web应用程序如何检测粘贴事件并检索要粘贴的数据?

我想在文本粘贴到富文本编辑器之前删除HTML内容。

在粘贴后清理文本是有效的,但问题是所有以前的格式都会丢失。例如,我可以在编辑器中编写一个句子并将其加粗,但当我粘贴新文本时,所有格式都会丢失。我只想清除粘贴的文本,并保留以前的任何格式不变。

理想情况下,解决方案应该可以跨所有现代浏览器(例如,MSIE、Gecko、Chrome和Safari)工作。

注意,MSIE有clipboardData.getData(),但我找不到其他浏览器的类似功能。


当前回答

首先想到的是谷歌的闭包库的pastehandler http://closure-library.googlecode.com/svn/trunk/closure/goog/demos/pastehandler.html

其他回答

写完这篇文章后,情况发生了变化:现在Firefox在版本22中添加了支持,所有主流浏览器现在都支持在粘贴事件中访问剪贴板数据。请看Nico Burns的回答。

在过去,这在跨浏览器的方式中通常是不可能的。最理想的情况是能够通过paste事件获取粘贴的内容,这在最近的浏览器中是可能的,但在一些较老的浏览器中是不可能的(特别是Firefox < 22)。

当你需要支持旧的浏览器时,你可以做的是相当复杂的和一点hack,可以在Firefox 2+, IE 5.5+和WebKit浏览器(如Safari或Chrome)中工作。TinyMCE和CKEditor的最新版本都使用了这种技术:

Detect a ctrl-v / shift-ins event using a keypress event handler In that handler, save the current user selection, add a textarea element off-screen (say at left -1000px) to the document, turn designMode off and call focus() on the textarea, thus moving the caret and effectively redirecting the paste Set a very brief timer (say 1 millisecond) in the event handler to call another function that stores the textarea value, removes the textarea from the document, turns designMode back on, restores the user selection and pastes the text in.

请注意,这将只适用于键盘粘贴事件,而不是粘贴上下文或编辑菜单。当粘贴事件触发时,将插入符号重定向到文本区域就太晚了(至少在某些浏览器中是这样)。

在不太可能的情况下,您需要支持Firefox 2,请注意您需要将文本区域放置在父文档中,而不是在该浏览器中的所见即所得编辑器iframe的文档中。

我写了一个小的概念证明蒂姆唐斯提议这里与屏幕文本区域。下面是代码:

<html>
<head>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4/jquery.min.js"></script> 
<script language="JavaScript">
 $(document).ready(function()
{

var ctrlDown = false;
var ctrlKey = 17, vKey = 86, cKey = 67;

$(document).keydown(function(e)
{
    if (e.keyCode == ctrlKey) ctrlDown = true;
}).keyup(function(e)
{
    if (e.keyCode == ctrlKey) ctrlDown = false;
});

$(".capture-paste").keydown(function(e)
{
    if (ctrlDown && (e.keyCode == vKey || e.keyCode == cKey)){
        $("#area").css("display","block");
        $("#area").focus();         
    }
});

$(".capture-paste").keyup(function(e)
{
    if (ctrlDown && (e.keyCode == vKey || e.keyCode == cKey)){                      
        $("#area").blur();
        //do your sanitation check or whatever stuff here
        $("#paste-output").text($("#area").val());
        $("#area").val("");
        $("#area").css("display","none");
    }
});

});
</script>

</head>
<body class="capture-paste">

<div id="paste-output"></div>


    <div>
    <textarea id="area" style="display: none; position: absolute; left: -99em;"></textarea>
    </div>

</body>
</html>

只需复制并粘贴整个代码到一个html文件,并尝试粘贴(使用ctrl-v)文本从剪贴板的任何地方的文档。

我在IE9和新版本的Firefox、Chrome和Opera中测试了它。工作得很好。另外,用户可以使用任何他喜欢的组合键来触发这个功能。当然,不要忘记包含jQuery源代码。

请随意使用此代码,如果您有一些改进或问题,请将它们发布回来。还要注意,我不是Javascript开发人员,所以我可能错过了一些东西(=>做你自己的测试)。

这个解决方案是替换html标签,简单,跨浏览器;查看这个jsfiddle: http://jsfiddle.net/tomwan/cbp1u2cx/1/,核心代码:

var $plainText = $("#plainText");
var $linkOnly = $("#linkOnly");
var $html = $("#html");

$plainText.on('paste', function (e) {
    window.setTimeout(function () {
        $plainText.html(removeAllTags(replaceStyleAttr($plainText.html())));
    }, 0);
});

$linkOnly.on('paste', function (e) {
    window.setTimeout(function () {
        $linkOnly.html(removeTagsExcludeA(replaceStyleAttr($linkOnly.html())));
    }, 0);
});

function replaceStyleAttr (str) {
    return str.replace(/(<[\w\W]*?)(style)([\w\W]*?>)/g, function (a, b, c, d) {
        return b + 'style_replace' + d;
    });
}

function removeTagsExcludeA (str) {
    return str.replace(/<\/?((?!a)(\w+))\s*[\w\W]*?>/g, '');
}

function removeAllTags (str) {
    return str.replace(/<\/?(\w+)\s*[\w\W]*?>/g, '');
}

注意:你应该在后面做一些关于XSS过滤器的工作,因为这个解决方案不能过滤像'<<>>'这样的字符串

这对于Nico的回答来说太长了,我认为它在Firefox上已经不起作用了(根据评论),在Safari上也不起作用了。

首先,您现在似乎可以直接从剪贴板读取。而不是像这样的代码:

if (/text\/plain/.test(e.clipboardData.types)) {
    // shouldn't this be writing to elem.value for text/plain anyway?
    elem.innerHTML = e.clipboardData.getData('text/plain');
}

use:

types = e.clipboardData.types;
if (((types instanceof DOMStringList) && types.contains("text/plain")) ||
    (/text\/plain/.test(types))) {
    // shouldn't this be writing to elem.value for text/plain anyway?
    elem.innerHTML = e.clipboardData.getData('text/plain');
}

因为Firefox有一个类型字段,它是一个DOMStringList,它不实现测试。

Next Firefox将不允许粘贴,除非焦点位于contentteditable =true字段中。

最后,Firefox将不允许可靠地粘贴,除非焦点在文本区域(或者可能是输入),这不仅是contenteditable=true,而且:

不显示:没有 隐藏不可见性: 不是零大小

I was trying to hide the text field so I could make paste work over a JS VNC emulator (i.e. it was going to a remote client and there was no actually textarea etc to paste into). I found trying to hide the text field in the above gave symptoms where it worked sometimes, but typically failed on the second paste (or when the field was cleared to prevent pasting the same data twice) as the field lost focus and would not properly regain it despite focus(). The solution I came up with was to put it at z-order: -1000, make it display:none, make it as 1px by 1px, and set all the colours to transparent. Yuck.

在Safari上,你应用上面的第二部分,即你需要有一个不显示的文本区域:none。

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