Re: Adding class to SVG Export

[Hans Breuer <hans breuer org>]

At 21.10.2013 16:48, jul gil gmail com wrote:
> Hi
>
> I am trying to use Dia to generate svg diagram for presentations build
> using reveal.js, and I need to modify the way the svg is exported.
>
> Context : Reveal.js https://github.com/hakimel/reveal.js/ is a small
> framework for creating presentation using HTML. Of course SVG can be
> included in the HTML file.
> One of the feature of reveal.js is to be able to display the content
> of a slide step by step using the class "fragment"( See
> https://github.com/hakimel/reveal.js/#fragments and
> http://lab.hakim.se/reveal-js/#/fragments ).
> A small test shows that it work for SVG too : I can have a beautiful
> diagramm in my page that appears step by step, the problem is I just
> need to edit the SVG by hand...I would like to use Dia for that, of
> course.
>
> I have actually 2 problems :
>
> - include class and data-fragment-index in the properties :
> easy for the shapes thanks to <ext_attributes>, but I have no idea of
> what to modify to add a property to arrow, lines, polygon, etc...
It might be possible to use the objects meta data dicitionary for this, but 
only the current development version has a GUI for it.

Another idea could be to manage you animations by distributing objects to 
layers and encode class and index in the layer name.

> - SVG export : it seems to me that 2 exports exists : diasvg.py and an
> integrated export.
> The python script is called when using export "SVG plain" or "SVG
> compressed", the integrated export is called on "Scalable Vector
> Graphic". Right ?
Mostly. There usually is a third SVG exporter provided by the cairo 
plug-in, but it's availability depends on the buid system configuration.

> The 2 exports are not exactly the same, the integrated export
> generated <g> for each element, and that's on this element I want to
> add the class. The python script seems not be able to add those tag,
> but I am perhaps wrong.
The two exporters are definitely not exactly the same. They are 
intentionally producing different output. With the current development 
version it is possible to handle group creation on the object's rendering 
level. See:
https://git.gnome.org/browse/dia/commit/?id=3cf5a400d9924a7dc6fc5e67cec166a466885887

> So my questions are : am I on the right way ? Is it possible to do
> what I want without modifying a single line of code ?
How is the behavior of the source code supposed to be changed without 
changing the source code?

> is it worth it ?
Not sure I get this question. Shouldn't you be the one to answer it?

-------- Hans "at" Breuer "dot" Org -----------
Tell me what you need, and I'll tell you how to
get along without it.                -- Dilbert