Provided by: libbiblio-thesaurus-perl_0.43-3_all 
NAME
Biblio::Thesaurus - Perl extension for managing ISO thesaurus
SYNOPSIS
use Biblio::Thesaurus;
$obj = thesaurusNew();
$obj = thesaurusLoad('iso-file');
$obj = thesaurusRetrieve('storable-file');
$obj = thesaurusMultiLoad('iso-file1','iso-file2',...);
$obj->save('iso-file');
$obj->storeOn('storable-file');
$obj->addTerm('term');
$obj->addRelation('term','relation','term1',...,'termn');
$obj->deleteTerm('term');
$obj->isDefined('term');
$obj->describe( { rel='NT', desc="Narrow Term", lang=>"UK" } );
$obj->addInverse('Relation1','Relation2');
$obj->order('rela1', 'rel2', ....);
@order = $obj->order();
$obj->languages('l1', 'l2', ....);
@langs = $obj->languages();
$obj->baselang('l');
$lang = $obj->baselang();
$obj->topName('term');
$term = $obj->topName();
$html = $obj->navigate(+{configuration},%parameters);
$html = $obj->getHTMLTop();
$output = $obj->downtr(\%handler);
$output = $obj->downtr(\%handler,'term', ... );
$obj->appendThesaurus("iso-file");
$obj->appendThesaurus($tobj);
$obj->tc('term', 'relation1', 'relation2');
$obj->depth_first('term', 2, "NT", "UF")
$latex = $obj->toTex( ...)
$xml = $obj->toXml( ...)
ABSTRACT
This module provides transparent methods to maintain Thesaurus files. The module uses a
subset from ISO 2788 which defines some standard features to be found on thesaurus files.
The module also supports multilingual thesaurus and some extensions to the ISOs standard.
DESCRIPTION
A Thesaurus is a classification structure. We can see it as a graph where nodes are terms
and the vertices are relations between terms.
This module provides transparent methods to maintain Thesaurus files. The module uses a
subset from ISO 2788 which defines some standard features to be found on thesaurus files.
This ISO includes a set of relations that can be seen as standard but, this program can
use user defined ones. So, it can be used on ISO or not ISO thesaurus files.
File Structure
Thesaurus used with this module are standard ASCII documents. This file can contain
processing instructions, comments or term definitions. The instructions area is used to
define new relations and mathematical properties between them.
We can see the file with this structure:
______________
| |
| HEADER | --> Can contain, only, processing instructions,
|______________| comment or empty lines.
| |
| Def Term 1 | --> Each term definition should be separated
| | from each other with an empty line.
| Def Term 2 |
| |
| ..... |
| |
| Def Term n |
|______________|
Comments can appear on any line. Meanwhile, the comment character (#) should be the first
character on the line (with no spaces before). Comments line span to the end of the line
(until the first carriage return).
Processing instructions lines, like comments, should start with the percent sign (%). We
describe these instructions later on this document.
Terms definitions can't contain any empty line because they are used to separate
definitions from each other. On the first line of term definition record should appear the
defined term. Next lines defines relations with other terms. The first characters should
be an abbreviation of the relation (on upper case) and spaces. Then, should appear a comma
separated list of terms.
There can be more than one line with the same relation. Thesaurus module will concatenate
the lists. If you want to continue a list on the next line you can repeat the relation
term of leave some spaces between the start of the line and the terms list.
Here is an example:
Animal
NT cat, dog, cow
fish, ant
NT camel
BT Life being
cat
BT Animal
SN domestic animal to be kicked when
anything bad occurs.
There can be defined a special term ("_top_"). It should be used when you want a top tree
for thesaurus navigation. So, we normally define the "_top_" term with the more
interesting terms to be navigated.
The ISO subset used are:
TT - Top Term
The broadest term we can define about the current term.
NT - Narrower Term
Terms more specific than current term.
BT - Broader Term
More generic terms than current term.
USE - Synonym
Another chances when finding a Synonym.
