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Diffstat (limited to 'forms/source/xforms/computedexpression.cxx')
| -rw-r--r-- | forms/source/xforms/computedexpression.cxx | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/forms/source/xforms/computedexpression.cxx b/forms/source/xforms/computedexpression.cxx new file mode 100644 index 000000000..633492335 --- /dev/null +++ b/forms/source/xforms/computedexpression.cxx @@ -0,0 +1,184 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + + +#include "computedexpression.hxx" +#include "evaluationcontext.hxx" + +#include <com/sun/star/uno/Sequence.hxx> +#include <com/sun/star/xml/xpath/XPathAPI.hpp> +#include <com/sun/star/xml/xpath/XPathExtension.hpp> +#include <com/sun/star/util/SearchAlgorithms2.hpp> + +#include <osl/diagnose.h> + +#include <i18nutil/searchopt.hxx> +#include <unotools/textsearch.hxx> +#include <comphelper/processfactory.hxx> + +using namespace com::sun::star::uno; +using com::sun::star::xml::xpath::XPathAPI; +using com::sun::star::xml::xpath::XXPathAPI; +using com::sun::star::xml::xpath::XPathExtension; +using com::sun::star::xml::xpath::XXPathExtension; +using com::sun::star::xml::xpath::XPathObjectType_XPATH_UNDEFINED; + + +namespace xforms +{ + +ComputedExpression::ComputedExpression() + : msExpression(), + mbIsEmpty( true ), + mbIsSimple( true ), + mxResult() +{ +} + +ComputedExpression::~ComputedExpression() +{ +} + + +void ComputedExpression::setExpression( const OUString& rExpression ) +{ + // set new expression, and clear pre-computed results + msExpression = rExpression; + mbIsEmpty = _checkExpression( " *" ); + mbIsSimple = false; + mxResult.clear(); +} + + +bool ComputedExpression::_checkExpression( const char* pExpression ) const +{ + assert(pExpression && "no expression?"); + + // call RegExp engine + i18nutil::SearchOptions2 aSearchOptions; + aSearchOptions.AlgorithmType2 = css::util::SearchAlgorithms2::REGEXP; + aSearchOptions.searchString = OUString( pExpression, strlen(pExpression), RTL_TEXTENCODING_ASCII_US ); + utl::TextSearch aTextSearch( aSearchOptions ); + + sal_Int32 nLength = msExpression.getLength(); + sal_Int32 nStart = 0; + sal_Int32 nEnd = nLength; + bool bSearch = aTextSearch.SearchForward( msExpression, &nStart, &nEnd ); + + // our expression is static only if 1) we found our regexp, and 2) + // the regexp goes from beginning to end. + return ( nLength == 0 || bSearch ) + && ( nStart == 0 && nEnd == nLength ); +} + +bool ComputedExpression::isSimpleExpression() const +{ + // actual work is done by setExpression + return mbIsEmpty || mbIsSimple; +} + + +bool ComputedExpression::_evaluate( + const xforms::EvaluationContext& rContext, + const OUString& sExpression ) +{ + OSL_ENSURE( rContext.mxContextNode.is(), "no context node in context" ); + + // obtain value by evaluating XPath expression + mxResult.clear(); + try + { + mxResult = _getXPathAPI(rContext)->eval( rContext.mxContextNode, + sExpression ); + } + catch( const Exception& ) + { + ; // ignore exception -> mxResult will be empty + } + + return hasValue(); +} + +bool ComputedExpression::evaluate( const EvaluationContext& rContext ) +{ + // for simple expression we don't need to re-evaluate (if we have + // an older result); neither for empty expressions + if( mbIsEmpty || (mxResult.is() && mbIsSimple) ) + return true; + + return _evaluate( rContext, _getExpressionForEvaluation() ); +} + + +bool ComputedExpression::hasValue() const +{ + return mxResult.is() && + mxResult->getObjectType() != XPathObjectType_XPATH_UNDEFINED; +} + +void ComputedExpression::clear() +{ + mxResult.clear(); +} + + +OUString ComputedExpression::getString() const +{ + return mxResult.is() ? mxResult->getString() : OUString(); +} + +bool ComputedExpression::getBool( bool bDefault ) const +{ + return mxResult.is() ? mxResult->getBoolean() : bDefault; +} + + +Reference<XXPathAPI> ComputedExpression::_getXPathAPI(const xforms::EvaluationContext& aContext) +{ + // create XPath API, then register namespaces + Reference<XXPathAPI> xXPath( XPathAPI::create( comphelper::getProcessComponentContext() ) ); + + // register xforms extension# + Reference< XComponentContext > aComponentContext = comphelper::getProcessComponentContext(); + Reference< XXPathExtension > aExtension = XPathExtension::createWithModel(aComponentContext, aContext.mxModel, aContext.mxContextNode); + xXPath->registerExtensionInstance(aExtension); + + // register namespaces + if( aContext.mxNamespaces.is() ) + { + Sequence<OUString> aPrefixes =aContext.mxNamespaces->getElementNames(); + sal_Int32 nCount = aPrefixes.getLength(); + const OUString* pPrefixes = aPrefixes.getConstArray(); + for( sal_Int32 i = 0; i < nCount; i++ ) + { + const OUString* pNamePrefix = &pPrefixes[i]; + OUString sNameURL; + aContext.mxNamespaces->getByName( *pNamePrefix ) >>= sNameURL; + xXPath->registerNS( *pNamePrefix, sNameURL ); + } + } + + // done, so return xXPath-object + return xXPath; +} + + +} // namespace xforms + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |