Child elements in primitives (e.g. title tag)

[rorso]

The graphical primitives allow for sub elements like "title". The latter usually will be used as tooltip when hovering above the element.

I cannot add a "title" to a SVGCircle, as this is not based on SVGNodeContainer but onSVGNode.

After I changed the inheritance to "SVGNodeContainer", I can successfully add a "title" that renders as expected.

$title = new SVGTitle;
$title->setValue("this is a tooltip title");
$circle->addChild($title);

However SVGTitle too lacks a good

__construct($txt="")
to be rally useful

I' opt for generally inherit the primitives from SVGNodeContainer, as this does no harm.

[meyfa]

I see your point. It would probably make sense to merge the SVGNodeContainer features into SVGNode then, as there would be no real need for completely child-less elements, right?

P.S. SVGTitle constructor added in 34401ed.

[rorso]

Unfortunately there is no official XML Schema declaration for SVG 1.1 which would define which elements may contain which sub elements - or not.

But there is a DTD available to check the validity of the resulting SVG.
https://www.w3.org/TR/SVG11/svgdtd.html

I don't see a real problem allowing sub elements on every object, even if they would not result in a renderable SVG property. After all, it's all XML and the elements might serve for "internal use" without interfering with the validity of the produced SVG file.

if you want to check how this feature is used, please visit https://sterntaufe.astronomie.at and click any of the "Vorschau im Browser (SVG)" links. Objecs are tagged with "title" elements to show their name on hovering.

I meanwhile have extended the classes for some useful (for me) spline calculations. I send you my code. Maybe you find something suitable for general use.

[rorso]

... it's on this page: https://sterntaufe.astronomie.at/select.php

[meyfa]

That's a nice project you got there!

I looked through the DTD and couldn't find any element type that forbids child nodes, so I went ahead and made them all inherit from SVGNodeContainer as you proposed. Getting rid of the SVGNode/SVGNodeContainer separation altogether would make sense but it'd require a rather big refactoring and isn't strictly necessary right now.