@ -27,13 +27,13 @@ An `HttpInterceptor` is able to catch `HttpErrorResponse` and can be used for
## RestService
ABP core module has a utility service for HTTP requests: `RestService`. Unless explicitly configured otherwise, it catches HTTP errors and dispatches a `RestOccurError` action. This action is then captured by the `ErrorHandler` introduced by the `ThemeSharedModule`. Since you should already import this module in your app, when the `RestService` is used, all HTTP errors get automatically handled by deafult.
ABP core module has a utility service for HTTP requests: `RestService`. Unless explicitly configured otherwise, it catches HTTP errors and dispatches a `RestOccurError` action. This action is then captured by the `ErrorHandler` introduced by the `ThemeSharedModule`. Since you should already import this module in your app, when the `RestService` is used, all HTTP errors get automatically handled by default.
### Getting Started with RestService
In order to use the `RestService`, you must inject it in your class as a dependency.
In order to use the `RestService`, you must inject it in your class as a dependency.
```js
import { RestService } from '@abp/ng.core';
@ -200,6 +200,101 @@ getSomeCustomHeaderValue() {
}
```
You may find `Rest.Observe` enum [here](https://github.com/abpframework/abp/blob/dev/npm/ng-packs/packages/core/src/lib/models/rest.ts#L10).
You may find `Rest.Observe` enum [here](https://github.com/abpframework/abp/blob/dev/npm/ng-packs/packages/core/src/lib/models/rest.ts#L10).
## HTTP Error Handling
When the `RestService` is used, all HTTP errors are automatically handled by `ErrorHandler` which is a service that exposed by the `@abp/ng.theme.shared` package.
### Custom HTTP Error Handler
A custom HTTP error handler can be registered to an injection token named `HTTP_ERROR_HANDLER`. If a custom handler function is registered, the `ErrorHandler` executes that function.
See an example:
```js
// http-error-handler.ts
import { ContentProjectionService, PROJECTION_STRATEGY } from '@abp/ng.core';
import { ToasterService } from '@abp/ng.theme.shared';
import { HttpErrorResponse } from '@angular/common/http';
import { Injector } from '@angular/core';
import { throwError } from 'rxjs';
import { Error404Component } from './error404/error404.component';
export function handleHttpErrors(injector: Injector, httpError: HttpErrorResponse) {
- Created a function named `handleHttpErrors` and defined as value of the `HTTP_ERROR_HANDLER` provider in app.module. After this, the function executes when an HTTP error occurs.
- 400 bad request errors is handled. When a 400 error occurs, backend error message will be displayed as shown below:
- Since `throwError(httpError)` is returned at bottom of the `handleHttpErrors`, the `ErrorHandler` will handle the HTTP errors except 400 and 404 errors.
**Note 1:** If you put `return` to next line of handling an error, default error handling will not work for that error.
```js
export function handleHttpErrors(injector: Injector, httpError: HttpErrorResponse) {
if (httpError.status === 403) {
// handle 403 errors here
return; // put return to skip default error handling
}
}
```
**Note 2:** If you put `return throwError(httpError)`, default error handling will work.
- `throwError` is a function. It can be imported from `rxjs`.
- `httpError` is the second parameter of the error handler function which is registered to the `HTTP_ERROR_HANDLER` provider. Type of the `httpError` is `HttpErrorResponse`.
```js
import { throwError } from 'rxjs';
export function handleHttpErrors(injector: Injector, httpError: HttpErrorResponse) {
if (httpError.status === 500) {
// handle 500 errors here
return;
}
// you can return the throwError(httpError) at bottom of the function to run the default handler of ABP for HTTP errors that you didn't handle above.
`RouterEvents` is a utility service to provide an easy implementation for one of the most frequent needs in Angular templates: `TrackByFunction`. Please see [this page in Angular docs](https://angular.io/guide/template-syntax#ngfor-with-trackby) for its purpose.
`RouterEvents` is a utility service for filtering specific router events and reacting to them. Please see [this page in Angular docs](https://angular.io/api/router/Event) for available router events.
Ilkay Ilknur
6 years ago
