Creating dynamic form groups in Angular 4

I am currently working on a dynamic form group and I am facing a particular challenge.

https://i.sstatic.net/m20IO.png

Whenever I click on "add more," it should add 2 dynamic fields. Here is the function I am using:

onAddSurgeries(){
    const control = new FormGroup({
        'surgery': new FormControl(null),
        'illness': new FormControl(null)
    });
      (<FormArray>this.form.get('surgeries')).push(control);
}

This is how my HTML code looks:

<tr *ngFor="let ctrl of form.get('surgeries')['controls']; let i = index">
   <td><input type="text" class="form-control" [formControlName]="ctrl['controls'].surgery"></td>
   <td><input type="text" class="form-control" [formControlName]="ctrl['controls'].illness"></td>
</tr>

I am aware that I am making a mistake by using "ctrl['controls'].surgery" as the formControlName. Instead, I should use "i" as formcontrolname when I have only one formcontrol instead of 2 controls in a formgroup. However, in this scenario, I am unsure of what to enter in the formControlName because when I submit the form, the values of both inputs are empty as they are not synced with the formgroup controls.

Answer №1

Your question is missing the designation of the formArrayName. Additionally, when pushing formgroups to your formarray, ensure that they are identified with the index value in your iteration within the template. The formControlNames should correspond to the names you specified, such as surgery and illness:

<table>
  <ng-container formArrayName="surgeries">
    <tr *ngFor="let ctrl of form.get('surgeries')['controls']; let i = index" 
      [formGroupName]="i">
      <td><input type="text" class="form-control" formControlName="surgery"></td>
      <td><input type="text" class="form-control" formControlName="illness"></td>
    </tr>
  </ng-container>
</table>

DEMO

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

Exploring TypeScript's type checking functionality

I've been pondering about the concept of type guards in TypeScript, particularly regarding their necessity when only one type is defined in a method signature. Most examples in the TypeScript documentation focus on scenarios involving union types, lik ...

Encountering difficulties in creating a custom Response type in Express.js with TypeScript

I have encountered a TypeScript error while trying to create my own custom Response interface by extending some methods instead of using the default Response type of Express.js: The last overload resulted in the following error: Argument of type '(r ...

Activate the Keypress event to update the input value in React upon pressing the Enter

I am facing an issue where I need to reset the value of an input using a method triggered by onPressEnter. Here is the input code: <Input type="text" placeholder="new account" onPressEnter={(event) => this.onCreateAccount(event)}> < ...

Tips for preventing duplicate Java Script code within if statements

In my function, there are various statements to check the visibility of fields: isFieldVisible(node: any, field: DocumentField): boolean { if (field.tag === 'ADDR_KOMU') { let field = this.dfs_look(node.children, 'ADDR_A ...

The dropdown navigation bar fails to close upon being clicked

I'm currently facing an issue with the navbar in my project. The bootstrap navbar doesn't close automatically after clicking on a link. I have to move my mouse away from the navbar for it to close, which is not ideal. Additionally, I'm worki ...

Using observable object fields as query parameters in Firestore allows for dynamic filtering and retrieval

I have two separate services in my Angular project: an Auth service and a query service. The Auth service handles user authentication by managing the login process and observing changes to the user object. import {Injectable} from '@angular/core&apo ...

What could be causing the lack of reflection of Angular changes in the browser post-build process?

I'm having trouble seeing changes reflected in my Angular project after making them. I've tried clearing the cache pages and cookies in Chrome, as well as enabling disable cache in the network tab of developer tools. In addition, I cleared the a ...

I must remove the thumb from the input range control

I am looking for a way to remove the thumb from the progress bar in my music player. I have tried various methods without success, and I simply want the progress bar to move forward with color change as it advances based on the Progress variable. For refe ...

While attempting to utilize npm install, I encounter an error on a discord bot stating "msvsVersion is not defined."

Struggling with self-hosting a TypeScript discord bot, the setup process has been a puzzle. It's supposed to generate a build directory with an index.js file, but it's unclear. Installed Visual Studio Build Tools 2017 as required, yet running npm ...

Don't initialize each variable within the constructor of a class, find a more efficient approach

I have a collection of JavaScript classes representing different models for my database. Each model contains attributes such as name, email, and password. Is there a more efficient way to create a new User instance without manually assigning values to ea ...

Tips for creating a Next.js "Link" component with an optional "href" property

I've created a custom React function using typescript for the Next.js Link component. The "href" property is necessary for the "Link" to be used anywhere, so it couldn't be utilized as a button that functions as a submit button in forms. import N ...

What is the best way to incorporate intervals and polling in Angular 2 for seamless integration with Protractor?

I have an angular2 application that I am looking to test using protractor. Within this application, there is a page featuring a graph that updates at regular intervals with data generated on its own. It appears that one aspect of protractor is the abilit ...

Deactivate user session in LoopBack 4 API

Can anyone provide a clear example of an API endpoint for logging out that allows for deleting the token stored during login instead of relying on the web browser? It seems there is no documentation available on how LoopBack generates a default user when ...

Angula 5 presents a glitch in its functionality where the on click events fail

I have successfully replicated a screenshot in HTML/CSS. You can view the screenshot here: https://i.stack.imgur.com/9ay9W.jpg To demonstrate the functionality of the screenshot, I created a fiddle. In this fiddle, clicking on the "items waiting" text wil ...

Enhancing Security and Privacy of User Information with JWT Tokens and NgRx Integration in Angular Application

I'm facing a security concern with my Angular application. Currently, I store user details like isAdmin, isLoggedIn, email, and more in local storage. However, I'm worried about the risks of unauthorized updates to this data, especially since my ...

Angular 2's updated router feature, routerCanReuse, provides improved functionality

I'm curious about the changes in the Angular 2 router, particularly the removal of the CanReuse interface. Is there another feature in the router that can achieve the same functionality of forcing a component reload? ...

Troubleshooting: Why is the Array in Object not populated with values when passed during Angular App instantiation?

While working on my Angular application, I encountered an issue with deserializing data from an Observable into a custom object array. Despite successfully mapping most fields, one particular field named "listOffices" always appears as an empty array ([]). ...

Tips for retrieving the Solana unix_timestamp on the front-end using JavaScript

Solana Rust smart contracts have access to solana_program::clock::Clock::get()?.unix_timestamp which is seconds from epoch (midnight Jan 1st 1970 GMT) but has a significant drift from any real-world time-zone as a result of Solana's processing delays ...

Error encountered when utilizing a mixin in TypeScript due to a parameter issue

Recently, I delved into learning Typescript and decided to experiment with the mixin concept. The code snippet below may seem trivial, but it's all part of the learning process. Surprisingly, everything runs smoothly except for line 42, myInput.sendKe ...

Error with the type of CanvasGradient in the NPM package for converting text to image

I attempted to generate an image using a specific text by utilizing npm's text-to-image package, but encountered an error during typescript compilation. The errors I encountered upon running the typescript compilation command are related to files with ...