Can't bind to 'ngForOf' since it isn't a known property of 'tr' (final release)

Question

I'm using Angular2 2.1.0. When I want to display a list of companies, I got this error.

in file.component.ts :

public companies: any[] = [
    { "id": 0, "name": "Available" },
    { "id": 1, "name": "Ready" },
    { "id": 2, "name": "Started" }
];

In file.component.html :

<tbody>
  <tr *ngFor="let item of companies; let i =index">
     <td>{{i}}</td>
     <td>{{item.name}}</td>
  </tr>
</tbody>

Answer 1

Add BrowserModule to imports: [] in @NgModule() if it's the root module (AppModule), otherwise the CommonModule.

// older Angular versions
// import {BrowserModule, CommonModule} from '@angular/common';

import { BrowserModule } from '@angular/platform-browser'
..
..
@NgModule({
  imports: [BrowserModule, /* or CommonModule */],
  ..
})

Answer 2

In my case, the issue was that my teammate mentioned *ngfor in templates instead of *ngFor. Strange that there is no correct error to handle this issue (In Angular 4).

Answer 3

You have to import CommonModule in the module where you are using these in-built directives like ngFor, ngIf, etc.

import { CommonModule } from '@angular/common'
       
@NgModule({
    imports: [
        CommonModule
    ]
})
    
export class ProductModule { }

Answer 4

There can be any possible reason:

1. Your module does not have CommonModule in imports[]
2. Your component, where you are using *ngFor or *ngIf is not a part of any module.
3. You might have typo in *ngFor i.e. **ngFor or *ngfor etc.
4. If everything seems fine then restart your app i.e. ng serve or IDE i.e. VS Code, IntelliJ etc.

Answer 5

For me the problem was that I did not import the custom made module HouseModule in my app.module.ts. I had the other imports.

File: app.module.ts

import { HouseModule } from './Modules/house/house.module';

@NgModule({
  imports: [
    HouseModule
  ]
})

Answer 6

This can also happen if you don't declare a route component in your feature module. So for example:

feature.routing.module.ts:

...
    {
        path: '',
        component: ViewComponent,
    }
...

feature.module.ts:

     imports: [ FeatureRoutingModule ],
     declarations: [],

Notice the ViewComponent is not in the declarations array, whereas it should be.

Answer 7

I received the error because the component I was using wasn't registered in the declarations: [] section of the module.

After adding the component the error went away. I would have hoped for something less obscure than this error message to indicate the real problem.

Answer 8

Things to remember:

When custom modules are used (modules other than AppModule) then it is necessary to import the common module in it.

yourmodule.module.ts

import { CommonModule } from '@angular/common';

@NgModule({
  imports: [
    CommonModule
  ],
  exports:[ ],
  declarations: []
})

Answer 9

I was getting the same error, You can fix through one of this method:

1. If you don't have any nested module

   a. Import the CommonModule in your App module

   b. Import your Component where you are adding the *ngFor in the App Module, define in declarations

// file App.modules.ts
@NgModule({
  declarations: [
    LoginComponent // declarations of your component
  ],
  imports: [
    BrowserModule
    DemoMaterialModule,
    FormsModule,
    HttpClientModule,
    ReactiveFormsModule,
    AppRoutingModule,
    BrowserAnimationsModule,
    ServiceWorkerModule.register('ngsw-worker.js', { enabled: environment.production })
  ],
  providers: [
    ApiService, 
    CookieService, 
    {
      provide: HTTP_INTERCEPTORS,
      useClass: ApiInterceptor,
      multi: true
    }
  ],
  bootstrap: [AppComponent]
})

c. If you are using the separate module file for routing then Import the CommonModule in your Routing module else Import the CommonModule in your App module

// file app.routing.modules.ts
import { LoginComponent } from './login/login.component';
import { CommonModule } from "@angular/common";

const routes: Routes = [
  { path: '', component: LoginComponent },
  { path: 'login', component: LoginComponent }
];

@NgModule({
  imports: [RouterModule,RouterModule.forRoot(routes), CommonModule],
  exports: [RouterModule]
})

2. If you have nested module then perform the 1st step in that particular module

In my case, the 2nd method solved my issue.
Hope this will help you

Answer 10

Future Readers

Check each of the following:

1. The component is declared in a SINGLE angular module
2. Make sure you have import { CommonModule } from '@angular/common';
3. Restart the IDE/editor
4. Restart the dev server (ng serve)

Answer 11

If you are making your own module then add CommonModule in imports in your own module

Answer 12

Just in case someone still facing an error after trying to import CommonModule, try to restart the server. It surprisingly work

Answer 13

Add the component to your app.module

import { ModalComponent } from './modal/modal.component';

@NgModule({
  declarations: [ModalComponent],
  entryComponents: [ModalComponent],
  
  }),
  providers: [
  ],
  bootstrap: [AppComponent]
})

Answer 14

In my case the component wasn't listed in app.module.ts.

Answer 15

For Angular 10:

1. Add BrowserModule to the imports of your routes module.
2. Make sure that you added the component that not working to the app module declarations.

Failing to do step 2 will trigger this error!

Make sure to RESTART ng serve !!!

Answer 16

So please make sure

1. No syntax error in directives

2. Browser (in App Module) and Common (in other/child) Modules are imported (Same what Günter Zöchbauer mentioned above)

3. If you've routes in the application then route module should be imported in App Module

4. All the routed component's Module are also imported in App Module, for eg: app-routing.module.ts is as follows:

   const routes: Routes = [

   {path: '', component: CustomerComponent},

   {path: 'admin', component: AdminComponent}

   ];

Then App module must imports modules of CustomerComponent and AdminComponent in @NgModule().

Answer 17

A lot of answers seem to converge by importing CommonModule in other(new/custom) modules.
This step only isn't enough in all situations.

The full solution consist in two steps:

1. Make directives NgIf, NgFor etc visible to your project.
2. Reassemble everything in a correct way in the main component (app.module.ts)

Point 1
BrowserModule in main module seems to be enough for having access to NgFor. Angular Documentation stands it here: .

CommonModule Exports all the basic Angular directives and pipes, such as NgIf, NgForOf, DecimalPipe, and so on. Re-exported by BrowserModule,

See also accepted answer here: CommonModule vs BrowserModule in angular

Point 2
The only changes needed (in my case) are the followings:

1. import Module OtherModule
2. import Component OtherComponent
3. ng build (important!)
4. ng serve

app.module.ts

@NgModule({
    imports: [
        BrowserModule,
        OtherModule
    ],
    declarations: [OtherComponent, AppComponent],
    bootstrap: [AppComponent]
})
export class AppModule {
}

other.html

<div *ngFor='let o of others;'> 
</div>

other.component.ts

@Component({
    selector: 'other-component',
    templateUrl: './other.html'
})
export class OtherComponent {
}

app.module.ts

@NgModule({
    imports: [],
    providers: []
})
export class OtherModule{
}

Answer 18

After using correct syntax in all of your code, please see if you have mentioned your component in the declarations of your angular module. Something like below:

@NgModule({ declarations: [ AppComponent, YourComponent ],

Answer 19

I had the same problem, even though I had imported "BrowserModule" and "CommonModule" in "module.ts" it didn't work, my error was, not adding in "NgModule.declarations" my Component.

@NgModule ({
   declarations: [
     Your_Component // here
   ]
}) 

Answer 20

Custom Module Needs common module

import { CommonModule } from "@angular/common";


@NgModule({
  imports: [
    CommonModule
  ]
})

Answer 21

I had the same error but I had the CommonModule imported. Instead I left a comma where it shouldn't be because of copy/paste when splitting a module:

@NgModule({
    declarations: [
        ShopComponent,
        ShoppingEditComponent
    ],
    imports: [
        CommonModule,
        FormsModule,
        RouterModule.forChild([
            { path: 'shop', component: ShopComponent }, <--- offensive comma
        ])
    ]
})

Answer 22

app.module.ts fixed and changed to: import the BrowserModule in your app module

import { BrowserModule } from '@angular/platform-browser';

@NgModule({
  declarations: [
    AppComponent    
  ],
  imports: [
    BrowserModule, 
  ],     
  providers: [],
  bootstrap: [AppComponent]
})

Answer 23

I have encountered a similar error (*ngIf) even if all my imports were OK and the component was rendered without any other error + routing was OK.

In my case AppModule was not including that specific module. The strange thing is that it did not complain about this, but this might be related with how Ivy works with ng serve (kind of loads modules according to routing, but its dependencies are not considered).

