Please add a @Pipe/@Directive/@Component annotatio

Question

I am stuck in a situation here. I am getting an error like this.

 compiler.es5.js:1694 Uncaught Error: Unexpected value 'LoginComponent' declared by the module 'AppModule'. Please add a @Pipe/@Directive/@Component annotation.
    at syntaxError (compiler.es5.js:1694)
    at compiler.es5.js:15595
    at Array.forEach (<anonymous>)
    at CompileMetadataResolver.webpackJsonp.../../../compiler/@angular/compiler.es5.js.CompileMetadataResolver.getNgModuleMetadata (compiler.es5.js:15577)
    at JitCompiler.webpackJsonp.../../../compiler/@angular/compiler.es5.js.JitCompiler._loadModules (compiler.es5.js:26965)
    at JitCompiler.webpackJsonp.../../../compiler/@angular/compiler.es5.js.JitCompiler._compileModuleAndComponents (compiler.es5.js:26938)
    at JitCompiler.webpackJsonp.../../../compiler/@angular/compiler.es5.js.JitCompiler.compileModuleAsync (compiler.es5.js:26867)
    at PlatformRef_.webpackJsonp.../../../core/@angular/core.es5.js.PlatformRef_._bootstrapModuleWithZone (core.es5.js:4536)
    at PlatformRef_.webpackJsonp.../../../core/@angular/core.es5.js.PlatformRef_.bootstrapModule (core.es5.js:4522)
    at Object.../../../../../src/main.ts (main.ts:11)

My Login Component Looks like this

import { Component } from '@angular/Core';

@Component({
    selector:'login-component',
    templateUrl:'./login.component.html'
})

export class LoginComponent{}

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { CommonModule } from '@angular/common'
import { HttpModule } from '@angular/http';
import { ReactiveFormsModule} from '@angular/forms';
import { RouterModule, Routes } from '@angular/router';
import { AppComponent } from './main/app.component';

import {LoginComponent} from './login/login.component';


const appRoutes: Routes = [
  {path:'', redirectTo:'login', pathMatch:'full'},
  { path: 'home', component: AppComponent },
  { path: 'login', component: LoginComponent }
];

@NgModule({
  imports: [
    BrowserModule,
    RouterModule.forRoot(appRoutes),
  ],
  declarations: [
    AppComponent,
    LoginComponent
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

I got this error when I try to import LoginComponent into declaration. Am I missing something here.

Answer 1

You have a typo in the import in your LoginComponent's file

import { Component } from '@angular/Core';

It's lowercase c, not uppercase

import { Component } from '@angular/core';

Answer 2

If you are exporting another class in that module, make sure that it is not in between @Component and your ClassComponent. For example:

@Component({ ... })

export class ExampleClass{}

export class ComponentClass{}  --> this will give this error.

FIX:

export class ExampleClass{}

@Component ({ ... })

export class ComponentClass{}

Answer 3

You get this error when you wrongly add shared service to "declaration" in your appmodules instead of adding it to "provider".

Answer 4

I faced the same error when I used another class instead of component down the component decorator.

Component class must come just after the component decorator

  @Component({
 selector: 'app-smsgtrecon',
 templateUrl: './smsgtrecon.component.html',
 styleUrls: ['./smsgtrecon.component.css'],
 providers: [ChecklistDatabase]
 })


// THIS CAUSE ISSUE MOVE THIS UP TO COMPONENT DECORATOR
/**
* Node for to-do item
*/
 export class TodoItemNode {
 children: TodoItemNode[];
 item: string;
}


 export class SmsgtreconComponent implements OnInit {

After moving TodoItemNode to the top of component decorator it worked

Solution

// THIS CAUSE ISSUE MOVE THIS UP TO COMPONENT DECORATOR
/**
* Node for to-do item
*/
 export class TodoItemNode {
 children: TodoItemNode[];
 item: string;
}


@Component({
 selector: 'app-smsgtrecon',
 templateUrl: './smsgtrecon.component.html',
 styleUrls: ['./smsgtrecon.component.css'],
 providers: [ChecklistDatabase]
 })


 export class SmsgtreconComponent implements OnInit {

Answer 5

Not a solution to the concrete example above, but there may be many reasons why you get this error message. I got it when I accidentally added a shared module to the module declarations list and not to imports.

In app.module.ts:

import { SharedModule } from './modules/shared/shared.module';

@NgModule({
  declarations: [
     // Should not have been added here...
  ],
  imports: [
     SharedModule
  ],

Answer 6

In my case, I accidentally added the package in the declaration but it should be in imports.