ReferencecatchError
Reference · 32
catchError
catchError
Catches an error and returns a fallback Observable.
Signature
catchError(selector: (err: any, caught: Observable) => ObservableInput): OperatorFunctionMarble diagram
in: --1--2--#
catch->fallback: --1--2--f|What it does
On a source error it calls selector(err, caught). The returned Observable becomes the stream's continuation. The second argument, caught, is the original Observable; re-subscribing to it implements a "retry by hand".
When to use
A fallback value (catchError(() => of([]))), transforming errors (throwError(() => new MyError(...))), a silencer (EMPTY).
Gotcha
catchError replaces the stream. After it, the following operators work with the new stream, and the original no longer emits.
See also
retry, finalize, throwError
script.ts
CONSOLE · Console output
Hit Run to see the result...