How to get nodes lying inside a range with javascr

2019-01-07 12:52发布

站内文章 / JavaScript
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问题:

I'm trying to get all the DOM nodes that are within a range object, what's the best way to do this?

var selection = window.getSelection(); //what the user has selected
var range = selection.getRangeAt(0); //the first range of the selection
var startNode = range.startContainer;
var endNode = range.endContainer;
var allNodes = /*insert magic*/;

I've been been thinking of a way for the last few hours and came up with this:

var getNextNode = function(node, skipChildren){
    //if there are child nodes and we didn't come from a child node
    if (node.firstChild && !skipChildren) {
        return node.firstChild;
    }
    if (!node.parentNode){
        return null;
    }
    return node.nextSibling 
        || getNextNode(node.parentNode, true);
};

var getNodesInRange = function(range){
    var startNode = range.startContainer.childNodes[range.startOffset]
            || range.startContainer;//it's a text node
    var endNode = range.endContainer.childNodes[range.endOffset]
            || range.endContainer;

    if (startNode == endNode && startNode.childNodes.length === 0) {
        return [startNode];
    };

    var nodes = [];
    do {
        nodes.push(startNode);
    }
    while ((startNode = getNextNode(startNode)) 
            && (startNode != endNode));
    return nodes;
};

However when the end node is the parent of the start node it returns everything on the page. I'm sure I'm overlooking something obvious? Or maybe going about it in totally the wrong way.

MDC/DOM/range

回答1:

The getNextNode will skip your desired endNode recursively if its a parent node.

Perform the conditional break check inside of the getNextNode instead:

var getNextNode = function(node, skipChildren, endNode){
  //if there are child nodes and we didn't come from a child node
  if (endNode == node) {
    return null;
  }
  if (node.firstChild && !skipChildren) {
    return node.firstChild;
  }
  if (!node.parentNode){
    return null;
  }
  return node.nextSibling 
         || getNextNode(node.parentNode, true, endNode); 
};

and in while statement:

while (startNode = getNextNode(startNode, false , endNode));


回答2:

Here's an implementation I came up with to solve this:

function getNextNode(node)
{
    if (node.firstChild)
        return node.firstChild;
    while (node)
    {
        if (node.nextSibling)
            return node.nextSibling;
        node = node.parentNode;
    }
}

function getNodesInRange(range)
{
    var start = range.startContainer;
    var end = range.endContainer;
    var commonAncestor = range.commonAncestorContainer;
    var nodes = [];
    var node;

    // walk parent nodes from start to common ancestor
    for (node = start.parentNode; node; node = node.parentNode)
    {
        nodes.push(node);
        if (node == commonAncestor)
            break;
    }
    nodes.reverse();

    // walk children and siblings from start until end is found
    for (node = start; node; node = getNextNode(node))
    {
        nodes.push(node);
        if (node == end)
            break;
    }

    return nodes;
}


回答3:

The Rangy library has a Range.getNodes([Array nodeTypes[, Function filter]]) function.



回答4:

below code solve your problem 

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>payam jabbari</title>
<script src="http://code.jquery.com/jquery-2.0.2.min.js" type="text/javascript"></script>
<script type="text/javascript">

$(document).ready(function(){
    var startNode = $('p.first').contents().get(0);
var endNode = $('span.second').contents().get(0);
var range = document.createRange();
range.setStart(startNode, 0);
range.setEnd(endNode, 5);
var selection = document.getSelection();
selection.addRange(range);
// below code return all nodes in selection range. this code work in all browser
var nodes = range.cloneContents().querySelectorAll("*");
for(var i=0;i<nodes.length;i++)
{
   alert(nodes[i].innerHTML);
}
});
</script>
</head>

<body>
<div>

<p class="first">Even a week ago, the idea of a Russian military intervention in Ukraine seemed far-fetched if not totally alarmist. But the arrival of Russian troops in Crimea over the weekend has shown that he is not averse to reckless adventures, even ones that offer little gain. In the coming days and weeks</p>

<ol>
    <li>China says military will respond to provocations.</li>
    <li >This Man Has Served 20 <span class="second"> Years—and May Die—in </span> Prison for Marijuana.</li>
    <li>At White House, Israel's Netanyahu pushes back against Obama diplomacy.</li>
</ol>
</div>
</body>
</html>


回答5:

I made 2 additional fixes based on MikeB's answer to improve the accuracy of the selected nodes.

I'm particularly testing this on select all operations, other than range selection made by dragging the cursor along text spanning across multiple elements.

In Firefox, hitting select all (CMD+A) returns a range where it's startContainer & endContainer is the contenteditable div, the difference is in the startOffset & endOffset where it's respectively the index of the first and the last child node.

In Chrome, hitting select all (CMD+A) returns a range where it's startContainer is the first child node of the contenteditable div, and the endContainer is the last child node of the contenteditable div.

