Step-by-Step Guide to Building Dynamic Modals in JavaScript Using Data Attributes

Step-by-Step Guide to Building Dynamic Modals in JavaScript Using Data Attributes

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Modals are a fundamental part of modern web design, offering a sleek way to display content without redirecting users to a new page. While libraries like Bootstrap provide pre-built modal components, understanding how to create dynamic modals using JavaScript and data attributes opens up a world of possibilities for web developers. In this step-by-step guide, we'll walk through the process of building dynamic modals from scratch using JavaScript and data attributes.

Prerequisites

Before we dive in, make sure you have a basic understanding of HTML, CSS, and JavaScript. Familiarity with data attributes will be helpful but not necessary, as we'll cover them in detail.

Step 1: HTML Structure

Let's start by creating the basic HTML structure for our modal. We will use a combination of div elements to define the modal container, content, and close button.

<!-- Modal container -->
<div class="modal" id="custom-modal">
    <!-- Modal content -->
    <div class="modal-content">
        <!-- Modal header -->
        <div class="modal-header">
            <h4 class="modal-title">Modal Title</h4>
            <!-- Close modal -->
            <span class="close" data-modal-hide="custom-modal">&times;</span>
        </div>
        <!-- Modal body -->
        <div class="modal-body">
            <p>
            Lorem, ipsum dolor sit amet consectetur adipisicing elit.
            Consectetur harum reiciendis iusto dolore maxime aliquam alias. Rem
            aliquam minima excepturi.
            </p>
        </div>
    </div>
</div>
  • The div element with id="custom-modal" will be our modal container.

  • The div element with class="modal-content" will be our modal content wrapper.

  • Inside the modal header, span element with a data-modal-hide attribute will be our trigger button to close the modal and data-modal-hide attribute's value will be our modal id value.

Now, let's add a trigger button to open our modal.

<button class="btn-primary" data-modal-show="custom-modal">
    Open Modal
</button>

We have added a data-modal-show attribute to the button element with our modal's id value.

Step 2: Styling Our Modal

Add CSS to style your modal. Customize the appearance, animation, and positioning to match your design preferences. Here's a basic example to get you started:

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
}

.modal-content {
    background: #fff;
    border-radius: 5px;
    padding: 20px;
    text-align: center;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 350px;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-title {
    margin: 0;
    font-size: 20px;
}

.close {
    color: #aaa;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
}
.modal-body {
    padding-top: 5px;
    font-size: 16px;
}

.btn-primary {
    background-color: #008CBA;
    border: none;
    color: white;
    padding: 15px 32px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    border-radius: 8px;
    cursor: pointer;
}

Step 3: JavaScript Functionality

As we are done with our HTML and CSS part, we will now dive into JavaScript. First, we will create two functions which responsible for opening and closing the modal.

Function: openModal()

We will wrap our modal opening operations in this function.

// Open modal function
function openModal(modalId) {
  const modal = document.querySelector(`#${modalId}`);
  modal.style.display = "block";
}
  1. Parameter:

    • modalId: This parameter represents the id value of the modal that needs to be opened. It is passed to the function when calling it.
  2. Selecting the Modal:

    • const modal: This line of code uses document.querySelector to select the modal element based on its id attribute, which matches the provided modalId.
  3. Show the Modal:

    • modal.style.display = "block";: This line of code makes modal visible by changing its CSS display property to 'block'.

Function: closeModal()

We will wrap our modal closing operations in this function.

// Close modal function
function closeModal(modalId) {
  const modal = document.querySelector(`#${modalId}`);
  modal.style.display = "none";
}
  1. Parameter:

    • modalId: This parameter represents the id value of the modal that needs to be closed. It is passed to the function when calling it.
  2. Selecting the Modal:

    • const modal: This line of code uses document.querySelector to select the modal element based on its id attribute, which matches the provided modalId.
  3. Hide the Modal:

    • modal.style.display = "none";: This line of code makes modal invisible by changing its CSS display property to 'none'.

Now, we have to call these functions when the respective trigger button is clicked.

Click Event Listener

Let's add click event listeners to the trigger buttons.

In HTML,

  • Elements with data-modal-show attribute will be trigger buttons to open the modal.

  • Elements with data-modal-hide attribute will be trigger buttons to close the modal.

First, we will add an event listener to all the elements with the data-modal-show attribute.

// Open modal when trigger button is clicked
document.querySelectorAll("[data-modal-show]").forEach((triggerButton) => {
  triggerButton.addEventListener("click", () => {
    const modalId = triggerButton.getAttribute("data-modal-show");
    openModal(modalId);
  });
});
  • document.querySelectorAll("[data-modal-show]"): This part of the code selects all elements in the document that have the attribute data-modal-show.

  • .forEach((triggerButton) => { ... }): The forEach method is used to loop through all the elements selected in the previous step.

  • triggerButton.addEventListener("click", () => { ... }): Here we are adding a click event listener to the element.

  • Inside the event listener's arrow function:

    • const modalId = triggerButton.getAttribute("data-modal-show");: Using getAttribute() method, we retrieved the data-modal-show attribute value of the element.

    • openModal(modalId);: At the last, we called the previously created openModal function with modalId parameter.

We are now able to open our modals, let's add an event listener to all the elements with the data-modal-hide attribute to hide our modals.

// Close modal when close button is clicked
document.querySelectorAll("[data-modal-hide]").forEach((closeButton) => {
  closeButton.addEventListener("click", () => {
    const modalId = closeButton.getAttribute("data-modal-hide");
    closeModal(modalId);
  });
});
  • document.querySelectorAll("[data-modal-hide]"): This part of the code selects all elements in the document that have the attribute data-modal-hide.

  • .forEach((triggerButton) => { ... }): The forEach method is used to loop through all the elements selected in the previous step.

  • triggerButton.addEventListener("click", () => { ... }): Here we are adding a click event listener to the element.

  • Inside the event listener's arrow function:

    • const modalId = triggerButton.getAttribute("data-modal-hide");: Using getAttribute() method, we retrieved the data-modal-hide attribute value of the element.

    • closeModal(modalId);: At the last, we called the previously created closeModal function with modalId parameter.

Wrapping Up

Congratulations! We have successfully built dynamic modals in JavaScript using data attributes.

Checkout:

Happy Coding!