这应该适用于所有支持onpaste事件和突变观察者的浏览器。
这个解决方案不仅仅只是获取文本,它实际上允许您在粘贴到元素之前编辑粘贴的内容。
它通过使用contentteditable, onpaste事件(所有主要浏览器支持)在突变观察者(Chrome, Firefox和IE11+支持)中工作。
步骤1
创建一个带有contentteditable的html元素
<div contenteditable="true" id="target_paste_element"></div>
步骤2
在Javascript代码中添加以下事件
document.getElementById("target_paste_element").addEventListener("paste", pasteEventVerifierEditor.bind(window, pasteCallBack), false);
我们需要绑定pasteCallBack,因为突变观察者将被异步调用。
步骤3
向代码中添加以下函数
function pasteEventVerifierEditor(callback, e)
{
//is fired on a paste event.
//pastes content into another contenteditable div, mutation observer observes this, content get pasted, dom tree is copied and can be referenced through call back.
//create temp div
//save the caret position.
savedCaret = saveSelection(document.getElementById("target_paste_element"));
var tempDiv = document.createElement("div");
tempDiv.id = "id_tempDiv_paste_editor";
//tempDiv.style.display = "none";
document.body.appendChild(tempDiv);
tempDiv.contentEditable = "true";
tempDiv.focus();
//we have to wait for the change to occur.
//attach a mutation observer
if (window['MutationObserver'])
{
//this is new functionality
//observer is present in firefox/chrome and IE11
// select the target node
// create an observer instance
tempDiv.observer = new MutationObserver(pasteMutationObserver.bind(window, callback));
// configuration of the observer:
var config = { attributes: false, childList: true, characterData: true, subtree: true };
// pass in the target node, as well as the observer options
tempDiv.observer.observe(tempDiv, config);
}
}
function pasteMutationObserver(callback)
{
document.getElementById("id_tempDiv_paste_editor").observer.disconnect();
delete document.getElementById("id_tempDiv_paste_editor").observer;
if (callback)
{
//return the copied dom tree to the supplied callback.
//copy to avoid closures.
callback.apply(document.getElementById("id_tempDiv_paste_editor").cloneNode(true));
}
document.body.removeChild(document.getElementById("id_tempDiv_paste_editor"));
}
function pasteCallBack()
{
//paste the content into the element.
restoreSelection(document.getElementById("target_paste_element"), savedCaret);
delete savedCaret;
pasteHtmlAtCaret(this.innerHTML, false, true);
}
saveSelection = function(containerEl) {
if (containerEl == document.activeElement)
{
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) {
containerEl.focus();
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);
}
function pasteHtmlAtCaret(html, returnInNode, selectPastedContent) {
//function written by Tim Down
var sel, range;
if (window.getSelection) {
// IE9 and non-IE
sel = window.getSelection();
if (sel.getRangeAt && sel.rangeCount) {
range = sel.getRangeAt(0);
range.deleteContents();
// Range.createContextualFragment() would be useful here but is
// only relatively recently standardized and is not supported in
// some browsers (IE9, for one)
var el = document.createElement("div");
el.innerHTML = html;
var frag = document.createDocumentFragment(), node, lastNode;
while ( (node = el.firstChild) ) {
lastNode = frag.appendChild(node);
}
var firstNode = frag.firstChild;
range.insertNode(frag);
// Preserve the selection
if (lastNode) {
range = range.cloneRange();
if (returnInNode)
{
range.setStart(lastNode, 0); //this part is edited, set caret inside pasted node.
}
else
{
range.setStartAfter(lastNode);
}
if (selectPastedContent) {
range.setStartBefore(firstNode);
} else {
range.collapse(true);
}
sel.removeAllRanges();
sel.addRange(range);
}
}
} else if ( (sel = document.selection) && sel.type != "Control") {
// IE < 9
var originalRange = sel.createRange();
originalRange.collapse(true);
sel.createRange().pasteHTML(html);
if (selectPastedContent) {
range = sel.createRange();
range.setEndPoint("StartToStart", originalRange);
range.select();
}
}
}
代码的作用:
Somebody fires the paste event by using ctrl-v, contextmenu or other means
In the paste event a new element with contenteditable is created (an element with contenteditable has elevated privileges)
The caret position of the target element is saved.