The modifications I've added work around the discrepancies between the two. You can see the comments in the code for additional explanation.

function getNextNode(node) {
    if (node.firstChild)
        return node.firstChild;

    while (node) {
        if (node.nextSibling) return node.nextSibling;
        node = node.parentNode;
    }
}

function getNodesInRange(range) {

    // MOD #1
    // When the startContainer/endContainer is an element, its
    // startOffset/endOffset basically points to the nth child node
    // where the range starts/ends.
    var start = range.startContainer.childNodes[range.startOffset] || range.startContainer;
    var end = range.endContainer.childNodes[range.endOffset] || range.endContainer;
    var commonAncestor = range.commonAncestorContainer;
    var nodes = [];
    var node;

    // walk parent nodes from start to common ancestor
    for (node = start.parentNode; node; node = node.parentNode)
    {
        nodes.push(node);
        if (node == commonAncestor)
            break;
    }
    nodes.reverse();

    // walk children and siblings from start until end is found
    for (node = start; node; node = getNextNode(node))
    {
        // MOD #2
        // getNextNode might go outside of the range
        // For a quick fix, I'm using jQuery's closest to determine
        // when it goes out of range and exit the loop.
        if (!$(node.parentNode).closest(commonAncestor)[0]) break;

        nodes.push(node);
        if (node == end)
            break;
    }

    return nodes;
};


回答6:

Annon, great work. I've modified the original plus included Stefan's modifications in the following.

In addition, I removed the reliance on Range, which converts the function into an generic algorithm to walk between two nodes. Plus, I've wrapped everything into a single function.

Thoughts on other solutions:

  • Not interested in relying on jquery
  • Using cloneNode lifts the results to a fragment, which prevents many operations one might want to conduct during filtering.
  • Using querySelectAll on a cloned fragment is wonky because the start or end nodes may be within a wrapping node, hence the parser may not have the closing tag?

Example:

<div>
    <p>A</p>
    <div>
        <p>B</p>
        <div>
            <p>C</p>
        </div>
    </div>
</div>

Assume start node is the "A" paragraph, and the end node is the "C" paragraph . The resulting cloned fragment would be:

<p>A</p>
    <div>
        <p>B</p>
        <div>
            <p>C</p>

and we're missing closing tags? resulting in funky DOM structure?

Anyway, here's the function, which includes a filter option, which should return TRUE or FALSE to include/exclude from results.

var getNodesBetween = function(startNode, endNode, includeStartAndEnd, filter){
    if (startNode == endNode && startNode.childNodes.length === 0) {
        return [startNode];
    };

    var getNextNode = function(node, finalNode, skipChildren){
        //if there are child nodes and we didn't come from a child node
        if (finalNode == node) {
            return null;
        }
        if (node.firstChild && !skipChildren) {
            return node.firstChild;
        }
        if (!node.parentNode){
            return null;
        }
        return node.nextSibling || getNextNode(node.parentNode, endNode, true);
    };

    var nodes = [];

    if(includeStartAndEnd){
        nodes.push(startNode);
    }

    while ((startNode = getNextNode(startNode, endNode)) && (startNode != endNode)){
        if(filter){
            if(filter(startNode)){
                nodes.push(startNode);
            }
        } else {
            nodes.push(startNode);
        }
    }

    if(includeStartAndEnd){
        nodes.push(endNode);
    }

    return nodes;
};


回答7:

bob. the function only returns the startNode and endNode. the nodes in between do not get pushed to the array.

seems the while loop returns null on getNextNode() hence that block never gets executed.



回答8:

here is function return you array of sub-ranges

function getSafeRanges(range) {

var doc = document;

var commonAncestorContainer = range.commonAncestorContainer;
var startContainer = range.startContainer;
var endContainer = range.endContainer;
var startArray = new Array(0),
    startRange = new Array(0);
var endArray = new Array(0),
    endRange = new Array(0);
// @@@@@ If start container and end container is same
if (startContainer == endContainer) {
    return [range];
} else {
    for (var i = startContainer; i != commonAncestorContainer; i = i.parentNode) {
        startArray.push(i);
    }
    for (var i = endContainer; i != commonAncestorContainer; i = i.parentNode) {
        endArray.push(i);
    }
}
if (0 < startArray.length) {
    for (var i = 0; i < startArray.length; i++) {
        if (i) {
            var node = startArray[i - 1];
            while ((node = node.nextSibling) != null) {
                startRange = startRange.concat(getRangeOfChildNodes(node));
            }
        } else {
            var xs = doc.createRange();
            var s = startArray[i];
            var offset = range.startOffset;
            var ea = (startArray[i].nodeType == Node.TEXT_NODE) ? startArray[i] : startArray[i].lastChild;
            xs.setStart(s, offset);
            xs.setEndAfter(ea);
            startRange.push(xs);
        }
    }
}
if (0 < endArray.length) {
    for (var i = 0; i < endArray.length; i++) {
        if (i) {
            var node = endArray[i - 1];
            while ((node = node.previousSibling) != null) {
                endRange = endRange.concat(getRangeOfChildNodes(node));
            }
        } else {
            var xe = doc.createRange();
            var sb = (endArray[i].nodeType == Node.TEXT_NODE) ? endArray[i] : endArray[i].firstChild;
            var end = endArray[i];
            var offset = range.endOffset;
            xe.setStartBefore(sb);
            xe.setEnd(end, offset);
            endRange.unshift(xe);
        }
    }
}
var topStartNode = startArray[startArray.length - 1];
var topEndNode = endArray[endArray.length - 1];
var middleRange = getRangeOfMiddleElements(topStartNode, topEndNode);
startRange = startRange.concat(middleRange);
response = startRange.concat(endRange);
return response;

}



标签： javascript dom range traversal
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