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How to create a Drag and Drop interface using Vanilla JS

February 20, 2023

3 minute read

Hi! I’m back after a long break with a new post on how to create a Drag and Drop interface using Vanilla JS.

Let’s have look what we are going to create in this tutorial

Drag and drop functionality is a great way to enhance the user experience of a web application. With drag and drop, users can easily move elements around a page, reorder lists, and perform other interactive actions. In this tutorial, we’ll cover how to create a simple drag and drop interface with vanilla JavaScript.

We’ll be using TailwindCSS for styling you may use pure CSS or any other CSS framework.

So, let’s write the HTML for our project in index.html

HTML



       </span>Drag and Drop Example<span class="nt">


     id="list">
         id="item1" draggable="true">Item 1
         id="item2" draggable="true">Item 2
         id="item3" draggable="true">Item 3
         id="item4" draggable="true">Item 4
         id="item5" draggable="true">Item 5
    
   id="target">

Now add the Tailwind CDN in and add classes to it




    </span>Drag and Drop Example<span class="nt">
    
     rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/tailwindcss/2.2.7/tailwind.min.css">

    

 class="bg-gray-100">

     class="max-w-md mx-auto mt-8">

        
         class="p-4 bg-white rounded-lg shadow-lg">
             id="list" class="list-none p-0 m-0 bg-gray-100 border border-gray-300 min-h-40">
                 id="item1" draggable="true" class="bg-white border border-gray-300 p-4 mb-2 cursor-move">Item 1
                 id="item2" draggable="true" class="bg-white border border-gray-300 p-4 mb-2 cursor-move">Item 2
                 id="item3" draggable="true" class="bg-white border border-gray-300 p-4 mb-2 cursor-move">Item 3
                 id="item4" draggable="true" class="bg-white border border-gray-300 p-4 mb-2 cursor-move">Item 4
                 id="item5" draggable="true" class="bg-white border border-gray-300 p-4 mb-2 cursor-move">Item 5



        
         id="target" class="mt-4 p-4 bg-white rounded-lg shadow-lg border-dashed border-2 border-gray-300 min-h-60">
             class="text-center text-gray-400">Drop items here

Now create index.js and add this to index.html

JavaScript:-
Now write some JS for our drag and drop interface.

const listItems = document.querySelectorAll("#list li");
        const target = document.querySelector("#target");

        for (const listItem of listItems) {
          listItem.addEventListener("dragstart", dragStart);
        }

        target.addEventListener("dragover", dragOver);
        target.addEventListener("drop", drop);

        function dragStart(event) {
          event.dataTransfer.setData("text/plain", event.target.id);
        }

        function dragOver(event) {
          event.preventDefault();
          target.classList.add("border-gray-500");
        }

        function drop(event) {
          event.preventDefault();
          const itemId = event.dataTransfer.getData("text/plain");
          const item = document.getElementById(itemId);
          target.appendChild(item);
          target.classList.remove("border-gray-500");
        }

Code Explanation:-
First, it selects all the list items on the page and the target element using document.querySelectorAll and document.querySelector. This is done using CSS selectors: #list li selects all the li elements inside the element with the ID list, and #target selects the element with the ID target.

Next, it adds a dragstart event listener to each list item using a for...of loop. This event listener is triggered when the user starts dragging an item.

The dragStart function is called when the event is triggered. It sets the data that is being dragged by calling event.dataTransfer.setData("text/plain", event.target.id). The first argument specifies the data type (text/plain in this case), and the second argument is the ID of the element being dragged.

The code then adds a dragover event listener to the target element. This event listener is triggered when the user drags an item over the target element.

The dragOver function is called when the event is triggered. It calls event.preventDefault() to allow the drop event to be triggered. It also adds a CSS class to the target element to indicate that it can be dropped onto.

Finally, the code adds a drop event listener to the target element. This event listener is triggered when the user drops an item onto the target element.

The drop function is called when the event is triggered. It calls event.preventDefault() to prevent the default behavior (which is to navigate to a new page). It then gets the ID of the element being dragged by calling event.dataTransfer.getData("text/plain"). It retrieves the element by its ID using document.getElementById(itemId), and appends it to the target element using target.appendChild(item). Finally, it removes the CSS class that was added to the target element in the dragOver function.

Finally the Drag and Drop Interface is ready.

I hope you loved this.

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