Tips for collecting user input while iterating through an array

Question

Tips for collecting user input while iterating through an array

I am working on a list that iterates over an array and includes input tags. I need to figure out how to retrieve the values from the text boxes after clicking a button, as the input boxes are generated based on the length of the list.

<div>
  <div *ngFor="let arrayitems of arrayElements">
    <P>{{arrayitems}}</P>
    <input type ="text" placeholder="{{arrayitems}}">
  </div>
  <button (click)="submitFunction()" style="margin-top:10px">CLICK ME!</button>
</div>

TypeScript:

 arrayElements : any;

  ngOnInit(){
    this.arrayElements=["listElementOne","listElementTwo","listElementThree","listElementFour","listElementFive","listElementSix"];
  }
  submitFunction(){
    alert("Function Called");
    console.log("print all the values taken from the input tag");

  }

Access the Stack Blitz Link here

angular typescript loops angular-ngmodel

Answer 1

Answer №1

To properly bind values, it is necessary to store them in a separate array and then utilize ngModel for binding.

Here is the revised app.component.ts file:

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

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent implements OnInit  {
  arrayElements : any;

  items: string[] = [];

  ngOnInit(){
    this.arrayElements=["listElementOne","listElementTwo","listElementThree","listElementFour","listElementFive","listElementSix"];
  }
  submitFunction(){
    console.log(this.items);
  }
}

For the updated app.component.html:

<div>
  <div *ngFor="let arrayitems of arrayElements;let i = index;">
    <p>{{arrayitems}}</p>
    <input type ="text" [(ngModel)]="items[i]" placeholder="{{arrayitems}}">
  </div>
  <button (click)="submitFunction()" style="margin-top:10px">CLICK ME!</button>
</div>

An updated version of your code can be found at https://stackblitz.com/edit/input-tag-iterating-over-array-2fezah

Answer 2

To properly bind values, it is necessary to store them in a separate array and then utilize ngModel for binding.

Here is the revised app.component.ts file:

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

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent implements OnInit  {
  arrayElements : any;

  items: string[] = [];

  ngOnInit(){
    this.arrayElements=["listElementOne","listElementTwo","listElementThree","listElementFour","listElementFive","listElementSix"];
  }
  submitFunction(){
    console.log(this.items);
  }
}

For the updated app.component.html:

<div>
  <div *ngFor="let arrayitems of arrayElements;let i = index;">
    <p>{{arrayitems}}</p>
    <input type ="text" [(ngModel)]="items[i]" placeholder="{{arrayitems}}">
  </div>
  <button (click)="submitFunction()" style="margin-top:10px">CLICK ME!</button>
</div>

An updated version of your code can be found at https://stackblitz.com/edit/input-tag-iterating-over-array-2fezah

Answer 3

Answer №2

Even though this may not be the conventional angular approach, you have the option to utilize ElemenRef for querying all inputs.

constructor(private elRef: ElementRef) { }

submitFunction() {
  const list: NodeList = this.elRef.nativeElement.querySelectorAll("input");

  list.forEach((el: HTMLInputElement, idx) => {
    console.log(`el${idx}: ${el.value}`);
  });
}

Check out a live demo

However, it is recommended to explore ReactiveForms as well.

Answer 4

Even though this may not be the conventional angular approach, you have the option to utilize ElemenRef for querying all inputs.

constructor(private elRef: ElementRef) { }

submitFunction() {
  const list: NodeList = this.elRef.nativeElement.querySelectorAll("input");

  list.forEach((el: HTMLInputElement, idx) => {
    console.log(`el${idx}: ${el.value}`);
  });
}

Check out a live demo

However, it is recommended to explore ReactiveForms as well.

Answer 5

Answer №3

Could you please provide further details regarding the response you are receiving?

<P>{{arrayitems}}</P>.

I assume it is returning as undefined?

Answer 6

Could you please provide further details regarding the response you are receiving?

<P>{{arrayitems}}</P>.

I assume it is returning as undefined?

Answer 7

Answer №4

Make sure to assign unique identifiers to each input field on the page.

<input type ="text" id="{{uniqueId}}" placeholder="{{placeholderText}}">

When submitting the form, locate elements by their ids and retrieve their contents from the "value" property.

for (const elementId of this.arrayElements) {
    const element = <HTMLInputElement>document.getElementById(elementId)
    const content = element.value
    console.log(content)
}

It appears to be functioning properly, although I am uncertain about the usage of the "arrayItems" syntax in app.component.html.

