SparqlModel Class Reference

from PyKDE4.soprano import *

Inherits: Soprano.Model → QObject
Namespace: Soprano::Client

Detailed Description

\class SparqlModel sparqlmodel.h Soprano/Client/SparqlModel

Remote client Model for Http SPARQL end points.

The SparqlModel provides a very simple way of accessing remote SPARQL (SPARQL Protocol and RDF Query Language) web services via Http.

Its usage is simple: set hostname and optionally user credentials, then call the well known Model methods like Model.executeQuery to work with the remote repository.

Author:: Rajeev J Sebastian <rajeev.sebastian@gmail.com>
Sebastian Trueg <trueg@kde.org>

Since:: 2.2

Methods
	__init__ (self, QString host=QString(), int port=80, QString user=QString(), QString password=QString())
Soprano.Error.ErrorCode	addStatement (self, Soprano.Statement statement)
bool	containsAnyStatement (self, Soprano.Statement statement)
bool	containsStatement (self, Soprano.Statement statement)
Soprano.Node	createBlankNode (self)
Soprano.QueryResultIterator	executeQuery (self, QString query, Soprano.Query.QueryLanguage language=Query.QueryLanguageSparql, QString userQueryLanguage=QString())
Soprano.Util.AsyncResult	executeQueryAsync (self, QString query, Soprano.Query.QueryLanguage language=Query.QueryLanguageSparql, QString userQueryLanguage=QString())
bool	isEmpty (self)
Soprano.NodeIterator	listContexts (self)
Soprano.StatementIterator	listStatements (self, Soprano.Statement partial)
Soprano.Error.ErrorCode	removeAllStatements (self, Soprano.Statement statement)
Soprano.Error.ErrorCode	removeStatement (self, Soprano.Statement statement)
	setHost (self, QString host, int port=80)
	setPath (self, QString path)
	setUser (self, QString user, QString password=QString())
int	statementCount (self)

Method Documentation

__init__	(	self,
		QString	host=QString(),
		int	port=80,
		QString	user=QString(),
		QString	password=QString()
	)

Create a new SparqlModel instance.

Parameters:

host

The host to connect to (example: dbpedia.org)

Parameters:

port

The port on which to connect the host (most Http services run on port 80.

Parameters:

user

The userName in case the host does not allow anonymous access.

Parameters:

password

The password for user in case the host does not allow anonymous access.

Soprano.Error.ErrorCode addStatement	(	self,
		Soprano.Statement	statement
	)

Add a statement to the remote model.

This method is realized using the SPARQL/Update language extension. Thus, it will only work on services supporting this extension.

Parameters:

statement

The Statement to add.

Returns:: Error.ErrorNone on success and an error code if statement was invalid or an error occured. Check Error.ErrorCache.lastError for detailed error information.

bool containsAnyStatement	(	self,
		Soprano.Statement	statement
	)

bool containsStatement	(	self,
		Soprano.Statement	statement
	)

Soprano.Node createBlankNode ( self )

Creation of blank nodes is not supported by the SparqlModel.

Returns:: an invalid Node

Soprano.QueryResultIterator executeQuery	(	self,
		QString	query,
		Soprano.Query.QueryLanguage	language=Query.QueryLanguageSparql,
		QString	userQueryLanguage=QString()
	)

Execute a query on the SPARQL endpoint.

Parameters:

query

The query to evaluate.

Parameters:

language

The query language used to encode query. Be aware that the SparqlModel does only support one query language: Query.QueryLanguageSparql.

Parameters:

userQueryLanguage

unused since language needs to be set to Query.QueryLanguageSparql.

Returns:: An iterator over all results matching the query, on error an invalid iterator is returned.

Soprano.Util.AsyncResult executeQueryAsync	(	self,
		QString	query,
		Soprano.Query.QueryLanguage	language=Query.QueryLanguageSparql,
		QString	userQueryLanguage=QString()
	)

Asyncroneously execute the given query over the Model.

Parameters:

query

The query to evaluate.

Parameters:

language

The %query language used to encode query.

Parameters:

userQueryLanguage

If language equals Query.QueryLanguageUser userQueryLanguage defines the language to use.

\sa executeQuery

Returns:: an AsyncResult with result type QueryResultIterator object which will signal when the result is ready.

bool isEmpty ( self )

Not supported by the SparqlModel.

Returns:: false

Soprano.NodeIterator listContexts ( self )

Soprano.StatementIterator listStatements	(	self,
		Soprano.Statement	partial
	)

Soprano.Error.ErrorCode removeAllStatements	(	self,
		Soprano.Statement	statement
	)

Remove all statements that match the partial statement. For removing one specific statement see removeStatement().

This method is realized using the SPARQL/Update language extension. Thus, it will only work on services supporting this extension.

Parameters:

statement

A possible partially defined statement that serves as a filter for all statements that should be removed.

Returns:: Error.ErrorNone on success and an error code if statement was invalid or an error occured. Check Error.ErrorCache.lastError for detailed error information.

Soprano.Error.ErrorCode removeStatement	(	self,
		Soprano.Statement	statement
	)

Removed a statement from the remote model.

This method is realized using the SPARQL/Update language extension. Thus, it will only work on services supporting this extension.

Parameters:

statement

The Statement to remove.

Returns:: Error.ErrorNone on success and an error code if statement was invalid or an error occured. Check Error.ErrorCache.lastError for detailed error information.

setHost	(	self,
		QString	host,
		int	port=80
	)

Set the host to connect to.

Parameters:

host

The host to connect to (example: dbpedia.org)

Parameters:

port

The port on which to connect the host (most Http services run on port 80.

setPath	(	self,
		QString	path
	)

Set the path to where the SPARQL endpoint is exposed on the server.

For historical reasons the default path is set to "/sparql".

Since:: 2.2.1

setUser	(	self,
		QString	user,
		QString	password=QString()
	)

Set the user name and password to access the host.

Parameters:

user

The userName in case the host does not allow anonymous access.

Parameters:

password

The password for user in case the host

int statementCount ( self )

Retrieving the number of statements is not supported by the SparqlModel.

Returns:: -1

SparqlModel Class Reference

Detailed Description

Methods

Method Documentation

Modules