Passing asp.net server parameters to Angular 2 app

Question

================================================================

EDIT : SOLUTION After upgrading to 2.0 Final - Passing server parameters to ngModule after RC5 upgrade

==================================================================

Any way to have server parameters passed to an Angular 2 application?

i.e. I would like to use the MVC object "HttpContext.User.Identity.Name" and have it injectable anywhere in my angular 2 app.

In angular 1 this was possible using ng ".constant" and serializing .Net objects to JSON in index.cshtml.

Looks like there's a way to pass params but this doesn't work with .Net code. Define global constants in Angular 2

        //HTML - Bootstrapping
        <script>

            System.import('app/main').then(null, console.error.bind(console));
            //I WOULD LIKE TO PASS SOME PARAMS TO APP/MAIN HERE
        </script>

FINAL SOLUTION: (big thanks to Thierry)

index.cshtml:

<script>
    System.import('app/main').then(
        module => 
            module.main(
                {
                    name: '@User.Identity.Name',
                    isAuthenticated: User.Identity.IsAuthenticated.ToString().ToLowerInvariant(),
                }
            ),
        console.error.bind(console)
    );
</script>

main.ts:

...
    import {provide} from '@angular/core';
...

    export function main(params) {
        bootstrap(AppComponent,
            [
                provide('Name', { useValue: params.name }),
                provide('IsAuthenticated', { useValue: params.isAuthenticated }),
                ROUTER_PROVIDERS,
                HTTP_PROVIDERS,
                LoggerService,
                AuthenticationService
            ]);
    }

Usage:

import {Component, Injectable, Inject} from '@angular/core';
import {ROUTER_DIRECTIVES} from '@angular/router';

@Component({
    selector: 'navbar',
    templateUrl: 'app/components/header/navbar.html',
    directives: [ROUTER_DIRECTIVES]
})
export class SomeComponent {

    constructor(@Inject('Name') public username: string) {

    }

}

Thierry Templier · Accepted Answer · 2017-06-21 06:02:39Z

9

+50

An option would be to add a method in the module you import. So you can then call it to provide the object you want.

Here is a sample of the app/main module:

import {bootstrap} from '...';
import {provide} from '...';
import {AppComponent} from '...';

export function main(params) {
  let userIdentityName = params.name; // for example
  bootstrap(AppComponent, [
    provide('userIdentityName', { useValue: userIdentityName })
  ]);
}

Then you can import it from your HTML main page like this:

<script>
  System.import('app/main').then((module) => {
    module.main({
      userIdentityName: 'something from asp.net'
    });
  });
</script>

Update

With latest versions of Angular, you need to leverage modules this way:

export const USER_IDENTITY_NAME_TOKEN =
  new  InjectionToken('userIdentityName');

@NgModule({
  (...)
  providers: [
    {
      provide: USER_IDENTITY_NAME_TOKEN,
      useValue: userIdentityName
    }
  ]
})
export class MainModule() { }

edited Jun 21, 2017 at 6:02

answered May 23, 2016 at 6:56

Thierry Templier

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5 Comments

vidalsasoon Over a year ago

any idea how this could be done after RC5? ngModule is giving me a lot of problems with my params.

ravi punjwani Over a year ago

This doesn't work in @Angular RC6. "provide" is no longer supported in @angular/core. Any workaround please

A. Morel Over a year ago

Thank for the tips but where I can find "bootstrap" and "provide" please ?

Thierry Templier Over a year ago

@amorel I updated my answer for latest versions of Angular... hope it'll help you ;-)

Norcino Over a year ago

Is there any way to achieve this without using systemjs ?

cyberguest · Accepted Answer · 2016-09-27 15:21:23Z

4

thanks for info, for those using platformBrowserDynamic to boot:

main.ts:



//platformBrowserDynamic().bootstrapModule(asstModule);

export function main(appSettings: any) {   
    platformBrowserDynamic([{ provide: 'AppSettings', useValue: appSettings }]).bootstrapModule(asstModule);
}

edited Sep 27, 2016 at 15:21

answered Sep 26, 2016 at 19:01

cyberguest

1941 silver badge9 bronze badges

Comments

jsgoupil · Accepted Answer · 2016-11-05 01:05:45Z

With a .NET Core server, I recommend to use a the IOptions<> and a ViewComponent

Startup.cs

public void ConfigureServices(IServiceCollection services)
{
    // ...

    services.AddOptions();
    services.Configure<Models.EnvironmentSettings>(Configuration.GetSection("client"));
    services.Configure<Models.EnvironmentSettings>(options =>
    {
        options.OtherSetting = "Other";
    });

    services.AddMvc();
}

Models/EnvironmentSettings.cs

public class EnvironmentSettings
{
    public string OtherSetting { get; set; }
    public string LoginUrl { get; set; }
}

appsettings.json

{
    "client": {
        "LoginUrl": "http://localhost:45290/Token"
    }
}

Controllers/Components/BootstrapViewComponent.cs

public class BootstrapViewComponent : ViewComponent
{
    private IOptions<EnvironmentSettings> environmentSettings;

    public BootstrapViewComponent(
        IOptions<EnvironmentSettings> environmentSettings
    )
    {
        this.environmentSettings = environmentSettings;
    }

    public async Task<IViewComponentResult> InvokeAsync()
    {
        return View(environmentSettings.Value);
    }
}

Views/Shared/Components/Bootstrap/Default.cshtml

@model YourApp.Models.EnvironmentSettings
<script>
    System.import('app')
        .then(function (module) {
            module.main({
                other: "@Model.OtherSetting",
                loginUrl: "@Model.LoginUrl"
            })
        })
        .catch(function (err) {
            console.error(err);
        });
</script>

Views/Shared/_Layout.cshtml

<head>
...
@await Component.InvokeAsync("Bootstrap")
</head>

main.ts

export function main(settings: any) {
    platformBrowserDynamic([{ provide: 'EnvironmentSettings', useValue: settings }]).bootstrapModule(AppModule);
}

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