如何获取突出显示的所有元素 [英] How to get all elements that are highlighted

问题描述

我想获取用户突出显示区域中的所有元素。问题是，当元素位于树的不同部分时，我不知道如何遍历DOM的不同部分。我的代码到目前为止只能从选择范围的startContainer中获取元素。我需要某种递归吗？这是我的代码：

I want to get all of the elements in a user highlighted area. The problem is that I don't know how to traverse to different parts of the DOM, when the elements are on a different part of the tree. My code so far can only get the elements off the startContainer of the selection range. Do I need some sort of recursion? Here is my code:

    getSelectedElementTags:function() 
{
    var range, sel, container;
    sel = content.window.getSelection();
    if (sel.getRangeAt) 
    {
        if (sel.rangeCount > 0) 
        {
            range = sel.getRangeAt(0);              
        }
    } 
    else 
    {       
        range = content.window.createRange();
        range.setStart(sel.anchorNode, sel.anchorOffset);
        range.setEnd(sel.focusNode, sel.focusOffset);
        alert("range created");
    }


    if (range)
    {
        container = range["startContainer"];
        var elms = container.parentNode.getElementsByTagName("*");          
        elmlist = "parent: "+container.parentNode.tagName + " (" + elms.length + ")\n";
        for (i in elms)
        {
            if (elms[i].tagName != null)
            {
                elmlist += elms[i].tagName+"\n";
            }
        }

        alert(elmlist);
    }
},

推荐答案

您可以使用 TreeWalker 使用 document.createTreeWalker 。下面是一个例子。它列出部分或完全选择的所有元素。您可以通过修改传递给的参数来轻松更改行为。document.createTreeWalker 。

请注意，在Firefox中，不需要检查选择的 getRangeAt 方法的存在。此检查仅适用于旧版本的WebKit。另外，IE< 9不支持TreeWalker或Range，因此以下内容将无法在这些浏览器中使用。

Note that in Firefox you don't need to check for the existence of the getRangeAt method of a selection. This check is only required for older versions of WebKit. Also, IE < 9 does not support TreeWalker or Range, so the following won't work in those browsers.

修改 p>

Edit Fixed as per comments below.

function rangeIntersectsNode(range, node) {
    var nodeRange;
    if (range.intersectsNode) {
        return range.intersectsNode(node);
    } else {
        nodeRange = node.ownerDocument.createRange();
        try {
            nodeRange.selectNode(node);
        } catch (e) {
            nodeRange.selectNodeContents(node);
        }

        return range.compareBoundaryPoints(Range.END_TO_START, nodeRange) == -1 &&
            range.compareBoundaryPoints(Range.START_TO_END, nodeRange) == 1;
    }
}

function getSelectedElementTags(win) {
    var range, sel, elmlist, treeWalker, containerElement;
    sel = win.getSelection();
    if (sel.rangeCount > 0) {
        range = sel.getRangeAt(0);
    }

    if (range) {
        containerElement = range.commonAncestorContainer;
        if (containerElement.nodeType != 1) {
            containerElement = containerElement.parentNode;
        }

        treeWalker = win.document.createTreeWalker(
            containerElement,
            NodeFilter.SHOW_ELEMENT,
            function(node) { return rangeIntersectsNode(range, node) ? NodeFilter.FILTER_ACCEPT : NodeFilter.FILTER_REJECT; },
            false
        );

        elmlist = [treeWalker.currentNode];
        while (treeWalker.nextNode()) {
            elmlist.push(treeWalker.currentNode);
        }

        console.log(elmlist);
    }
}

<input type="button" onclick="getSelectedElementTags(window)" value="Get selected elements">

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