HTML | DOM ondragover Event

The HTML DOM ondragover event occurs when a draggable element is being dragged over a valid dropzone.

Note: Links and images are draggable by default.

There are some events that are used and occurred in the different stages of a drag and drop operation:

ondragstart: occurs when dragging of an element started.
ondrag: occurs while an element is dragging.
ondragend: occurs when dragging of an element finished.

ondragenter: occurs when the dragged element entered into the drop target.
ondragover: occurs when the dragged element is over the drop target.
ondragleave: occurs when the dragged element leaves from the drop target.
ondrop: occurs when the dragged element is dropped on the drop target.

Note: the ondragover event fires every 350 milliseconds while dragging an element.

Syntax:

In HTML:
```
<element ondragover="myScript">
```

In JavaScript:

object.ondragover = function(){myScript};

In JavaScript, using the addEventListener() method:
```
object.addEventListener("dragover", myScript);
```

Example: Using HTML.

<!DOCTYPE HTML> 
<html> 
  
<head> 
    <style> 
        #droptarget { 
            float: center; 
            width: 300px; 
            height: 50px; 
            margin: 20px; 
            margin-top: 30px; 
            padding: 5px; 
            border: 6px solid green; 
        } 
    </style> 
</head> 
  
<body> 
    <center> 
        <h1 style="color:green"> 
          GeeksforGeeks 
      </h1> 
        <h2> 
          HTML DOM ondragover Event 
      </h2> 
        <p ondragstart="dragStartEle(event)" 
           draggable="true" 
           id="dragtarget"> 
          Draggable element 
      </p> 
        
        <div id="droptarget" 
             ondrop="dropEle(event)" 
             ondragover="allowDropEle(event)"> 
        </div> 
  
        <p id="try"></p> 
  
        <script> 
            function dragStartEle(event) { 
                event.dataTransfer.setData( 
                  "Text", event.target.id); 
            } 
  
            function allowDropEle(event) { 
                event.preventDefault(); 
                document.getElementById( 
                  "try").innerHTML =  
                  "Element is over the dropzone"; 
                event.target.style.border = "6px dotted green"; 
            } 
  
            function dropEle(event) { 
                event.preventDefault(); 
                var data =  
                    event.dataTransfer.getData("Text"); 
                
                event.target.appendChild( 
                  document.getElementById(data)); 
                
                document.getElementById( 
                  "try").innerHTML = "Dragging finished"; 
            } 
        </script> 
    </center> 
</body> 
  
</html> 

Output:

Example: Using JavaScript

<!DOCTYPE HTML> 
<html> 
  
<head> 
    <style> 
        #droptarget { 
            float: center; 
            width: 300px; 
            height: 50px; 
            margin: 20px; 
            margin-top: 30px; 
            padding: 5px; 
            border: 6px solid green; 
        } 
    </style> 
</head> 
  
<body> 
    <center> 
        <h1 style="color:green"> 
          GeeksforGeeks 
      </h1> 
        <h2>HTML DOM ondragover Event</h2> 
        <p draggable="true" 
           id="dragtarget"> 
          Draggable element 
      </p> 
  
        <div id="droptarget"></div> 
  
        <p id="demo"></p> 
  
        <script> 
            var drag = document.getElementById( 
              "dragtarget"); 
            var drop = document.getElementById( 
              "droptarget"); 
  
            // Events fired on the drag target  
            drag.ondragstart = function(event) { 
                event.dataTransfer.setData( 
                  "Text", event.target.id); 
            }; 
  
            drag.ondrag = function(event) { 
                document.getElementById( 
                  "demo").innerHTML =  
                  "Dragging starts"; 
            }; 
  
            // Events fired on the drop target 
            drop.ondragover = function(event) { 
                event.preventDefault(); 
                document.getElementById( 
                  "demo").innerHTML =  
                  "Element is over the dropzone"; 
                event.target.style.border = 
                  "6px dotted green"; 
            }; 
  
            drop.ondrop = function(event) { 
                event.preventDefault(); 
                var data =  
                    event.dataTransfer.getData("Text"); 
                event.target.appendChild( 
                  document.getElementById(data)); 
                document.getElementById( 
                  "demo").innerHTML = "Dragging finished"; 
            }; 
        </script> 
    </center> 
</body> 
  
</html> 

Output:

Example: Using the addEventListener() method

<!DOCTYPE HTML> 
<html> 
  
<head> 
    <style> 
        #droptarget { 
            float: center; 
            width: 300px; 
            height: 50px; 
            margin: 20px; 
            margin-top: 30px; 
            padding: 5px; 
            border: 6px solid green; 
        } 
    </style> 
</head> 
  
<body> 
    <center> 
        <h1 style="color:green"> 
          GeeksforGeeks 
      </h1> 
        <h2>HTML DOM ondragover Event</h2> 
        <p draggable="true" id="dragtarget"> 
          Draggable element 
      </p> 
  
        <div id="droptarget"></div> 
  
        <p id="try"></p> 
  
        <script> 
            var drag = document.getElementById( 
              "dragtarget"); 
            var drop = document.getElementById( 
              "droptarget"); 
  
            // Events fired on the drag target  
  
            drag.addEventListener( 
              "dragstart", function(event) { 
                event.dataTransfer.setData( 
                  "Text", event.target.id); 
            }); 
  
            drag.addEventListener( 
              "drag", function(event) { 
                document.getElementById( 
                  "try").innerHTML = "Dragging starts"; 
            }); 
  
            // Events fired on the drop target  
            drop.addEventListener("dragover", function(event) { 
                event.preventDefault(); 
                document.getElementById( 
                  "try").innerHTML = "Element is over the dropzone"; 
                event.target.style.border = "6px dotted green"; 
            }); 
  
            drop.addEventListener("drop", function(event) { 
                event.preventDefault(); 
                var data = event.dataTransfer.getData("Text"); 
                
                event.target.appendChild( 
                  document.getElementById(data)); 
                
                document.getElementById( 
                  "try").innerHTML = "Dragging finished"; 
            }); 
        </script> 
    </center> 
</body> 
  
</html> 

Output:

Supported Browsers: The browsers supported by HTML DOM ondragover Event are listed below:

Google Chrome 4.0
Internet Explorer 9.0
Firefox 3.5
Apple Safari 6.0
Opera 12.0

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