利用vue对比两组数据差异的可视化组件详解

目录

• 需求：
• 大概要点：
• 根据刚才的要点可以建立一下组件的props：
• 组件的基本样式也很简单：
• 完事了，最后贴一下完整代码：
• 使用示例：
• 效果预览：
• 扩展功能TODO：
• 总结

props: {
  uniqueKey: {
    type: String,
    default: "id"
  },
  dataGroup: {
    type: Array,
    validator: val => val.length === 2
  },
  columns: {
    type: Array,
    required: true
  }
}

<template>
  <div class="diff-table-container">
    <el-table
      v-for="(data, i) in completedData"
      :key="i"
      :data="data"
      :row-style="markRowStyles"
      :cell-style="markCellStyles"
    >
      <el-table-column v-for="item in columns" :key="`${i}${item.prop}`" align="center" v-bind="item" />
    </el-table>
  </div>
</template>
<style lang="scss" scoped>
.diff-table-container {
  display: flex;
  align-items: flex-start;
  .el-table + .el-table {
    margin-left: 20px;
  }
}
</style>

data() {
  return {
    DIFF_CELL_KEY: Symbol("diffCells"), // 一个数组，存储有差异的cell属性名
    COMPLETED_KEY: Symbol("completed") // 标记已完成处理
  };
}

methods: {
  // 完成处理之后没有标记的，就表示只在一组数据中出现，也就是新增数据
  markRowStyles({ row }) {
    return (
      !row[this.COMPLETED_KEY] && {
        backgroundColor: "#E1F3D8"
      }
    );
  },
  // 根据当前行的唯一key，找到map中缓存的行数据
  // 就是dataGroup[0].find(item => item[uniqueKey] === row[uniqueKey])
  // 然后判断DIFF_CELL_KEY数组中是否包含当前列的属性名
  markCellStyles({ row, column }) {
    const { $_cacheMap, uniqueKey, DIFF_CELL_KEY } = this;
    const _cacheRow = $_cacheMap.get(row[uniqueKey]);
    return (
      _cacheRow &&
      _cacheRow[DIFF_CELL_KEY].includes(column.property) && {
        backgroundColor: "#FDE2E2"
      }
    );
  }
}

computed: {
  // 处理完成的数据
  completedData({ dataGroup, uniqueKey, columns, DIFF_CELL_KEY, COMPLETED_KEY }) {
    // 这一步不是必要的，根据业务需求来，如果规定不能修改原数据的话就做一下深拷贝
    const _dataGroup = deepClone(dataGroup);
    // Map<string|number, object>，ts不太熟，应该是这么写，其实就是row[unique]: row
    const cacheMap = new Map();
    // 先遍历一次第一组数据，初始化DIFF_CELL_KEY数组，然后存进map中
    for (const _row of _dataGroup[0]) {
      _row[DIFF_CELL_KEY] = [];
      cacheMap.set(_row[uniqueKey], _row);
    }
    // 遍历第二组数据，里面还有一次循环，因为只处理columns里面定义的属性，其他属性不做对比
    for (const _row of _dataGroup[1]) {
      for (const { prop } of columns) {
        // 如果是唯一key就直接跳过
        if (prop === uniqueKey) continue;
        // 从缓存中查找相同的一条数据
        const original = cacheMap.get(_row[uniqueKey]);
        // 如果找不到就说明这条数据是新增的，直接跳过
        if (!original) continue;
        // 否则就在两组数据中打一个标识表示已处理过，不是新增的
        _row[COMPLETED_KEY] = true;
        original[COMPLETED_KEY] = true;
        // 最后对比两个属性值，如果相同就push进DIFF_CELL_KEY数组中
        // 注意这里DIFF_CELL_KEY数组只存在于第一组数据当中
        // 因为只要有差异就会在所有表格中显示，所以不用每一组数据都存
        _row[prop] !== original[prop] && original[DIFF_CELL_KEY].push(prop);
      }
    }
    // 将map存一份到this中，因为会在处理样式的时候用到
    this.$_cacheMap = cacheMap;
    return _dataGroup;
  }
}

