Re: [docbook] XML/XSL Revision Control/ Source Code Versioning: Ideas, Methods, Tools for Specific scenario as a Content Writer?

[Thomas Schraitle <tom_schr@web.de>]

Hi Alex,

Am Samstag, 8. Dezember 2012, 21:55:59 schrieb Alex S:
> Thank you for your time & responses. I remember reading somewhere that a
> pure text/ linear comparison based tool/ system may not be ideal to compare
> & merge XML tree structure based documents.

Right. In some cases.


> Are there any that are more XML aware?

Well, all the version control system that I know uses a line-based diff 
algorithm. As such, XML is for them just ordinary text. However, I don't think 
this is really a problem.

There are two options:

1. Delegate the Diff Process
   If I'm not mistaken, you can define a separate diff program for your VCS.
   That would give you (at least theoretically) the opportunity to delegate
   the diff process to a separate program which is able to do a tree-based
   diff instead of a line-based diff.

2. Normalize it before diffing
   Tree-based diffs are rather complex and there are not many open source
   tools available. Does anybody know one?
   However, line-based diffs are well-known and "cheap". Why not use that 
   as a solution?
   The only problem is to "normalize" your XML before diffing. "Normalize"
   in this context means, making all indendation the same. You can do that 
   by using a "XML pretty print program" which indents all the tags and
   attributes correctly. In most cases, this is enough and shows you only
   the lines which are affected.

 
> Also, I was wondering if I wanted to do compare/ merges visually using
> Altova Diffdog or similar tools then which source control systems would
> allow me to access/ load the individual versions into such a tool to merge
> into the newer or create a newer version?
> 
> Are some of these systems XML tree structure aware?

I have the feeling we are talking about different things. :)

In regards to XML, it means, it's not the task of the VCS to do a "XML tree 
merge". No VCS tool has that feature. Actually, no VCS knows how to handle XML 
-- it's just ordinary text. As such, a VCS operates on text files and knows 
how to change lines.

However, every VCS allows you to get the changes from one version to another. 
There are even graphical user interfaces who can display that for you. The 
oXygen XML editor, for example, has a Subversion client which does exactly 
this. But these changes are line-based.

I work with VCS and XML for some years now. There were few situations where I 
would liked to have a XML diffing tool. Usually, it was enough to use the VCS' 
diff tool. Or, sometimes, I used oXygen's XML diff. 

Well, that worked for _me_, your situation may vary. 


-- 
Gruß/Regards
  Thomas Schraitle