The QSparqlQueryModel class provides a read-only data model for SPARQL result sets. More...
Signals |
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| void | finished () |
| void | started () |
Public Member Functions |
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| QSparqlQueryModel (QObject *parent=0) | |
| virtual | ~QSparqlQueryModel () |
| int | rowCount (const QModelIndex &parent=QModelIndex()) const |
| int | columnCount (const QModelIndex &parent=QModelIndex()) const |
| QSparqlResultRow | resultRow (int row) const |
| QSparqlResultRow | resultRow () const |
| QVariant | data (const QModelIndex &item, int role=Qt::DisplayRole) const |
| QVariant | headerData (int section, Qt::Orientation orientation, int role=Qt::DisplayRole) const |
| bool | setHeaderData (int section, Qt::Orientation orientation, const QVariant &value, int role=Qt::EditRole) |
| bool | insertColumns (int column, int count, const QModelIndex &parent=QModelIndex()) |
| bool | removeColumns (int column, int count, const QModelIndex &parent=QModelIndex()) |
| void | setQuery (const QSparqlQuery &query, QSparqlConnection &conn) |
| QSparqlQuery | query () const |
| virtual void | clear () |
| QSparqlError | lastError () const |
Protected Member Functions |
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| virtual void | queryChange () |
| QModelIndex | indexInQuery (const QModelIndex &item) const |
| void | setLastError (const QSparqlError &error) |
The QSparqlQueryModel class provides a read-only data model for SPARQL result sets.
QSparqlQueryModel is a high-level interface for executing SPARQL statements and traversing the result set. It is built on top of the lower-level QSparqlQuery and can be used to provide data to view classes such as QTableView.
QSparqlQueryModel can also be used to access a connection programmatically, without binding it to a view.
| QSparqlQueryModel::QSparqlQueryModel | ( | QObject * | parent = 0 |
) | [explicit] |
Creates an empty QSparqlQueryModel with the given parent.
| QSparqlQueryModel::~QSparqlQueryModel | ( | ) | [virtual] |
Destroys the object and frees any allocated resources.
| void QSparqlQueryModel::clear | ( | ) | [virtual] |
Clears the model and releases any acquired resources. After this function, the model is not usable until setQuery() has been called.
| int QSparqlQueryModel::columnCount | ( | const QModelIndex & | parent = QModelIndex() |
) | const |
Returns the number of columns, which is the number of variables in the select part of the query
Reimplemented from QAbstractItemModel.
| QVariant QSparqlQueryModel::data | ( | const QModelIndex & | item, | |
| int | role = Qt::DisplayRole |
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| ) | const |
Returns the value for the specified item and role.
If item is out of bounds or if an error occurred, an invalid QVariant is returned.
Reimplemented from QAbstractItemModel.
| void QSparqlQueryModel::finished | ( | ) | [signal] |
This signal is emitted when the QSparqlResult, used by the model, has finished retrieving its data or when there was an error.
| QVariant QSparqlQueryModel::headerData | ( | int | section, | |
| Qt::Orientation | orientation, | |||
| int | role = Qt::DisplayRole |
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| ) | const [virtual] |
Returns the header data for the given role in the section of the header with the specified orientation.
Reimplemented from QAbstractItemModel.
| QModelIndex QSparqlQueryModel::indexInQuery | ( | const QModelIndex & | item | ) | const [protected] |
Returns the index of the value in the connection result set for the given item in the model.
The return value is identical to item if no columns or rows have been inserted, removed, or moved around.
Returns an invalid model index if item is out of bounds or if item does not point to a value in the result set.
| bool QSparqlQueryModel::insertColumns | ( | int | column, | |
| int | count, | |||
| const QModelIndex & | parent = QModelIndex() |
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| ) | [virtual] |
Inserts count columns into the model at position column. The parent parameter must always be an invalid QModelIndex, since the model does not support parent-child relationships.
Returns true if column is within bounds; otherwise returns false.
By default, inserted columns are empty. To fill them with data, reimplement data() and handle any inserted column separately.
Reimplemented from QAbstractItemModel.
| QSparqlError QSparqlQueryModel::lastError | ( | ) | const |
Returns information about the last error that occurred on the connection.
| QSparqlQuery QSparqlQueryModel::query | ( | ) | const |
Returns the QSparqlQuery associated with this model.
| void QSparqlQueryModel::queryChange | ( | ) | [protected, virtual] |
This virtual function is called whenever the query changes. The default implementation does nothing.
query() returns the new query.
| bool QSparqlQueryModel::removeColumns | ( | int | column, | |
| int | count, | |||
| const QModelIndex & | parent = QModelIndex() |
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| ) | [virtual] |
Removes count columns from the model starting from position column. The parent parameter must always be an invalid QModelIndex, since the model does not support parent-child relationships.
Removing columns effectively hides them. It does not affect the underlying QSparqlQuery.
Returns true if the columns were removed; otherwise returns false.
Reimplemented from QAbstractItemModel.
| QSparqlResultRow QSparqlQueryModel::resultRow | ( | ) | const |
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Returns an empty record containing information about the fields of the current query.
If the model is not initialized, an empty record will be returned.
| QSparqlResultRow QSparqlQueryModel::resultRow | ( | int | row | ) | const |
Returns the record containing information about the fields of the current query. If row is the index of a valid row, the record will be populated with values from that row.
If the model is not initialized, an empty record will be returned.
| int QSparqlQueryModel::rowCount | ( | const QModelIndex & | parent = QModelIndex() |
) | const |
If the connection supports returning the size of a query (see QSparqlConnection::hasFeature()), the number of rows of the current query is returned. Otherwise, returns the number of rows currently cached on the client.
parent should always be an invalid QModelIndex.
Reimplemented from QAbstractItemModel.
| bool QSparqlQueryModel::setHeaderData | ( | int | section, | |
| Qt::Orientation | orientation, | |||
| const QVariant & | value, | |||
| int | role = Qt::EditRole |
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| ) | [virtual] |
Sets the caption for a horizontal header for the specified role to value. This is useful if the model is used to display data in a view (e.g., QTableView).
Returns true if orientation is Qt::Horizontal and the section refers to a valid section; otherwise returns false.
Note that this function cannot be used to modify values in the connection since the model is read-only.
Reimplemented from QAbstractItemModel.
| void QSparqlQueryModel::setLastError | ( | const QSparqlError & | error | ) | [protected] |
Protected function which allows derived classes to set the value of the last error that occurred on the connection to error.
| void QSparqlQueryModel::setQuery | ( | const QSparqlQuery & | query, | |
| QSparqlConnection & | connection | |||
| ) |
Executes the query query for the given connection connection connection. If no connection is specified, the default connection is used.
lastError() can be used to retrieve verbose information if there was an error setting the query.
| void QSparqlQueryModel::started | ( | ) | [signal] |
This signal is emitted when the QSparqlResult, used by the model, has started to execute.
| Copyright (C) 2010-2011 Nokia Corporation and/or its subsidiary(-ies). Commercial Qt/LGPL 2.1 with Nokia exception/GPL 3.0 |
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