Angular2 Firebase数据分组
我希望有一个重复的数据，每个新组都有一个标题。我的数据模型非常简单Angular2 Firebase数据分组,angular,typescript,firebase,firebase-realtime-database,angularfire,Angular,Typescript,Firebase,Firebase Realtime Database,Angularfire,我希望有一个重复的数据，每个新组都有一个标题。我的数据模型非常简单 { "-K_kNx9_F2-eTul8548y": { "title": "Registration", "startTime": "2017-02-04T08:00-06:00" }, "-K_kQhBAJFTYEEqaXDp_": { "room": "Cafeteria", "startTime": "2017-02-04T12:00-06:00", "title": "
{
"-K_kNx9_F2-eTul8548y": {
"title": "Registration",
"startTime": "2017-02-04T08:00-06:00"
},
"-K_kQhBAJFTYEEqaXDp_": {
"room": "Cafeteria",
"startTime": "2017-02-04T12:00-06:00",
"title": "Lunch",
"track": "all"
},
...
}
<div *ngFor="**magic happens**">
<h2>{{time.label}}</h2>
<div *ngFor="let session of schedule | async">
{{session.title}}
</div>
</div>
您可以修改实现，每次执行单独的查询，方法如下：
import 'rxjs/add/operator/do';
import 'rxjs/add/operator/map';
export class ScheduleComponent {
times;
timesWithSchedules;
constructor(public af: AngularFire) {
// A list of times, as per your the code in your question:
this.times = af.database.list(PATH + '/scheduletimes');
// Compose an observable that adds the schedule for each time. Each
// emitted value will be an array of time entries. Enumerate the array
// and add an observable for the time's schedule:
this.timesWithSchedules = this.times.do(times => times.forEach(time => {
time.schedule = af.database
// Query the schedule entries that correspond the time:
.list(PATH + '/schedule', {
query: {
orderByChild: 'startTime'
startAt: time.time,
endAt: time.time
}
})
// Sort the emmitted array of sessions by title:
.map(schedule => schedule.sort(compareTitles));
function compareTitles(a, b) {
if (a.title < b.title) {
return -1;
}
if (a.title > b.title) {
return 1;
}
return 0;
}
}));
}
}
<div *ngFor="let time of timesWithSchedules | async">
<h2>{{time.label}}</h2>
<div *ngFor="let session of time.schedule | async">
{{session.title}}
</div>
</div>
导入'rxjs/add/operator/do'；
导入'rxjs/add/operator/map'；
导出类ScheduleComponent{
时代；
时间表；
建造商（公共af:AngularFire）{
//根据您的问题代码列出的时间列表：
this.times=af.database.list（PATH+'/scheduletimes'）；
//编写一个可观察的表格，为每一次添加时间表
//发出的值将是一个时间项数组。枚举该数组
//并为时间计划添加一个可观察的：
this.timesWithSchedules=this.times.do（times=>times.forEach（time=>{
time.schedule=af.database
//查询与时间对应的计划条目：
.列表（路径+“/计划”{
查询：{
orderByChild:“开始时间”
时间，时间，
endAt:time.time
}
})
//按标题对emmitted会话数组进行排序：
.map（schedule=>schedule.sort（compareTiles））；
函数比较（a、b）{
如果（a.标题b.标题）{
返回1；
}
返回0；
}
}));
}
}
import 'rxjs/add/operator/do';
import 'rxjs/add/operator/map';
export class ScheduleComponent {
times;
timesWithSchedules;
constructor(public af: AngularFire) {
// A list of times, as per your the code in your question:
this.times = af.database.list(PATH + '/scheduletimes');
// Compose an observable that adds the schedule for each time. Each
// emitted value will be an array of time entries. Enumerate the array
// and add an observable for the time's schedule:
this.timesWithSchedules = this.times.do(times => times.forEach(time => {
time.schedule = af.database
// Query the schedule entries that correspond the time:
.list(PATH + '/schedule', {
query: {
orderByChild: 'startTime'
startAt: time.time,
endAt: time.time
}
})
