"Can't bind to 'ngModel' since it isn't a known property of 'p-calendar'" error message trying to use PrimeNG component, why?

Question

I am very new in Angular 2\4 and I am trying to follow this quick video tutorial to add PrimeNG components to my Angular project:

https://www.youtube.com/watch?v=6Nvze0dhzkE

and the Get started section of the PrimeNG tutorial page: https://www.primefaces.org/primeng/#/setup

So this is my app.component.html view:

<!--The whole content below can be removed with the new code.-->
<div style="text-align:center">
  <h1>
    Welcome to {{title}}!!
  </h1>
</div>

<p-calendar [(ngModel)]="value"></p-calendar>

{{value | date:'dd.mm.yyy'}}

As you can see I have inserted this tag to show the calendar component:

<p-calendar [(ngModel)]="value"></p-calendar>

(as shown also on the official documentation of this component: https://www.primefaces.org/primeng/#/calendar )

Here I have the first problem because IntelliJ give me this error message:

Error:(9, 13) Angular: Can't bind to 'ngModel' since it isn't a known property of 'p-calendar'.
1. If 'p-calendar' is an Angular component and it has 'ngModel' input, then verify that it is part of this module.
2. If 'p-calendar' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message.
3. To allow any property add 'NO_ERRORS_SCHEMA' to the '@NgModule.schemas' of this component.

I think that it is strange because this line should bind the value selected on the calendar by the user to the value variable of my model.

Following the tutorial I have modified the app.module.ts file in this way:

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

import { AppComponent } from './app.component';
import {CalendarModule} from 'primeng/primeng';


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

export class MyModel {
  value: Date;
}

As you can see here I have exported this class:

export class MyModel {
  value: Date;
}

having the value property (having type Date) so it should be the property bound by this line in the view:

<p-calendar [(ngModel)]="value"></p-calendar>

But it can't work and when I access to this application in the JavaScript browser console I obtain this error message:

compiler.es5.js:1690 Uncaught Error: Template parse errors:
Can't bind to 'ngModel' since it isn't a known property of 'p-calendar'.
1. If 'p-calendar' is an Angular component and it has 'ngModel' input, then verify that it is part of this module.
2. If 'p-calendar' is a Web Component then add 'CUSTOM_ELEMENTS_SCHEMA' to the '@NgModule.schemas' of this component to suppress this message.
3. To allow any property add 'NO_ERRORS_SCHEMA' to the '@NgModule.schemas' of this component. ("<p-calendar [ERROR ->][(ngModel)]="value"></p-calendar {{value | date:'dd.mm.yyy'}}
"): ng:///AppModule/AppComponent.html@8:12
    at syntaxError (http://localhost:4200/vendor.bundle.js:7283:34)
    at TemplateParser.webpackJsonp../node_modules/@angular/compiler/@angular/compiler.es5.js.TemplateParser.parse (http://localhost:4200/vendor.bundle.js:18403:19)
    at JitCompiler.webpackJsonp../node_modules/@angular/compiler/@angular/compiler.es5.js.JitCompiler._compileTemplate (http://localhost:4200/vendor.bundle.js:32555:39)
    at http://localhost:4200/vendor.bundle.js:32475:62
    at Set.forEach (native)
    at JitCompiler.webpackJsonp../node_modules/@angular/compiler/@angular/compiler.es5.js.JitCompiler._compileComponents (http://localhost:4200/vendor.bundle.js:32475:19)
    at http://localhost:4200/vendor.bundle.js:32362:19
    at Object.then (http://localhost:4200/vendor.bundle.js:7272:148)
    at JitCompiler.webpackJsonp../node_modules/@angular/compiler/@angular/compiler.es5.js.JitCompiler._compileModuleAndComponents (http://localhost:4200/vendor.bundle.js:32361:26)
    at JitCompiler.webpackJsonp../node_modules/@angular/compiler/@angular/compiler.es5.js.JitCompiler.compileModuleAsync (http://localhost:4200/vendor.bundle.js:32290:37)
syntaxError @   compiler.es5.js:1690
webpackJsonp../node_modules/@angular/compiler/@angular/compiler.es5.js.TemplateParser.parse @   compiler.es5.js:12810
webpackJsonp../node_modules/@angular/compiler/@angular/compiler.es5.js.JitCompiler._compileTemplate @   compiler.es5.js:26962
(anonymous) @   compiler.es5.js:26882
webpackJsonp../node_modules/@angular/compiler/@angular/compiler.es5.js.JitCompiler._compileComponents   @   compiler.es5.js:26882
(anonymous) @   compiler.es5.js:26769
then    @   compiler.es5.js:1679
webpackJsonp../node_modules/@angular/compiler/@angular/compiler.es5.js.JitCompiler._compileModuleAndComponents  @   compiler.es5.js:26768
webpackJsonp../node_modules/@angular/compiler/@angular/compiler.es5.js.JitCompiler.compileModuleAsync   @   compiler.es5.js:26697
webpackJsonp../node_modules/@angular/core/@angular/core.es5.js.PlatformRef_._bootstrapModuleWithZone    @   core.es5.js:4536
webpackJsonp../node_modules/@angular/core/@angular/core.es5.js.PlatformRef_.bootstrapModule @   core.es5.js:4522
./src/main.ts   @   main.ts:11
__webpack_require__ @   bootstrap a55b161…:54
2   @   main.ts:11
__webpack_require__ @   bootstrap a55b161…:54
webpackJsonpCallback    @   bootstrap a55b161…:25
(anonymous)

Why? What is wrong? What am I missing? How can I try to fix this issue? It seems to me that I followed the tutorial...

Answer 1

Add FormsModule in your AppModule:

// ...
import { FormsModule } from '@angular/forms';
// ...

@NgModule({
  // ...
  imports: [
    BrowserModule,
    FormsModule,
    CalendarModule
  ],
  // ...
})
export class AppModule { }