[Insight-developers] MetaDataObject Checkins

[Hans Johnson]

Stephen,

The itk::MetaDataDictionary is a map (inherits from 
std::map<std::string,itk::MetaDataObjectBase>).  The 
itk::MetaDataObjectBase is an abstract class that defines the interface 
to itk::MetaDataObject<T> where T is any type.

I am working on the doing extactly what you want for the itkAnalyzeIO, 
and I hope to have that done by this afternoon or early tomarrow with 
documentation and examples in a test case.

Right now I am trying to clean up the mess I made in committing this 
information.

Regards,
Hans J. Johnson




Stephen R. Aylward wrote:
> Hi,
> 
> I thought the MetaData stuff was part of the effort to establish a 
> dictionary.   As such, I thought it was going to be tagged data - 
> std::map or something similar.  This was probably on Friday's TCon. 
> Sorry about that.
> 
> I was hoping to tie your MetaData with MetaObjectIO.   That way we could 
> read/write these objects/dictionaries.
> 
> Right now they look a bit like a base class for traits...
> 
> Stephen
> 
> Hans Johnson wrote:
> 
>> Bill,
>>
>> 2)-------------
>> Can you tell me what part of the specializations is not portable?
>>
>> The idea behind the itkMetaDataObject is that it can encapsulate
>> anything.  Because of that I made a default
>> itk::MetaDataObject<T>::PrintSelf that just printed a string stating
>> that the type can not print itself.  Then specializations of that
>> function could be written for cases where print self was well defined.
>>
>> For example, encapsulating a native C types would be done with the
>> trivial implementations of:
>> itk::MetaDataObject<int>
>> ::PrintSelf(std::ostream& os, Indent indent) const
>> {
>>    os << indent << this->m_MetaDataObjectValue << std::endl;
>> }
>>
>> whereas encapsulating an itk::Image would use:
>>
>> itk::MetaDataObject<int>
>> ::PrintSelf(std::ostream& os, Indent indent) const
>> {
>>    this->m_MetaDataObjectValue->PrintSelf(os,indent);
>> }
>>
>> and non itk-application developers could write:
>> itk::MetaDataObject<MyElephantClass>
>> ::PrintSelf(std::ostream& os, Indent indent) const
>> {
>>    std::cout << indent
>>              << this->m_MetaDataObjectValue->GetTrunk()
>>              << " "
>>              << this->m_MetaDataObjectValue->GetEars()
>>              << " "
>>              << this->m_MetaDataObjectValue->GetTail()
>>              << std::endl;
>> }
>>
>> The current implementation will have to be changed, because it will work
>> only for classes that have the operator<< defined to work with ostreams.
>>
>> If you or anyone else has a portable way of doing this, please let me
>> know, and I will implement it right away.
>>
>> Again, sorry about causing all these problems.
>>
>> Regards,
>> Hans J. Johnson
>> hans-johnson@uiowa.edu
>>
>>
>>
>> Lorensen, William E (Research) wrote:
>>  > Hans,
>>  >
>>  > I corrected a couple of problems with your checkins.
>>  >
>>  > 1) itkMetaDataObject.txx did not have #define guards around the 
>> code. In itk, all .txx files must be
>>  > includable on their own. To enforce this, the header test generator 
>> will include the .txx file if one
>>  > exists. I added guards.
>>  >
>>  > 2) I removed the specialization of the printself methods. The usage 
>> was not portable, but looking
>>  > into at the code it l;ooks like you don't need the specialization. 
>> I moved the output into the
>>  > class's PrintSelf. I lalso removed all the code form the 
>> itkMetaDataObject.cxx file. I did not remove
>>  > that file form CMakeLists.txt file because I wasn't sure if you 
>> have future plans for this file.
>>  >
>>  > I made the changes so that we can get some clean continuous builds 
>> early today. I know that Bill Hoff
>>  > is ready to check in his vnl changes.
>>  >
>>  > Bill
>>  >
>>  > _______________________________________________
>>  > Insight-developers mailing list
>>  > Insight-developers@public.kitware.com
>>  > http://public.kitware.com/mailman/listinfo/insight-developers
>>
>>
> 
> 


-- 
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Hans J. Johnson                              W294 GH
hans-johnson@uiowa.edu                       Dept. of Psychiatry
http://www.psychiatry.uiowa.edu/~hjohnson    The University of Iowa
(319) 353-8587                               Iowa City, IA 52242
===================================================================