Allow xml references

[ggreif]

When I have a green circle and want to duplicate it to many translated positions, then the circle's svg source will get textually duplicated. When the duplicand has a lot of source this can get very verbose. Any chance to use xml references optionally to refer to the original?

[byorgey]

This is definitely something we want to support. It shouldn't be too hard to get a simple version working: add a new type of Annotation (in diagrams-core) specifying some sort of id, then modify the SVG backend to notice these and only generate one copy, with references. However, doing it that way requires the user to come up with unique names (giving the same name to different subdiagrams would result in wrong output). I've thought a bit about how to do recovery of sharing automatically, using a system of hashes, but that would be more work.

[ggreif]

Here is a way how to do it: http://vanseodesign.com/web-design/svg-definition-reuse/