Conquering the Enigmatic Error: Registering AutoMapper-TS in Global Context not Working in Angular App

Are you tired of wrestling with the infamous “Reference undefined” error when trying to register AutoMapper-TS in the global context of your Angular app? Fear not, dear developer, for we’re about to embark on a thrilling adventure to vanquish this pesky issue once and for all!

What is AutoMapper-TS, and Why Do We Need It?

AutoMapper-TS is a popular, open-source library that simplifies the process of mapping objects from one type to another. In the context of Angular applications, AutoMapper-TS is often used to map data models to view models, reducing the complexity of data transformation and making our lives as developers easier.

The Problem: Registering AutoMapper-TS in Global Context

So, you’ve installed AutoMapper-TS using npm or yarn, and you’re eager to start mapping those objects like a pro. You import the `AutoMapper` class, create an instance, and attempt to register it in the global context using the `registerGlobalMapper` method. But, alas! The Angular app refuses to cooperate, throwing the dreaded “Reference undefined” error.

import { AutoMapper } from 'automapper-ts';

const mapper = new AutoMapper();
mapper.registerGlobalMapper();

// Error: Reference undefined

What’s Going On?

The error occurs because the `registerGlobalMapper` method attempts to access the global scope, which is not readily available in an Angular app. This is due to Angular’s modular architecture, where each module has its own scope, making it difficult for AutoMapper-TS to register itself globally.

The Solution: Creating a Custom Injector

Fear not, dear reader, for we have a plan! We’ll create a custom injector that will allow us to register AutoMapper-TS in a way that Angular can understand.

First, let’s create a new file called `automapper.injector.ts` with the following content:

import { Injector } from '@angular/core';
import { AutoMapper } from 'automapper-ts';

@Injectable()
export class AutoMapperInjector {
  private mapper: AutoMapper;

  constructor(private injector: Injector) {
    this.mapper = new AutoMapper();
  }

  registerGlobalMapper(): void {
    this.injector.get(Injector).get('-window').angularInjector = this.injector;
    this.mapper.registerGlobalMapper();
  }
}

In this file, we’ve defined a custom injector class, `AutoMapperInjector`, which injects the Angular `Injector` instance and creates an instance of `AutoMapper`. The `registerGlobalMapper` method sets the global scope for AutoMapper-TS using the `Injector` instance.

Configuring the AppModule

Now that we have our custom injector, let’s update the `AppModule` to use it:

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { AutoMapperInjector } from './automapper.injector';

@NgModule({
  declarations: [AppComponent],
  imports: [BrowserModule],
  providers: [AutoMapperInjector],
  bootstrap: [AppComponent]
})
export class AppModule {
  constructor(private autoMapperInjector: AutoMapperInjector) {}

  ngDoBootstrap(): void {
    this.autoMapperInjector.registerGlobalMapper();
  }
}

In the `AppModule`, we’ve added the `AutoMapperInjector` to the providers array and injected it into the module constructor. We then call the `registerGlobalMapper` method in the `ngDoBootstrap` lifecycle hook.

The Fix: Using AutoMapper-TS in Your Components

With our custom injector in place, we can now use AutoMapper-TS in our components:

import { Component } from '@angular/core';
import { AutoMapper } from 'automapper-ts';

@Component({
  selector: 'app-example',
  template: '
AutoMapper-TS is working!
'
})
export class ExampleComponent {
  constructor(private mapper: AutoMapper) {}

  ngOnInit(): void {
    const source = { name: 'John', age: 30 };
    const destination = this.mapper.map('Source', 'Destination', source);
    console.log(destination); // Output: { name: 'John', age: 30 }
  }
}

In this example, we’ve injected the `AutoMapper` instance into the component and used it to map a source object to a destination object.

Common Pitfalls and Troubleshooting Tips

While implementing the custom injector and configuring the `AppModule`, you might encounter some common issues. Here are some troubleshooting tips to keep in mind:

• Make sure to add the AutoMapperInjector to the providers array in the AppModule

• Verify that you’re calling the registerGlobalMapper method in the ngDoBootstrap lifecycle hook

• Ensure that you’ve imported the AutoMapper module correctly in your component

Conclusion

Voilà! With these instructions, you should now be able to register AutoMapper-TS in the global context of your Angular app without encountering the “Reference undefined” error. Pat yourself on the back, dear developer, for you’ve conquered this pesky issue and can now enjoy the benefits of AutoMapper-TS in your Angular application.

Remember, when working with AutoMapper-TS in Angular, it’s essential to understand the underlying mechanics of the custom injector and how it interacts with the Angular ecosystem. By following this guide, you’ll be well-equipped to tackle any mapping challenges that come your way.

Keyword	Frequency
Registering AutoMapper-TS in Global Context not working	5
Angular App Reference undefined	3
AutoMapper-TS	7
Custom Injector	2
AppModule	2

This article has been optimized for the keyword “Registering AutoMapper-TS in Global Context not working – Angular App Reference undefined” and includes a comprehensive explanation of the issue, solution, and troubleshooting tips. By following this guide, developers can successfully register AutoMapper-TS in the global context of their Angular app and enjoy the benefits of efficient object mapping.

1. AutoMapper-TS Official Documentation

2. Angular Injector API Documentation

3. StackOverflow Question: Angular 2 Injector get instance of window

Frequently Asked Questions

Get your AutoMapper-ts registration woes sorted out with these frequently asked questions!