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Diffstat (limited to 'src/imports/localstorage/qquicklocalstorage.cpp')
-rw-r--r-- | src/imports/localstorage/qquicklocalstorage.cpp | 792 |
1 files changed, 792 insertions, 0 deletions
diff --git a/src/imports/localstorage/qquicklocalstorage.cpp b/src/imports/localstorage/qquicklocalstorage.cpp new file mode 100644 index 0000000000..333e697e3c --- /dev/null +++ b/src/imports/localstorage/qquicklocalstorage.cpp @@ -0,0 +1,792 @@ +/**************************************************************************** +** +** Copyright (C) 2019 The Qt Company Ltd. +** Contact: https://www.qt.io/licensing/ +** +** This file is part of the test suite of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see https://www.qt.io/terms-conditions. For further +** information use the contact form at https://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 3 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL3 included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 3 requirements +** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 2.0 or (at your option) the GNU General +** Public license version 3 or any later version approved by the KDE Free +** Qt Foundation. The licenses are as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 +** included in the packaging of this file. Please review the following +** information to ensure the GNU General Public License requirements will +** be met: https://www.gnu.org/licenses/gpl-2.0.html and +** https://www.gnu.org/licenses/gpl-3.0.html. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qquicklocalstorage_p.h" + +#include <QtQml/private/qqmlengine_p.h> +#include <QtQml/private/qv4global_p.h> +#include <QtQml/private/qv4scopedvalue_p.h> +#include <QtQml/private/qv4object_p.h> +#include <QtQml/private/qv4sqlerrors_p.h> +#include <QtQml/private/qv4jscall_p.h> +#include <QtQml/private/qv4objectiterator_p.h> + +#include <QtCore/qfileinfo.h> +#include <QtCore/qdir.h> + +#include <QtSql/qsqldatabase.h> +#include <QtSql/qsqlquery.h> +#include <QtSql/qsqlrecord.h> +#include <QtSql/qsqlerror.h> + +#if QT_CONFIG(settings) +#include <QtCore/qsettings.h> +#endif + +QT_BEGIN_NAMESPACE + +#define V4THROW_SQL(error, desc) { \ + QV4::ScopedString v(scope, scope.engine->newString(desc)); \ + QV4::ScopedObject ex(scope, scope.engine->newErrorObject(v)); \ + ex->put(QV4::ScopedString(scope, scope.engine->newIdentifier(QStringLiteral("code"))).getPointer(), QV4::ScopedValue(scope, Value::fromInt32(error))); \ + scope.engine->throwError(ex); \ + RETURN_UNDEFINED(); \ +} + +#define V4THROW_SQL2(error, desc) { \ + QV4::ScopedString v(scope, scope.engine->newString(desc)); \ + QV4::ScopedObject ex(scope, scope.engine->newErrorObject(v)); \ + ex->put(QV4::ScopedString(scope, scope.engine->newIdentifier(QStringLiteral("code"))).getPointer(), QV4::ScopedValue(scope, Value::fromInt32(error))); \ + args->setReturnValue(scope.engine->throwError(ex)); \ + return; \ +} + +#define V4THROW_REFERENCE(string) { \ + QV4::ScopedString v(scope, scope.engine->newString(string)); \ + scope.engine->throwReferenceError(v); \ + RETURN_UNDEFINED(); \ +} + + +class QQmlSqlDatabaseData : public QV4::ExecutionEngine::Deletable +{ +public: + QQmlSqlDatabaseData(QV4::ExecutionEngine *engine); + ~QQmlSqlDatabaseData() override; + + QV4::PersistentValue databaseProto; + QV4::PersistentValue queryProto; + QV4::PersistentValue rowsProto; +}; + +V4_DEFINE_EXTENSION(QQmlSqlDatabaseData, databaseData) + +namespace QV4 { + +namespace Heap { + struct QQmlSqlDatabaseWrapper : public Object { + enum Type { Database, Query, Rows }; + void init() + { + Object::init(); + type = Database; + database = new QSqlDatabase; + version = new QString; + sqlQuery = new QSqlQuery; + } + + void destroy() { + delete database; + delete version; + delete sqlQuery; + Object::destroy(); + } + + Type type; + QSqlDatabase *database; + + QString *version; // type == Database + + bool inTransaction; // type == Query + bool readonly; // type == Query + + QSqlQuery *sqlQuery; // type == Rows + bool forwardOnly; // type == Rows + }; +} + +class QQmlSqlDatabaseWrapper : public Object +{ +public: + V4_OBJECT2(QQmlSqlDatabaseWrapper, Object) + V4_NEEDS_DESTROY + + static Heap::QQmlSqlDatabaseWrapper *create(QV4::ExecutionEngine *engine) + { + return engine->memoryManager->allocate<QQmlSqlDatabaseWrapper>(); + } + + ~QQmlSqlDatabaseWrapper() { + } + + static ReturnedValue virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty); +}; + +} + +using namespace QV4; + +DEFINE_OBJECT_VTABLE(QV4::QQmlSqlDatabaseWrapper); + + + +static ReturnedValue qmlsqldatabase_version(const FunctionObject *b, const Value *thisObject, const QV4::Value *, int) +{ + Scope scope(b); + QV4::Scoped<QQmlSqlDatabaseWrapper> r(scope, thisObject->as<QQmlSqlDatabaseWrapper>()); + if (!r || r->d()->type != Heap::QQmlSqlDatabaseWrapper::Database) + V4THROW_REFERENCE("Not a SQLDatabase object"); + + RETURN_RESULT(Encode(scope.engine->newString(*r->d()->version))); +} + +static ReturnedValue qmlsqldatabase_rows_length(const FunctionObject *b, const Value *thisObject, const QV4::Value *, int) +{ + Scope scope(b); + QV4::Scoped<QQmlSqlDatabaseWrapper> r(scope, thisObject->as<QQmlSqlDatabaseWrapper>()); + if (!r || r->d()->type != Heap::QQmlSqlDatabaseWrapper::Rows) + V4THROW_REFERENCE("Not a SQLDatabase::Rows object"); + + int s = r->d()->sqlQuery->size(); + if (s < 0) { + // Inefficient + if (r->d()->sqlQuery->last()) { + s = r->d()->sqlQuery->at() + 1; + } else { + s = 0; + } + } + RETURN_RESULT(Encode(s)); +} + +static ReturnedValue qmlsqldatabase_rows_forwardOnly(const FunctionObject *b, const Value *thisObject, const QV4::Value *, int) +{ + Scope scope(b); + QV4::Scoped<QQmlSqlDatabaseWrapper> r(scope, thisObject->as<QQmlSqlDatabaseWrapper>()); + if (!r || r->d()->type != Heap::QQmlSqlDatabaseWrapper::Rows) + V4THROW_REFERENCE("Not a SQLDatabase::Rows object"); + RETURN_RESULT(Encode(r->d()->sqlQuery->isForwardOnly())); +} + +static ReturnedValue qmlsqldatabase_rows_setForwardOnly(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc) +{ + Scope scope(b); + QV4::Scoped<QQmlSqlDatabaseWrapper> r(scope, thisObject->as<QQmlSqlDatabaseWrapper>()); + if (!r || r->d()->type != Heap::QQmlSqlDatabaseWrapper::Rows) + V4THROW_REFERENCE("Not a SQLDatabase::Rows object"); + if (argc < 1) + RETURN_RESULT(scope.engine->throwTypeError()); + + r->d()->sqlQuery->setForwardOnly(argv[0].toBoolean()); + RETURN_UNDEFINED(); +} + +QQmlSqlDatabaseData::~QQmlSqlDatabaseData() +{ +} + +static ReturnedValue qmlsqldatabase_rows_index(const QQmlSqlDatabaseWrapper *r, ExecutionEngine *v4, quint32 index, bool *hasProperty = nullptr) +{ + Scope scope(v4); + + if (r->d()->sqlQuery->at() == (int)index || r->d()->sqlQuery->seek(index)) { + QSqlRecord record = r->d()->sqlQuery->record(); + // XXX optimize + ScopedObject row(scope, v4->newObject()); + for (int ii = 0; ii < record.count(); ++ii) { + QVariant v = record.value(ii); + ScopedString s(scope, v4->newIdentifier(record.fieldName(ii))); + ScopedValue val(scope, v.isNull() ? Encode::null() : v4->fromVariant(v)); + row->put(s.getPointer(), val); + } + if (hasProperty) + *hasProperty = true; + return row.asReturnedValue(); + } else { + if (hasProperty) + *hasProperty = false; + return Encode::undefined(); + } +} + +ReturnedValue QQmlSqlDatabaseWrapper::virtualGet(const Managed *m, PropertyKey id, const Value *receiver, bool *hasProperty) +{ + if (!id.isArrayIndex()) + return Object::virtualGet(m, id, receiver, hasProperty); + + uint index = id.asArrayIndex(); + Q_ASSERT(m->as<QQmlSqlDatabaseWrapper>()); + const QQmlSqlDatabaseWrapper *r = static_cast<const QQmlSqlDatabaseWrapper *>(m); + if (!r || r->d()->type != Heap::QQmlSqlDatabaseWrapper::Rows) + return