jQuery：将文本URL转换为链接作为输入

对于其他浏览器,我建议在用户不活动一段时间后进行替换.以下是我的答案,说明了如何进行替换：

https://stackoverflow.com/a/4045531/96100

这是一个与(坏)链接正则表达式和讨论类似的：

https://stackoverflow.com/a/4026684/96100

为了保存和恢复选择,我建议使用基于字符偏移的方法.以下代码一般存在缺点,但对于在更改格式但保持文本不变的情况下保存和恢复选择的特定情况,这是理想的.这是一个例子：

https://stackoverflow.com/a/13950376/96100

最后,这里有一些讨论的答案以及如何等待用户不活动的示例：

> https://stackoverflow.com/a/7837001/96100
> https://stackoverflow.com/a/1621309/96100

把它们放在一起：

var saveSelection,restoreSelection;

if (window.getSelection && document.createRange) {
    saveSelection = function(containerEl) {
        var range = window.getSelection().getRangeAt(0);
        var preSelectionRange = range.cloneRange();
        preSelectionRange.selectNodeContents(containerEl);
        preSelectionRange.setEnd(range.startContainer,range.startOffset);
        var start = preSelectionRange.toString().length;

        return {
            start: start,end: start + range.toString().length
        }
    };

    restoreSelection = function(containerEl,savedSel) {
        var charIndex = 0,range = document.createRange();
        range.setStart(containerEl,0);
        range.collapse(true);
        var nodeStack = [containerEl],node,foundStart = false,stop = false;

        while (!stop && (node = nodeStack.pop())) {
            if (node.nodeType == 3) {
                var nextCharIndex = charIndex + node.length;
                if (!foundStart && savedSel.start >= charIndex && savedSel.start <= nextCharIndex) {
                    range.setStart(node,savedSel.start - charIndex);
                    foundStart = true;
                }
                if (foundStart && savedSel.end >= charIndex && savedSel.end <= nextCharIndex) {
                    range.setEnd(node,savedSel.end - charIndex);
                    stop = true;
                }
                charIndex = nextCharIndex;
            } else {
                var i = node.childNodes.length;
                while (i--) {
                    nodeStack.push(node.childNodes[i]);
                }
            }
        }

        var sel = window.getSelection();
        sel.removeAllRanges();
        sel.addRange(range);
    }
} else if (document.selection) {
    saveSelection = function(containerEl) {
        var selectedTextRange = document.selection.createRange();
        var preSelectionTextRange = document.body.createTextRange();
        preSelectionTextRange.movetoElementText(containerEl);
        preSelectionTextRange.setEndPoint("EndToStart",selectedTextRange);
        var start = preSelectionTextRange.text.length;

        return {
            start: start,end: start + selectedTextRange.text.length
        }
    };

    restoreSelection = function(containerEl,savedSel) {
        var textRange = document.body.createTextRange();
        textRange.movetoElementText(containerEl);
        textRange.collapse(true);
        textRange.moveEnd("character",savedSel.end);
        textRange.moveStart("character",savedSel.start);
        textRange.select();
    };
}

function createLink(matchedTextNode) {
    var el = document.createElement("a");
    el.href = matchedTextNode.data;
    el.appendChild(matchedTextNode);
    return el;
}

function shouldLinkifyContents(el) {
    return el.tagName != "A";
}

function surroundInElement(el,regex,surrounderCreateFunc,shouldSurroundFunc) {
    var child = el.lastChild;
    while (child) {
        if (child.nodeType == 1 && shouldSurroundFunc(el)) {
            surroundInElement(child,createLink,shouldSurroundFunc);
        } else if (child.nodeType == 3) {
            surroundMatchingText(child,surrounderCreateFunc);
        }
        child = child.prevIoUsSibling;
    }
}

function surroundMatchingText(textNode,surrounderCreateFunc) {
    var parent = textNode.parentNode;
    var result,surroundingNode,matchedTextNode,matchLength,matchedText;
    while ( textNode && (result = regex.exec(textNode.data)) ) {
        matchedTextNode = textNode.splitText(result.index);
        matchedText = result[0];
        matchLength = matchedText.length;
        textNode = (matchedTextNode.length > matchLength) ?
            matchedTextNode.splitText(matchLength) : null;
        surroundingNode = surrounderCreateFunc(matchedTextNode.cloneNode(true));
        parent.insertBefore(surroundingNode,matchedTextNode);
        parent.removeChild(matchedTextNode);
    }
}

var textBox = document.getElementById("textBox");
var urlRegex = /http(s?):\/\/($|[^\s]+)/;

function updateLinks() {
    var savedSelection = saveSelection(textBox);
    surroundInElement(textBox,urlRegex,shouldLinkifyContents);
    restoreSelection(textBox,savedSelection);
}

var $textBox = $(textBox);

$(document).ready(function () {
    $textBox.focus();

    var keyTimer = null,keyDelay = 1000;

    $textBox.keyup(function() {
        if (keyTimer) {
            window.clearTimeout(keyTimer);
        }
        keyTimer = window.setTimeout(function() {
            updateLinks();
            keyTimer = null;
        },keyDelay);
    });
});

body { font:.8rem/1.5 sans-serif;  margin:2rem; }
div {
    border:thin solid gray;
    padding:1rem;
    height:10rem;
    margin:1rem 0;
    color:black;
    font-size:1rem;
}
a { color:blue; background:lightblue; }

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
Start typing a message with a link i.e. <code>http://example.com</code>...
<div id="textBox" contenteditable></div>