= Multilingual editing =

|| '''Date''' || 2008/08/13 ||
|| '''Contact(s)''' || fxprunayre ||
|| '''Last edited''' || [[Timestamp]] ||
|| '''Status''' || draft ||
|| '''Assigned to release''' || to be determined ||
|| '''Resources''' || Resource available ||

== Overview ==

Adding the support for multilingual metadatas. For ISO based standards, all the gco:CharacterString elements and their translation can be stored in !GeoNetwork. This also allows editing mulitilingual metadatas.
Add multilingual metadata support in view mode and editing

=== Proposal Type ===
 * '''Type''': GUI Change, Module Change
 * '''App''': !GeoNetwork
 * '''Module''': SchemaLoader, Data Manager, Metadata Import, Lucene Index, Search Interface

=== Links ===
 * '''Documents''':
 * '''Email discussions''':
 * '''Other wiki discussions''':

=== Voting History ===
 * Vote proposed by X on Y, result was +/-n (m non-voting members).


== Motivations ==


== Proposal == 

Allow multilingual editing in GeoNetwork. One metadata record define :
 * one main language (using gmd:language element)
 * n other languages (using gmd:locale element)

[[Image(editor-multilingual.png, 400px)]]

In view mode, according to GUI language :
 * if GUI language is available in the metadata, the element is displayed in this language
 * else the elemenet is displayed in metadata default language.

Then multilingual content need to be indexed in lucene.

=== Backwards Compatibility Issues ===
 * Only ISO compliant


=== Implementation ===

Metadata is defined by one main language (gmd:MD_Metadata/gmd:language:gco:CharacterString) and other locale (gmd:MD_Metadata/gmd:locale/*).

If user add new translation, a new local element has to be added:
{{{
<gmd:locale>
  <gmd:PT_Locale id="FR">
    <gmd:languageCode><gmd:LanguageCode codeList="#LanguageCode" codeListValue="fra">French</gmd:LanguageCode></gmd:languageCode>			
    <gmd:characterEncoding><gmd:MD_CharacterSetCode codeList="#MD_CharacterSetCode" codeListValue="utf8">UTF 8</gmd:MD_CharacterSetCode></gmd:characterEncoding>
  </gmd:PT_Locale>
</locale>
}}}

After editing, the new translated element is stored with:
 * an xsi:type= « gmd:PT_FreeText_PropertyType»
 * a first gco:CharacterString in the metadata language (in the example "en")
 * n gmd:PT_FreeText elements with each translation
{{{
<scope xsi:type="gmd:PT_FreeText_PropertyType">
  <gco:CharacterString>Codelists for description of metadata datasets compliant with ISO/TC 211 19115:2003 and 19139</gco:CharacterString>
  <gmd:PT_FreeText>
    <gmd:textGroup>
      <gmd:LocalisedCharacterString locale="#FR ">Listes de codes pour la description de lots de métadonnées conforme ISO TC/211 19115:2003 et 19139</gmd:LocalisedCharacterString>
    </gmd:textGroup>
  </gmd:PT_FreeText>
</scope>
}}}


In the editor any gco:CharacterString could be multilingual. The gco:CharacterString is in default language, the other PT_FreeText elements has to use a locale declared in the metadata document.

=== Index ===
One index by language is created and specific language analyzer could be define (eg. FrenchAnalyzer, GermanAnalyzer provided by Lucene).
Lucene index is stored in WEB-INF/lucene directory :
{{{
lucene
 +-- nonspatial_eng
 +-- nonspatial_fra
 +-- nonspatial_deu
}}}

Metadata indexing is done in default language using index-fields.xsl and multilingual content using language-index-fields.xsl which will extract all fragments to be stored in index.

More details on indexing mechanism MultilingualIndexMechanism .

=== Search ===
Search is done using a MultiSearcher (ie. in all index) and the index corresponding to GUI language is "boost" to be on top.
A duplicate filter filter search result in order to not to have duplicate in results as one record will appear in more than on index.

== Risks ==

== Participants ==
 * List of participants and role (if necessary) in current GIP