UF - Quasi-Synonym
Terms that are no synonyms of current term but can be used, sometimes with that
meaning.
RT - Related Term
Related term that can't be inserted on any other category.
SN - Scope Note
Text. Note of context of the current term. Use for definitions or comments about the
scope you are using that term.
Processing Instructions
Processing instructions, as said before, are written on a line starting with the percent
sign. Current commands are:
top When presenting a thesaurus, we need a term, to know where to start. Normally, we
want the thesaurus to have some kind of top level, where to start navigating. This
command specifies that term, the term that should be used when no term is specified.
Example:
%top Contents
Contents
NT Biography ...
RT ...
encoding
This command defines the encoding used in the thesaurus file.
Example:
%enc utf8
inverse
This command defines the mathematic inverse of the relation. That is, if you define
"inverse A B" and you know that "foo" is related by "A" with "bar", then, "bar" is
related by "B" with "foo".
Example:
%inv BT NT
%inverse UF USE
description
This command defines a description for some relation class. These descriptions are
used when outputting thesaurus on HTML.
Example:
%desc SN Note of Scope
%description IOF Instance of
If you are constructing a multilingual thesaurus, you will want to translate the
relation class description. To do this, you should use the "description" command with
the language in from of it:
%desc[PT] SN Nota de Contexto
%description[PT] IOF Instancia de
externals
This defines classes that does not relate terms but, instead, relate a term with some
text (a scope note, an url, etc.). This can be used like this:
%ext SN URL
%externals SN URL
Note that you can specify more than one relation type per line.
languages
This other command permits the construction of a multilingual thesaurus. TO specify
languages classifiers (like PT, EN, FR, and so on) you can use one of these lines:
%lang PT EN FR
%languages PT EN FR
To describe (legend) the language names, you should use the description command, so,
you could append:
%description PT Portuguese
%description EN English
%description FR French
baselanguage
This one makes it possible to explicitly name the base language for the thesaurus.
This command should be used with the "description" one, to describe the language name.
Here is a simple example:
%baselang PT
%languages EN FR
%description PT Portuguese
%description EN English
%description FR French
I18N
Internationalization functions, "languages" and "setLanguage" should be used before any
other function or constructor. Note that when loading a saved thesaurus, descriptions
defined on that file will be not translated. That's important!
interfaceLanguages()
This function returns a list of languages that can be used on the current Thesaurus
version.
interfaceSetLanguage( <lang-name> )
This function turns on the language specified. So, it is the first function you should
call when using this module. By default, it uses Portuguese. Future version can change
this, so you should call it any way.
API
This module uses a perl object oriented model programming, so you must create an object
with one of the "thesaurusNew", "thesaurusLoad" or "thesaurusRetrieve" commands. Next
commands should be called using the OO fashion.
Constructors
thesaurusNew
To create an empty thesaurus object. The returned newly created object contains the
inversion properties from the ISO classes and some stub descriptions for the same classes.
thesaurusLoad
To use the "thesaurusLoad" function, you must supply a file name. This file name should
correspond to the ISO ASCII file as defined on earlier sections. It returns the object
with the contents of the file. If the file does not defined relations and descriptions
about the ISO classes, they are added.
Also,
$obj = thesaurusLoad({ completed => 1}, 'iso-file');
can be used to say that the thesaurus needs not to be complete after load.
thesaurusMultiLoad
You can join different thesaurus ISO files using this function:
$obj = thesaurusMultiLoad('iso-file1','iso-file2',...);
appendThesaurus
You can also append a thesaurus ISO (or another thesaurus object) to a loaded thesaurus.
For that, use one of:
$obj->appendThesaurus("iso-file");
$obj->appendThesaurus( $other_thesaurus_object );
thesaurusLoadM
This method is used to load a thesaurus on the meta-thesaurus format. This is still under
development.
thesaurusRetrieve
Everybody knows that text access and parsing of files is not efficient. So, this module
can save and load thesaurus from Storable files. This function should receive a file name
from a file which was saved using the "storeOn" function.
