ELement-UI之树形表格（treeTable&&treeGrid）

‘use strict‘
import Vue from ‘vue‘
export default function treeToArray(data, expandAll, parent = null, level = null) {
  let tmp = []
  Array.from(data).forEach(function(record) {
    if (record._expanded === undefined) {
      Vue.set(record, ‘_expanded‘, expandAll)
    }
    let _level = 1
    if (level !== undefined && level !== null) {
      _level = level + 1
    }
    Vue.set(record, ‘_level‘, _level)
    // 如果有父元素
    if (parent) {
      Vue.set(record, ‘parent‘, parent)
    }
    tmp.push(record)
    if (record.children && record.children.length > 0) {
      const children = treeToArray(record.children, expandAll, record, _level)
      tmp = tmp.concat(children)
    }
  })
  return tmp
}

<template>
  <div>
    <el-table :data="formatData" :row-style="showRow" v-bind="$attrs" @row-click="singleClick"
              style="width: 100%;height: 700px;overflow: hidden" tooltip-effect="dark"
    >
      <el-table-column v-if="columns.length===0" width="150">
        <template slot-scope="scope">
          <span v-for="space in scope.row._level" class="ms-tree-space" :key="space"></span>
          <span class="tree-ctrl" v-if="iconShow(0,scope.row)" @click="toggleExpanded(scope.$index)">
          <i v-if="!scope.row._expanded" class="el-icon-plus"></i>
          <i v-else class="el-icon-minus"></i>
        </span>
          {{scope.$index}}
        </template>
      </el-table-column>
      <el-table-column v-else v-for="(column, index) in columns" :key="column.value" :label="column.text"
                       :width="column.width">
        <template slot-scope="scope">
          <span v-if="index === 0" v-for="space in scope.row._level" class="ms-tree-space" :key="space"></span>
          <span class="tree-ctrl" v-if="iconShow(index,scope.row)" @click="toggleExpanded(scope.$index)">
          <i v-if="!scope.row._expanded" class="el-icon-plus"></i>
          <i v-else class="el-icon-minus"></i>
        </span>
          {{scope.row[column.value]}}
        </template>
      </el-table-column>
      <slot></slot>
    </el-table>
  </div>
</template>

<script>

  import treeToArray from ‘./eval‘

  export default {
    name: ‘treeTable‘,
    props: {
      data: {
        type: [Array, Object],
        required: true
      },
      columns: {
        type: Array,
        default: () => []
      },
      evalFunc: Function,
      evalArgs: Array,
      expandAll: {
        type: Boolean,
        default: false
      },
      singleClick: Function,
    },
    computed: {
      // 格式化数据源
      formatData: function () {
        let tmp;
        if (!Array.isArray(this.data)) {
          tmp = [this.data]
        } else {
          tmp = this.data
        }
        const func = this.evalFunc || treeToArray;
        const args = this.evalArgs ? Array.concat([tmp, this.expandAll], this.evalArgs) : [tmp, this.expandAll];
        return func.apply(null, args)//赋值function里前两位值data与expandAll
      },
    },
    methods: {
      showRow(row) {
        const show = (row.row.parent ? (row.row.parent._expanded && row.row.parent._show) : true);
        row.row._show = show;
        return show ? ‘animation:treeTableShow 1s;-webkit-animation:treeTableShow 1s;‘ : ‘display:none;‘
      },
      // 切换下级是否展开
      toggleExpanded(trIndex) {
        const record = this.formatData[trIndex]
        record._expanded = !record._expanded
      },
      // 图标显示
      iconShow(index, record) {
        return (index === 0 && record.children && record.children.length > 0)
      },

    }
  }
</script>
<style rel="stylesheet/css">
  @keyframes treeTableShow {
    from {
      opacity: 0;
    }
    to {
      opacity: 1;
    }
  }

  @-webkit-keyframes treeTableShow {
    from {
      opacity: 0;
    }
    to {
      opacity: 1;
    }
  }
</style>

<style lang="scss" rel="stylesheet/scss" scoped>
  /*$color-blue:*/
  /*$space-width: */
  .ms-tree-space {
    position: relative;
    top: 1px;
    display: inline-block;
    font-style: normal;
    font-weight: 400;
    line-height: 1;
    width: 18px;
    height: 14px;

