I have a basic service that has a single string parameter
import {Injectable} from 'angular2/core';
@Injectable()
export class MyService {
constructor(someValue: string) {
}
}
If I remove the string param from the constructor the service will inject fine but I can't seem to figure out how to get a simple string to get injected.
I have defined a config to store application settings
import {OpaqueToken} from 'angular2/core';
export let APP_CONFIG = new OpaqueToken('app.config');
export interface Config {
appSetting: string,
}
export const CONFIG: Config = {
appSetting: "my application nsetting"
};
I defined a factory for MyService
import {provide} from 'angular2/core';
import {MyService} from './my.service';
import {Config, CONFIG} from './app.config';
let myServiceFactory = (config: Config) => {
return new MyService(config.appSetting);
}
export let myServiceProvider =
provide(MyService, {
useFactory: myServiceFactory,
deps: [CONFIG]
});
in my bootstrapping I register the provider
import {bootstrap} from 'angular2/platform/browser';
import {AppComponent} from './app.component';
import {provide} from 'angular2/core';
import {APP_CONFIG, CONFIG} from './app.config';
import {myServiceProvider} from './my.service.provider';
bootstrap(AppComponent,
[provide(APP_CONFIG, { useValue: CONFIG }),
myServiceProvider
]);
in my app component I try to inject myService
import {Component} from 'angular2/core';
import {MyService} from './my.service';
@Component({
selector: 'my-app',
template: '<h1>Angular 2 is running</h1>'
providers: [
MyService
]
})
export class AppComponent {
constructor(private _myService: MyService) {
}
}
the application never starts up and I get this error
0x800a139e - JavaScript runtime error: Uncaught (in promise): No provider for String! (AppComponent -> MyService -> String)
Check this plank, i've tried to fix your sample. You could inject string values in the same way as Config object using OpaqueTokens.
The most important parts:
deps: [APP_CONFIG]
provide(APP_CONFIG, { useValue: CONFIG })