Methods
save
This method dumps the object on an ISO ASCII file. Note that the sequence "thesaurusLoad",
"save" is not the identity function. Comments are removed and processing instructions can
be added. To use it, you should supply a file name.
Note: if the process fails, this method will return 0. Any other method die when failing
to save on a file.
meta2str
This method returns the ISO ascii description of the metadata.
storeOn
This method saves the thesaurus object in Storable format. You should use it when you want
to load with the "thesaurusRetrieve" function.
addTerm
You can add terms definitions using the perl API. This method adds a term on the
thesaurus. Note that if that term already exists, all its relations will be deleted.
all_terms
Returns an array with all terms for the thesaurus base language. NOTE: this function is
deprecated. Use allTerms instead.
allTerms
Returns an array with all terms for the thesaurus base language.
topName
Returns the term in the top of the thesaurus, or defined a new one if called with an
argument.
top_name
Deprecated. See "<topName">;
addRelation
To add relations to a term, use this method. It can be called again and again. Previous
inserted relations will not be deleted. This method can be used with a list of terms for
the relation like:
$obj->addRelation('Animal','NT','cat','dog','cow','camel');
Note: After you add a big amount of relations, autocomplete the thesaurus using the
$obj->complete() method. Completing after each relation addiction is time and cpu
consuming.
hasRelation
Checks if a specific relation exists in the Thesaurus:
if ($obj->hasRelation('Animal','NT','cat')) { ... }
You can check if a term has a relation "X" with anything:
if ($obj->hasRelation('Animal','SN')) { ... }
deleteRelation
$obj->deleteRelation('Animal','NT','cat','dog','cow','camel');
deleteTerm
Use this method to remove all references of the term supplied. Note that all references
will be deleted.
describe
You can use this method to describe some relation class. You can use it to change the
description of an existing class (like the ISO ones) or to define a new class.
isDefined
Use this method to check if a term exists in the thesaurus.
setExternal
Use this method to define that a relation is "extern".
isExternal
Use this method to check if a relation is "extern".
isLanguage
Use this method to check if a relation is a Language.
getdefinition
Deprecated. Use "<getDefinition"
getDefinition
Returns the definition for a term. The definition is a feature structure containing the
term information.
getDescription
Given a relation name and a language (or the default will be used), it returns the
description for that relation.
relations
Call this method with a term, and it returns a list of the relations defined for that
term.
addInverse
This method should be used to describe the inversion property to relation classes. Note
that if there is some previous property about any of the relations, it will de deleted. If
any of the relations does not exist, it will be added.
order
With this method you can define (and access) the order of classes. This order is used
whenever you call a dump function, or the navigation CGI.
navigate
This function is a some what type of CGI included on a object method. You must supply an
associative array of CGI parameters. This method prints an HTML thesaurus for Web
Navigation.
The typical thesaurus navigation CGI is:
#!/usr/bin/perl -w
use CGI qw/:standard/;
use Biblio::Thesaurus;
print header;
for (param()) { $arg{$_} = param($_) }
$thesaurus = thesaurusLoad("thesaurus_file");
print $thesaurus->navigate(%arg);
This method can receive, as first argument, a reference to an associative array with some
configuration variables like what relations to be expanded and what language to be used by
default.
So, in the last example we could write
$thesaurus->navigate(+{expand=>['NT', 'USE'],
lang =>'EN'})
meaning that the structure should show two levels of 'NT' and 'USE' relations, and that it
should use the English language.