The focus is set to the new element
The content gets pasted into the new element and is rendered in the DOM.
The mutation observer catches this (it registers all changes to the dom tree and content). Then fires the mutation event.
The dom of the pasted content gets cloned into a variable and returned to the callback. The temporary element is destroyed.
The callback receives the cloned DOM. The caret is restored. You can edit this before you append it to your target. element. In this example I'm using Tim Downs functions for saving/restoring the caret and pasting HTML into the element.
例子
document.getElementById("target_paste_element").addEventListener("paste", pasteEventVerifierEditor.bind(window, pasteCallBack), false);
function pasteEventVerifierEditor(callback, e) {
//is fired on a paste event.
//pastes content into another contenteditable div, mutation observer observes this, content get pasted, dom tree is copied and can be referenced through call back.
//create temp div
//save the caret position.
savedCaret = saveSelection(document.getElementById("target_paste_element"));
var tempDiv = document.createElement("div");
tempDiv.id = "id_tempDiv_paste_editor";
//tempDiv.style.display = "none";
document.body.appendChild(tempDiv);
tempDiv.contentEditable = "true";
tempDiv.focus();
//we have to wait for the change to occur.
//attach a mutation observer
if (window['MutationObserver']) {
//this is new functionality
//observer is present in firefox/chrome and IE11
// select the target node
// create an observer instance
tempDiv.observer = new MutationObserver(pasteMutationObserver.bind(window, callback));
// configuration of the observer:
var config = {
attributes: false,
childList: true,
characterData: true,
subtree: true
};
// pass in the target node, as well as the observer options
tempDiv.observer.observe(tempDiv, config);
}
}
function pasteMutationObserver(callback) {
document.getElementById("id_tempDiv_paste_editor").observer.disconnect();
delete document.getElementById("id_tempDiv_paste_editor").observer;
if (callback) {
//return the copied dom tree to the supplied callback.
//copy to avoid closures.
callback.apply(document.getElementById("id_tempDiv_paste_editor").cloneNode(true));
}
document.body.removeChild(document.getElementById("id_tempDiv_paste_editor"));
}
function pasteCallBack() {
//paste the content into the element.
restoreSelection(document.getElementById("target_paste_element"), savedCaret);
delete savedCaret;
//edit the copied content by slicing
pasteHtmlAtCaret(this.innerHTML.slice(3), false, true);
}
saveSelection = function(containerEl) {
if (containerEl == document.activeElement) {
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) {
containerEl.focus();
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);
}
function pasteHtmlAtCaret(html, returnInNode, selectPastedContent) {
//function written by Tim Down
var sel, range;
if (window.getSelection) {
// IE9 and non-IE
sel = window.getSelection();
if (sel.getRangeAt && sel.rangeCount) {
range = sel.getRangeAt(0);
range.deleteContents();
// Range.createContextualFragment() would be useful here but is
// only relatively recently standardized and is not supported in
// some browsers (IE9, for one)
var el = document.createElement("div");
el.innerHTML = html;
var frag = document.createDocumentFragment(),
node, lastNode;
while ((node = el.firstChild)) {
lastNode = frag.appendChild(node);
}
var firstNode = frag.firstChild;
range.insertNode(frag);
// Preserve the selection
if (lastNode) {
range = range.cloneRange();
if (returnInNode) {
range.setStart(lastNode, 0); //this part is edited, set caret inside pasted node.
} else {
range.setStartAfter(lastNode);
}
if (selectPastedContent) {
range.setStartBefore(firstNode);
} else {
range.collapse(true);
}
sel.removeAllRanges();
sel.addRange(range);
}
}
} else if ((sel = document.selection) && sel.type != "Control") {
// IE < 9
var originalRange = sel.createRange();
originalRange.collapse(true);
sel.createRange().pasteHTML(html);
if (selectPastedContent) {
range = sel.createRange();
range.setEndPoint("StartToStart", originalRange);
range.select();
}
}
}
div {
border: 1px solid black;
height: 50px;
padding: 5px;
}
<div contenteditable="true" id="target_paste_element"></div>
非常感谢Tim Down
请看这篇文章的答案:
在粘贴事件上获取文档上的粘贴内容