  &
  ::before {
    content: ""
  }

  }
  .processContainer {
    width: 100%;
    height: 100%;
  }

  table td {
    line-height: 26px;
  }

  .tree-ctrl {
    position: relative;
    cursor: pointer;
    color: #2196F3;
    margin-left: -18px;
  }

  .el-table__body tr.current-row > td {
    background: rgba(185, 221, 249, .75) !important;
  }
</style>

## 写在前面
此组件仅提供一个创建TreeTable的解决思路

## prop说明
#### *data*
  **必填**

  原始数据,要求是一个数组或者对象
  ```javascript
    [{
      key1: value1,
      key2: value2,
      children: [{
        key1: value1
      },
      {
        key1: value1
      }]
    },
    {
      key1: value1
    }]
  ```
  或者
 ```javascript
    {
      key1: value1,
      key2: value2,
      children: [{
        key1: value1
      },
      {
        key1: value1
      }]
    }
  ```

#### columns
  列属性,要求是一个数组

  1. text: 显示在表头的文字
  2. value: 对应data的key。treeTable将显示相应的value
  3. width: 每列的宽度，为一个数字(可选)
  
  如果你想要每个字段都有自定义的样式或者嵌套其他组件，columns可不提供，直接像在el-table一样写即可，如果没有自定义内容，提供columns将更加的便捷方便
  
  如果你有几个字段是需要自定义的，几个不需要，那么可以将不需要自定义的字段放入columns，将需要自定义的内容放入到slot中，详情见后文
  ```javascript
  [{
    value:string,
    text:string,
    width:number
  },{
    value:string,
    text:string,
    width:number
  }]
  ```

#### expandAll
  是否默认全部展开，boolean值，默认为false

#### evalFunc
  解析函数，function，非必须

  如果不提供，将使用默认的[evalFunc](./eval.js)

  如果提供了evalFunc,那么会用提供的evalFunc去解析data，并返回treeTable渲染所需要的值。如何编写一个evalFunc，请参考[*eval.js*](https://github.com/PanJiaChen/vue-element-admin/blob/master/src/components/TreeTable/eval.js)或[*customEval.js*](https://github.com/PanJiaChen/vue-element-admin/blob/master/src/views/example/table/treeTable/customEval.js)

#### evalArgs
  解析函数的参数，是一个数组

  **请注意，自定义的解析函数参数第一个为this.data，第二个参数为， this.expandAll,你不需要在evalArgs填写。一定记住，这两个参数是强制性的，并且位置不可颠倒** *this.data为需要解析的数据，this.expandAll为是否默认展开*

  如你的解析函数需要的参数为`(this.data, this.expandAll,1,2,3,4)`，那么你只需要将`[1,2,3,4]`赋值给`evalArgs`就可以了
  
  如果你的解析函数参数只有`(this.data, this.expandAll)`,那么就可以不用填写evalArgs了
  
  具体可参考[*customEval.js*](https://github.com/PanJiaChen/vue-element-admin/blob/master/src/views/example/table/treeTable/customEval.js)的函数参数和[customTreeTable](https://github.com/PanJiaChen/vue-element-admin/blob/master/src/views/example/table/treeTable/customTreeTable.vue)的`evalArgs`属性值

 ## slot
 这是一个自定义列的插槽。
 
 默认情况下，treeTable只有一行行展示数据的功能。但是一般情况下，我们会要给行加上一个操作按钮或者根据当行数据展示不同的样式，这时我们就需要自定义列了。请参考[customTreeTable](https://github.com/PanJiaChen/vue-element-admin/blob/master/src/views/example/table/treeTable/customTreeTable.vue)，[实例效果](http://panjiachen.github.io/vue-element-admin/#/example/table/custom-tree-table)
 
 `slot`和`columns属性`可同时存在,columns里面的数据列会在slot自定义列的左边展示

 ## 其他
  如果有其他的需求，请参考[el-table](http://element-cn.eleme.io/#/en-US/component/table)的api自行修改index.vue