NullInjectorError: No provider for SwUpdate! SwUpdate does not work Angular 5

问题

Now I know there are a million posts about No Provider for such and such service, I know it needs to go in the providers please read my entire post.

Basically I am trying to use SwUpdate to check to see if there is an update if so, refresh the browser:

import { SwUpdate } from '@angular/service-worker';
...

export class ...

constructor(
    private _swUp: SwUpdate
){} 


ngOnInit() {
    this.checkForUpdate();
}

checkForUpdate() {
    if (this._swUp.isEnabled) {
       this._swUp.available
           .subscribe(() => {
               window.location.reload();
           });
    }
}

now I have registered my serviceworker:

import { ServiceWorkerModule } from '@angular/service-worker'; 
...

imports: [
    environment.production ? ServiceWorkerModule.register('ngsw-worker.js') : [],
]

now when I run my app I get this error:

NullInjectorError: No provider for SwUpdate!

so obviously I try and add it to the providers array in my component module:

import { ServiceWorkerModule, SwUpdate } from '@angular/service-worker'; 
...

imports: [
    environment.production ? ServiceWorkerModule.register('ngsw-worker.js') : [],
],
providers: [
    SwUpdate
]

now this should work but now this time when I run the application I get the following error:

NullInjectorError: No provider for NgswCommChannel!

Now when I try to import NgswCommChannel I get an error saying it does not exist in @angular/service-worker;

I've tried googling around but I cannot find a reference to NgswCommChanel anywhere...

So my question is how can I fix this, or how can I properly use SwUpdate ??

any help would be appreciated

EDIT

I have also tried to do it the EXACT same way it is done in the official angular docs and it is giving me the same error:

constructor(
    updates: SwUpdate
) {
    updates.available
        .subscribe(() => {
            updates.activateUpdate()
                .then(() => document.location.reload());
        });
}

EDIT 2 This is what I get when I run ng -v

Angular CLI: 1.7.4
Node: 10.15.1
OS: win32 x64
Angular: 5.1.2
... animations, common, compiler, compiler-cli, core, forms
... http, platform-browser, platform-browser-dynamic
... platform-server, router

@angular/cli: 1.7.4
@angular/service-worker: 7.2.7
@angular-devkit/build-optimizer: 0.3.2
@angular-devkit/core: 0.3.2
@angular-devkit/schematics: 0.0.40
@ngtools/json-schema: 1.1.0
@ngtools/webpack: 1.10.2
typescript: 2.4.2
webpack: 3.11.0

EDIT 3

Upon further investigation it seems as if you can not use SwUpdate when running your project locally, I saw this article angular-pwa-pitfalls and there solution is to install ng-toolkit, but this just allows you to build your project and then run a mock server, which is pointless because ill lose the ability to develop locally without building the project everytime.

EDIT 4

I changed my app.module.ts to register the service worker:

ServiceWorkerModule.register('ngsw-worker.js', { enabled: environment.production })

but now I'm getting a whole new bunch of errors

Any other suggestions would be great.

Thanks

回答1:

Your issue is in the app.module.ts.

You need to import your service worker like this:

imports: [
    ServiceWorkerModule.register('ngsw-worker.js', { enabled: environment.production }) : [],
],

The code you had before was only including the module when you were in production mode, so during development it wasn't including the module at all.

EDIT:

Inside my app.component.ts I have:

constructor(private swUpdate: SwUpdate) { }

ngAfterViewInit() {
  if (this.swUpdate.isEnabled) {
    this.swUpdate.available
      .subscribe(() => {
        this.swUpdate
          .activateUpdate()
          .then(() => {
            window.location.reload();
          });
      });
  }
}

EDIT:

As per your comment, updating to latest version of Angular fixed your issue, it's nice they've made upgrading so simple now :)

回答2:

After much research it seems like it was an issue with angular 5.2.1 so..

I upgraded my project to angular 7, ran ng add @angular/pwa and that solved my problem!

回答3:

Try below code, Add update into ngOnInit() method.

 constructor(private updates: SwUpdate) {}

 ngOnInit(){
     this.updates.available
    .subscribe(() => {
        this.updates.activateUpdate()
            .then(() => document.location.reload());
    });
 }

来源：https://stackoverflow.com/questions/54779752/nullinjectorerror-no-provider-for-swupdate-swupdate-does-not-work-angular-5

标签

angular

typescript

service-worker

progressive-web-apps

angular-pwa