[Wiki] Errors

errors.md

Errors

Types of errors

• unexpected
  • server offline
  • unhandled exceptions
  • network is down
• expected
  • 400 - Bad Request
  • 404 - Not Found

Make sure you handle those types accordingly(by status code checks, etc.)

Handling HTTP errors in Angular

Make sure you've already set up a service for dealing with data.
Use the catch operator to return new observable which contains the error

...
Obervable.throw(...{type of error})
...

type of error - specific to our application domain
which means, create new class which represents app specific errors

class AppError {
  constructor(public originalError?: any) {}
}

Create specific app domain errors which inherit from the general app error

class NotFoundError extends AppError {}

Service level - check the status and return new Observable based on the type of app domain error
Component level - check if the error is an instance of specific type of app domain class error and act accordingly

Angular does provide global error handler