Editing API:EPrints/Plugin/Search (section)

==DESCRIPTION==
Search plugins implement the features required to render search query form inputs, perform queries and return matching objects.

The main function of a search plugin is to retrieve objects from a [[API:EPrints/DataSet|dataset]] based on a set of search criteria. The criteria are search fields and search filters. The terms used in search fields are usually provided by the user (e.g. from a Web form) while filters are defined by the search configuration. Search fields also define the "setness" of a search - if the user hasn't supplied any search terms the search is deemed to be empty. Filters tend to provide more options than those currently available from the Web UI, for instance testing whether a value is or is not set.

In the default EPrints configuration there are <code>simple</code> and <code>advanced</code> searches for objects of class [[API:EPrints/DataObj/EPrint|EPrints::DataObj::EPrint]]. These (at least) define the form input boxes provided to the user and the fields that those user-supplied values are matched against. The search configuration can also define the choice of ordering of results, additional filters etc. Not all options will be supported by every engine - see the engine-specific plugins for details.

There are currently two engines provided as part of the EPrints core:

* Internal
: [[API:EPrints/Plugin/Search/Internal|EPrints::Plugin::Search::Internal]] is a wrapper around [[API:EPrints/Search|EPrints::Search]].

: This supports querying any object type and in any search configuration (matches <code>*/*</code>).

* Xapian
: [[API:EPrints/Plugin/Search/Xapian|EPrints::Plugin::Search::Xapian]] is a wrapper around the {{API:PodLink|file=Search/Xapian|package_name=Search::Xapian|section=|text=Search::Xapian}} module (must be installed separately). Xapian supports relevance matches, phrase searching, stemming and other advanced text index approaches.

: Currently only <code>simple</code> searches are supported.

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