Appending path child within SVG Using Javascript

Question

Good Day,

I am having incredible difficulty in creating a path and displaying it using "appendChild" within an SVG element.

I have to be missing something critically simple as I have poured over W3C's specs, w3schools.com, various posts here and trying to ninja google in various ways.

I am testing within FireFox and Chrome.

I have a simple svg file thus:

<svg xmlns:svg ... id="fullPageID">  <image id="timer1" x="100" y="100" width="100px" height="100px" xlink:href="../component/timer/timer1.svg" />    <image id="battery1" x="200" y="200" width="100px" height="100px" xlink:href="../component/battery/30x20_ochre.svg" />  <script xlink:href="pathMaker.js" type="text/javascript" id="pathMaker" />   </svg> 

The script I am attempting to use looks like:

newpath = document.createElementNS("SVG","path");   newpath.setAttribute("id", "pathIdD");   newpath.setAttribute("d", "M 1,97.857143 C 19.285714,96.428571 24.016862,131.64801 90.714286,132.85714 140.78762,133.7649 202.79376,66.16041 202.79376,66.16041");   newpath.setAttribute("stroke", "black");   newpath.setAttribute("stroke-width", 3);   newpath.setAttribute("opacity", 1);   newpath.setAttribute("fill", "none");  document.getElementById("fullPageID").appendChild(newpath); 

I just want to make something simple work. Am I wrong to think that I don't require a solution as complicated as the one found at Library to generate SVG Path with Javascript??

Thanks Kindly.

Answer 1

There are two issues:

1. As already pointed out, you have to use the full namespace uri, so in this case:

   newpath = document.createElementNS('http://www.w3.org/2000/svg',"path");   

2. Attributes also need to be set with namespace in mind. The good news is that you can pass in null as the namespace uri, so:

   newpath.setAttributeNS(null, "d", "M 1,97.857143 C 19.285714,96.428571 24.016862,131.64801 90.714286,132.85714 140.78762,133.7649 202.79376,66.16041 202.79376,66.16041"); 

Also, here are two ways to make dealing with the svg namespace easier (assuming that it is a standalone svg, not embedded in HTML):

• To refer to the svg element, instead of giving it an ID, you can use document.rootElement.
• document.rootElement.getAttribute(null, "xmlns") returns an empty string (while requesting other attributes does work using this method. Instead, use document.rootElement.namespaceURI.

So in your code, you could make the following rewrites:

From:

 newpath = document.createElementNS("http://www.w3.org/2000/svg","path"); 

To:

 newpath = document.createElementNS(document.rootElement.namespaceURI,"path");   

And to append the element, you can go from:

document.getElementById("fullPageID").appendChild(newpath); 

to:

document.rootElement.appendChild(newpath); 

So the final script would be:

newpath = document.createElementNS(document.rootElement.namespaceURI,"path");   newpath.setAttributeNS(null, "id", "pathIdD");   newpath.setAttributeNS(null, "d", "M 1,97.857143 C 19.285714,96.428571 24.016862,131.64801 90.714286,132.85714 140.78762,133.7649 202.79376,66.16041 202.79376,66.16041");   newpath.setAttributeNS(null, "stroke", "black");  newpath.setAttributeNS(null, "stroke-width", 3);   newpath.setAttributeNS(null, "opacity", 1);   newpath.setAttributeNS(null, "fill", "none");  document.rootElement.appendChild(newpath);