fixed: Fixed an issue where multiple selections across pages could no…

…t be reversed

src/components/Table/DataTable/compenents/el-data-table/utils/select-strategy.js

@@ -34,12 +34,14 @@ class StrategyNormal extends StrategyAbstract {
   onSelectionChange(val) {
     this.elDataTable.selected = val
   }
+
   /**
    * toggleRowSelection和clearSelection的表现与el-table一致
    */
   toggleRowSelection(...args) {
     return this.elTable.toggleRowSelection(...args)
   }
+
   clearSelection() {
     return this.elTable.clearSelection()
   }
@@ -50,26 +52,32 @@ class StrategyNormal extends StrategyAbstract {
  */
 class StrategyPersistSelection extends StrategyAbstract {
   /**
-   * el-table的selection-change事件不适用于开启跨页保存的情况。
-   * 比如，当开启persistSelection时，发生以下两个场景：
+   * el-table 的 selection-change 事件不适用于开启跨页保存的情况。
+   * 比如，当开启 persistSelection时，发生以下两个场景：
    * 1. 用户点击翻页
    * 2. 用户点击行首的切换全选项按钮，清空当前页多选项数据
-   * 其中场景1应该保持selected不变；而场景2只应该从selected移除当前页所有行，保留其他页面的多选状态。
-   * 但el-table的selection-change事件在两个场景中无差别发生，所以这里不处理这个事件
+   * 其中场景 1 应该保持 selected 不变；而场景 2 只应该从 selected 移除当前页所有行，保留其他页面的多选状态。
+   * 但 el-table 的 selection-change 事件在两个场景中无差别发生，所以这里不处理这个事件
    */
 
   /**
    * 用户切换某一行的多选
    */
   onSelect(selection, row) {
     const isChosen = selection.indexOf(row) > -1
+
     this.toggleRowSelection(row, isChosen)
   }
   /**
    * 用户切换当前页的多选
    */
   onSelectAll(selection, selectable = () => true) {
-    const isSelected = !!selection.length
+    // 获取当前所有已选择的项
+    const selectedRows = this.elDataTable.data.filter(r => selection.includes(r))
+
+    // 判断是否已全选
+    const isSelected = this.elDataTable.data.every(r => selectable(r) && selectedRows.includes(r))
+
     this.elDataTable.data.forEach(r => {
       if (selectable(r)) {
         this.toggleRowSelection(r, isSelected)
@@ -83,33 +91,42 @@ class StrategyPersistSelection extends StrategyAbstract {
   toggleRowSelection(row, isSelected) {
     const { id, selected } = this.elDataTable
     const foundIndex = selected.findIndex(r => r[id] === row[id])
+
     if (typeof isSelected === 'undefined') {
       isSelected = foundIndex <= -1
     }
+
     if (isSelected && foundIndex === -1) {
       selected.push(row)
     } else if (!isSelected && foundIndex > -1) {
       selected.splice(foundIndex, 1)
     }
+
     this.elDataTable.$emit('toggle-row-selection', isSelected, row)
     this.updateElTableSelection()
   }
+
   clearSelection() {
     this.elDataTable.selected = []
     this.updateElTableSelection()
   }
+
   /**
    * 将selected状态同步到el-table中
    */
   updateElTableSelection() {
     const { data, id, selected } = this.elDataTable
+
     // 历史勾选的行已经不在当前页了，所以要将当前页的行数据和selected合并
     const mergeData = _.uniqWith([...data, ...selected], _.isEqual)
+
     mergeData.forEach(r => {
       const isSelected = !!selected.find(r2 => r[id] === r2[id])
+
       if (!this.elTable) {
         return
       }
+
       this.elTable.toggleRowSelection(r, isSelected)
     })
   }