// Sort the emmitted array of sessions by title:
.map(schedule => schedule.sort(compareTitles));
function compareTitles(a, b) {
if (a.title < b.title) {
return -1;
}
if (a.title > b.title) {
return 1;
}
return 0;
}
}));
}
}
<div *ngFor="let time of timesWithSchedules | async">
<h2>{{time.label}}</h2>
<div *ngFor="let session of time.schedule | async">
{{session.title}}
</div>
</div>
{{time.label}
{{session.title}
import 'rxjs/add/operator/do';
import 'rxjs/add/operator/map';
export class ScheduleComponent {
times;
timesWithSchedules;
constructor(public af: AngularFire) {
// A list of times, as per your the code in your question:
this.times = af.database.list(PATH + '/scheduletimes');
// Compose an observable that adds the schedule for each time. Each
// emitted value will be an array of time entries. Enumerate the array
// and add an observable for the time's schedule:
this.timesWithSchedules = this.times.do(times => times.forEach(time => {
time.schedule = af.database
// Query the schedule entries that correspond the time:
.list(PATH + '/schedule', {
query: {
orderByChild: 'startTime'
startAt: time.time,
endAt: time.time
}
})
// Sort the emmitted array of sessions by title:
.map(schedule => schedule.sort(compareTitles));
function compareTitles(a, b) {
if (a.title < b.title) {
return -1;
}
if (a.title > b.title) {
return 1;
}
return 0;
}
}));
}
}
<div *ngFor="let time of timesWithSchedules | async">
<h2>{{time.label}}</h2>
<div *ngFor="let session of time.schedule | async">
{{session.title}}
</div>
</div>
导入'rxjs/add/operator/do'；
导入'rxjs/add/operator/map'；
导出类ScheduleComponent{
时代；
时间表；
建造商（公共af:AngularFire）{
//根据您的问题代码列出的时间列表：
this.times=af.database.list（PATH+'/scheduletimes'）；
//编写一个可观察的表格，为每一次添加时间表
//发出的值将是一个时间项数组。枚举该数组
//并为时间计划添加一个可观察的：
this.timesWithSchedules=this.times.do（times=>times.forEach（time=>{
time.schedule=af.database
//查询与时间对应的计划条目：
.列表（路径+“/计划”{
查询：{
orderByChild:“开始时间”
时间，时间，
endAt:time.time
}
})
//按标题对emmitted会话数组进行排序：
.map（schedule=>schedule.sort（compareTiles））；
函数比较（a、b）{
如果（a.标题b.标题）{
返回1；
}
返回0；
}
}));
}
}
import 'rxjs/add/operator/do';
import 'rxjs/add/operator/map';
export class ScheduleComponent {
times;
timesWithSchedules;
constructor(public af: AngularFire) {
// A list of times, as per your the code in your question:
this.times = af.database.list(PATH + '/scheduletimes');
// Compose an observable that adds the schedule for each time. Each
// emitted value will be an array of time entries. Enumerate the array
// and add an observable for the time's schedule:
this.timesWithSchedules = this.times.do(times => times.forEach(time => {
time.schedule = af.database
// Query the schedule entries that correspond the time:
.list(PATH + '/schedule', {
query: {
orderByChild: 'startTime'
startAt: time.time,
endAt: time.time
}
})
// Sort the emmitted array of sessions by title:
.map(schedule => schedule.sort(compareTitles));
function compareTitles(a, b) {
if (a.title < b.title) {
return -1;
}
if (a.title > b.title) {
return 1;
}
return 0;
}
}));
}
}
<div *ngFor="let time of timesWithSchedules | async">
<h2>{{time.label}}</h2>
<div *ngFor="let session of time.schedule | async">
{{session.title}}
</div>
</div>
{{time.label}
{{session.title}