Angular2 RC6 HttpModule manual injection

问题

I'm migrating a project from angular2 RC4 to RC6 and I have a custom Form Validator which needs Http. Before the migration I used the ReflectiveInjector with the HTTP_PROVIDERS, but with RC6 this is not possible anymore as HTTP_PROVIDERS is deprecated, respectively not present anymore. This is the static method in the Validator:

    static checkVat(control: FormControl) {
    let checkVatUrl = "http://localhost:8080/checkvat";


    let injector = ReflectiveInjector.resolveAndCreate([HTTP_PROVIDERS]);
    let http = injector.get(Http);
    let authHttp = new AuthHttp(new AuthConfig(), http);

    if (control.value === "") {
        return new Observable((obs: any) => {
            obs.next(null);
            obs.complete();
        });
    } else {
        return authHttp.get(checkVatUrl + "/" + control.value)
            .map((data: Response) => {
                if (data.json().valid) {
                    return null;
                } else {
                    let reason = "isNotValidVat";
                    return {[reason]: true};
                }
            })
            .catch(function (e) {
                return new Observable((obs: any) => {
                    obs.complete();
                });
            });
    }
}

Just replacing HTTP_PROVIDERS with HttpModule didn't work, I found a similar problem here on stackoverflow (NG2 RC5: HTTP_PROVIDERS is deprecated) regarding testing, but the only answer is specific for testing.

How do I manually "inject" Http or HttpModule with RC6, if there is another or better solution for this custom Validator I'm open to that too.

Thanks in advance.

UPDATE: The checkVat method is static, that is why I had to use the ReflectiveInjector and not just inject it via the constructor, like everywhere else. The custom Validator gets used like this:

this.vatCtrl = new FormControl("", Validators.compose([Validators.pattern(this.vatService.vatPattern)]),VatValidator.checkVat);

UPDATE2: With the help of Günther Zöchbauer's answer I changed the Code as follows to get it working without a static function and no need for manual injection:

The Validator:

@Injectable()

export class VatValidator {

constructor(private http: Http) {
}

checkVat(control: FormControl) {

    let checkVatUrl = "http://localhost:8080/checkvat";

    let authHttp = new AuthHttp(new AuthConfig(), this.http);

    if (control.value === "") {
        return new Observable((obs: any) => {
            obs.next(null);
            obs.complete();
        });
    } else {
        return authHttp.get(checkVatUrl + "/" + control.value)
            .map((data: Response) => {
                if (data.json().valid) {
                    return null;
                } else {
                    let reason = "isNotValidVat";
                    return {[reason]: true};
                }
            })
            .catch(function (e) {
                return new Observable((obs: any) => {
                    obs.complete();
                });
            });
    }

}

}

In the component which has the FormControl:

    constructor(private vatValidator: VatValidator) {

    this.vatCtrl = new FormControl("", Validators.compose([Validators.pattern(vatPattern)]), this.vatValidator.checkVat.bind(this.vatValidator));

}

回答1:

If you change your validator class a bit, you don't need a static method

@Injectable()
class PatternValidator {
  constructor(private http:Http){}

  // this is a method that returns a validator function  
  // configured with a pattern
  pattern(pattern) {
    return (control:Control) => {
      this.http.get(...)

    ...
    }
  }
}

You can use it like:

• inject it to your component so DI passes it's dependencies in (Http)

constructor(private pattern:PatternValidator) {}

• pass it with bind(pattern) so .this keeps working inside the validator function

this.vatCtrl = new FormControl("", 
    Validators.compose([
        this.pattern(this.vatService.vatPattern).bind(this.pattern)
    ]), VatValidator.checkVat);

See also Inject Http manually in angular 2

回答2:

import { ReflectiveInjector } from '@angular/core';
import { Http, XHRBackend, ConnectionBackend, BrowserXhr, ResponseOptions, XSRFStrategy, BaseResponseOptions, CookieXSRFStrategy, RequestOptions, BaseRequestOptions } from '@angular/http';

class MyCookieXSRFStrategy extends CookieXSRFStrategy {}

...

let http =  ReflectiveInjector.resolveAndCreate([
        Http, BrowserXhr, 
        { provide: ConnectionBackend, useClass: XHRBackend },
        { provide: ResponseOptions, useClass: BaseResponseOptions },
        { provide: XSRFStrategy, useClass: MyCookieXSRFStrategy },
        { provide: RequestOptions, useClass: BaseRequestOptions }
      ]).get(Http);

Sure, you still need HttpModule included, enjoy!

回答3:

With and after RC5 what you can do is,

import { HttpModule} from '@angular/http';
@NgModule({
  imports:      [ BrowserModule,HttpModule ],  //<------HttpModule
  declarations: [ AppComponent],
  providers:    [service],

  bootstrap:    [ AppComponent ]
})

And In service or component,

import { Http, Response } from '@angular/http';
@Injectable()
export class service{
  constructor(private http:Http){}           //<----inject here

  // use http here
}

来源：https://stackoverflow.com/questions/39406933/angular2-rc6-httpmodule-manual-injection