Answer 24

if you already imopted (BrowserModule, CommonModule, FormsModule) and its still not working

then all you have to do is check if the component that has the error is declared in the module

Answer 25

If you have module implementation, then you must import the component and set the component in the declaration

Good Luck on your coding :)

Answer 26

When use "app-routing.module" we forget import "CommonModule". Remember to import!

import { CommonModule } from "@angular/common";
@NgModule({  imports: [ CommonModule]})

Answer 27

I am started on Angular8 base live project got the above issue but When use "app-routing.module" we forget import "CommonModule". Remember to import!

import { CommonModule } from '@angular/common';

@NgModule({
  imports: [
    CommonModule
]})

It will solve your error.

Answer 28

I had a problem because of ** instead *

*ngFor="let ingredient of ingredients"

**ngFor="let ingredient of ingredients"

Answer 29

For future reference, I'm doing some unit testing on Angular 12 and ran into this.

My issue was that I was using the ng bootstrap library and testing a method that was creating a new modal with NgbModal.

I was getting these warnings because I had forgotten to import the component being created by the popup.

I did not need to import FormsModule, CommonModule, or BrowserModule.

So, if you run into these errors make sure that the component you're trying to create an instance of is listed in the imports.

Answer 30

A bit late to the party, but I recently ran into this situation. This answer didn't solve my problem.

My premises

• I was using a custom directory structure for the project. The offending component sits inside the components directory.

  

• The component where I found a similar error was created using CLI schematics with the
  --skip-import option

    npx ng g c --skip-import ../components/my-component
  

Solution

Because I used the --skip-import(see note) option, I found that my component was not added to the declarations array in my module. Adding the component to the same solved the problem.

^{Note : Well,you can't create the component outside the app directory without this.}

Answer 31

Just had the same issue after modifying a couple of components. There was no syntax error and all modules were imported, but a restart of the server fixed the issue. The error occurred in a component, that was added several dozen successful commits ago.

Just in case someone else experiences the same issue.

Answer 32

I think my scenario is a rare case, but I will answer anyway.

I didn't have any syntax errors, I imported BrowserModule, I restated my IDE (VS Code), but I still got red lines in my template because I used *ngFor.

I happened because I was using an extension, Angular Language Service, but it was quite old. After updating it, the error stopped appearing.

Answer 33

This error can also be thrown when the ngFor syntax isn't written correctly, in my case I had:

<ng-template *ngForOf="let key of SomeObject; index as i">

And it got fixed by using the following syntax:

<ng-template ngFor let-key [ngForOf]="SomeObject" let-i="index">

Answer 34

I had a problem because of blank space in the json data.

Answer 35

In my case, the problem was, that I used const instead of let inside the *ngFor.

Answer 36

In my case, I already had CommonModule included in my shared module & the feature module where the component was to be used, but in my case I saved some files while server was starting (compiling) maybe that's why it did not took registry of included modules properly

=> I restarted my local server it solved the problem for me

Answer 37

I had imported CommonModule in the mycomponent.module.ts, and BrowserModule in the app.module.ts, added the MyComponent to @ngModule's declarations and reset vscode just like all the solutions had mentioned.

Finally resolved the issue by instead of iterating through data recieved through a fetch request, I mocked the elements array with hardcoded data matching the ElementModel.ts data And it worked no issues.

Realized that my ElementModel interface didn't match the data I was receiving from my fetch request.

Hope this helps someone.

Answer 38

I ran into this problem and for me the issue was that I had mistakenly named two components the same thing

Answer 39

If you face the error in angular version 14+ where a component can stand alone, just add NgFor to the imports of your component like this :

import { NgFor } from '@angular/common'; 

@Component({
selector     : 'my-component',
templateUrl  : './my-component.component.html',
encapsulation: ViewEncapsulation.None,
standalone   : true,
imports      : [ NgFor],
})

export class MyComponent implements OnInit
{
   ...
}

Answer 40

In my case, when doing lazy loading I mistakenly let auto complete finish the import that imported the routing module instead of module

 {
    path: "list-management",
    loadChildren: () =>
      import(
        "./views/pages/list-management/list-management-routing.module"
      ).then((m) => m.ListManagementRoutingModule)
}

Then I changed that to correct module

    {
        path: "list-management",
        loadChildren: () =>
          import(
            "./views/pages/list-management/list-management.module"
          ).then((m) => m.ListManagementModule)
    }

 

Answer 41

For me, what solved the problem was to do a git clone of my project and run (as usual):

npm install