import { Injectable },angular,compilation,try-catch"/>
	














    

		

        

            
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首页  > 解决方案 > “可观察”类型上不存在“捕获”'





import { Injectable }












angular - “可观察”类型上不存在“捕获”'





import { Injectable }





问题描述







import { Injectable } from '@angular/core';
import { HttpClient, HttpErrorResponse } from '@angular/common/http';
import { catchError } from 'rxjs/operators';
import { Observable, throwError } from 'rxjs';
import { AppError } from './../common/app-error';
import 'rxjs/add/operator/catch';
import 'rxjs/add/observable/throw';

@Injectable({
  providedIn: 'root'
})
export class PostService {
  private url = 'http://jsonplaceholder.typicode.com/posts';

  constructor(private http:HttpClient) { }
    
    getPosts(){
    return this.http.get(this.url);
    }
    createPost(post){
    return this.http.post(this.url, JSON.stringify(post));
    }
    updatePost(post){
    return this.http.put(this.url + '/' + post.id, JSON.stringify(post));
    }
    deletePost(id){
    return this.http.delete(this.url + '/' + id)
      .catch((error:Response)=>{
       return Observable.throw(new AppError(error));
        
      });
    }
  }









here compile time error in .catch part.
I just want to perform error Handeling. and use catch by importing it but it will show error. that 'catch' does not exist on type
'Observable'









With a combination of position and substring functions.



substring(val,position('-' in val)+1,8)




To reformat in the hyphenated format, use to_char, after casting the substring to date.(The assumption is that the substring is a valid date)



to_char(substring(val,position('-' in val)+1,8)::date,'yyyy-MM-dd')



标签： angularcompilationtry-catch


解决方案









使用 rxjs错误处理的错误处理函数 - catch。您的代码将如下所示：



deletePost(id){
return this.http.delete(this.url + '/' + id)
   .pipe(catchError(err => of(new AppError(err))))
}











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