perf[uploadExcel]: add beforeUpload hock

src/components/UploadExcel/index.vue

@@ -12,6 +12,10 @@
 import XLSX from 'xlsx'
 
 export default {
+  props: {
+    beforeUpload: Function,
+    onSuccess: Function
+  },
   data() {
     return {
       loading: false,
@@ -25,7 +29,7 @@ export default {
     generateDate({ header, results }) {
       this.excelData.header = header
       this.excelData.results = results
-      this.$emit('success', this.excelData)
+      this.onSuccess && this.onSuccess(this.excelData)
     },
     handleDrop(e) {
       e.stopPropagation()
@@ -36,8 +40,8 @@ export default {
         this.$message.error('Only support uploading one file!')
         return
       }
-      const itemFile = files[0] // only use files[0]
-      this.readerData(itemFile)
+      const rawFile = files[0] // only use files[0]
+      this.upload(rawFile)
       e.stopPropagation()
       e.preventDefault()
     },
@@ -51,13 +55,23 @@ export default {
     },
     handleClick(e) {
       const files = e.target.files
-      const itemFile = files[0] // only use files[0]
-      if (!itemFile) return
-      this.readerData(itemFile).then(() => {
-        this.$refs['excel-upload-input'].value = null // fix can't select the same excel
-      })
+      const rawFile = files[0] // only use files[0]
+      if (!rawFile) return
+      this.upload(rawFile)
+    },
+    upload(rawFile) {
+      this.$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(itemFile) {
+    readerData(rawFile) {
       this.loading = true
       return new Promise((resolve, reject) => {
         const reader = new FileReader()
@@ -73,7 +87,7 @@ export default {
           this.loading = false
           resolve()
         }
-        reader.readAsArrayBuffer(itemFile)
+        reader.readAsArrayBuffer(rawFile)
       })
     },
     fixdata(data) {

src/views/excel/uploadExcel.vue

 <template>
   <div class="app-container">
-    <upload-excel-component @success='handleSuccess'></upload-excel-component>
+    <upload-excel-component :on-success='handleSuccess' :before-upload="beforeUpload"></upload-excel-component>
     <el-table :data="tableData" border highlight-current-row style="width: 100%;margin-top:20px;">
       <el-table-column v-for='item of tableHeader' :prop="item" :label="item" :key='item'>
       </el-table-column>
@@ -21,6 +21,18 @@ export default {
     }
   },
   methods: {
+    beforeUpload(file) {
+      const isLt2M = file.size / 1024 / 1024 < 1
+
+      if (isLt2M) {
+        return true
+      }
+      this.$message({
+        message: 'Please do not upload files larger than 2m in size.',
+        type: 'warning'
+      })
+      return false
+    },
     handleSuccess({ results, header }) {
       this.tableData = results
       this.tableHeader = header