How to prevent closing of modal Dialog in EJ2 TypeScript Dialog

4 Sep 202610 minutes to read

You can prevent the closing of a modal Dialog by setting the beforeClose event argument’s cancel value to true. Note that the args parameter is of type BeforeCloseEventArgs, whose cancel property controls whether the Dialog closes; this approach works for both modal and non-modal Dialogs.
In the following sample, the Dialog is closed when you enter a username value with a minimum of 4 characters and a non-empty password. Otherwise, it will not be closed.

index.ts

import { Dialog } from '@syncfusion/ej2-popups';
import { enableRipple } from '@syncfusion/ej2-base';

// To get the all input fields and its container.
let inputElement = document.querySelectorAll('.e-input-group .e-input,.e-float-input.e-input-group input');

// Add 'e-input-focus' class to the input for achive ripple effect when focus on the input field.
for (let i = 0; i < inputElement.length; i++) {
    inputElement[i].addEventListener("focus", function () {
        let parentElement = this.parentNode;
        if (parentElement.classList.contains('e-input-in-wrap')) {
            parentElement.parentNode.classList.add('e-input-focus');
        } else {
            this.parentNode.classList.add('e-input-focus');
        }
    });
    inputElement[i].addEventListener("blur", function () {
        let parentElement = this.parentNode;
        if (parentElement.classList.contains('e-input-in-wrap')) {
            parentElement.parentNode.classList.remove('e-input-focus');
        } else {
            this.parentNode.classList.remove('e-input-focus');
        }
    });
}

// Add 'e-input-btn-ripple' class to the icon element for achive ripple effect when click on the icon.
var inputIcon = document.querySelectorAll('.e-input-group-icon');
for (let i = 0; i < inputIcon.length; i++) {
    inputIcon[i].addEventListener('mousedown', function () {
        this.classList.add('e-input-btn-ripple');
    });
    inputIcon[i].addEventListener('mouseup', function () {
        let element = this;
        setTimeout(function () {
            element.classList.remove('e-input-btn-ripple');
        }, 500);
    });
}

enableRipple(true);

// Initialize Dialog component
let dialog: Dialog = new Dialog({
    // Enables the header
    header: 'Sign in',
    // Dialog content
    content: document.getElementById("dlgContent"),
    // Enables the footer buttons
    buttons: [{
        // Accessing button component properties by buttonModel property
        buttonModel: {
            //Enables the primary button
            isPrimary: true,
            content: 'Log in',
            cssClass: 'e-primary',
        },
        // Click the footer buttons to hide the Dialog
        click: function () {
            this.hide();
        }
    }],
    // The Dialog shows within the target element
    target: document.getElementById("container"),
    // Dialog width
    width: '300px',
    beforeClose: validation,
    isModal: true,
    beforeOpen: onBeforeopen
});
// Render initialized Dialog
dialog.appendTo('#dialog');

document.getElementById('targetButton').onclick = (): void => {
    dialog.show();
    document.getElementById("textvalue").value = "";
    document.getElementById("textvalue2").value = "";
};

function validation(args) {
    let text = document.getElementById('textvalue');
    let text1 = document.getElementById('textvalue2');
    if (text.value === "" && text1.value === "") {
        args.cancel= true;
        alert("Enter the username and password")
    } else if (text.value === "") {
        args.cancel= true;
        alert("Enter the username")
    } else if (text1.value === "") {
        args.cancel= true;
        alert("Enter the password")
    } else if (text.value.length < 4) {
        args.cancel= true;
        alert("Username must be minimum 4 characters")
    } else {
        args.cancel= false;
        document.getElementById("textvalue").value = "";
        document.getElementById("textvalue2").value = "";
    }
}

function onBeforeopen(): void {
    document.getElementById('dlgContent').style.visibility = 'visible';
}

index.html

<!DOCTYPE html>
<html lang="en">

<head>
    <title>Essential JS 2 Dialog</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="TypeScript UI Components" />
    <meta name="author" content="Syncfusion" />
    <link href="styles.css" rel="stylesheet" />
    <link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-buttons/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/34.2.2/ej2-popups/styles/material.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
</head>

<body>
    <div id='loader'>LOADING....</div>
    <div id='container'>
        <button class="e-control e-btn" id="targetButton" role="button" e-ripple="true" style="position: absolute;" >Open Dialog</button>
        <div id='dialog'></div>
        <div id="dlgContent" style="visibility: hidden" class='wrap'>
            <div id='input-container'>
              <div class='e-float-input'>
                <input id='textvalue' type='text' required/>
                <span class='e-float-line'></span>
                <label class='e-float-text'>Username</label>
              </div>
            </div>
            <div class='form-group'>
                <div class='e-float-input'>
                    <input id='textvalue2' type='Password' required/>
                    <span class='e-float-line'></span>
                    <label class='e-float-text'>Password</label>
                </div>
            </div>
        </div>
    </div>
</body>
</html>