新增 Excel 上传组件 xlsx 更新到 ^0.14.1 (#100)

* xlsx 更新版本到^0.14.1

* 新增 Excel 上传组件 及上传示例

package.json

@@ -65,7 +65,7 @@
     "vuedraggable": "2.20.0",
     "vuex": "3.1.0",
     "wangeditor": ">=3.0.0",
-    "xlsx": "^0.11.16",
+    "xlsx": "^0.14.1",
     "vue-image-crop-upload": "^2.5.0"
   },
   "devDependencies": {

src/components/UploadExcel/index.vue

+<template>
+  <div>
+    <input ref="excel-upload-input" class="excel-upload-input" type="file" accept=".xlsx, .xls" @change="handleClick">
+    <div class="drop" @drop="handleDrop" @dragover="handleDragover" @dragenter="handleDragover">
+      拖拽excel文件到此处 或者
+      <el-button :loading="loading" style="margin-left:16px;" size="mini" type="primary" @click="handleUpload">
+        浏览
+      </el-button>
+    </div>
+  </div>
+</template>
+
+<script>
+import XLSX from 'xlsx'
+
+export default {
+  props: {
+    beforeUpload: Function, // eslint-disable-line
+    onSuccess: Function// eslint-disable-line
+  },
+  data() {
+    return {
+      loading: false,
+      excelData: {
+        header: null,
+        results: null
+      }
+    }
+  },
+  methods: {
+    generateData({ header, results }) {
+      this.excelData.header = header
+      this.excelData.results = results
+      this.onSuccess && this.onSuccess(this.excelData)
+    },
+    handleDrop(e) {
+      e.stopPropagation()
+      e.preventDefault()
+      if (this.loading) return
+      const files = e.dataTransfer.files
+      if (files.length !== 1) {
+        this.$message.error('只支持单个文件上传!')
+        return
+      }
+      const rawFile = files[0]
+
+      if (!this.isExcel(rawFile)) {
+        this.$message.error('只支持.xlsx, .xls, .csv 格式文件')
+        return false
+      }
+      this.upload(rawFile)
+      e.stopPropagation()
+      e.preventDefault()
+    },
+    handleDragover(e) {
+      e.stopPropagation()
+      e.preventDefault()
+      e.dataTransfer.dropEffect = 'copy'
+    },
+    handleUpload() {
+      this.$refs['excel-upload-input'].click()
+    },
+    handleClick(e) {
+      const files = e.target.files
+      const rawFile = files[0] // only use files[0]
+      if (!rawFile) return
+      this.upload(rawFile)
+    },
+    upload(rawFile) {
+      this.$refs['excel-upload-input'].value = null // fix can't select the same excel
+
+      if (!this.beforeUpload) {
+        this.readerData(rawFile)
+        return
+      }
+      const before = this.beforeUpload(rawFile)
+      if (before) {
+        this.readerData(rawFile)
+      }
+    },
+    readerData(rawFile) {
+      this.loading = true
+      return new Promise((resolve, reject) => {
+        const reader = new FileReader()
+        reader.onload = e => {
+          const data = e.target.result
+          const workbook = XLSX.read(data, { type: 'array' })
+          const firstSheetName = workbook.SheetNames[0]
+          const worksheet = workbook.Sheets[firstSheetName]
+          const header = this.getHeaderRow(worksheet)
+          const results = XLSX.utils.sheet_to_json(worksheet)
+          this.generateData({ header, results })
+          this.loading = false
+          resolve()
+        }
+        reader.readAsArrayBuffer(rawFile)
+      })
+    },
+    getHeaderRow(sheet) {
+      const headers = []
+      const range = XLSX.utils.decode_range(sheet['!ref'])
+      let C
+      const R = range.s.r
+      /* start in the first row */
+      for (C = range.s.c; C <= range.e.c; ++C) { /* walk every column in the range */
+        const cell = sheet[XLSX.utils.encode_cell({ c: C, r: R })]
+        /* find the cell in the first row */
+        let hdr = 'UNKNOWN ' + C // <-- replace with your desired default
+        if (cell && cell.t) hdr = XLSX.utils.format_cell(cell)
+        headers.push(hdr)
+      }
+      return headers
+    },
+    isExcel(file) {
+      return /\.(xlsx|xls|csv)$/.test(file.name)
+    }
+  }
+}
+</script>
+
+<style scoped>
+.excel-upload-input{
+  display: none;
+  z-index: -9999;
+}
+.drop{
+  border: 2px dashed #bbb;
+  width: 600px;
+  height: 160px;
+  line-height: 160px;
+  margin: 0 auto;
+  font-size: 24px;
+  border-radius: 5px;
+  text-align: center;
+  color: #bbb;
+  position: relative;
+}
+</style>

src/views/components/excel/upload-excel.vue

+<template>
+  <div class="app-container">
+    <upload-excel-component :on-success="handleSuccess" :before-upload="beforeUpload" />
+    <el-table :data="tableData" border highlight-current-row style="width: 100%;margin-top:20px;">
+      <el-table-column v-for="item of tableHeader" :key="item" :prop="item" :label="item" />
+    </el-table>
+  </div>
+</template>
+
+<script>
+import UploadExcelComponent from '@/components/UploadExcel/index.vue'
+
+export default {
+  name: 'UploadExcel',
+  components: { UploadExcelComponent },
+  data() {
+    return {
+      tableData: [],
+      tableHeader: []
+    }
+  },
+  methods: {
+    beforeUpload(file) {
+      const isLt1M = file.size / 1024 / 1024 < 1
+      if (isLt1M) {
+        return true
+      }
+
+      this.$message({
+        message: '请不要上传大于1m的文件.',
+        type: 'warning'
+      })
+      return false
+    },
+    handleSuccess({ results, header }) {
+      this.tableData = results
+      this.tableHeader = header
+    }
+  }
+}
+</script>