Object::virtualGet(m, id, receiver, hasProperty); + + return qmlsqldatabase_rows_index(r, r->engine(), index, hasProperty); +} + +static ReturnedValue qmlsqldatabase_rows_item(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc) +{ + Scope scope(b); + QV4::Scoped<QQmlSqlDatabaseWrapper> r(scope, thisObject->as<QQmlSqlDatabaseWrapper>()); + if (!r || r->d()->type != Heap::QQmlSqlDatabaseWrapper::Rows) + V4THROW_REFERENCE("Not a SQLDatabase::Rows object"); + + RETURN_RESULT(qmlsqldatabase_rows_index(r, scope.engine, argc ? argv[0].toUInt32() : 0)); +} + +static QVariant toSqlVariant(QV4::ExecutionEngine *engine, const QV4::ScopedValue &value) +{ + // toVariant() maps a null JS value to QVariant(VoidStar), but the SQL module + // expects a null variant. (this is because of QTBUG-40880) + if (value->isNull()) + return QVariant(); + return engine->toVariant(value, /*typehint*/-1); +} + +static ReturnedValue qmlsqldatabase_executeSql(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc) +{ + Scope scope(b); + QV4::Scoped<QQmlSqlDatabaseWrapper> r(scope, thisObject->as<QQmlSqlDatabaseWrapper>()); + if (!r || r->d()->type != Heap::QQmlSqlDatabaseWrapper::Query) + V4THROW_REFERENCE("Not a SQLDatabase::Query object"); + + if (!r->d()->inTransaction) + V4THROW_SQL(SQLEXCEPTION_DATABASE_ERR,QQmlEngine::tr("executeSql called outside transaction()")); + + QSqlDatabase db = *r->d()->database; + + QString sql = argc ? argv[0].toQString() : QString(); + + if (r->d()->readonly && !sql.startsWith(QLatin1String("SELECT"),Qt::CaseInsensitive)) { + V4THROW_SQL(SQLEXCEPTION_SYNTAX_ERR, QQmlEngine::tr("Read-only Transaction")); + } + + QSqlQuery query(db); + bool err = false; + + ScopedValue result(scope, Value::undefinedValue()); + + if (query.prepare(sql)) { + if (argc > 1) { + ScopedValue values(scope, argv[1]); + if (values->as<ArrayObject>()) { + ScopedArrayObject array(scope, values); + quint32 size = array->getLength(); + QV4::ScopedValue v(scope); + for (quint32 ii = 0; ii < size; ++ii) { + query.bindValue(ii, toSqlVariant(scope.engine, (v = array->get(ii)))); + } + } else if (values->as<Object>()) { + ScopedObject object(scope, values); + ObjectIterator it(scope, object, ObjectIterator::EnumerableOnly); + ScopedValue key(scope); + QV4::ScopedValue val(scope); + while (1) { + key = it.nextPropertyName(val); + if (key->isNull()) + break; + QVariant v = toSqlVariant(scope.engine, val); + if (key->isString()) { + query.bindValue(key->stringValue()->toQString(), v); + } else { + Q_ASSERT(key->isInteger()); + query.bindValue(key->integerValue(), v); + } + } + } else { + query.bindValue(0, toSqlVariant(scope.engine, values)); + } + } + if (query.exec()) { + QV4::Scoped<QQmlSqlDatabaseWrapper> rows(scope, QQmlSqlDatabaseWrapper::create(scope.engine)); + QV4::ScopedObject p(scope, databaseData(scope.engine)->rowsProto.value()); + rows->setPrototypeUnchecked(p.getPointer()); + rows->d()->type = Heap::QQmlSqlDatabaseWrapper::Rows; + *rows->d()->database = db; + *rows->d()->sqlQuery = query; + + ScopedObject resultObject(scope, scope.engine->newObject()); + result = resultObject.asReturnedValue(); + // XXX optimize + ScopedString s(scope); + ScopedValue v(scope); + resultObject->put((s = scope.engine->newIdentifier("rowsAffected")).getPointer(), (v = Value::fromInt32(query.numRowsAffected()))); + resultObject->put((s = scope.engine->newIdentifier("insertId")).getPointer(), (v = scope.engine->newString(query.lastInsertId().toString()))); + resultObject->put((s = scope.engine->newIdentifier("rows")).getPointer(), rows); + } else { + err = true; + } + } else { + err = true; + } + if (err) + V4THROW_SQL(SQLEXCEPTION_DATABASE_ERR,query.lastError().text()); + + RETURN_RESULT(result->asReturnedValue()); +} + +struct TransactionRollback { + QSqlDatabase *db; + bool *inTransactionFlag; + + TransactionRollback(QSqlDatabase *database, bool *transactionFlag) + : db(database) + , inTransactionFlag(transactionFlag) + { + if (inTransactionFlag) + *inTransactionFlag = true; + } + + ~TransactionRollback() + { + if (inTransactionFlag) + *inTransactionFlag = false; + if (db) + db->rollback(); + } + + void clear() { + db = nullptr; + if (inTransactionFlag) + *inTransactionFlag = false; + inTransactionFlag = nullptr; + } +}; + + +static ReturnedValue qmlsqldatabase_changeVersion(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc) +{ + Scope scope(b); + if (argc < 2) + RETURN_UNDEFINED(); + + Scoped<QQmlSqlDatabaseWrapper> r(scope, *thisObject); + if (!r || r->d()->type != Heap::QQmlSqlDatabaseWrapper::Database) + V4THROW_REFERENCE("Not a SQLDatabase object"); + + QSqlDatabase db = *r->d()->database; + QString from_version = argv[0].toQString(); + QString to_version = argv[1].toQString(); + ScopedFunctionObject callback(scope, argc > 2 ? argv[2] : Value::undefinedValue()); + + if (from_version != *r->d()->version) + V4THROW_SQL(SQLEXCEPTION_VERSION_ERR, QQmlEngine::tr("Version mismatch: expected %1, found %2").arg(from_version).arg(*r->d()->version)); + + bool ok = true; + if (!!callback) { + Scoped<QQmlSqlDatabaseWrapper> query(scope, QQmlSqlDatabaseWrapper::create(scope.engine)); + ScopedObject p(scope, databaseData(scope.engine)->queryProto.value()); + query->setPrototypeUnchecked(p.getPointer()); + query->d()->type = Heap::QQmlSqlDatabaseWrapper::Query; + *query->d()->database = db; + *query->d()->version = *r->d()->version; + + ok = false; + db.transaction(); + + JSCallData jsCall(scope, 1); + *jsCall->thisObject = scope.engine->globalObject; + jsCall->args[0] = query; + + TransactionRollback rollbackOnException(&db, &query->d()->inTransaction); + callback->call(jsCall); + rollbackOnException.clear(); + if (!db.commit()) { + db.rollback(); + V4THROW_SQL(SQLEXCEPTION_UNKNOWN_ERR,QQmlEngine::tr("SQL transaction failed")); + } else { + ok = true; + } + } + + if (ok) { + Scoped<QQmlSqlDatabaseWrapper> w(scope, QQmlSqlDatabaseWrapper::create(scope.engine)); + ScopedObject p(scope, databaseData(scope.engine)->databaseProto.value()); + w->setPrototypeUnchecked(p.getPointer()); + w->d()->type = Heap::QQmlSqlDatabaseWrapper::Database; + *w->d()->database = db; + *w->d()->version = to_version; +#if QT_CONFIG(settings) + const QQmlEnginePrivate *enginePrivate = QQmlEnginePrivate::get(scope.engine->qmlEngine()); + QSettings ini(enginePrivate->offlineStorageDatabaseDirectory() + db.connectionName() + QLatin1String(".ini"), QSettings::IniFormat); + ini.setValue(QLatin1String("Version"), to_version); +#endif + RETURN_RESULT(w.asReturnedValue()); + } + + RETURN_UNDEFINED(); +} + +static ReturnedValue qmlsqldatabase_transaction_shared(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc, bool readOnly) +{ + Scope scope(b); + QV4::Scoped<QQmlSqlDatabaseWrapper> r(scope, thisObject->as<QQmlSqlDatabaseWrapper>()); + if (!r || r->d()->type != Heap::QQmlSqlDatabaseWrapper::Database) + V4THROW_REFERENCE("Not a SQLDatabase object"); + + const FunctionObject *callback = argc ? argv[0].as<FunctionObject>() : nullptr; + if (!callback) + V4THROW_SQL(SQLEXCEPTION_UNKNOWN_ERR, QQmlEngine::tr("transaction: missing callback")); + + QSqlDatabase db = *r->d()->database; + + Scoped<QQmlSqlDatabaseWrapper> w(scope, QQmlSqlDatabaseWrapper::create(scope.engine)); + QV4::ScopedObject p(scope, databaseData(scope.engine)->queryProto.value()); + w->setPrototypeUnchecked(p.getPointer()); + w->d()->type = Heap::QQmlSqlDatabaseWrapper::Query; + *w->d()->database = db; + *w->d()->version = *r->d()->version; + w->d()->readonly = readOnly; + + db.transaction(); + if (callback) { + JSCallData jsCall(scope, 1); + *jsCall->thisObject = scope.engine->globalObject; + jsCall->args[0] = w; + TransactionRollback rollbackOnException(&db, &w->d()->inTransaction); + callback->call(jsCall); + rollbackOnException.clear(); + + if (!db.commit()) + db.rollback(); + } + + RETURN_UNDEFINED(); +} + +static ReturnedValue qmlsqldatabase_transaction(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc) +{ + return qmlsqldatabase_transaction_shared(f, thisObject, argv, argc, false); +} + +static ReturnedValue qmlsqldatabase_read_transaction(const FunctionObject *f, const Value *thisObject, const Value *argv, int argc) +{ + return qmlsqldatabase_transaction_shared(f, thisObject, argv, argc, true); +} + +QQmlSqlDatabaseData::QQmlSqlDatabaseData(ExecutionEngine *v4) +{ + Scope scope(v4); + { + ScopedObject proto(scope, v4->newObject()); + proto->defineDefaultProperty(QStringLiteral("transaction"), qmlsqldatabase_transaction); + proto->defineDefaultProperty(QStringLiteral("readTransaction"), qmlsqldatabase_read_transaction); + proto->defineAccessorProperty(QStringLiteral("version"), qmlsqldatabase_version, nullptr); + proto->defineDefaultProperty(QStringLiteral("changeVersion"), qmlsqldatabase_changeVersion); + databaseProto = proto; + } + + { + ScopedObject proto(scope, v4->newObject()); + proto->defineDefaultProperty(QStringLiteral("executeSql"), qmlsqldatabase_executeSql); + queryProto = proto; + } + { + ScopedObject proto(scope, v4->newObject()); + proto->defineDefaultProperty(QStringLiteral("item"), qmlsqldatabase_rows_item); + proto->defineAccessorProperty(QStringLiteral("length"), qmlsqldatabase_rows_length, nullptr); + proto->defineAccessorProperty(QStringLiteral("forwardOnly"), + qmlsqldatabase_rows_forwardOnly, qmlsqldatabase_rows_setForwardOnly); + rowsProto = proto; + } +} + +/* +HTML5 "spec" says "rs.rows[n]", but WebKit only impelments "rs.rows.item(n)". We do both (and property iterator). +We add a "forwardOnly" property that stops Qt caching results (code promises to only go forward +through the data. +*/ + + +/*! + \qmlmodule QtQuick.LocalStorage 2.\QtMinorVersion + \title Qt Quick Local Storage QML Types + \ingroup qmlmodules + \brief Provides a JavaScript object singleton type for accessing a local + SQLite database + + This is a singleton type for reading and writing to SQLite databases. + + + \section1 Methods + + \list + \li object \b{\l{#openDatabaseSync}{openDatabaseSync}}(string name, string version, string description, int estimated_size, jsobject callback(db)) + \endlist + + + \section1 Detailed Description + + To use the types in this module, import the module and call the + relevant functions using the \c LocalStorage type: + + \qml \QtMinorVersion + import QtQuick 2.\1 + import QtQuick.LocalStorage 2.\1 + + Item { + Component.onCompleted: { + var db = LocalStorage.openDatabaseSync(...) + } + } + \endqml + + +These databases are user-specific and QML-specific, but accessible to all QML applications. +They are stored in the \c Databases subdirectory +of QQmlEngine::offlineStoragePath(), currently as SQLite databases. + +Database connections are automatically closed during Javascript garbage collection. + +The API can be used from JavaScript functions in your QML: + +\snippet qml/localstorage/hello.qml 0 + +The API conforms to the Synchronous API of the HTML5 Web Database API, +\link http://www.w3.org/TR/2009/WD-webdatabase-20091029/ W3C Working Draft 29 October 2009\endlink. + +The \l{Qt Quick Examples - Local Storage}{SQL Local Storage example} demonstrates the basics of +using the Offline Storage API. + +\section3 Open or Create a Database + +\qml \QtMinorVersion +import QtQuick.LocalStorage 2.