If I use es6/7 (babel - stage 1) instead of TypeScript, how are services, and specifically Http, injected?
Here's my component JS:
import {Component, Inject, View, CORE_DIRECTIVES, ViewEncapsulation} from 'angular2/angular2';
import {Http} from 'angular2/http';
@Component({
selector: 'login'
})
@View({
templateUrl: './components/login/login.html',
styleUrls: ['components/login/login.css'],
directives: [CORE_DIRECTIVES],
encapsulation: ViewEncapsulation.Emulated
})
export class Login {
constructor(@Inject(Http) http) {
console.log('http', http);
}
authenticate(username, password) {
// this.http.get('/login');
}
}
I have tried:
export class Login {
constructor(@Inject(Http) http) {
console.log('http', http);
}
}
/********************/
@Inject(Http)
export class Login {
constructor(http) {
console.log('http', http);
}
}
/********************/
export class Login {
constructor(Http: http) {
console.log('http', http);
}
}
/********************/
export class Login {
constructor(http = Http) {
console.log('http', http);
}
}
/********************/
export class Login {
constructor(Http) {
this.http = new Http()
console.log('http', this.http);
}
}
/********************/
export class Login {
constructor(http = new Http()) {
console.log('http', http);
}
}
All but the first compiles. Others give me access to either the Http class or an http instance. But none works.
I tried to following the discussion referenced by Eric Martinez in his comment. Login.js now:
import {Component, Inject, View, CORE_DIRECTIVES, ViewEncapsulation} from 'angular2/angular2';
import {HTTP_BINDINGS, Http, BaseRequestOptions, RequestOptions, RequestMethods} from 'angular2/http';
@Component({
selector: 'login'
})
@View({
templateUrl: './components/login/login.html',
styleUrls: ['components/login/login.css'],
directives: [CORE_DIRECTIVES],
encapsulation: ViewEncapsulation.Emulated,
bindings: [Http]
})
export class Login {
constructor(http) {
this.http = http;
console.log('http', http);
}
authenticate(usernameEl, passwordEl) {
var username = usernameEl.value;
var password = passwordEl.value;
console.log('username', username, password);
// this.http.get('/login');
}
}
Login.parameters = [Http];
It compiles now but generates the following error:
Uncaught (in promise) NoBindingError {message: "No provider for Http! (Login -> Http)", stack: "Error: DI Exception↵ at NoBindingError.BaseExce…or._new (http://localhost:3000/bundle.js:7319:22)", keys: Array[2], injectors: Array[2]}constructResolvingMessage: (keys)arguments: (...)caller: (...)length: 1name: ""prototype: Object__proto__: ()context: (...)injectors: Array[2]0: Injector1: Injectorlength: 2__proto__: Array[0]keys: Array[2]message: "No provider for Http! (Login -> Http)"stack: "Error: DI Exception↵ at NoBindingError.BaseException [as constructor] (http://localhost:3000/bundle.js:8400:24)↵ at NoBindingError.AbstractBindingError [as constructor] (http://localhost:3000/bundle.js:9066:17)↵ at new NoBindingError (http://localhost:3000/bundle.js:9102:17)↵ at Injector._throwOrNull (http://localhost:3000/bundle.js:7469:20)↵ at Injector._getByKeyDefault (http://localhost:3000/bundle.js:7516:22)↵
at Injector._getByKey (http://localhost:3000/bundle.js:7461:26)↵ at Injector._getByDependency (http://localhost:3000/bundle.js:7447:26)↵
at Injector._instantiate (http://localhost:3000/bundle.js:7339:37)↵
at Injector._instantiateBinding (http://localhost:3000/bundle.js:7330:26)↵ at Injector._new (http://localhost:3000/bundle.js:7319:22)"proto: __
Since you have @Decorators
enabled in Babel
...I'll fine-tune this answer to work with your specific setup.
1. You're missing HTTP_PROVIDERS
The HTTP_PROVIDERS constant includes a number of functions required to handle HTTP requests/responses.
import {Http, HTTP_PROVIDERS} from 'angular2/http';
@Component({
selector: 'login',
providers: [ HTTP_PROVIDERS ]
})
2. You need to desugar the DI (Dependency Injection) syntax
As mentioned in @alexpods' answer.
Remove the static typing
constructor(http) {
@Inject handles DI implicitly but is only supported in Angular2+Typescript. Since you're using Angular2+ES6 you need to attach a static getter parameter to your class to provide the ES6-specific equivalent.
static get parameters() {
return [[Http]];
}
3. You need to bind the Http instance to your class in the constructor
By doing this, it will become accessible in your authenticate()
method.
constructor(http) {
this.http = http;
console.log('http', this.http);
}
...and the full implementation:
import {Component, Inject, View, CORE_DIRECTIVES, ViewEncapsulation} from 'angular2/angular2';
import {Http, HTTP_PROVIDERS} from 'angular2/http';
@Component({
selector: 'login',
// required for Http
providers: [ HTTP_PROVIDERS ]
})
@View({
templateUrl: './components/login/login.html',
styleUrls: ['components/login/login.css'],
directives: [CORE_DIRECTIVES],
encapsulation: ViewEncapsulation.Emulated
})
export class Login {
constructor(http) {
// bind http to your class during construction
// so it's available to authenticate()
this.http = http;
}
// Angular2 DI desugar'd
static get parameters() {
return [[Http]];
}
authenticate(username, password) {
this.http.get('/login');
}
}
Aside: I know for a fact this works because I'm using it for the <ng2-markdown>
component on EvanPlaice.com.
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