Formvalidation if checkbox with value true is clicked RRS feed

  • Question

  • User-1121540557 posted


    I have a Angular form where I need to at some validation.
    Problem is that the user may only submit the form if the email and answer is correct.

    The answer is in a checkbbox array.. (value = true) the other two checkboxes have false value.

    ts code:

    import { Component, OnInit } from '@angular/core';
    import { FormGroup, FormBuilder, FormArray, FormControl, Validators, AbstractControl, ValidatorFn, ValidationErrors, NgModel } from '@angular/forms';
    import { Router } from '@angular/router';
    import { ToastrService } from 'ngx-toastr'
    import { UserService } from "./../../services/user.service";
    import { questionMode} from "./../../models/questionMode.model";
    import { User } from "./../../models/user.model";
    import { makeStyles } from '@material-ui/core/styles';
      selector: 'app-confirmquestion',
      templateUrl: './confirmquestion.component.html',
      styleUrls: []
    export class ConfirmQuestionComponent implements OnInit {
      form: FormGroup;
        private userServive: UserService,
        private router: Router,
        private toastr: ToastrService,
        private fb: FormBuilder
      ) {
      colorList: any[] = [
          names: ['blue', 'indigo', 'purple', 'pink', 'orange', 'red', 'yellow', 'green', 'teal', 'cyan', 'white', 'gray', 'gray-dark', 'black'],
          colors: ['#007bff', '#6610f2', '#6f42c1', '#e83e8c', '#fd7e14', '#fd7e14', '#ffc107', '#28a745', '#20c997', '#17a2b8', '#fff', '#6c757d', '#343a40', '#000']
      emailPattern: "^[a-z0-9!#$%&'*+\/=?^_`{|}~.-]+@[a-z0-9]([a-z0-9-]*[a-z0-9])?(\.[a-z0-9]([a-z0-9-]*[a-z0-9])?)*$";
      exampleDiv: any[] = [];
      colorDivs: any[] = [];
      colorNames: any[] = [];
      anwserNumber: number = 0;
      anwsers: boolean[] = [];
      answer: any[] = [];
      answerName: string;
      answerColors: any[] = [];
      answerColor: string;
      props: any;
      useStyles: any;
     ngOnInit() {
        this.useStyles = makeStyles({
          answerStyle: {
            height: '125px;',
            width: '125px;',
            backgroundColor: this.answerColor
        this.form = this.fb.group({
          email: new FormControl(['', [Validators.required, Validators.pattern(this.emailPattern)]]),
          answer: new FormControl(this.answer),
          checkArray: this.fb.array([], this.answerValidator )
        this.form.status === 'INVALID';
    // also tried Validators.requiredTrue on the array but not working...
      get f() {
        return this.form.controls;
      onCheckboxChange(e) {// <=== Not working
        const checkArray: FormArray = this.form.get('checkArray') as FormArray;
        if (e.target.checked) {
          var sValue: any = e.target.value;      
          if (sValue == "true") {
            this.toastr.success('form is valid', 'the form is ready to send');
            this.form.status === 'VALID';// <=== Not working
          else {
            this.toastr.error('Invalid answer', 'Please try again.');
            this.form.status === 'INVALID'; 
      checkAnswer(res: any): boolean {
        if (this.answerName == res) {
          this.answer = [];
          this.answer.push({ value: "true" });
          this.toastr.success('form is valid', 'the form is ready to send');
          this.form.status === 'VALID';
          return true;
        else {
          this.toastr.error('incorrect answer', 'Try again.');
          this.form.status === 'INVALID';
          return false;
      answerValidator(control: AbstractControl): {
        [key: string]: boolean
      } | null {
        // const answerValue = this.form.get('answer');
        if (control.value !== undefined && (isNaN(control.value) || control.value == 'true')) {
          return { 'cAnwser': true };
        return null;


    <form [formGroup]="form" (ngSubmit)="submitForm()">
                <div class="form-group required">
                    <div class="md-form">
                        <input type="text" #email id="ipEmail" formControlName="email" required class="form-control" placeholder="Please add a valid emailaddress" autocomplete="email" [(ngModel)]="form.email">
                        <label class="text-danger" *ngIf="form.get('email').touched && form.get('email').errors?.required">Add a valid emailaddress.</label>
                        <label class="text-danger" *ngIf="form.get('email').touched && form.get('email').errors?.email">invalid email address</label>
                <div class="form-group">
                    <div class="form-row col-lg-12">
                        <div class="col col-md-1">
                            <div style="height: 100px; width: 100px;">
                                <ul *ngFor="let color of answerColors; let j=index">
                                    <div class="row">
                                    <div class="row">
                                        <div [style.background-color]="color" style="height: 60px; width: 60px;">
                <div class="form-group" *ngFor="let data of colorDivs; let i=index">
                        <input type="checkbox" [value]="data[0]['isAnswer']" name="dcolorNames" required (change)="onCheckboxChange($event)" /><strong>{{data[0]['name']}}</strong>                    
    <!-- validator also not working -->
                <p class="error" *ngIf="this.form.controls['checkArray'].errors?.required">
                    please supply one answer..
                <button mdbBtn class="btn form-btn-save-r text-center" outline="true" rounded="true" block="true" type="submit" [disabled]="form.invalid">Submit</button>

    Monday, February 17, 2020 11:43 PM

All replies

  • User-474980206 posted

    as this is a pure angular question and nothing to do with asp.net / SPA interaction, you might try an angular support forum. google for angular support forums


    Tuesday, March 17, 2020 8:13 PM