\1 as Sql + +db = Sql.openDatabaseSync(identifier, version, description, estimated_size, callback(db)) +\endqml + +The above code returns the database identified by \e identifier. If the database does not already exist, it +is created, and the function \e callback is called with the database as a parameter. \e identifier is the +name of the physical file (with or without full path) containing the database. \e description and +\e estimated_size are written to the INI file (described below), but are currently unused. + +May throw exception with code property SQLException.DATABASE_ERR, or SQLException.VERSION_ERR. + +When a database is first created, an INI file is also created specifying its characteristics: + +\table +\header \li \b {Key} \li \b {Value} +\row \li Identifier \li The name of the database passed to \c openDatabase() +\row \li Version \li The version of the database passed to \c openDatabase() +\row \li Description \li The description of the database passed to \c openDatabase() +\row \li EstimatedSize \li The estimated size (in bytes) of the database passed to \c openDatabase() +\row \li Driver \li Currently "QSQLITE" +\endtable + +This data can be used by application tools. + +\section3 db.changeVersion(from, to, callback(tx)) + +This method allows you to perform a \e{Scheme Upgrade}. If it succeeds it returns a new +database object of version \e to. Otherwise it returns \e undefined. + +If the current version of \e db is not \e from, then an exception is thrown. + +Otherwise, a database transaction is created and passed to \e callback. In this function, +you can call \e executeSql on \e tx to upgrade the database. + +May throw exception with code property SQLException.DATABASE_ERR or SQLException.UNKNOWN_ERR. + +See example below. + +\badcode + var db = LocalStorage.openDatabaseSync("ActivityTrackDB", "", "Database tracking sports activities", 1000000); + if (db.version == "0.1") { + db.changeVersion("0.1", "0.2", function(tx) { + tx.executeSql("INSERT INTO trip_log VALUES(?, ?, ?)", + [ "01/10/2016","Sylling - Vikersund", "53" ]); + } + }); +\endcode + +\section3 db.transaction(callback(tx)) + +This method creates a read/write transaction and passed to \e callback. In this function, +you can call \e executeSql on \e tx to read and modify the database. + +If the callback throws exceptions, the transaction is rolled back. +Below you will find an example of a database transaction which catches exceptions. + + +\quotefromfile localstorage/localstorage/Database.js +\skipuntil dbInit() +\printto dbGetHandle + +In the example you can see an \c insert statement where values are assigned to the fields, +and the record is written into the table. That is an \c insert statement with a syntax that is usual +for a relational database. It is however also possible to work with JSON objects and +store them in a table. + +Let's suppose a simple example where we store trips in JSON format using \c date as the unique key. +An example of a table that could be used for that purpose: + +\badcode + create table trip_log(date text, data text) +\endcode + +The assignment of values to a JSON object: + +\badcode + var obj = {description = "Vikersund - Noresund", distance = "60"} +\endcode + +In that case, the data could be saved in the following way: + +\badcode + db.transaction(function(tx) { + result = tx.executeSQL("insert into trip_log values (?,?)", + ["01/11/2016", JSON.stringify(obj)]) + +\endcode + +\section3 db.readTransaction(callback(tx)) + +This method creates a read-only transaction and passed to \e callback. In this function, +you can call \e executeSql on \e tx to read the database (with \c select statements). + +\section3 results = tx.executeSql(statement, values) + +This method executes an SQL \e statement, binding the list of \e values to SQL positional parameters ("?"). + +It returns a results object, with the following properties: + +\table +\header \li \b {Type} \li \b {Property} \li \b {Value} \li \b {Applicability} +\row \li int \li rows.length \li The number of rows in the result \li SELECT +\row \li var \li rows.item(i) \li Function that returns row \e i of the result \li SELECT +\row \li int \li rowsAffected \li The number of rows affected by a modification \li UPDATE, DELETE +\row \li string \li insertId \li The id of the row inserted \li INSERT +\endtable + +May throw