OptionsLoader.h

/****************************************************************************/
// Eclipse SUMO, Simulation of Urban MObility; see https://eclipse.dev/sumo
// Copyright (C) 2001-2025 German Aerospace Center (DLR) and others.
// This program and the accompanying materials are made available under the
// terms of the Eclipse Public License 2.0 which is available at
// https://www.eclipse.org/legal/epl-2.0/
// This Source Code may also be made available under the following Secondary
// Licenses when the conditions for such availability set forth in the Eclipse
// Public License 2.0 are satisfied: GNU General Public License, version 2
// or later which is available at
// https://www.gnu.org/licenses/old-licenses/gpl-2.0-standalone.html
// SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
/****************************************************************************/
/// @file    OptionsLoader.h
/// @author  Daniel Krajzewicz
/// @author  Michael Behrisch
/// @date    Mon, 17 Dec 2001
///
// A SAX-Handler for loading options
/****************************************************************************/
#pragma once
#include <config.h>

#include <xercesc/sax/HandlerBase.hpp>
#include <xercesc/sax/AttributeList.hpp>
#include <xercesc/sax/SAXParseException.hpp>
#include <xercesc/sax/SAXException.hpp>
#include <string>


// ===========================================================================
// class declarations
// ===========================================================================

class OptionsCont;

// ===========================================================================
// class definitions
// ===========================================================================
/**
 * @class OptionsLoader
 * @brief A SAX-Handler for loading options
 */
class OptionsLoader : public XERCES_CPP_NAMESPACE::HandlerBase {

public:
    /// @brief Constructor for default option container
    OptionsLoader(OptionsCont& customOptions, const bool routeOnly = false);

    /// @brief destructor
    ~OptionsLoader();

    /// @name Handlers for the SAX DocumentHandler interface
    /// @{

    /** @brief Called on the occurrence of the beginning of a tag
     *
     * Sets the name of the last item
     */
    virtual void startElement(const XMLCh* const name,
                              XERCES_CPP_NAMESPACE::AttributeList& attributes);

    /** @brief Called on the occurrence of character data
     *
     * If this occurs inside a single tag it sets the option named
     *  by the tag to the value given by the character data.
     *  This is considered deprecated in favor of attributes.
     * @todo Describe better
     */
    void characters(const XMLCh* const chars, const XERCES3_SIZE_t length);

    /** @brief Called on the end of an element
     *
     * Resets the element name
     */
    void endElement(const XMLCh* const name);

    /// @}

    /// @name Handlers for the SAX ErrorHandler interface
    /// @{

    /** @brief Called on an XML-warning
     *
     * The warning is reported to the warning-instance of MsgHandler
     */
    void warning(const XERCES_CPP_NAMESPACE::SAXParseException& exception);

    /** @brief Called on an XML-error
     *
     * The warning is reported to the error-instance of MsgHandler
     */
    void error(const XERCES_CPP_NAMESPACE::SAXParseException& exception);

    /** @brief Called on an XML-fatal error
     *
     * The warning is reported to the error-instance of MsgHandler
     */
    void fatalError(const XERCES_CPP_NAMESPACE::SAXParseException& exception);
    /// @}

    /// @brief Returns the information whether an error occurred
    bool errorOccurred() const;

    /// @brief Returns the last item read
    const std::string& getItem() const {
        return myItem;
    }

private:
    /// @brief The information whether only the root element should be parsed
    const bool myRootOnly;

    /// @brief The information whether an error occurred
    bool myError = false;

    /// @brief The options to fill
    OptionsCont& myOptions;

    /// @brief The name of the currently parsed option
    std::string myItem;

    /// @brief The currently read characters string
    std::string myValue;

    /// @brief Whether a value attribute was read
    bool myFoundValue;

    /** @brief Tries to set the named option to the given value
     *
     * Also evaluates whether it is a boolean or a filename option and
     *  does the relevant checks / modifications.
     *
     * @param[in] key The name of the option to set
     * @param[in] value The new value for the option
     */
    void setValue(const std::string& key, const std::string& value);

    /** @brief Tries to set the named option to the given value
     *
     * Checks the item whether it was default before setting it.
     * Returns the information whether the item was set before (was not a default value)
     *
     * @param[in] name The name of the option to set
     * @param[in] value The new value for the option
     * @return Whether the option could be set
     */
    bool setSecure(OptionsCont& options, const std::string& name, const std::string& value) const;

    /// @brief invalid copy constructor
    OptionsLoader(const OptionsLoader& s) = delete;

    /// @brief invalid assignment operator
    OptionsLoader& operator=(const OptionsLoader& s) = delete;
};