',
          disabled: true,
          children: [{
            value: 'disciplines',
            label: 'Disciplines',
            children: [{
              value: 'consistency',
              label: 'Consistency'
            }, {
              value: 'feedback',
              label: 'Feedback'
            }, {
              value: 'efficiency',
              label: 'Efficiency'
            }, {
              value: 'controllability',
              label: 'Controllability'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'side nav',
              label: 'Side Navigation'
            }, {
              value: 'top nav',
              label: 'Top Navigation'
            }]
          }]
        }, {
          value: 'component',
          label: 'Component',
          children: [{
            value: 'basic',
            label: 'Basic',
            children: [{
              value: 'layout',
              label: 'Layout'
            }, {
              value: 'color',
              label: 'Color'
            }, {
              value: 'typography',
              label: 'Typography'
            }, {
              value: 'icon',
              label: 'Icon'
            }, {
              value: 'button',
              label: 'Button'
            }]
          }, {
            value: 'form',
            label: 'Form',
            children: [{
              value: 'radio',
              label: 'Radio'
            }, {
              value: 'checkbox',
              label: 'Checkbox'
            }, {
              value: 'input',
              label: 'Input'
            }, {
              value: 'input-number',
              label: 'InputNumber'
            }, {
              value: 'select',
              label: 'Select'
            }, {
              value: 'cascader',
              label: 'Cascader'
            }, {
              value: 'switch',
              label: 'Switch'
            }, {
              value: 'slider',
              label: 'Slider'
            }, {
              value: 'time-picker',
              label: 'TimePicker'
            }, {
              value: 'date-picker',
              label: 'DatePicker'
            }, {
              value: 'datetime-picker',
              label: 'DateTimePicker'
            }, {
              value: 'upload',
              label: 'Upload'
            }, {
              value: 'rate',
              label: 'Rate'
            }, {
              value: 'form',
              label: 'Form'
            }]
          }, {
            value: 'data',
            label: 'Data',
            children: [{
              value: 'table',
              label: 'Table'
            }, {
              value: 'tag',
              label: 'Tag'
            }, {
              value: 'progress',
              label: 'Progress'
            }, {
              value: 'tree',
              label: 'Tree'
            }, {
              value: 'pagination',
              label: 'Pagination'
            }, {
              value: 'badge',
              label: 'Badge'
            }]
          }, {
            value: 'notice',
            label: 'Notice',
            children: [{
              value: 'alert',
              label: 'Alert'
            }, {
              value: 'loading',
              label: 'Loading'
            }, {
              value: 'message',
              label: 'Message'
            }, {
              value: 'message-box',
              label: 'MessageBox'
            }, {
              value: 'notification',
              label: 'Notification'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'menu',
              label: 'NavMenu'
            }, {
              value: 'tabs',
              label: 'Tabs'
            }, {
              value: 'breadcrumb',
              label: 'Breadcrumb'
            }, {
              value: 'dropdown',
              label: 'Dropdown'
            }, {
              value: 'steps',
              label: 'Steps'
            }]
          }, {
            value: 'others',
            label: 'Others',
            children: [{
              value: 'dialog',
              label: 'Dialog'
            }, {
              value: 'tooltip',
              label: 'Tooltip'
            }, {
              value: 'popover',
              label: 'Popover'
            }, {
              value: 'card',
              label: 'Card'
            }, {
              value: 'carousel',
              label: 'Carousel'
            }, {
              value: 'collapse',
              label: 'Collapse'
            }]
          }]
        }, {
          value: 'resource',
          label: 'Resource',
          children: [{
            value: 'axure',
            label: 'Axure Components'
          }, {
            value: 'sketch',
            label: 'Sketch Templates'
          }, {
            value: 'docs',
            label: 'Design Documentation'
          }]
        }]
      };
    }
  };
</script>
```
:::

### Mostrar sólo el último nivel

Puede mostrar sólo el último nivel en lugar de todos los niveles.

:::demo El atributo `show-all-levels` define si se visualizan todos los niveles. Si es `false`, sólo se muestra el último nivel.

