添加课程分类-前端实现
1、添加路由
//添加 课程分类管理 路由
{
path: '/subject',
component: Layout,
redirect: '/subject/list',
name: '课程分类管理',
meta: { title: '课程分类管理', icon: 'example' },
children: [{
path: 'list',
name: '课程分类列表',
component: () =>
import ('@/views/edu/subject/list'),
meta: { title: '课程分类列表', icon: 'table' }
},
{
path: 'save',
name: '添加课程分类',
component: () =>
import ('@/views/edu/subject/save'),
meta: { title: '添加课程分类', icon: 'tree' }
}
]
},
2、添加页面
选用 饿了么 上传组件
edu-subject-save.vue
<template>
<div class="app-container">
<el-form label-width="120px">
<el-form-item label="信息描述">
<el-tag type="info">excel模版说明</el-tag>
<el-tag>
<i class="el-icon-download"/>
<a :href="'/static/01.xlsx'">点击下载模版</a>
</el-tag>
</el-form-item>
<el-form-item label="选择Excel">
<el-upload
ref="upload"
:auto-upload="false"
:on-success="fileUploadSuccess"
:on-error="fileUploadError"
:disabled="importBtnDisabled"
:limit="1"
:action="BASE_API+'/eduservice/subject/addSubject'"
name="file"
accept="application/vnd.ms-excel">
<el-button slot="trigger" size="small" type="primary">选取文件</el-button>
<el-button
:loading="loading"
style="margin-left: 10px;"
size="small"
type="success"
@click="submitUpload">上传到服务器</el-button>
</el-upload>
</el-form-item>
</el-form>
</div>
</template>
<script>
export default {
data() {
return {
BASE_API: process.env.VUE_APP_BASE_API, // 接口API地址 20210128需要修改。
importBtnDisabled: false, // 按钮是否禁用,
loading: false
}
},
created() {
},
methods:{
//点击按钮上传文件到接口里面
submitUpload() {
this.importBtnDisabled = true
this.loading = true
// js: document.getElementById("upload").submit()
this.$refs.upload.submit()
},
//上传成功
fileUploadSuccess(response) {
//提示信息
this.loading = false
this.$message({
type: 'success',
message: '添加课程分类成功'
})
//跳转课程分类列表
//路由跳转
this.$router.push({path:'/subject/list'})
},
//上传失败
fileUploadError() {
this.loading = false
this.$message({
type: 'error',
message: '添加课程分类失败'
})
}
}
}
</script>
list.vue
<template>
<div class="app-container">
<el-input v-model="filterText" placeholder="Filter keyword" style="margin-bottom:30px;" />
<el-tree
ref="tree2"
:data="data2"
:props="defaultProps"
:filter-node-method="filterNode"
class="filter-tree"
default-expand-all
/>
</div>
</template>
<script>
import subject from '@/api/edu/subject'
export default {
data() {
return {
filterText: '',
data2: [], //返回所有分类数据
defaultProps: {
children: 'children',
label: 'title'
}
}
},
created() {
this.getAllSubjectList()
},
watch: {
filterText(val) {
this.$refs.tree2.filter(val)
}
},
methods: {
getAllSubjectList() {
subject.getSubjectList()
.then(response => {
this.data2 = response.data.list
})
},
filterNode(value, data) {
if (!value) return true
return data.title.toLowerCase().indexOf(value.toLowerCase()) !== -1
}
}
}
</script>
创建接口，返回特定格式得json数据
后台代码
EduSubjectController
//课程分类列表（树形）
@GetMapping("getAllSubject")
public R getAllSubject() {
//list集合泛型是一级分类
List<OneSubject> list = subjectService.getAllOneTwoSubject();
return R.ok().data("list",list);
}
因为需要返回特定格式得json数据，为了区分一级分类和二级分类，建两个实体类
实体类之间得关系
//一级分类
@Data
public class OneSubject {
private String id;
private String title;
//一个一级分类有多个二级分类
private List<TwoSubject> children = new ArrayList<>();
}
写实现类
EduSubjectServiceImpl.java
分析
//1 查询所有一级分类 parentid = 0
service需要调用mapper，而实现类中已经自动注入了，只需要调用baseMapper即可
//2 查询所有二级分类 parentid != 0
//3 封装一级分类
//4 封装二级分类
//1 查询所有一级分类 parentid = 0
QueryWrapper<EduSubject> wrapperOne = new QueryWrapper<>();
wrapperOne.eq("parent_id","0");
List<EduSubject> oneSubjectList = baseMapper.selectList(wrapperOne);
//2 查询所有二级分类 parentid != 0
QueryWrapper<EduSubject> wrapperTwo = new QueryWrapper<>();
wrapperTwo.ne("parent_id","0");
List<EduSubject> twoSubjectList = baseMapper.selectList(wrapperTwo);
分析：List
但是并不是我们希望传到前端得格式，因此需要把查出来得数据封装成Json格式。放到list集合中
//创建list集合，用于存储最终封装数据
List<OneSubject> finalSubjectList = new ArrayList<>();
//3 封装一级分类
//4 封装二级分类
嵌套for循环
//3 封装一级分类
//查询出来所有的一级分类list集合遍历，得到每个一级分类对象，获取每个一级分类对象值，
//封装到要求的list集合里面 List<OneSubject> finalSubjectList
for (int i = 0; i < oneSubjectList.size(); i++) { //遍历oneSubjectList集合
//得到oneSubjectList每个eduSubject对象
EduSubject eduSubject = oneSubjectList.get(i);
//把eduSubject里面值获取出来，放到OneSubject对象里面
OneSubject oneSubject = new OneSubject();
//eduSubject值复制到对应oneSubject对象里面
BeanUtils.copyProperties(eduSubject,oneSubject);
//多个OneSubject放到finalSubjectList里面
finalSubjectList.add(oneSubject);
//在一级分类循环遍历查询所有的二级分类
//创建list集合封装每个一级分类的二级分类
List<TwoSubject> twoFinalSubjectList = new ArrayList<>();
//遍历二级分类list集合
for (int m = 0; m < twoSubjectList.size(); m++) {
//获取每个二级分类
EduSubject tSubject = twoSubjectList.get(m);
//判断二级分类parentid和一级分类id是否一样
if(tSubject.getParentId().equals(eduSubject.getId())) {
//把tSubject值复制到TwoSubject里面，放到twoFinalSubjectList里面
TwoSubject twoSubject = new TwoSubject();
BeanUtils.copyProperties(tSubject,twoSubject);
twoFinalSubjectList.add(twoSubject);
}
}
//把一级下面所有二级分类放到一级分类里面
oneSubject.setChildren(twoFinalSubjectList);
}
前端接口：
import request from '@/utils/request'
export default {
//1 课程分类列表
getSubjectList() {
return request({
url: '/eduservice/subject/getAllSubject',
method: 'get'
})
}
}
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