<template>
  <div class="diff-table-container">
    <el-table
      v-for="(data, i) in completedData"
      :key="i"
      :data="data"
      :row-style="markRowStyles"
      :cell-style="markCellStyles"
    >
      <el-table-column v-for="item in columns" :key="`${i}${item.prop}`" v-bind="item" align="center" />
    </el-table>
  </div>
</template>
<script>
function deepClone(val) {
  // 看需求要不要做深拷贝
  return val;
}
export default {
  name: "DiffTable",
  props: {
    uniqueKey: {
      type: String,
      default: "id"
    },
    dataGroup: {
      type: Array,
      validator: val => val.length === 2
    },
    columns: {
      type: Array,
      required: true
    }
  },
  data() {
    return {
      DIFF_CELL_KEY: Symbol("diffCells"),
      COMPLETED_KEY: Symbol("completed")
    };
  },
  computed: {
    completedData({ dataGroup, uniqueKey, columns, DIFF_CELL_KEY, COMPLETED_KEY }) {
      const _dataGroup = deepClone(dataGroup);
      const cacheMap = new Map();
      for (const _row of _dataGroup[0]) {
        _row[DIFF_CELL_KEY] = [];
        cacheMap.set(_row[uniqueKey], _row);
      }
      for (const _row of _dataGroup[1]) {
        for (const { prop } of columns) {
          if (prop === uniqueKey) continue;
          const original = cacheMap.get(_row[uniqueKey]);
          if (!original) continue;
          _row[COMPLETED_KEY] = true;
          original[COMPLETED_KEY] = true;
          _row[prop] !== original[prop] && original[DIFF_CELL_KEY].push(prop);
        }
      }
      this.$_cacheMap = cacheMap;
      return _dataGroup;
    }
  },
  methods: {
    markRowStyles({ row }) {
      return (
        !row[this.COMPLETED_KEY] && {
          backgroundColor: "#E1F3D8"
        }
      );
    },
    markCellStyles({ row, column }) {
      const { $_cacheMap, uniqueKey, DIFF_CELL_KEY } = this;
      const _cacheRow = $_cacheMap.get(row[uniqueKey]);
      return (
        _cacheRow &&
        _cacheRow[DIFF_CELL_KEY].includes(column.property) && {
          backgroundColor: "#FDE2E2"
        }
      );
    }
  }
};
</script>
<style lang="scss" scoped>
.diff-table-container {
  display: flex;
  align-items: flex-start;
  .el-table + .el-table {
    margin-left: 20px;
  }
}
</style>

<template>
  <diff-table :data-group="[oldData, newData]" :columns="tableColumns" />
</template>
<script>
import DiffTable from "./DiffTable.vue";
export default {
  name: "Index",
  components: {
    DiffTable
  },
  data() {
    return {
      oldData: [
        { id: 1, name: "zhangsan1", age: 23, address: "zxczxczxc" },
        { id: 2, name: "zhangsan2", age: 23.5, address: "zxczxczxc" },
        { id: 3, name: "zhangsan34", age: 23, address: "zxczxczxc" },
        { id: 4, name: "zhangsan4", age: 23, address: "zxczxczxc" },
        { id: 5, name: "zhangsan5", age: 23, address: "zxczxczxc" },
        { id: 6, name: "zhangsan5", age: 23, address: "zxczxczxc" }
      ],
      newData: [
        { id: 1, name: "zhangsan1", age: 23, address: "zxczxczxc" },
        { id: 2, name: "zhangsan2", age: 23, address: "zxczxczxc" },
        { id: 4, name: "zhangsan4", age: 23, address: "地址地址地址" },
        { id: 3, name: "zhangsan3", age: 23, address: "zxczxczxc" },
        { id: 5, name: "zhangsan5", age: 23, address: "zxczxczxc" },
        { id: 7, name: "zhangsan5", age: 23, address: "zxczxczxc" },
        { id: 8, name: "zhangsan5", age: 23, address: "zxczxczxc" }
      ],
      tableColumns: [
        { label: "唯一id", prop: "id" },
        { label: "名称", prop: "name" },
        { label: "年龄", prop: "age" },
        { label: "地址", prop: "address" }
      ]
    };
  }
};
</script>