Drag and Drop
Drag and drop is a very common feature. It is when you "grab" an object and drag it to a different location.
In HTML5, drag and drop is part of the standard, and any element can be draggable.
Internet Explorer 9, Firefox, Opera 12, Chrome, and Safari 5 support drag and drop.
Note: Drag and drop does not work in Safari 5.1.2.
HTML5 Drag and Drop Example
The example below is a simple drag and drop example:
It might seem complicated, but lets go through all the different parts of a drag and drop event.
Make an Element Draggable
First of all: To make an element draggable, set the draggable attribute to true:
What to Drag - ondragstart and setData()
Then, specify what should happen when the element is dragged.
In the example above, the ondragstart attribute calls a function, drag(event), that specifies what data to be dragged.
The dataTransfer.setData() method sets the data type and the value of the dragged data:
In this case, the data type is "Text" and the value is the id of the draggable element ("drag1").
Where to Drop - ondragover
The ondragover event specifies where the dragged data can be dropped.
By default, data/elements cannot be dropped in other elements. To allow a drop, we must prevent the default handling of the element.
This is done by calling the event.preventDefault() method for the ondragover event:
Do the Drop - ondrop
When the dragged data is dropped, a drop event occurs.
In the example above, the ondrop attribute calls a function, drop(event):
- Call preventDefault() to prevent the browser default handling of the data (default is open as link on drop)
- Get the dragged data with the dataTransfer.getData("Text") method. This method will return any data that was set to the same type in the setData() method
- The dragged data is the id of the dragged element ("drag1")
- Append the dragged element into the drop element
Content Courtesy: http://www.w3schools.com