From: Bob Hutchison <hutch@...>
Date: 2007-11-23T22:43:31+09:00
Subject: Re: XML to Ruby?

Hi,

On 22-Nov-07, at 10:34 PM, Phrogz wrote:

> On Nov 22, 7:06 am, Jari Williamsson
> <jari.williams...@mailbox.swipnet.se> wrote:
>> Rolando Abarca wrote:
>> It seems like I need to specify a bit better what I need: I'm looking
>> for a utility that will _generate_ Ruby code (classes) from a
>> hierarchical XML file.
>>
>> Let's say this is the XML data:
>> mymodule.xml
>> ======
>> <root>
>>    <sub id="1">Some data</sub>
>>    <sub id="2>Some more data</sub>
>> </root>
>>
>> The utility would then generate 2 .rb module files, such as:
>>
>> root.rb:
>> ======
>> require 'mymodule/sub'
>> module MyModule
>> class Root < SomeBaseClass
>>     attr_accessor :sub_elements   # Array
>>     # Some more stuff
>> end
>>
>> sub.rb:
>> ======
>> module MyModule
>> class Sub < SomeBaseClass
>>    attr_accessor :id
>>    # Some more stuff
>> end
>> end
>>
>> The more I think about it, this kind of utility probably is  
>> required to
>> analyze the DTD rather than the XML to get the proper  
>> relationships. Any
>> such utility available?
>
> I really have no idea how your XML file above maps to the output you
> describe. It appears that you just look at the unique element names
> and create classes from them. You ignore the hierarchy of the XML
> file, you ignore all the attributes of the elements, and you ignore
> all the text content of the elements?

I think Jari might be confusing things with the test case he provided.  
It seems to me that he has shown the nesting of elements/classes (e.g.  
sub_elements -- the 'sub' is an element name) and attributes (e.g. the  
'id' accessor -- the 'id' is an attribute name). He's missed the text  
(and all that that implies), but he's looking for the tool not  
promoting one so that's okay.

FWIW, my thing, xampl, generates 2 classes, 2 modules, and 59 methods  
for Jari's example. Xampl defines a bunch of stuff to help you work  
with the generated code. Xampl doesn't use DTDs or schemas to do this.

Cheers,
Bob

>
>
> So, you just need something like this:
>
> raw_xml = IO.read( 'myfile.xml' )
> all_tag_names = raw_xml.scan( /<(\w+)/ ).flatten.uniq
> all_tag_names.each{ |tag_name|
>  # use ERB here to create new files using
>  # tag_name.capitalize as the foundation for the class name
> }
>

----
Bob Hutchison                  -- tumblelog at http://www.recursive.ca/so/
Recursive Design Inc.          -- weblog at http://www.recursive.ca/hutch
http://www.recursive.ca/       -- works on http://www.raconteur.info/cms-for-static-content/home/