<!--table組件需要使用ref="table"-->
<template>
 <div>
 <el-table :data="tableData" ref="table" stripe style="width: 100%" @selection-change="handleSelectionChange">
 <el-table-column type="selection" width="55"></el-table-column>
 <el-table-column prop="name" label="商品名稱"></el-table-column>
 <el-table-column prop="barcode" label="商品編碼"></el-table-column>
 <el-table-column prop="quantity" label="區域總庫存"></el-table-column>
 </el-table>
 <div class="block" v-show="page.pageTotal>10">
 <el-pagination @current-change="handleCurrentChange" :current-page.sync="page.currentPage" :page-size="page.pnum" layout="total, prev, pager, next , jumper" :total="page.pageTotal">
 </el-pagination>
 </div>
 <div>
 {{multipleSelectionAll.length}}
 </div>
 </div>
</template>

export default {
 data(){
 return {
 tableData: [], // 表格數據 
 multipleSelectionAll:[],//所有選中的數據包含跨頁數據
 multipleSelection:[],// 當前頁選中的數據
 idKey: 'barcode', // 標識列表數據中每一行的唯一鍵的名稱
 page:{
 //每頁數據量
 pnum:10,
 //數據總數
 pageTotal:0,
 //當前頁，從1開始
 currentPage:1,
 }
 }
 },
 methods: {
 handleCurrentChange(){
 this.changePageCoreRecordData();
 if(!this.$isNull(this.page.pageTotal)) this.getGoodsList();
 },
 handleSelectionChange (val) {
 this.multipleSelection = val;
 //實時記錄選中的數據
 setTimeout(()=>{
 this.changePageCoreRecordData();
 }, 50)
 },
 setSelectRow() {
 if (!this.multipleSelectionAll || this.multipleSelectionAll.length <= 0) {
 return;
 }
 // 標識當前行的唯一鍵的名稱
 let idKey = this.idKey;
 let selectAllIds = [];
 let that = this;
 this.multipleSelectionAll.forEach(row=>{
 selectAllIds.push(row[idKey]);
 })
 this.$refs.table.clearSelection();
 for(var i = 0; i < this.tableData.length; i++) { 
 if (selectAllIds.indexOf(this.tableData[i][idKey]) >= 0) {
 // 設置選中，記住table組件需要使用ref="table"
 this.$refs.table.toggleRowSelection(this.tableData[i], true);
 }
 }
 },
 // 記憶選擇核心方法
 changePageCoreRecordData () {
 // 標識當前行的唯一鍵的名稱
 let idKey = this.idKey;
 let that = this;
 // 如果總記憶中還沒有選擇的數據，那么就直接取當前頁選中的數據，不需要后面一系列計算
 if (this.multipleSelectionAll.length <= 0) {
 this.multipleSelectionAll = this.multipleSelection;
 return;
 }
 // 總選擇里面的key集合
 let selectAllIds = [];
 this.multipleSelectionAll.forEach(row=>{
 selectAllIds.push(row[idKey]);
 })
 let selectIds = []
 // 獲取當前頁選中的id
 this.multipleSelection.forEach(row=>{
 selectIds.push(row[idKey]);
 // 如果總選擇里面不包含當前頁選中的數據，那么就加入到總選擇集合里
 if (selectAllIds.indexOf(row[idKey]) < 0) {
 that.multipleSelectionAll.push(row);
 }
 })
 let noSelectIds = [];
 // 得到當前頁沒有選中的id
 this.tableData.forEach(row=>{
 if (selectIds.indexOf(row[idKey]) < 0) {
 noSelectIds.push(row[idKey]);
 }
 })
 noSelectIds.forEach(id=>{
 if (selectAllIds.indexOf(id) >= 0) {
 for(let i = 0; i< that.multipleSelectionAll.length; i ++) {
 if (that.multipleSelectionAll[i][idKey] == id) {
 // 如果總選擇中有未被選中的，那么就刪除這條
 that.multipleSelectionAll.splice(i, 1);
 break;
 }
 }
 }
 })
 },
 //請求接口部分
 getGoodsList(){
 let data = {};
 data['page'] = this.page.currentPage;
 data['pnum'] = this.page.pnum;
 this.$ajax({
 url:'goods/list',
 data:data
 }).then(val => {
 this.tableData = val.data.rows ? val.data.rows : [];
 this.page = {
 pnum:10,
 pageTotal:val.data.total,
 currentPage:val.data.page,
 };
 setTimeout(()=>{
 this.setSelectRow();
 }, 50)
 })
 }
 },
 created () {
 this.getGoodsList()
 }
 }