在这种情况下如何管理错误块-服务中的错误管理并发送给组件
首先将数据存储在BehaviorSubject中,然后从我需要的位置订阅数据。
仅在应用运行时从app.component初始化预加载功能-但我想在这里知道它是否出错
//**app component**
//just initializing preload function() when the app runs - but I want to know here if its an error
ngOnInit() {
this.projectsService.preloadAllProjects();
}
// == services ==
//preload all projects
preloadAllProjects(){
this.http.get('/api/project/allprojects').pipe( map( response => response )).subscribe(result => {
this.allProjectsBehavior.next(result);
});
};
答案 0 :(得分:1)
如果要遵循主题路径:
//**app component**
//just initializing preload function() when the app runs - but I want to know here if its an error
ngOnInit() {
this.projectsService.preloadAllProjects();
this.projectService.error$.subscribe(error => console.log(error));
}
// == services ==
//preload all projects
error$: Subject<string> = new Subject();
preloadAllProjects(){
this.http.get('/api/project/allprojects').pipe( map( response => response )).subscribe(result => {
this.allProjectsBehavior.next(result);
}, error => this.error$.next(error);
};
或者您基本上可以从preloadAllProjects
返回一个Observable:
//**app component**
//just initializing preload function() when the app runs - but I want to know here if its an error
ngOnInit() {
this.projectsService.preloadAllProjects().subscribe(success => {}, error => console.log(error))
}
// == services ==
//preload all projects
error$: Subject<string> = new Subject();
preloadAllProjects(){
return new Observable(observer => {
this.http.get('/api/project/allprojects').pipe( map( response => response )).subscribe(result => {
this.allProjectsBehavior.next(result);
observer.next(true);
observer.complete();
}, error => observer.error(error);
});
};
答案 1 :(得分:1)
您可以添加 catchError 运算符,或将第二个函数传递给您的 subscribe 函数。
解决方案1。:
preloadAllProjects(){
this.http.get('/api/project/allprojects').pipe(
catchError(err => console.error(err)),
map( response => response )).subscribe(result => {
this.allProjectsBehavior.next(result);
});
};
解决方案2:
preloadAllProjects(){
this.http.get('/api/project/allprojects').pipe(
map( response => response )).subscribe(result => {
this.allProjectsBehavior.next(result);
},
error => console.error(error)
);
};