```html
<el-cascader
    :options="options"
    :show-all-levels="false"
></el-cascader>
<script>
  export default {
    data() {
      return {
        options: [{
          value: 'guide',
          label: 'Guide',
          children: [{
            value: 'disciplines',
            label: 'Disciplines',
            children: [{
              value: 'consistency',
              label: 'Consistency'
            }, {
              value: 'feedback',
              label: 'Feedback'
            }, {
              value: 'efficiency',
              label: 'Efficiency'
            }, {
              value: 'controllability',
              label: 'Controllability'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'side nav',
              label: 'Side Navigation'
            }, {
              value: 'top nav',
              label: 'Top Navigation'
            }]
          }]
        }, {
          value: 'component',
          label: 'Component',
          children: [{
            value: 'basic',
            label: 'Basic',
            children: [{
              value: 'layout',
              label: 'Layout'
            }, {
              value: 'color',
              label: 'Color'
            }, {
              value: 'typography',
              label: 'Typography'
            }, {
              value: 'icon',
              label: 'Icon'
            }, {
              value: 'button',
              label: 'Button'
            }]
          }, {
            value: 'form',
            label: 'Form',
            children: [{
              value: 'radio',
              label: 'Radio'
            }, {
              value: 'checkbox',
              label: 'Checkbox'
            }, {
              value: 'input',
              label: 'Input'
            }, {
              value: 'input-number',
              label: 'InputNumber'
            }, {
              value: 'select',
              label: 'Select'
            }, {
              value: 'cascader',
              label: 'Cascader'
            }, {
              value: 'switch',
              label: 'Switch'
            }, {
              value: 'slider',
              label: 'Slider'
            }, {
              value: 'time-picker',
              label: 'TimePicker'
            }, {
              value: 'date-picker',
              label: 'DatePicker'
            }, {
              value: 'datetime-picker',
              label: 'DateTimePicker'
            }, {
              value: 'upload',
              label: 'Upload'
            }, {
              value: 'rate',
              label: 'Rate'
            }, {
              value: 'form',
              label: 'Form'
            }]
          }, {
            value: 'data',
            label: 'Data',
            children: [{
              value: 'table',
              label: 'Table'
            }, {
              value: 'tag',
              label: 'Tag'
            }, {
              value: 'progress',
              label: 'Progress'
            }, {
              value: 'tree',
              label: 'Tree'
            }, {
              value: 'pagination',
              label: 'Pagination'
            }, {
              value: 'badge',
              label: 'Badge'
            }]
          }, {
            value: 'notice',
            label: 'Notice',
            children: [{
              value: 'alert',
              label: 'Alert'
            }, {
              value: 'loading',
              label: 'Loading'
            }, {
              value: 'message',
              label: 'Message'
            }, {
              value: 'message-box',
              label: 'MessageBox'
            }, {
              value: 'notification',
              label: 'Notification'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'menu',
              label: 'NavMenu'
            }, {
              value: 'tabs',
              label: 'Tabs'
            }, {
              value: 'breadcrumb',
              label: 'Breadcrumb'
            }, {
              value: 'dropdown',
              label: 'Dropdown'
            }, {
              value: 'steps',
              label: 'Steps'
            }]
          }, {
            value: 'others',
            label: 'Others',
            children: [{
              value: 'dialog',
              label: 'Dialog'
            }, {
              value: 'tooltip',
              label: 'Tooltip'
            }, {
              value: 'popover',
              label: 'Popover'
            }, {
              value: 'card',
              label: 'Card'
            }, {
              value: 'carousel',
              label: 'Carousel'
            }, {
              value: 'collapse',
              label: 'Collapse'
            }]
          }]
        }, {
          value: 'resource',
          label: 'Resource',
          children: [{
            value: 'axure',
            label: 'Axure Components'
          }, {
            value: 'sketch',
            label: 'Sketch Templates'
          }, {
            value: 'docs',
            label: 'Design Documentation'
          }]
        }]
      };
    }
  };
</script>
```
:::

### Con valor por defecto

:::demo El valor por defecto se puede definir con un array.
```html
<el-cascader
  :options="options"
  v-model="selectedOptions3"
></el-cascader>
<script>
  export default {
    data() {
      return {
        options: [{
          value: 'guide',
          label: 'Guide',
          children: [{
            value: 'disciplines',
            label: 'Disciplines',
            children: [{
              value: 'consistency',
              label: 'Consistency'
            }, {
              value: 'feedback',
              label: 'Feedback'
            }, {
              value: 'efficiency',
              label: 'Efficiency'
            }, {
              value: 'controllability',
              label: 'Controllability'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'side nav',
              label: 'Side Navigation'
            }, {
              value: 'top nav',
              label: 'Top Navigation'
            }]
          }]
        }, {
          value: 'component',
          label: 'Component',
          children: [{
            value: 'basic',
            label: 'Basic',
            children: [{
              value: 'layout',
              label: 'Layout'
            }, {
              value: 'color',
              label: 'Color'
            }, {
              value: 'typography',
              label: 'Typography'
            }, {
              value: 'icon',
              label: 'Icon'
            }, {
              value: 'button',
              label: 'Button'
            }]
          }, {
            value: 'form',
            label: 'Form',
            children: [{
              value: 'radio',
              label: 'Radio'
            }, {
              value: 'checkbox',
              label: 'Checkbox'
            }, {
              value: 'input',
              label: 'Input'
            }, {
              value: 'input-number',
              label: 'InputNumber'
            }, {
              value: 'select',
              label: 'Select'
            }, {
              value: 'cascader',
              label: 'Cascader'
            }, {
              value: 'switch',
              label: 'Switch'
            }, {
              value: 'slider',
              label: 'Slider'
            }, {
              value: 'time-picker',
              label: 'TimePicker'
            }, {
              value: 'date-picker',
              label: 'DatePicker'
            }, {
              value: 'datetime-picker',
              label: 'DateTimePicker'
            }, {
              value: 'upload',
              label: 'Upload'
            }, {
              value: 'rate',
              label: 'Rate'
            }, {
              value: 'form',
              label: 'Form'
            }]
          }, {
            value: 'data',
            label: 'Data',
            children: [{
              value: 'table',
              label: 'Table'
            }, {
              value: 'tag',
              label: 'Tag'
            }, {
              value: 'progress',
              label: 'Progress'
            }, {
              value: 'tree',
              label: 'Tree'
            }, {
              value: 'pagination',
              label: 'Pagination'
            }, {
              value: 'badge',
              label: 'Badge'
            }]
          }, {
            value: 'notice',
            label: 'Notice',
            children: [{
              value: 'alert',
              label: 'Alert'
            }, {
              value: 'loading',
              label: 'Loading'
            }, {
              value: 'message',
              label: 'Message'
            }, {
              value: 'message-box',
              label: 'MessageBox'
            }, {
              value: 'notification',
              label: 'Notification'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'menu',
              label: 'NavMenu'
            }, {
              value: 'tabs',
              label: 'Tabs'
            }, {
              value: 'breadcrumb',
              label: 'Breadcrumb'
            }, {
              value: 'dropdown',
              label: 'Dropdown'
            }, {
              value: 'steps',
              label: 'Steps'
            }]
          }, {
            value: 'others',
            label: 'Others',
            children: [{
              value: 'dialog',
              label: 'Dialog'
            }, {
              value: 'tooltip',
              label: 'Tooltip'
            }, {
              value: 'popover',
              label: 'Popover'
            }, {
              value: 'card',
              label: 'Card'
            }, {
              value: 'carousel',
              label: 'Carousel'
            }, {
              value: 'collapse',
              label: 'Collapse'
            }]
          }]
        }, {
          value: 'resource',
          label: 'Resource',
          children: [{
            value: 'axure',
            label: 'Axure Components'
          }, {
            value: 'sketch',
            label: 'Sketch Templates'
          }, {
            value: 'docs',
            label: 'Design Documentation'
          }]
        }],
        selectedOptions3: ['component', 'data', 'tag']
      };
    }
  };
</script>
```
:::

### Change on select

También se pueden seleccionar las opciones del elemento padre.

:::demo Por defecto sólo se pueden seleccionar las opciones del último nivel. Al asignar `change-on-select` a `true`, también se pueden seleccionar opciones en los niveles superiores.

```html
<el-cascader
  :options="options"
  change-on-select
></el-cascader>
<script>
  export default {
    data() {
      return {
        options: [{
          value: 'guide',
          label: 'Guide',
          children: [{
            value: 'disciplines',
            label: 'Disciplines',
            children: [{
              value: 'consistency',
              label: 'Consistency'
            }, {
              value: 'feedback',
              label: 'Feedback'
            }, {
              value: 'efficiency',
              label: 'Efficiency'
            }, {
              value: 'controllability',
              label: 'Controllability'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'side nav',
              label: 'Side Navigation'
            }, {
              value: 'top nav',
              label: 'Top Navigation'
            }]
          }]
        }, {
          value: 'component',
          label: 'Component',
          children: [{
            value: 'basic',
            label: 'Basic',
            children: [{
              value: 'layout',
              label: 'Layout'
            }, {
              value: 'color',
              label: 'Color'
            }, {
              value: 'typography',
              label: 'Typography'
            }, {
              value: 'icon',
              label: 'Icon'
            }, {
              value: 'button',
              label: 'Button'
            }]
          }, {
            value: 'form',
            label: 'Form',
            children: [{
              value: 'radio',
              label: 'Radio'
            }, {
              value: 'checkbox',
              label: 'Checkbox'
            }, {
              value: 'input',
              label: 'Input'
            }, {
              value: 'input-number',
              label: 'InputNumber'
            }, {
              value: 'select',
              label: 'Select'
            }, {
              value: 'cascader',
              label: 'Cascader'
            }, {
              value: 'switch',
              label: 'Switch'
            }, {
              value: 'slider',
              label: 'Slider'
            }, {
              value: 'time-picker',
              label: 'TimePicker'
            }, {
              value: 'date-picker',
              label: 'DatePicker'
            }, {
              value: 'datetime-picker',
              label: 'DateTimePicker'
            }, {
              value: 'upload',
              label: 'Upload'
            }, {
              value: 'rate',
              label: 'Rate'
            }, {
              value: 'form',
              label: 'Form'
            }]
          }, {
            value: 'data',
            label: 'Data',
            children: [{
              value: 'table',
              label: 'Table'
            }, {
              value: 'tag',
              label: 'Tag'
            }, {
              value: 'progress',
              label: 'Progress'
            }, {
              value: 'tree',
              label: 'Tree'
            }, {
              value: 'pagination',
              label: 'Pagination'
            }, {
              value: 'badge',
              label: 'Badge'
            }]
          }, {
            value: 'notice',
            label: 'Notice',
            children: [{
              value: 'alert',
              label: 'Alert'
            }, {
              value: 'loading',
              label: 'Loading'
            }, {
              value: 'message',
              label: 'Message'
            }, {
              value: 'message-box',
              label: 'MessageBox'
            }, {
              value: 'notification',
              label: 'Notification'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'menu',
              label: 'NavMenu'
            }, {
              value: 'tabs',
              label: 'Tabs'
            }, {
              value: 'breadcrumb',
              label: 'Breadcrumb'
            }, {
              value: 'dropdown',
              label: 'Dropdown'
            }, {
              value: 'steps',
              label: 'Steps'
            }]
          }, {
            value: 'others',
            label: 'Others',
            children: [{
              value: 'dialog',
              label: 'Dialog'
            }, {
              value: 'tooltip',
              label: 'Tooltip'
            }, {
              value: 'popover',
              label: 'Popover'
            }, {
              value: 'card',
              label: 'Card'
            }, {
              value: 'carousel',
              label: 'Carousel'
            }, {
              value: 'collapse',
              label: 'Collapse'
            }]
          }]
        }, {
          value: 'resource',
          label: 'Resource',
          children: [{
            value: 'axure',
            label: 'Axure Components'
          }, {
            value: 'sketch',
            label: 'Sketch Templates'
          }, {
            value: 'docs',
            label: 'Design Documentation'
          }]
        }]
      };
    }
  };
</script>
```
:::

### Carga dinamica de elementos hijos

Se puede hacer una carga dinamica de elementos hijos cuando se hace clic en el elemento padre o se pasa el ratón sobre el.

:::demo En este ejemplo, el array de opciones no tiene datos de ciudades cuando se inicializa. Con el evento `active-item-change`, puede cargar dinámicamente las ciudades de un estado específico. Además, este ejemplo también demuestra cómo se utilizan los`props`.

