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[EP-tech] Re: Random question: Eprint core fields

On 05/07/12 08:16, Yuri wrote:

Il 04/07/2012 17:19, Sebastien Francois ha scritto:

Yuri,

This will work:

print $eprint->get_value( 'creators' )->[0];

Or:

print $eprint->get_value( 'creators' )->[0]->{name}->{given};

(but that's not very pretty! :-))


->[0] is orrible and unthinkable :-)


Not at all.... references are a thing of beauty and power!
"print $eprint->get_value( 'creators' )->[0]->{name}->{given};" breaks down very sensibly:
1) use the "get_value" method on the $eprint object, to get the value held in "creators". We are told in the documentation (stop laughing at the back) that this is a reference to an array. 2) From the reference, get element Zero. We are told in the documentation (stop laughing at the back) that this is a reference to an associative array. 3) From this reference, get 'name' element. We are told in the documentation (stop laughing at the back) that this is a reference to an associative array. 4) From this reference, get 'given' element. We are told in the documentation (stop laughing at the back) that this is a scalar value, a "string". 
5) Print the string.
Not to blow my own trumpet or anything, but have a look at http://devel.edina.ac.uk:1201/cgi/api5?format=text&org=4407 for an example of a fairly complex perl nested data-object. 

Anything in {} is a hash, anything in [] is a list.
'dec_lower' => '147.64.0.0' is a simple hash element
'identities' => [{},{}] is a hash element who's value is a reference to an anonymous array, each of who's elements are (in turn) references to an anonymous hash (and I'm not showing data in the hashes) 




--

Ian Stuart.
Developer: ORI, RJ-Broker, and OpenDepot.org
Bibliographics and Multimedia Service Delivery team,
EDINA,
The University of Edinburgh.

http://edina.ac.uk/

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