XML to Ruby?

J

Jari Williamsson

Is there any Ruby package that will read a XML file and build Ruby
classes for the tags found (classes that can handle reading, writing,
setting attributes, etc), using the object relationships from the XML?
Most preferably, get everything from the DTD and build the Ruby classes
from there?


Best regards,

Jari Williamsson
 
P

PWR

Is there any Ruby package that will read a XML file and build Ruby
classes for the tags found (classes that can handle reading, writing,
setting attributes, etc), using the object relationships from the XML?
Most preferably, get everything from the DTD and build the Ruby classes
from there?

Best regards,

Jari Williamsson

I've used REXML which worked very well. The only drawback is that it
is not a validating parser.

Peter.
 
R

Rolando Abarca

Is there any Ruby package that will read a XML file and build Ruby
classes for the tags found (classes that can handle reading,
writing, setting attributes, etc), using the object relationships
from the XML? Most preferably, get everything from the DTD and build
the Ruby classes from there?

some time ago, I built a small class to do that, you can check it here:

http://rolando.cl/xmlable/src/xmlable.rb
http://rolando.cl/xmlable/src/test.rb
http://rolando.cl/xmlable/doc/index.html
Best regards,

Jari Williamsson


Regards,
 
J

Jari Williamsson

Rolando said:

Thanks, but this seems to only make XML data accessible to an existing
class?
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?


Best regards,

Jari Williamsson
 
J

Jari Williamsson

PWR said:
I've used REXML which worked very well. The only drawback is that it
is not a validating parser.

How do you get REXML to generate Ruby classes?


Best regards,

Jari Williamsson
 
R

Rolando Abarca

Thanks, but this seems to only make XML data accessible to an
existing class?
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.

well, that's exactly what my class do: convert from xml to ruby
classes, convert from ruby classes to xml. Check the test file for
examples.

Rolando Abarca
Phone: +56-9 97851962
 
P

Phrogz

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?

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
}
 
B

Bob Hutchison

Hi,

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
 
J

Jari Williamsson

Thanks, Bob! You understood despite my bad sample code.

By reading the description of your Xampl tool, this seems to be the tool
I need! In my case, analyzing a bunch of XML files like your tool do
would work as good as working on the DTD.

Best regards,

Jari Williamsson
 
B

Bob Hutchison

Hi

Thanks, Bob! You understood despite my bad sample code.

By reading the description of your Xampl tool, this seems to be the
tool I need! In my case, analyzing a bunch of XML files like your
tool do would work as good as working on the DTD.

Great! If you need any help, let me know and I'll do what I can. An
understatement would be "the documentation is sparse".

Cheers,
Bob
Best regards,

Jari Williamsson
 

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