Angular 在可观察订阅方法中包含逻辑可以吗？
我在看@john_lindquist关于RxJS的书呆子教程，他反复强调不包括业务逻辑而不是Angular 在可观察订阅方法中包含逻辑可以吗？,angular,rxjs,observable,apollo-client,Angular,Rxjs,Observable,Apollo Client,我在看@john_lindquist关于RxJS的书呆子教程，他反复强调不包括业务逻辑而不是.subscribe（）方法 因此，我正在创建一个canActivate guard来防止用户进入无效路由，我不得不在subscribe方法中构建逻辑。有更好的方法吗 从'@angular/core'导入{Injectable}； 从'@angular/Router'导入{CanActivate，ActivatedRouteSnapshot，Router}； 从'rxjs/Subscription'导入{
.subscribe（）从'@angular/core'导入{Injectable}；
从'@angular/Router'导入{CanActivate，ActivatedRouteSnapshot，Router}；
从'rxjs/Subscription'导入{Subscription}；
从'rxjs/Subject'导入{Subject}；
从“阿波罗角度”导入{Apollo，ApolloQueryObservable}；
从“/ticket.model”导入{GQTicketId}；
@可注射（）
导出类TicketOutactivatorService实现CanActivate{
公众票；
private returnTrue:Subject=new Subject（）；
私家票认购：认购；
建造师（私人阿波罗：阿波罗，
专用路由器：路由器{}
canActivate（路由：ActivatedRouteSnapshot）{
this.ticketSubscription=this.apollo.watchQuery({
查询：GQTicketId，
变量：{
_id:+route.params['id']
}
}).subscribe（{data}）=>{
this.ticket=数据['ticket']；
//至少根据约翰·林奎斯特（John Linquidst）的指导，这似乎不对。这种逻辑应该是“Rx'd”吗？
如果（！这张票）{
this.router.navigate（['provision/requests/error/404']）；
}否则{
this.returnTrue.next（true）；
}
}
);
如果（this.returnTrue）返回true；
}
//我们需要退订吗？
ngOnDestroy（）：void{
此.ticketSubscription.unsubscribe（）；
}
}
canActivate(route: ActivatedRouteSnapshot) {
// canActivate can return an Observable -
// the Observable emitting a true or false value
// is similar to returning an explicit true or false
// but by returning the observable, you let the router
// manage the subscription (and unsubscription) instead of doing it yourself
// doing this removes the need for the `unsubscribe` in your code
return this.apollo.watchQuery({
query: GQTicketId,
variables: {
_id: +route.params['id']
}
})
// there should be no arguing about this point -
// you only care about the data['ticket'] property,
// not the entire data object, so let's map our observable
// to only deal with ticket
.map(response => response.data.ticket)
// you want to do a side effect if ticket is falsy
// so the do operator is your best friend for side effect code
.do(ticket => {
if(!ticket) {
this.router.navigate(['provision/requests/error/404']);
}
})
}
canActivate(route: ActivatedRouteSnapshot) {
return this.apollo.watchQuery({
query: GQTicketId,
variables: {
_id: +route.params['id']
}
}).map(response => response.data.ticket)
.do(ticket => {
if(!ticket) {
this.router.navigate(['provision/requests/error/404']);
}
})
}
我看了约翰的视频，但现在记不起具体细节了。但是，RxJS的关键之处在于，通过正确使用操作符，通常可以删除大量命令式代码，否则这些代码将最终出现在
subscribesubscribesubscribecanActivate(route: ActivatedRouteSnapshot) {
// canActivate can return an Observable -
// the Observable emitting a true or false value
// is similar to returning an explicit true or false
// but by returning the observable, you let the router
// manage the subscription (and unsubscription) instead of doing it yourself
// doing this removes the need for the `unsubscribe` in your code
return this.apollo.watchQuery({
query: GQTicketId,
variables: {
_id: +route.params['id']
}
})
// there should be no arguing about this point -
// you only care about the data['ticket'] property,
// not the entire data object, so let's map our observable
// to only deal with ticket
.map(response => response.data.ticket)
// you want to do a side effect if ticket is falsy
// so the do operator is your best friend for side effect code
.do(ticket => {
if(!ticket) {
this.router.navigate(['provision/requests/error/404']);
}
})
}
canActivate(route: ActivatedRouteSnapshot) {
return this.apollo.watchQuery({
query: GQTicketId,
variables: {
_id: +route.params['id']
}
}).map(response => response.data.ticket)
.do(ticket => {
if(!ticket) {
this.router.navigate(['provision/requests/error/404']);
}
})
}
我看了约翰的视频，但现在记不起具体细节了。但是，RxJS的关键之处在于，通过正确使用操作符，通常可以删除大量命令式代码，否则这些代码将最终出现在
subscribesubscribesubscribesubscribecanActivatecanActivatesubscribecanActivatecanActivatedotapdotap