exception with code property SQLException.DATABASE_ERR, SQLException.SYNTAX_ERR, or SQLException.UNKNOWN_ERR. + +See below for an example: + +\quotefromfile localstorage/localstorage/Database.js +\skipto dbReadAll() +\printto dbUpdate(Pdate + +\section1 Method Documentation + +\target openDatabaseSync +\code +object openDatabaseSync(string name, string version, string description, int estimated_size, jsobject callback(db)) +\endcode + +Opens or creates a local storage sql database by the given parameters. + +\list +\li \c name is the database name +\li \c version is the database version +\li \c description is the database display name +\li \c estimated_size is the database's estimated size, in bytes +\li \c callback is an optional parameter, which is invoked if the database has not yet been created. +\endlist + +Returns the created database object. + +*/ + +void QQuickLocalStorage::openDatabaseSync(QQmlV4Function *args) +{ +#if QT_CONFIG(settings) + QV4::Scope scope(args->v4engine()); + if (scope.engine->qmlEngine()->offlineStoragePath().isEmpty()) + V4THROW_SQL2(SQLEXCEPTION_DATABASE_ERR, QQmlEngine::tr("SQL: can't create database, offline storage is disabled.")); + + QV4::ScopedValue v(scope); + QString dbname = (v = (*args)[0])->toQStringNoThrow(); + QString dbversion = (v = (*args)[1])->toQStringNoThrow(); + QString dbdescription = (v = (*args)[2])->toQStringNoThrow(); + int dbestimatedsize = (v = (*args)[3])->toInt32(); + FunctionObject *dbcreationCallback = (v = (*args)[4])->as<FunctionObject>(); + QString basename = args->v4engine()->qmlEngine()->offlineStorageDatabaseFilePath(dbname); + QFileInfo dbFile(basename); + if (!QDir().mkpath(dbFile.dir().absolutePath())) { + const QString message = QQmlEngine::tr("LocalStorage: can't create path %1"). + arg(QDir::toNativeSeparators(dbFile.dir().absolutePath())); + V4THROW_SQL2(SQLEXCEPTION_DATABASE_ERR, message); + } + QString dbid = dbFile.fileName(); + bool created = false; + QString version = dbversion; + QSqlDatabase database; + + { + QSettings ini(basename+QLatin1String(".ini"),QSettings::IniFormat); + + if (QSqlDatabase::connectionNames().contains(dbid)) { + database = QSqlDatabase::database(dbid); + version = ini.value(QLatin1String("Version")).toString(); + if (version != dbversion && !dbversion.isEmpty() && !version.isEmpty()) + V4THROW_SQL2(SQLEXCEPTION_VERSION_ERR, QQmlEngine::tr("SQL: database version mismatch")); + } else { + created = !QFile::exists(basename+QLatin1String(".sqlite")); + if (created) { + ini.setValue(QLatin1String("Name"), dbname); + if (dbcreationCallback) + version = QString(); + ini.setValue(QLatin1String("Version"), version); + ini.setValue(QLatin1String("Description"), dbdescription); + ini.setValue(QLatin1String("EstimatedSize"), dbestimatedsize); + ini.setValue(QLatin1String("Driver"), QLatin1String("QSQLITE")); + } else { + if (!dbversion.isEmpty() && ini.value(QLatin1String("Version")) != dbversion) { + // Incompatible + V4THROW_SQL2(SQLEXCEPTION_VERSION_ERR,QQmlEngine::tr("SQL: database version mismatch")); + } + version = ini.value(QLatin1String("Version")).toString(); + } + database = QSqlDatabase::addDatabase(QLatin1String("QSQLITE"), dbid); + database.setDatabaseName(basename+QLatin1String(".sqlite")); + } + if (!database.isOpen()) + database.open(); + } + + QV4::Scoped<QQmlSqlDatabaseWrapper> db(scope, QQmlSqlDatabaseWrapper::create(scope.engine)); + QV4::ScopedObject p(scope, databaseData(scope.engine)->databaseProto.value()); + db->setPrototypeUnchecked(p.getPointer()); + *db->d()->database = database; + *db->d()->version = version; + + if (created && dbcreationCallback) { + JSCallData jsCall(scope, 1); + *jsCall->thisObject = scope.engine->globalObject; + jsCall->args[0] = db; + dbcreationCallback->call(jsCall); + } + + args->setReturnValue(db.asReturnedValue()); +#else + Q_UNUSED(args) +#endif // settings +} + +QT_END_NAMESPACE |