API:EPrints/Search

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NAME

EPrints::Search - Represents a single search

DESCRIPTION

The Search object represents the conditions of a single search.

It used to also store the results of the search, but now it returns an EPrints::List object.

A search expression can also render itself as a web-form, populate itself with values from that web-form and render the results as a web page.

EXAMPLES

Searching for Eprints

 $ds = $session->get_repository->get_dataset( "archive" );
 
 $searchexp = EPrints::Search->new(
   satisfy_all => 1,
   session => $session,
   dataset => $ds,
 );
 
 # Search for an eprint with eprintid 23
 # (ought to use EPrints::DataObj::EPrint->new( SESSION, ID ))
 $searchexp->add_field( $ds->get_field( "eprintid" ), 23 );
 
 $searchexp->add_field( $ds->get_field( "creators" ), "John Smith" );
 

Getting Results

 $results = $searchexp->perform_search;
 
 my $count = $searchexp->count;
 my $count = $results->count;
 
 my $ids = $results->get_ids( 0, 10 );
 my $ids = $results->get_ids; # Get all matching ids
 
 my $info = { matches => 0 };
 sub fn {
   my( $session, $dataset, $eprint, $info ) = @_;
   $info->{matches}++;
 };
 $results->map( \&fn, $info );
 
 $searchexp->dispose;
 

See EPrints::List for more.

METHODS

new

 $searchexp = EPrints::Search->new( %params )

Create a new search expression.

The parameters are split into two parts. The general parameters and those which influence how the HTML form is rendered, and the results displayed.

GENERAL PARAMETERS

session

 session (required)

The current EPrints::Session

dataset_id

 dataset OR dataset_id (required)

Either the EPrints::DataSet to search, or the ID of it.

allow_blank

 allow_blank (default 0)

Unless this is set, a search with no conditions will return zero records rather than all records.

satisfy_all

 satisfy_all (default 1)

If this is true than all search-fields much be satisfied, if false then results matching any search-field will be returned.

search_fields

A reference to an array of search field configuration structures. Each takes the form { id=>"...", default=>"..", meta_fields=>"..." } where the meaning is the same as for search configuration in ArchiveConfig.

Search fields can also be added to the search expression after it has been constructed.

order

The order the results should be returned. This is a key to the list of orders available to this dataset, defined in ArchiveConfig.pm

custom_order

"order" limits you to the orders specified in ArchiveConfig, and is usually used by the web page based searching. custom_order allows you to specify any order you like. The format is foo/-bar. This means that the results will be sorted by foo and then any with equal foo values will be reverse sorted by bar. More than 2 fields can be specified.

keep_cache

If true then the search results produced will be stored in the database even after the current script ends. This is useful for speeding up page 2 onwards of a search.

keep_cache may get set to true anyway for various reasons, but setting the parameter makes certain of it.

cache_id

The ID of a cached search. The cache contains both the results of the search, and the parameters used for the search.

If the cache still exists, it will set the default values of the search fields, and when the search is performed it will skip the search and build a search results object directly from the cache.

prefix

 prefix (default "")

When generating the web form and reading back from the web form, the prefix is inserted before the form names of all fields. This is useful if you need to put two search expressions in a single form for some reason.

staff

 staff (default 0)

If true then this is a "staff" search, which prevents searching unless the user is staff, and the results link to the staff URL of an item rather than the public URL.

filters

A reference to an array of filter definitions.

Filter definitions take the form of: { value=>"..", match=>"..", merge=>"..", id=>".." } and work much like normal search fields except that they do not appear in the web form so force certain search parameters on the user.

An optional parameter of describe=>0 can be set to supress the filter being mentioned in the description of the search.

from_cache

 $ok = $thing->from_cache( $id )

Populate this search expression with values from the given cache.

Return false if the cache does not exist.

add_field

 $searchfield = $searchexp->add_field( $metafields, $value, $match, $merge, $id, $filter, $show_help )

Adds a new search in $metafields which is either a single EPrints::MetaField or a list of fields in an array ref with default $value. If a search field already exists, the value of that field is replaced with $value.

get_searchfield

 $searchfield = $searchexp->get_searchfield( $sf_id )

Return a EPrints::Search::Field belonging to this Search with the given id.

Return undef if not searchfield of that ID belongs to this search.

clear

 $searchexp->clear

Clear the search values of all search fields in the expression.

Resets satisfy_all to true.

get_satisfy_all

 $bool = $searchexp->get_satisfy_all

Return true if this search requires that all the search fields with values are satisfied.

is_blank

 $boolean = $searchexp->is_blank

Return true is this searchexpression has no conditions set, otherwise true.

If any field is set to "exact" then it can never count as unset.

serialise

 $string = $searchexp->serialise

Return a text representation of the search expression, for persistent storage. Doesn't store table or the order by fields, just the field names, values, default order and satisfy_all.

from_string

 $searchexp->from_string( $string )

Unserialises the contents of $string but only into the fields alrdeady existing in $searchexp. Set the order and satisfy_all mode but do not affect the dataset or allow blank.

clone

 $newsearchexp = $searchexp->clone

Return a new search expression which is a duplicate of this one.

get_conditons

 $conditions = $searchexp->get_conditons

Return a tree of EPrints::Search::Condition objects describing the simple steps required to perform this search.

get_dataset

 $dataset = $searchexp->get_dataset

Return the EPrints::DataSet which this search relates to.

set_dataset

 $searchexp->set_dataset( $dataset )

Set the EPrints::DataSet which this search relates to.

render_description

 $xhtml = $searchexp->render_description

Return an XHTML DOM description of this search expressions current parameters.

render_conditions_description

 $xhtml = $searchexp->render_conditions_description

Return an XHTML DOM description of this search expressions conditions. ie title is "foo"

render_order_description

 $xhtml = $searchexp->render_order_description

Return an XHTML DOM description of how this search is ordered.

set_property

 $searchexp->set_property( $property, $value );

Set any single property of this search, such as the order.

get_searchfields

 @search_fields = $searchexp->get_searchfields()

Return the EPrints::Search::Field objects relating to this search.

get_non_filter_searchfields

 @search_fields = $searchexp->get_non_filter_searchfields();

Return the EPrints::Search::Field objects relating to this search, which are normal search fields, and not "filters".

get_set_searchfields

 @search_fields = $searchexp->get_set_searchfields

Return the searchfields belonging to this search expression which have a value set.

get_cache_id

 $cache_id = $searchexp->get_cache_id

Return the ID of the cache containing the results of this search, if known.

perform_search

 $results = $searchexp->perform_search

Execute this search and return a EPrints::List object representing the results.

get_ids_by_field_values

 $hash = $searchexp->get_ids_by_field_values( $field )

Find the ids for each unique value in $field.

UNDOCUMENTED METHODS

These methods were found in the source code but didn't have any POD associated with them. This may be because we haven't got around to documenting them yet or it could be because they are internal to the API and not intended for use by other parts of EPrints.