Minify XML with Ruby

Question

Given an XML string:

xml = "<org><people> <person>Joe Shmoe</person> <person>Bo Bob</person> 
    <person>New Guy</person> </people><other><![CDATA[ This string might 
have tags < >  < > and stuff, don't touch this ]]></other></org>"

How can I get rid of newlines and spaces between the tags, without affecting tag text, CDATA, etc?

Result should be:

xml = "<org><people><person>Joe Shmoe</person><person>Bo Bob</person><person>New Guy</person></people><other><![CDATA[ This string might 
have tags < >  < > and stuff, don't touch this ]]></other></org>"

UPDATE: This is what I've come up with so far- I just can't figure out how to have it ignore CDATA content...

xml.gsub(/>\s+</,"><")

Also, would much rather use an XML parser for this, as from what I hear regexing XML is a bad thing.

What exactly do you need to preserve? Could you give an example? — benjaminjosephw, Jan 18 '14 at 18:14
your gsub should look like this: `.gsub(/>\s+,"><")` otherwise you'll break the tags. After that fix, the example will return what you expect it to. If this is not the answer, could you develop the example to show why. Thanks :) — benjaminjosephw, Jan 18 '14 at 18:50

score 0 · Answer 1 · answered Jan 23 '14 at 02:51

Yes! What you want is canonicalization!

http://xml4r.github.io/libxml-ruby/rdoc/classes/LibXML/XML/Document.html#method-i-canonicalize

LibXML-Ruby gem can do this. Since the docs are shitty and doesn't even say what it does, here are the specs

http://www.w3.org/TR/xml-c14n

This is used a lot in XML signing.

And yes! Using regular expressions on XML is bad.

BTW you can also print your xml object as a string, and set indentation:

http://xml4r.github.io/libxml-ruby/rdoc/classes/LibXML/XML/Document.html#method-i-to_s

Minify XML with Ruby

1 Answers1