HTML5 Tutorial - Drag and Drop-HTML Tutorial-php.cn

Home

Web Front-end

HTML Tutorial

HTML5 Tutorial - Drag and Drop

黄舟

Dec 27, 2016 pm 03:24 PM

htmldrag and drop

Hi, front-end programmers, hello! I am very happy to explain to you a series of knowledge about HTML5 tutorials. This article mainly introduces HTML5 drag and drop events. Drag and drop is a common feature of HTML5.

Drag and drop are part of the HTML5 standard.

Drag and drop

Drag and drop is a common feature where you grab an object and then drag it to another location.

In HTML5, drag and drop is part of the standard, and any element can be dragged and dropped.

Browser support

Internet Explorer 9, Firefox, Opera 12, Chrome and Safari 5 support drag and drop.

Note: Drag and drop is not supported in Safari 5.1.2.

HTML5 drag and drop example

The following example is a simple drag and drop example:

The code is as follows:

<!DOCTYPE HTML>
<html>
<head>
<script type=”text/javascript”>
function allowDrop(ev)
{
ev.preventDefault();
}
function drag(ev)
{
ev.dataTransfer.setData(“Text”,ev.target.id);
}
function drop(ev)
{
ev.preventDefault();
var data=ev.dataTransfer.getData(“Text”);
ev.target.appendChild(document.getElementById(data));
}
</script>
</head>
<body>
<div id=”div1″ ondrop=”drop(event)”
ondragover=”allowDrop(event)”></div>
<img id=”drag1″ src=”img_logo.gif” draggable=”true”
ondragstart=”drag(event)” width=”336″ height=”69″ />
</body>
</html>

It may look a little complicated, But we can study different parts of the drag and drop event separately.

Set the element as draggable

First, in order to make the element draggable, set the draggable attribute to true:

<img  draggable=”true” / alt="HTML5 Tutorial - Drag and Drop" >

What to drag – ondragstart and setData()

Then, specify what happens when the element is dragged.

In the above example, the ondragstart attribute calls a function, drag(event), which specifies the data to be dragged.

dataTransfer.setData() method sets the data type and value of the dragged data:

function drag(ev)
{
ev.dataTransfer.setData(“Text”,ev.target.id);
}

In this example, the data type is "Text" and the value is the id of the draggable element ( "drag1").

Where to put it - ondragover

The ondragover event specifies where to place the dragged data.

By default, data/elements cannot be placed into other elements. If we need to allow placement, we must prevent the default handling of the element.

This is done by calling the event.preventDefault() method of the ondragover event:

event.preventDefault()

Placement - ondrop

When the dragged data is placed, the drop event will occur.

In the above example, the ondrop attribute calls a function, drop(event):

function drop(ev)
{
ev.preventDefault();
var data=ev.dataTransfer.getData(“Text”);
ev.target.appendChild(document.getElementById(data));
}

Code explanation:

Call preventDefault() to prevent the browser from modifying the data The default handling of drop events (the default behavior of drop events is to open as a link).

Get the dragged data through the dataTransfer.getData("Text") method. This method will return any data set to the same type in the setData() method.

The dragged data is the id of the dragged element (“drag1″).

Append the dragged element to the placed element (target element).

The above is the content of HTML5 tutorial-drag and drop. For more related content, please pay attention to the PHP Chinese website (www.php.cn)!

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

The Future of HTML, CSS, and JavaScript: Web Development TrendsApr 19, 2025 am 12:02 AM

The future trends of HTML are semantics and web components, the future trends of CSS are CSS-in-JS and CSSHoudini, and the future trends of JavaScript are WebAssembly and Serverless. 1. HTML semantics improve accessibility and SEO effects, and Web components improve development efficiency, but attention should be paid to browser compatibility. 2. CSS-in-JS enhances style management flexibility but may increase file size. CSSHoudini allows direct operation of CSS rendering. 3.WebAssembly optimizes browser application performance but has a steep learning curve, and Serverless simplifies development but requires optimization of cold start problems.

HTML: The Structure, CSS: The Style, JavaScript: The BehaviorApr 18, 2025 am 12:09 AM

The roles of HTML, CSS and JavaScript in web development are: 1. HTML defines the web page structure, 2. CSS controls the web page style, and 3. JavaScript adds dynamic behavior. Together, they build the framework, aesthetics and interactivity of modern websites.

The Future of HTML: Evolution and Trends in Web DesignApr 17, 2025 am 12:12 AM

The future of HTML is full of infinite possibilities. 1) New features and standards will include more semantic tags and the popularity of WebComponents. 2) The web design trend will continue to develop towards responsive and accessible design. 3) Performance optimization will improve the user experience through responsive image loading and lazy loading technologies.

HTML vs. CSS vs. JavaScript: A Comparative OverviewApr 16, 2025 am 12:04 AM

The roles of HTML, CSS and JavaScript in web development are: HTML is responsible for content structure, CSS is responsible for style, and JavaScript is responsible for dynamic behavior. 1. HTML defines the web page structure and content through tags to ensure semantics. 2. CSS controls the web page style through selectors and attributes to make it beautiful and easy to read. 3. JavaScript controls web page behavior through scripts to achieve dynamic and interactive functions.

HTML: Is It a Programming Language or Something Else?Apr 15, 2025 am 12:13 AM

HTMLisnotaprogramminglanguage;itisamarkuplanguage.1)HTMLstructuresandformatswebcontentusingtags.2)ItworkswithCSSforstylingandJavaScriptforinteractivity,enhancingwebdevelopment.

HTML: Building the Structure of Web PagesApr 14, 2025 am 12:14 AM

HTML is the cornerstone of building web page structure. 1. HTML defines the content structure and semantics, and uses, etc. tags. 2. Provide semantic markers, such as, etc., to improve SEO effect. 3. To realize user interaction through tags, pay attention to form verification. 4. Use advanced elements such as, combined with JavaScript to achieve dynamic effects. 5. Common errors include unclosed labels and unquoted attribute values, and verification tools are required. 6. Optimization strategies include reducing HTTP requests, compressing HTML, using semantic tags, etc.

From Text to Websites: The Power of HTMLApr 13, 2025 am 12:07 AM

HTML is a language used to build web pages, defining web page structure and content through tags and attributes. 1) HTML organizes document structure through tags, such as,. 2) The browser parses HTML to build the DOM and renders the web page. 3) New features of HTML5, such as, enhance multimedia functions. 4) Common errors include unclosed labels and unquoted attribute values. 5) Optimization suggestions include using semantic tags and reducing file size.

Understanding HTML, CSS, and JavaScript: A Beginner's GuideApr 12, 2025 am 12:02 AM

WebdevelopmentreliesonHTML,CSS,andJavaScript:1)HTMLstructurescontent,2)CSSstylesit,and3)JavaScriptaddsinteractivity,formingthebasisofmodernwebexperiences.

See all articles