#include <Nepomuk/Query/Query>

Inheritance diagram for Nepomuk::Query::Query:

Classes
class	RequestProperty

Public Types
enum	QueryFlag { NoQueryFlags = 0x0, NoResultRestrictions = 0x1, WithoutFullTextExcerpt = 0x2 }

enum	SparqlFlag { NoFlags = 0x0, CreateCountQuery = 0x1, HandleInverseProperties = 0x2, CreateAskQuery = 0x4 }

Public Member Functions
	Query ()

	Query (const Term &term)

	Query (const Query &)

	~Query ()

void	addRequestProperty (const RequestProperty &property)

bool	fullTextScoringEnabled () const

Qt::SortOrder	fullTextScoringSortOrder () const

bool	isFileQuery () const

bool	isValid () const

int	limit () const

int	offset () const

bool	operator!= (const Query &query) const

Query &	operator= (const Query &)

Query &	operator= (const Term &term)

bool	operator== (const Query &query) const

Query	optimized () const

QueryFlags	queryFlags () const

QList< RequestProperty >	requestProperties () const

RequestPropertyMap	requestPropertyMap () const

void	setFullTextScoringEnabled (bool enabled)

void	setFullTextScoringSortOrder (Qt::SortOrder order)

void	setLimit (int)

void	setOffset (int offset)

void	setQueryFlags (QueryFlags flags)

void	setRequestProperties (const QList< RequestProperty > &properties)

void	setTerm (const Term &)

Term	term () const

FileQuery	toFileQuery () const

KUrl	toSearchUrl (SparqlFlags flags=NoFlags) const

KUrl	toSearchUrl (const QString &customTitle, SparqlFlags flags=NoFlags) const

QString	toSparqlQuery (SparqlFlags flags=NoFlags) const

QString	toString () const

Static Public Member Functions
static Query	fromQueryUrl (const KUrl &url)

static Query	fromString (const QString &queryString)

static QString	sparqlFromQueryUrl (const KUrl &url)

static QString	titleFromQueryUrl (const KUrl &url)

Detailed Description

A Nepomuk desktop query.

A Query consists or a combination of Terms that can be optionally restricted via a limit (setLimit()) or folder filters (setIncludeFolders() and setExcludeFolders()).

Additionally setRequestProperties() allows to retrieve additional information about the results.

Queries can be easily converted to SPARQL via the toSparqlQuery() method or to search URLs ready for KIO::DirLister using toSearchUrl().

The typical usage of a Query instance would be QueryServiceClient::query(). However one can also use toSparqlQuery() to convert it into a SPARQL query string and use that string in QueryServiceClient::sparqlQuery() or even directly in Soprano::Model::executeQuery() via ResourceManager::instance()->mainModel() or in a custom Model.

See also: QueryParser, FileQuery

Author: Sebastian Trueg trueg.nosp@m.@kde.nosp@m..org

Since: 4.4

Definition at line 76 of file query.h.

Member Enumeration Documentation

enum Nepomuk::Query::Query::QueryFlag

A set of flags that influence the result of the query.

See also: setQueryFlags(), SparqlFlags

Since: 4.6

Enumerator

NoQueryFlags

No flags set.

This is the default.

NoResultRestrictions

By default queries that will only return results which are intended for the user's eyes.

In situations where an application needs to work on internal or statistical data this restriction is not desireable. This flag disables the restriction and returns the full set of results.

WithoutFullTextExcerpt

Disables the return of full text search excerpts for ComparisonTerm::Contains terms which are normally reported through Result::excerpt().

It might make sense to set this flag in case one has no need for excerpts and does not want to suffer the small performance penalty that comes from querying them

Definition at line 233 of file query.h.

enum Nepomuk::Query::Query::SparqlFlag

Aditional flags modifying the behaviour of toSparqlQuery() and toSearchUrl().

Enumerator
NoFlags	No flags, i.e. create a default query.
CreateCountQuery	Create a SPARQL count query which will return the number of results rather than the results themselves. The resuling query will have a single binding called `'cnt'`.
HandleInverseProperties	Automatically handle inverse properties, consider for example nie:isPartOf and nie:hasPart at the same time and even if only one of both is defined.
CreateAskQuery	Create a SPARQL ask query which will simply check if a matching result exists. Use Soprano::QueryResultIterator::boolValue() to check the result. Since 4.6

Definition at line 369 of file query.h.

