v-model 指令妙用/图片上传/富文本上传

在平常封装组件时候，需要子组件和父组件的值是响应式的，就是子组件的值初始状态由父组件决定，当子组件改变后，父组件需要接受到变化后的值

子组件

<template>
    <div>
        <h3>这是子组件；假如子组件初始值是父组件传过来的，当数据变化，实时需要父组件监听到子组件变化</h3>
        <button @click="changeHandle">改变子组件值</button>
    </div>  
</template>
<script>
export default {
    props: {
        msg: {
            type:String,
            default:""
        }
    },
    methods: {
        changeHandle() {
            this.msg = "改变后的值"
          // 在这里发送 input事件，外面父组件通过v-model可以监听到input事件，因为v-model底层就是通过监听input事件
            this.$emit("input", this.msg);
        }
    },
}
</script>

父组件

<template>
    <div>
        <!-- <p>通过v-model获取子组件的响应数据</p> -->
        <Vmodel  v-model="msg"/>
        <P>改变后的值:{{msg}}</P>
    </div>
</template>
<script>
import Vmodel from "@/components/vmodel/Vmodel.vue"
export default {
    components: {Vmodel},
    data() {
        return {
            msg:"这是父组件初始值"
        }
    }
}
</script>

<style scoped>

</style>

一般开发时封装子组件都是自定义事件，父组件监听自定义事件，这样可以监控到每一个过程中数据，方便自己可以在什么时机内写入自己的逻辑
建议一般 图片上传组件，和富文本组件，使用v-model指令监听子组件的变化

通过v-model封装图片上传组件

1. 子组件

<template>
  <div class="component-upload-image">
    <el-upload
      :action="uploadImgUrl"
      list-type="picture-card"
      :on-success="handleUploadSuccess"
      :before-upload="handleBeforeUpload"
      :on-error="handleUploadError"
      name="file"
      :show-file-list="false"
      :headers="headers"
      style="display: inline-block; vertical-align: top"
    >
      <el-image v-if="!value" :src="value">
        <div slot="error" class="image-slot">
          <i class="el-icon-plus" />
        </div>
      </el-image>
      <div v-else class="image">
        <el-image :src="value" :style="`width:150px;height:150px;`" fit="fill"/>
        <div class="mask">
          <div class="actions">
            <span title="预览" @click.stop="dialogVisible = true">
              <i class="el-icon-zoom-in" />
            </span>
            <span title="移除" @click.stop="removeImage">
              <i class="el-icon-delete" />
            </span>
          </div>
        </div>
      </div>
    </el-upload>
    <el-dialog :visible.sync="dialogVisible" title="预览" width="800" append-to-body>
      <img :src="value" style="display: block; max-width: 100%; margin: 0 auto;">
    </el-dialog>
  </div>
</template>

<script>
import { getToken } from "@/utils/auth";

export default {
  data() {
    return {
      dialogVisible: false,
      uploadImgUrl: process.env.VUE_APP_BASE_API + "/common/upload", // 上传的图片服务器地址
      headers: {
        Authorization: "Bearer " + getToken(),
      },
    };
  },
  props: {
    value: {
      type: String,
      default: "",
    },
  },
  methods: {
    removeImage() {
      this.$emit("input", "");
    },
    handleUploadSuccess(res) {
      this.$emit("input", res.url);
      this.loading.close();
    },
    handleBeforeUpload() {
      this.loading = this.$loading({
        lock: true,
        text: "上传中",
        background: "rgba(0, 0, 0, 0.7)",
      });
    },
    handleUploadError() {
      this.$message({
        type: "error",
        message: "上传失败",
      });
      this.loading.close();
    },
  },
  watch: {},
};
</script>

<style scoped lang="scss">
.image {
  position: relative;
  .mask {
    opacity: 0;
    position: absolute;
    top: 0;
    width: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    transition: all 0.3s;
  }
  &:hover .mask {
    opacity: 1;
  }
}
</style>

2. 父组件:方便进行新增和修改操作

   <el-form>
      <el-form-item label="图片路径">
          <imageUpload v-model="form.tpurl"/>
        </el-form-item>
      </el-form>

富文本组件

敬请期待