<template>
  <div>
    <h3>点击上传</h3>
    <el-upload
      class="upload-demo"
      action="https://jsonplaceholder.typicode.com/posts/"
      :on-preview="handlePreview"
      :on-remove="handleRemove"
      :before-remove="beforeRemove"
      multiple
      :limit="3"
      :on-exceed="handleExceed"
      :file-list="fileList">
      <el-button size="small" type="primary">点击上传</el-button>
      <div slot="tip" class="el-upload__tip">只能上传jpg/png文件，且不超过500kb</div>
    </el-upload>
    <h3>用户头像上传</h3>
    <p>使用 before-upload 限制用户上传的图片格式和大小。</p>
    <el-upload
      class="avatar-uploader"
      action="https://jsonplaceholder.typicode.com/posts/"
      :show-file-list="false"
      :on-success="handleAvatarSuccess"
      :before-upload="beforeAvatarUpload">
      <img v-if="imageUrl" :src="imageUrl" class="avatar">
      <i v-else class="el-icon-plus avatar-uploader-icon"></i>
    </el-upload>
    <h3>照片墙</h3>
    <p>使用 list-type 属性来设置文件列表的样式。</p>
    <el-upload
      action="https://jsonplaceholder.typicode.com/posts/"
      list-type="picture-card"
      :on-preview="handlePictureCardPreview"
      :on-remove="handleRemove">
      <i class="el-icon-plus"></i>
    </el-upload>
    <el-dialog :visible.sync="dialogVisible">
      <img width="100%" :src="dialogImageUrl" alt="">
    </el-dialog>
    <h3>拖拽上传</h3>
    <el-upload
      class="upload-demo"
      drag
      action="https://jsonplaceholder.typicode.com/posts/"
      multiple>
      <i class="el-icon-upload"></i>
      <div class="el-upload__text">将文件拖到此处，或<em>点击上传</em></div>
      <div class="el-upload__tip" slot="tip">只能上传jpg/png文件，且不超过500kb</div>
    </el-upload>
  </div>
</template>

<script>
export default {
  name: 'upload',
  data () {
    return {
      fileList: [{name: 'food.jpeg', url: 'https://fuss10.elemecdn.com/3/63/4e7f3a15429bfda99bce42a18cdd1jpeg.jpeg?imageMogr2/thumbnail/360x360/format/webp/quality/100'}, {name: 'food2.jpeg', url: 'https://fuss10.elemecdn.com/3/63/4e7f3a15429bfda99bce42a18cdd1jpeg.jpeg?imageMogr2/thumbnail/360x360/format/webp/quality/100'}],
      imageUrl: '',
      dialogImageUrl: '',
      dialogVisible: false
    }
  },
  methods: {
    handleRemove (file, fileList) {
      console.log(file, fileList)
    },
    handlePreview (file) {
      console.log(file)
    },
    handleExceed (files, fileList) {
      this.$message.warning(`当前限制选择 3 个文件，本次选择了 ${files.length} 个文件，共选择了 ${files.length + fileList.length} 个文件`)
    },
    beforeRemove (file, fileList) {
      return this.$confirm(`确定移除 ${file.name}？`)
    },
    handleAvatarSuccess(res, file) {
      this.imageUrl = URL.createObjectURL(file.raw);
    },
    beforeAvatarUpload(file) {
      const isJPG = file.type === 'image/jpeg';
      const isLt2M = file.size / 1024 / 1024 < 2;

      if (!isJPG) {
        this.$message.error('上传头像图片只能是 JPG 格式!');
      }
      if (!isLt2M) {
        this.$message.error('上传头像图片大小不能超过 2MB!');
      }
      return isJPG && isLt2M;
    },
    handlePictureCardPreview(file) {
      this.dialogImageUrl = file.url;
      this.dialogVisible = true;
    }
  }
}
</script>

<style lang="scss">
  .avatar-uploader .el-upload {
    border: 1px dashed #d9d9d9;
    border-radius: 6px;
    cursor: pointer;
    position: relative;
    overflow: hidden;
  }
  .avatar-uploader .el-upload:hover {
    border-color: #409EFF;
  }
  .avatar-uploader-icon {
    font-size: 28px;
    color: #8c939d;
    width: 178px;
    height: 178px;
    line-height: 178px;
    text-align: center;
  }
  .avatar {
    width: 178px;
    height: 178px;
    display: block;
  }
  h3{
    margin: 55px 0 20px;
    font-weight: 400;
    color: #1f2f3d;
    font-size: 22px;
  }
  p{
    font-size: 14px;
    color: #5e6d82;
    line-height: 1.5em;
  }
</style>