Answer 8

Make sure to assign unique identifiers to each input field on the page.

<input type ="text" id="{{uniqueId}}" placeholder="{{placeholderText}}">

When submitting the form, locate elements by their ids and retrieve their contents from the "value" property.

for (const elementId of this.arrayElements) {
    const element = <HTMLInputElement>document.getElementById(elementId)
    const content = element.value
    console.log(content)
}

It appears to be functioning properly, although I am uncertain about the usage of the "arrayItems" syntax in app.component.html.

Answer 9

Answer №5

In my app.component.html file, I have implemented a new change method for the input field.

<div>
  <div *ngFor="let arrayitems of arrayElements">
    <P>{{arrayitems}}</P>
    <input type ="text" (change)="inputChange($event, arrayitems)" 
           placeholder="{{arrayitems}}">
  </div>
  <button (click)="submitFunction()" style="margin-top:10px">CLICK ME! 
  </button>
</div>

The app.component.ts file contains the definition for the input change method which assigns the input value to the result with the element name as the key. The submitFunction filters the result and returns a list of results.

export class AppComponent implements OnInit  {
  arrayElements : any;
  result = {};

  ngOnInit(){
    this.arrayElements= ["listElementOne","listElementTwo","listElementThree","listElementFour","listElementFive","listElementSix"];
  }
  
  inputChange(e, itemName) {
    this.result[itemName] = e.target.value
  }

   submitFunction(){
    const submitResult = this.arrayElements.map(element => {
      if (this.result[element]) {
        return this.result[element];
      }
    })
    .filter(e => !!e)

    console.log(submitResult)
    alert("Function Called");
  }
}

I hope this explanation helps you understand the code better!

Answer 10

In my app.component.html file, I have implemented a new change method for the input field.

<div>
  <div *ngFor="let arrayitems of arrayElements">
    <P>{{arrayitems}}</P>
    <input type ="text" (change)="inputChange($event, arrayitems)" 
           placeholder="{{arrayitems}}">
  </div>
  <button (click)="submitFunction()" style="margin-top:10px">CLICK ME! 
  </button>
</div>

The app.component.ts file contains the definition for the input change method which assigns the input value to the result with the element name as the key. The submitFunction filters the result and returns a list of results.

export class AppComponent implements OnInit  {
  arrayElements : any;
  result = {};

  ngOnInit(){
    this.arrayElements= ["listElementOne","listElementTwo","listElementThree","listElementFour","listElementFive","listElementSix"];
  }
  
  inputChange(e, itemName) {
    this.result[itemName] = e.target.value
  }

   submitFunction(){
    const submitResult = this.arrayElements.map(element => {
      if (this.result[element]) {
        return this.result[element];
      }
    })
    .filter(e => !!e)

    console.log(submitResult)
    alert("Function Called");
  }
}

I hope this explanation helps you understand the code better!

Tips for collecting user input while iterating through an array

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

Similar questions

Maintaining a JavaScript script within the local project directory and integrating it for use with Angular

Using Angular 2 to round a calculated number within HTML

What is the best way to create a jumping animation for an object in Cannon.js and Three.js?

Angular 6 - detecting clicks outside of a menu

`Lively Flames But Repository Chills When Applying Techniques With Reaction`

Is there a way to establish a boundary for the forEach function in TypeScript?

Can an HTTP response be considered a single element in an Observable stream from RxJS?

Automatically assigning IDs to all elements on an Angular webpage

Creating a repeating sequence in HTML: A step-by-step guide

Is there a method in Node.js to pause file reading and terminate the entire process within the eachLine function of line-reader?

transfer item between a mother and offspring

Updating the value of a variable in a separate file with Node.js

Issue with text displaying as "-webkit-standard" in font dropdown menu on Safari browser detected in Tinymce

Toggle the visibility of an input field based on a checkbox's onchange event

Tips for displaying bar chart labels effectively with ChartJS

What is the best way to activate ngModelChange for a custom input field?

Can we refactor by using a distinct function?

The instance is referring to a property or method that is not defined, but being used during rendering. Verify that the property is reactive and included in the data option

Issue with ADFS 2016 oAuth: Users not being redirected to login page post logout

Challenges with utilizing Ionic Native in a cross-platform application