URLs requested via Http on the server must be absolute. URL: ./assets/i18n/en.json

Question

I am new to Angular 2 and I have the following issue in the ngx-translate component (URLs requested via Http on the server must be absolute. URL: ./assets/i18n/en.json). I am sure that this en.json file is there as I make http request to it and the request succeeds

Here is my app.module.server.ts file:

import { NgModule } from '@angular/core';
import { ServerModule } from '@angular/platform-server';
import { sharedConfig } from './app.module.shared';
import { HttpModule, Http } from '@angular/http';
import {
    TranslateModule,
    TranslateLoader,
    MissingTranslationHandler,
    MissingTranslationHandlerParams
} from '@ngx-translate/core';
import { TranslateHttpLoader } from '@ngx-translate/http-loader';

export function createTranslateLoader(http: Http) {
    return new TranslateHttpLoader(http, './assets/i18n/', '.json');
}

export class MyMissingTranslationHandler implements MissingTranslationHandler {
    handle(params: MissingTranslationHandlerParams) {
        return '[' + params.key + ']';
    }
}

@NgModule({
    bootstrap: sharedConfig.bootstrap,
    declarations: sharedConfig.declarations,
    imports: [
        ServerModule,
        HttpModule,
        TranslateModule.forRoot({
            loader: {
                provide: TranslateLoader,
                useFactory: (createTranslateLoader),
                deps: [Http]
            }
        }),
        ...sharedConfig.imports
    ]
})
export class AppModule {
}

---

and here is my app.module.cleint.ts file:

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { HttpModule,Http } from '@angular/http';
import { sharedConfig } from './app.module.shared';
import {
    TranslateModule,
    TranslateLoader,
    MissingTranslationHandler,
    MissingTranslationHandlerParams
} from '@ngx-translate/core';
import { TranslateHttpLoader } from '@ngx-translate/http-loader';
export function createTranslateLoader(http: Http) {
    return new TranslateHttpLoader(http, './assets/i18n/', '.json');
}

export class MyMissingTranslationHandler implements MissingTranslationHandler {
    handle(params: MissingTranslationHandlerParams) {
        return '[' + params.key + ']';
    }
}

@NgModule({
    bootstrap: sharedConfig.bootstrap,
    declarations: sharedConfig.declarations,
    imports: [
        BrowserModule,
        FormsModule,
        HttpModule,
        TranslateModule.forRoot({
            loader: {
                provide: TranslateLoader,
                useFactory: (createTranslateLoader),
                deps: [Http]
            }
        }),
        ...sharedConfig.imports
    ],
    providers: [
        { provide: 'ORIGIN_URL', useValue: location.origin },
        {
            provide: MissingTranslationHandler,
            useClass: MyMissingTranslationHandler
        }
    ]
})
export class AppModule {
}

and here is my app.module.shared.ts file:

import { NgModule } from '@angular/core';
import { RouterModule } from '@angular/router';
import { HttpModule, Http } from "@angular/http";
import { BrowserModule } from "@angular/platform-browser";

import { TranslateModule} from '@ngx-translate/core';

import { AppComponent } from './components/app/app.component'
import { NavMenuComponent } from './components/navmenu/navmenu.component';
import { HomeComponent } from './components/home/home.component';
import { FetchDataComponent } from './components/fetchdata/fetchdata.component';
import { EmployeesListComponent } from './components/employees/EmployeesList.component';
import { CounterComponent } from './components/counter/counter.component';

export const sharedConfig: NgModule = {
    bootstrap: [AppComponent],
    declarations: [
        AppComponent,
        NavMenuComponent,
        CounterComponent,
        FetchDataComponent,
        EmployeesListComponent,
        HomeComponent
    ],
    imports: [
        RouterModule.forRoot([
            { path: '', redirectTo: 'home', pathMatch: 'full' },
            { path: 'home', component: HomeComponent },
            { path: 'counter', component: CounterComponent },
            { path: 'fetch-data', component: FetchDataComponent },
            { path: 'employees-list', component: EmployeesListComponent },
            { path: '**', redirectTo: 'home' }
        ]),
        BrowserModule,
        HttpModule,TranslateModule
    ]
    , exports: [
        TranslateModule
    ]
};

Answer 1

Well the issue is just this. ./assets/i18n/en.json is not an absolute url like : http://foo.com/assets/i18n/en.json. I know that there are usually ways to indicate that you are serving from the same server as the client side code. Might it not be

export function createTranslateLoader(http: Http) {
    return new TranslateHttpLoader(http, '/assets/i18n/', '.json');
}

But when I poke around in the angular docs repos: I see this: https://github.com/angular/angular/issues/15349. So maybe the angular http service doesn't support calling the host on which the document was served. That is sort of really surprising, but you can get that in javascript using:

window.location.origin

So just prepend that to /assets/i18n/ when you set up the call.