Constructor & Destructor Documentation

Nepomuk::Query::Query::Query ( )

Create an empty invalid query object.

Nepomuk::Query::Query::Query ( const Term & term )

explicit

Create a query with root term term.

Nepomuk::Query::Query::Query ( const Query & )

Copy constructor.

Nepomuk::Query::Query::~Query ( )

Destructor.

Member Function Documentation

void Nepomuk::Query::Query::addRequestProperty ( const RequestProperty & property )

Add a property that should be reported with each search result.

Parameters

property The requested property.

ComparisonTerm::setVariableName() provides a more flexible (but also slightly more complicated) way to select additional results.

See also: setRequestProperties, requestProperties, ComparisonTerm::setVariableName()

static Query Nepomuk::Query::Query::fromQueryUrl ( const KUrl & url )

static

Extract a query from a nepomuksearch:/ query URL.

Returns: The query that was encoded in url or an invalid query if either url is not a nepomuksearch:/ URL or if it contains a pure SPARQL query. In the latter case sparqlFromQueryUrl() can be used to extract that query.

See also: sparqlFromQueryUrl()

Since: 4.5

static Query Nepomuk::Query::Query::fromString ( const QString & queryString )

static

Parse a Query that has been encoded as a string via toString().

Warning: This method can NOT parse SPARQL syntax.

See also: toString()

Since: 4.5

bool Nepomuk::Query::Query::fullTextScoringEnabled ( ) const

Returns: true if full text scoring has been enabled.

See also: setFullTextScoringEnabled()

Since: 4.6

Qt::SortOrder Nepomuk::Query::Query::fullTextScoringSortOrder ( ) const

Returns: The full text scoring sort order as set via setFullTextScoringSortOrder()

Since: 4.6

bool Nepomuk::Query::Query::isFileQuery ( ) const

Returns: true if this is a file query that will only return files and folders.

See also: FileQuery

Since: 4.5

bool Nepomuk::Query::Query::isValid ( ) const

Returns: true if the query is valid, i.e. it has a valid term().

int Nepomuk::Query::Query::limit ( ) const

The maximum number of results that this query should yield.

See also: setLimit()

int Nepomuk::Query::Query::offset ( ) const

The first result that should be retrieved.

See also: setOffset()

Since: 4.5

bool Nepomuk::Query::Query::operator!= ( const Query & query ) const

Comparison operator.

Returns: true if this query differs from query.

Since: 4.6

Query& Nepomuk::Query::Query::operator= ( const Query & )

Assignment operator.

Query& Nepomuk::Query::Query::operator= ( const Term & term )

Assignment operator.

Assigns term to this query without changing any other properties.

Since: 4.5

bool Nepomuk::Query::Query::operator== ( const Query & query ) const

Comparison operator.

Returns: true if this query is equal to query.

Query Nepomuk::Query::Query::optimized ( ) const

Optimizes the query without chaning its meaning.

This removes redundant terms such as NegationTerm and OptionalTerm nestings and flattens AndTerm and OrTerm hierarchies.

Returns: An optimized version of this query.

Since: 4.6

See also: Term::optimized()

QueryFlags Nepomuk::Query::Query::queryFlags ( ) const

Get the query flags to configure this query.

See also: setQueryFlags()

Since: 4.6

QList<RequestProperty> Nepomuk::Query::Query::requestProperties ( ) const

Returns: The list of RequestProperty instances set via addRequestProperty and setRequestProperties.

RequestPropertyMap Nepomuk::Query::Query::requestPropertyMap ( ) const

Build a request property map as used in QueryServiceClient::sparqlQuery() from the request properties set via addRequestProperty() and setRequestProperties().

Be aware that in most situations it is much simpler to use QueryServiceClient::query().

void Nepomuk::Query::Query::setFullTextScoringEnabled ( bool enabled )

Nepomuk supports scoring the results based on any full text matching used in the query (full text matching is done via ComparisonTerm with the ComparisonTerm::Contains comperator) and sorting the results based on that score.

By default full text scoring is disabled since it can mean a serious impact on query performance.

See also: setFullTextScoringSortOrder(), Result::score()

Since: 4.6

void Nepomuk::Query::Query::setFullTextScoringSortOrder ( Qt::SortOrder order )

Set the full text scoring sort order.

Ignored if full text scoring is disabled.

By default the sort order is Qt::DescendingOrder.

See also: setFullTextScoringEnabled()

Since: 4.6

void Nepomuk::Query::Query::setLimit ( int )

Set the maximum number of results this query should yield.