These options include:
capitalize
try to capitalize terms when they are the title of the page.
expand
a reference to a list of relations that should be expanded at first level; Defaults to
the empty list.
title
can be "yes" or "no". If it is "no", the current term will not be shown as a title;
Defaults to "yes".
scriptname
the name of the script the links should point on. Defaults to current page name.
level1hide
a reference to a list of relations to do not show on the first level. Defaults to the
empty list. Useful to hide the 'LEN' relation when using Library::Simple.
level2size
the number of terms to be shown on each second level relation; Defaults to 0 (all
terms).
level2hide
a reference to a list of relations to do not show on the second level. Defaults to the
empty list.
topic_name
the name of the topic CGI parameter (default: "t")
dumpHTML
This method returns a big string containing all the thesaurus in HTML. It is mainly used
for debug.
getHTMLTop
This method returns the HTML needed for the top level of the browsing thesaurus. It can be
useful when putting a top level on the first page of a portal.
complete
This function completes the thesaurus based on the invertibility properties. This
operation is only needed when adding terms and relations by this API. Whenever the system
loads a thesaurus ISO file, it is completed.
baselang
Use this method to set or retrieve the base language of the thesaurus. If no baselang is
provided, the value "_" is returned
downtr
The "downtr" method is used to produce something from a set of terms. When no term is
given, the all thesaurus is taken. It should be passed as argument a term and an
associative array (handler) with anonymous subroutines that process each relation. These
functions can use the pre-instantiated variables $term, $rel, @terms. The handler can
have three special functions: "-default" (default handler for relations that don't have a
defined function in the handler), "-eachTerm" executed with each term output (received as
$_), and "-end" executed over the output of the the other functions (received as $_),
If a "-order" array reference is provided, the correspondent order of the relations will
be used.
Example:
$the->downtr( { NT => sub{ ""}, #Do nothing with NT relations
-default => sub{ print "$rel", join(",",@terms) }
},
"frog" );
print $thesaurus->downtr(
{-default => sub { "\n$rel \t".join("\n\t",@terms)},
-eachTerm => sub { "\n______________ $term $_"},
-end => sub { "Thesaurus :\n $_ \nFIM\n"},
-order => ["BT","NT","RT"],
});
Both functions return a output value: the concatenation of the internal values (but
functions can also work with side effects)
depth_first
The "depth_first" method is used to get the list of terms (in fact the tree of terms)
related with $term by relations @r up to the level $lev
$hashref = $the->depth_first($term ,$lev, @r)
$hashref = $the->depth_first("frog", 2, "NT","UF")
$lev should be an integer greater then 0.
tc transitive closure
The "tc" method is used to eval the transitive closure of the relations @r starting from a
term $term
$the->tc($term , @r)
$the->tc("frog", "NT","UF")
terms
The "terms" method is used to get all the terms related by relations @r with $term
$the->terms($term , @r);
$the->terms("frog", "NT", "UF");
toTex
Writes a thesaurus in LaTeX format... The first argument is used to pass a tag
substitution hash. It uses downtr function to make the translation; a downtr handler can
be given to tune some transformations details...
print $thesaurus->toTex(
{EN=>["\\\\\\emph{Ingles} -- ",""]},
{FR => sub{""}})
toXml
This method writes a thesaurus in XML format... The first argument is used fo pass a tag
substitution hash. It uses downtr function to make the translation; a downtr handler can
be given to tune some transformations details...
print $thesaurus->toXml();
toJson
Returns a JSON tree based on NT relation. Other relation can be supplied as an argument.
Future versions might include language selection.
print $thesaurus->toJson();
toHash
Returns a Hash reference with a tree based on NT relation. Other relation can be supplied
as an argument. Future versions might include language selection.
print $thesaurus->toHash();
AUTHOR
Alberto Simoes, <albie@alfarrabio.di.uminho.pt>
Jos� Joao Almeida, <jj@di.uminho.pt>
Sara Correia, <sara.correia@portugalmail.com>
This module is included in the Natura project. You can visit it at
http://natura.di.uminho.pt, and access the SVN tree.
COPYRIGHT & LICENSE
Copyright 2000-2012 Project Natura.
This program is free software; you can redistribute it and/or modify it under the same
terms as Perl itself.
SEE ALSO
The example thesaurus file ("examples/thesaurus"),
Manpages:
Biblio::WebPortal(3)
Biblio::Catalog(3)
Biblio::Catalog::Bibtex(3)
perl(1) manpages.
loading from Iso 2788 =head2 building a thesaurus with internal constructors =head2 writing a
thesaurus in another format