In this blog post, we'll explore how to build dynamic forms using Angular and the Formly library. We'll walk through the setup, configuration, and implementation of a simple form that can be easily extended and customized.

Introduction

Dynamic forms are a powerful feature in web applications, allowing developers to create forms that can change based on user input or other conditions. Angular, combined with the Formly library, provides a robust solution for building such forms with minimal effort.

Project Setup

First, let's set up our Angular project. We'll use the Angular CLI to generate a new project and install the necessary dependencies.

ng new angular-formly
cd angular-formly
npm install @angular/forms @ngx-formly/core @ngx-formly/bootstrap --save

Project Structure

Here's a quick overview of the project structure:

src/
  app/
    app-routing.module.ts
    app.component.html
    app.component.scss
    app.component.spec.ts
    app.component.ts
    app.module.ts
  index.html
  main.ts
  styles.scss

Configuring Formly

Next, we'll configure Formly in our Angular application. Open src/app/app.module.ts and add the necessary imports and configuration:

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { ReactiveFormsModule } from '@angular/forms';
import { FormlyModule } from '@ngx-formly/core';
import { FormlyBootstrapModule } from '@ngx-formly/bootstrap';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';

@NgModule({
  declarations: [AppComponent],
  imports: [
    BrowserModule,
    AppRoutingModule,
    ReactiveFormsModule,
    FormlyModule.forRoot(),
    FormlyBootstrapModule,
  ],
  providers: [],
  bootstrap: [AppComponent],
})
export class AppModule {}

Creating the Form Component

Now, let's create our form component. Open src/app/app.component.ts and define the form structure:

import { Component } from '@angular/core';
import { FormGroup } from '@angular/forms';
import { FormlyFieldConfig } from '@ngx-formly/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrl: './app.component.scss',
})
export class AppComponent {
  title = 'Formly Example';
  form = new FormGroup({});
  model = { email: 'email@gmail.com' };
  fields: FormlyFieldConfig[] = [
    {
      key: 'email',
      type: 'input',
      props: {
        label: 'Email address',
        placeholder: 'Enter email',
        required: true,
      },
    },
  ];

  onSubmit(model: any) {
    console.log(model);
  }
}

Creating the Form Template

Next, we'll create the template for our form. Open src/app/app.component.html and add the following code:

<h1>{{ title }}</h1>
<form [formGroup]="form" (ngSubmit)="onSubmit(model)">
  <formly-form [form]="form" [fields]="fields" [model]="model"></formly-form>
  <button type="submit" class="btn btn-default">Submit</button>
</form>
{{ model | json }}

Running the Application

To run the application, use the following command:

ng serve

Navigate to http://localhost:4200/ in your browser to see the form in action.

Conclusion

In this blog post, we've seen how to set up and configure an Angular application with Formly to create dynamic forms. This setup allows for easy customization and extension of forms, making it a powerful tool for building complex form-based applications. Happy coding!

Building Dynamic Forms with Angular and Formly