```html
<el-cascader
  :options="options2"
  @active-item-change="handleItemChange"
  :props="props"
></el-cascader>

<script>
  export default {
    data() {
      return {
        options2: [{
          label: 'California',
          cities: []
        }, {
          label: 'Florida',
          cities: []
        }],
        props: {
          value: 'label',
          children: 'cities'
        }
      };
    },

    methods: {
      handleItemChange(val) {
        console.log('active item:', val);
        setTimeout(_ => {
          if (val.indexOf('California') > -1 && !this.options2[0].cities.length) {
            this.options2[0].cities = [{
              label: 'Los Angeles'
            }];
          } else if (val.indexOf('Florida') > -1 && !this.options2[1].cities.length) {
            this.options2[1].cities = [{
              label: 'Orlando'
            }];
          }
        }, 300);
      }
    }
  };
</script>
```
:::

### Filtrable

Buscar y seleccionar opciones con una palabra clave.

:::demo Añadir `filterable` a `el-cascader` permite filtrar

```html
<div class="block">
  <span class="demonstration">Only options of the last level can be selected</span>
  <el-cascader
    placeholder="Try searching: Guide"
    :options="options"
    filterable
  ></el-cascader>
</div>
<div class="block">
  <span class="demonstration">Options of all levels can be selected</span>
  <el-cascader
    placeholder="Try searching: Guide"
    :options="options"
    filterable
    change-on-select
  ></el-cascader>
</div>

<script>
  export default {
    data() {
      return {
        options: [{
          value: 'guide',
          label: 'Guide',
          children: [{
            value: 'disciplines',
            label: 'Disciplines',
            children: [{
              value: 'consistency',
              label: 'Consistency'
            }, {
              value: 'feedback',
              label: 'Feedback'
            }, {
              value: 'efficiency',
              label: 'Efficiency'
            }, {
              value: 'controllability',
              label: 'Controllability'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'side nav',
              label: 'Side Navigation'
            }, {
              value: 'top nav',
              label: 'Top Navigation'
            }]
          }]
        }, {
          value: 'component',
          label: 'Component',
          children: [{
            value: 'basic',
            label: 'Basic',
            children: [{
              value: 'layout',
              label: 'Layout'
            }, {
              value: 'color',
              label: 'Color'
            }, {
              value: 'typography',
              label: 'Typography'
            }, {
              value: 'icon',
              label: 'Icon'
            }, {
              value: 'button',
              label: 'Button'
            }]
          }, {
            value: 'form',
            label: 'Form',
            children: [{
              value: 'radio',
              label: 'Radio'
            }, {
              value: 'checkbox',
              label: 'Checkbox'
            }, {
              value: 'input',
              label: 'Input'
            }, {
              value: 'input-number',
              label: 'InputNumber'
            }, {
              value: 'select',
              label: 'Select'
            }, {
              value: 'cascader',
              label: 'Cascader'
            }, {
              value: 'switch',
              label: 'Switch'
            }, {
              value: 'slider',
              label: 'Slider'
            }, {
              value: 'time-picker',
              label: 'TimePicker'
            }, {
              value: 'date-picker',
              label: 'DatePicker'
            }, {
              value: 'datetime-picker',
              label: 'DateTimePicker'
            }, {
              value: 'upload',
              label: 'Upload'
            }, {
              value: 'rate',
              label: 'Rate'
            }, {
              value: 'form',
              label: 'Form'
            }]
          }, {
            value: 'data',
            label: 'Data',
            children: [{
              value: 'table',
              label: 'Table'
            }, {
              value: 'tag',
              label: 'Tag'
            }, {
              value: 'progress',
              label: 'Progress'
            }, {
              value: 'tree',
              label: 'Tree'
            }, {
              value: 'pagination',
              label: 'Pagination'
            }, {
              value: 'badge',
              label: 'Badge'
            }]
          }, {
            value: 'notice',
            label: 'Notice',
            children: [{
              value: 'alert',
              label: 'Alert'
            }, {
              value: 'loading',
              label: 'Loading'
            }, {
              value: 'message',
              label: 'Message'
            }, {
              value: 'message-box',
              label: 'MessageBox'
            }, {
              value: 'notification',
              label: 'Notification'
            }]
          }, {
            value: 'navigation',
            label: 'Navigation',
