angular-cn/packages/core/src/error_handler.ts

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/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {getDebugContext, getErrorLogger, getOriginalError} from './errors';
/**
* Provides a hook for centralized exception handling.
*
* The default implementation of `ErrorHandler` prints error messages to the `console`. To
* intercept error handling, write a custom exception handler that replaces this default as
* appropriate for your app.
*
* @usageNotes
* ### Example
*
* ```
* class MyErrorHandler implements ErrorHandler {
* handleError(error) {
* // do something with the exception
* }
* }
*
* @NgModule({
* providers: [{provide: ErrorHandler, useClass: MyErrorHandler}]
* })
* class MyModule {}
* ```
*
* @publicApi
*/
export class ErrorHandler {
/**
* @internal
*/
_console: Console = console;
handleError(error: any): void {
const originalError = this._findOriginalError(error);
const context = this._findContext(error);
// Note: Browser consoles show the place from where console.error was called.
// We can use this to give users additional information about the error.
const errorLogger = getErrorLogger(error);
errorLogger(this._console, `ERROR`, error);
if (originalError) {
errorLogger(this._console, `ORIGINAL ERROR`, originalError);
}
if (context) {
errorLogger(this._console, 'ERROR CONTEXT', context);
}
}
/** @internal */
_findContext(error: any): any {
if (error) {
return getDebugContext(error) ? getDebugContext(error) :
this._findContext(getOriginalError(error));
}
return null;
}
/** @internal */
_findOriginalError(error: Error): any {
let e = getOriginalError(error);
while (e && getOriginalError(e)) {
e = getOriginalError(e);
}
return e;
}
}