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Creating SVG markers programmatically with Javascript

Is it possible to create a marker in SVG using Javascript and then apply it to a newly created line? If so, please can you tell me what is wrong with the code below. I would expect the red and green lines to both have an arrow head but in both Chrome and Firefox 3.6 only the green line does.

<?php

header('Content-type: application/xhtml+xml');
echo '<?xml version="1.0" encoding="utf-8" ?>';

?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>SVG test</title>
<script type="text/javascript">
function init()
{
    var div = document.getElementById('mainDiv');

    var svgNode = document.createElementNS('http://www.w3.org/2000/svg', 'svg');

    svgNode.style.width = "200px";
    svgNode.style.height = "200px";
    svgNode.style.overflow = 'visible';
    svgNode.style.position = 'absolute';
    svgNode.setAttribute('version', '1.1');
    svgNode.setAttribute('xmlns', 'http://www.w3.org/2000/svg');
    div.appendChild(svgNode);

    var defs = document.createElementNS('http://www.w3.org/2000/svg', 'defs');
    var marker = document.createElementNS('http://www.w3.org/2000/svg', 'marker');
    marker.setAttribute('id', 'Triangle');
    marker.setAttribute('viewBox', '0 0 10 10');
    marker.setAttribute('refX', '0');
    marker.setAttribute('refY', '5');
    marker.setAttribute('markerUnits', 'strokeWidth');
    marker.setAttribute('markerWidth', '4');
    marker.setAttribute('markerHeight', '3');
    marker.setAttribute('orient', 'auto');
    var path = document.createElementNS('http;//www.w3.org/2000/svg', 'path');
    marker.appendChild(path);
    path.setAttribute('d', 'M 0 0 L 10 5 L 0 10 z');

    svgNode.appendChild(defs);
    defs.appendChild(marker);

    var obj = document.createElementNS('http://www.w3.org/2000/svg', 'line');
    obj.setAttribute('x1', 50);
    obj.setAttribute('y1', 50);
    obj.setAttribute('x2', 50);
    obj.setAttribute('y2', 150);
    obj.setAttribute('stroke', '#ff0000');
    obj.setAttribute('stroke-width', 7);
    obj.setAttribute('marker-end', 'url(#Triangle)');

    svgNode.appendChild(obj);


}
</script>
</head>

<body onload="init();">
<div id="mainDiv" style="width: 100%; height: 100%; visibility: visible; overflow: visible; position: absolute; background: white;">
    <svg version="1.1" xmlns="http://www.w3.org/2000/svg" style="width: 200px; height: 200px; position: absolute;">
        <defs>
            <marker id="Triangle-static" viewBox="0 0 10 10" refX="0" refY="5" markerUnits="strokeWidth" markerWidth="4" markerHeight="3" orient="auto">
                <path d="M 0 0 L 10 5 L 0 10 z"></path>
            </marker>
        </defs>
        <line x1="150" y1="50" x2="150" y2="150" stroke="#00ff00" stroke-width="7" marker-end="url(#Triangle-static)" />
    </svg>
</div>
</body>

</html>
like image 995
ngreatorex Avatar asked Nov 05 '22 10:11

ngreatorex


1 Answers

It worked fine if I changed some parts of your code like this:

var newmarker = oldmarker.cloneNode(true);
newmarker.setAttribute("id", "Triangle");

...which suggests that the error lies in the code that creates the marker element.

like image 110
Erik Dahlström Avatar answered Nov 12 '22 10:11

Erik Dahlström