See also: limit

void Nepomuk::Query::Query::setOffset ( int offset )

The first result that should be retrieved.

This can be combined with setLimit() to do paged results.

Since: 4.5

void Nepomuk::Query::Query::setQueryFlags ( QueryFlags flags )

Set the query flags to configure this query.

See also: queryFlags()

Since: 4.6

void Nepomuk::Query::Query::setRequestProperties ( const QList< RequestProperty > & properties )

Set the properties that should be reported with each search result.

Parameters

properties The requested properties.

ComparisonTerm::setVariableName() provides a more flexible (but also slightly more complicated) way to select additional results.

See also: addRequestProperty, requestProperties, ComparisonTerm::setVariableName()

void Nepomuk::Query::Query::setTerm ( const Term & )

Set the root term of the query.

See also: term

static QString Nepomuk::Query::Query::sparqlFromQueryUrl ( const KUrl & url )

static

Extract the SPARQL query from a nepomuksearch:/ query URL.

All kinds of nepomuksearch:/ URLs are supported.

Returns: The SPARQL query string representing the query encoded in url.

See also: fromQueryUrl()

Since: 4.5

Term Nepomuk::Query::Query::term ( ) const

The root term of the query.

This can be any type of term.

See also: setTerm()

static QString Nepomuk::Query::Query::titleFromQueryUrl ( const KUrl & url )

static

Extact the title from a nepomuksearch:/ query URL.

The title is either a custom title which has been specified in toSearchUrl(const QString&, SparqlFlags) or the user query string in case of nepomuksearch:/myquery URLs.

Returns: A title for the query url or an empty string in case url is not a nepomuksearch:/ URL or a useful title cannot be extracted.

Since: 4.5

FileQuery Nepomuk::Query::Query::toFileQuery ( ) const

Returns: A copy of this query which is restricted to files.

Since: 4.6

KUrl Nepomuk::Query::Query::toSearchUrl ( SparqlFlags flags = NoFlags ) const

Convert the query into a URL which can be listed using KIO::DirLister.

The URL will use the nepomuksearch:/ KIO protocol to handle the listing of search results.

Parameters

flags Optional flags to change the query. Query::CreateCountQuery is not supported and will silently be dropped from flags.

Returns: A URL which will list a virtual folder containing all search results from this query or an invalid URL in case this query is invalid.

See also: toSparqlQuery(), SparqlFlag

KUrl Nepomuk::Query::Query::toSearchUrl	(	const QString &	customTitle,
		SparqlFlags	flags = `NoFlags`
	)		const

Convert the query into a URL which can be listed using KIO::DirLister.

The URL will use the nepomuksearch:/ KIO protocol to handle the listing of search results.

This is the perfect method for listing results in file managers or file dialogs.

Parameters

customTitle	An optional custom title that will be used for the listing of the results. This is achieved by setting the KIO::UDSEntry::UDS_DISPLAY_NAME to the customTitle value.
flags	Optional flags to change the query. Query::CreateCountQuery is not supported and will silently be dropped from `flags`.

Returns: A URL which will list a virtual folder containing all search results from this query or an invalid URL in case this query is invalid.

See also: toSparqlQuery(), SparqlFlag

Since: 4.5

QString Nepomuk::Query::Query::toSparqlQuery ( SparqlFlags flags = NoFlags ) const

Convert the query into a SPARQL query which can be used with the Nepomuk query service or directly in Soprano::Model::executeQuery.

It is recommended to use QueryServiceClient instead of creating the SPARQL query this way.

The resulting query will bind the results to variable 'r'. Request properties will be bound to variables 'reqProp1' through 'reqPropN' (the only exception is a count query created via the CreateCountQuery flag).

If you are looking for a serialization of a Query which can be parsed again use toString() instead.

Warning: The SPARQL queries created by this method contain SPARQL extensions from Virtuoso and will not work with other RDF storage solutions!

Parameters

flags Optional flags to change the query.

Returns: The SPARQL representation of this query or an empty string if the query could not be converted (invalid query.)

See also: toString(), toSearchUrl(), SparqlFlag

QString Nepomuk::Query::Query::toString ( ) const

Encode the Query in a string.

Be aware that this does NOT create a SPARQL query. The returned string can be used to serialize queries that can later be read via fromString().

See also: fromString(), toSparqlQuery()

Since: 4.5

The documentation for this class was generated from the following file:

query.h

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