            children: [{
              value: 'menu',
              label: 'NavMenu'
            }, {
              value: 'tabs',
              label: 'Tabs'
            }, {
              value: 'breadcrumb',
              label: 'Breadcrumb'
            }, {
              value: 'dropdown',
              label: 'Dropdown'
            }, {
              value: 'steps',
              label: 'Steps'
            }]
          }, {
            value: 'others',
            label: 'Others',
            children: [{
              value: 'dialog',
              label: 'Dialog'
            }, {
              value: 'tooltip',
              label: 'Tooltip'
            }, {
              value: 'popover',
              label: 'Popover'
            }, {
              value: 'card',
              label: 'Card'
            }, {
              value: 'carousel',
              label: 'Carousel'
            }, {
              value: 'collapse',
              label: 'Collapse'
            }]
          }]
        }, {
          value: 'resource',
          label: 'Resource',
          children: [{
            value: 'axure',
            label: 'Axure Components'
          }, {
            value: 'sketch',
            label: 'Sketch Templates'
          }, {
            value: 'docs',
            label: 'Design Documentation'
          }]
        }]
      };
    }
  };
</script>
```
:::

### Atributos
| Atributo         | Descripción                              | Tipo            | Opciones              | Por defecto |
| ---------------- | ---------------------------------------- | --------------- | --------------------- | ----------- |
| value / v-model   | valor enlazado                           | boolean / string / number | —                     | —           |
| options          | datos de las opciones                    | array           | —                     | —           |
| props            | opciones de configuracion,  mire la tabla siguiente | object          | —                     | —           |
| value            | valor seleccionado                       | array           | —                     | —           |
| popper-class     | nombre de clase para el Cascader's dropdown | string          | —                     | —           |
| placeholder      | input placeholder                        | string          | —                     | Select      |
| disabled         | si Cascader esta disabled                | boolean         | —                     | false       |
| clearable        | si se puede borrar el valor seleccionado | boolean         | —                     | false       |
| expand-trigger   | evento del elemento actual para expandirse. | string          | click / hover         | click       |
| show-all-levels  | si mostrar todos los niveles del valor seleccionado en la entrada | boolean         | —                     | true        |
| filterable       | si se pueden buscar las opciones         | boolean         | —                     | —           |
| debounce         | retardo al escribir la palabra clave del filtro, en milisegundos | number          | —                     | 300         |
| change-on-select | si se permite seleccionar una opción de cualquier nivel | boolean         | —                     | false       |
| size             | tamaño del input                         | string          | medium / small / mini | —           |
| before-filter    | funcion antes de filtrar con el valor a filtrar como parámetro. Si se devuelve `false` o se devuelve una `Promise` y luego es rechazada, el filtrado será abortado. | function(value) | —                     | —           |

### props
| Atributo | Descripción                              | Tipo   | Valores aceptados | Por defecto |
| -------- | ---------------------------------------- | ------ | ----------------- | ----------- |
| label    | especifica qué clave del elemento de la opción se utiliza como etiqueta | string | —                 | —           |
| value    | especifica qué clave del elemento de la opción se utiliza como valor | string | —                 | —           |
| children | especifica qué clave del elemento de la opción se utiliza como hijo | string | —                 | —           |
| disabled | especifica qué clave del elemento de la opción indica si está deshabilitada | string | —                 | —           |

### Eventos
| Nombre             | Descripción                                                  | Parametros                |
| ------------------ | ------------------------------------------------------------ | ------------------------- |
| change             | se dispara cuando el valor cambia                            | valor                     |
| active-item-change | se dispara cuando la opcion activa del parent cambia, sólo funciona cuando `change-on-select` es `false`. | array de opciones activas |
| blur               | se dispara cuando Cascader pierde el foco                    | (event: Event)            |
| focus              | se dispara cuando Cascader obtiene el foco                   | (event: Event)            |
| visible-change     | se dispara cuando el menu desplegable aparece o desaparece   | true cuando aparece, y false en otro caso |

