一、新增

1、定义api

src/api/edu/teacher.js

save(teacher) {
    return request({
        url: api_name,
        method: 'post',
        data: teacher
    })
}

2、初始化组件

src/views/edu/teacher/form.vue

html

<template>
  <div class="app-container">
    <el-form label-width="120px">
      <el-form-item label="讲师名称">
        <el-input v-model="teacher.name"/>
      </el-form-item>
      <el-form-item label="讲师排序">
        <el-input-number v-model="teacher.sort" controls-position="right" min="0"/>
      </el-form-item>
      <el-form-item label="讲师头衔">
        <el-select v-model="teacher.level" clearable placeholder="请选择">
          <!--
            数据类型一定要和取出的json中的一致，否则没法回填
            因此，这里value使用动态绑定的值，保证其数据类型是number
          -->
          <el-option :value="1" label="高级讲师"/>
          <el-option :value="2" label="首席讲师"/>
        </el-select>
      </el-form-item>
      <el-form-item label="讲师资历">
        <el-input v-model="teacher.career"/>
      </el-form-item>
      <el-form-item label="讲师简介">
        <el-input v-model="teacher.intro" :rows="10" type="textarea"/>
      </el-form-item>

      <!-- 讲师头像：TODO -->

      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>

js

<script>
export default {
  data() {
    return {
      teacher: {
        name: '',
        sort: 0,
        level: 1,
        career: '',
        intro: '',
        avatar: ''
      },
      saveBtnDisabled: false // 保存按钮是否禁用,
    }
  },

  methods: {

    saveOrUpdate() {
      this.saveBtnDisabled = true
      this.saveData()
    },

    // 保存
    saveData() {

    }

  }
}
</script>

3、实现新增功能

引入teacher api模块

import teacher from '@/api/edu/teacher'

完善save方法

    // 保存
    saveData() {
      teacher.save(this.teacher).then(response => {
        return this.$message({
          type: 'success',
          message: '保存成功!'
        })
      }).then(resposne => {
        this.$router.push({ path: '/edu/teacher' })
      }).catch((response) => {
        // console.log(response)
        this.$message({
          type: 'error',
          message: '保存失败'
        })
      })
    }

二、回显

1、定义api

src/api/edu/teacher.js

getById(id) {
    return request({
        url: `${api_name}/${id}`,
        method: 'get'
    })
}

2、组件中调用api

methods中定义fetchDataById

// 根据id查询记录
fetchDataById(id) {
    teacher.getById(id).then(response => {
        this.teacher = response.data.item
    }).catch((response) => {
        this.$message({
            type: 'error',
            message: '获取数据失败'
        })
    })
}

3、页面渲染前调用fetchDataById

  created() {
    console.log('created')
    if (this.$route.params && this.$route.params.id) {
      const id = this.$route.params.id
      this.fetchDataById(id)
    }
  }

三、更新

1、定义api

updateById(teacher) {
    return request({
        url: `${api_name}/${teacher.id}`,
        method: 'put',
        data: teacher
    })
}

2、组件中调用api

methods中定义updateData

// 根据id更新记录
updateData() {
    this.saveBtnDisabled = true
    teacher.updateById(this.teacher).then(response => {
        return this.$message({
            type: 'success',
            message: '修改成功!'
        })
    }).then(resposne => {
        this.$router.push({ path: '/edu/teacher' })
    }).catch((response) => {
        // console.log(response)
        this.$message({
            type: 'error',
            message: '保存失败'
        })
    })
}

3、完善saveOrUpdate方法

saveOrUpdate() {
    this.saveBtnDisabled = true
    if (!this.teacher.id) {
        this.saveData()
    } else {
        this.updateData()
    }
}

四、存在问题

vue-router导航切换 时，如果两个路由都渲染同个组件，组件会重（chong）用,

组件的生命周期钩子（created）不会再被调用, 使得组件的一些数据无法根据 path的改变得到更新

因此：

1、我们可以在watch中监听路由的变化，当路由变化时，重新调用created中的内容

2、在init方法中我们判断路由的变化，如果是修改路由，则从api获取表单数据，

如果是新增路由，则重新初始化表单数据

<script>
import teacher from '@/api/edu/teacher'

const defaultForm = {
  name: '',
  sort: 0,
  level: '',
  career: '',
  intro: '',
  avatar: ''
}

export default {
  data() {
    return {
      teacher: defaultForm,
      saveBtnDisabled: false // 保存按钮是否禁用,
    }
  },

  watch: {
    $route(to, from) {
      console.log('watch $route')
      this.init()
    }
  },

  created() {
    console.log('created')
    this.init()
  },

  methods: {

    init() {
      if (this.$route.params && this.$route.params.id) {
        const id = this.$route.params.id
        this.fetchDataById(id)
      } else {
        // 使用对象拓展运算符，拷贝对象，而不是引用，
        // 否则新增一条记录后，defaultForm就变成了之前新增的teacher的值
        this.teacher = { ...defaultForm }
      }
    },

    ......
  }
}
</script>