include/assimp/XmlParser.h

/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

Copyright (c) 2006-2021, assimp team

All rights reserved.

Redistribution and use of this software in source and binary forms,
with or without modification, are permitted provided that the
following conditions are met:

* Redistributions of source code must retain the above
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following disclaimer.

* Redistributions in binary form must reproduce the above
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following disclaimer in the documentation and/or other
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* Neither the name of the assimp team, nor the names of its
contributors may be used to endorse or promote products
derived from this software without specific prior
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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*/

#ifndef INCLUDED_AI_IRRXML_WRAPPER
#define INCLUDED_AI_IRRXML_WRAPPER

#include <assimp/ai_assert.h>
#include <assimp/DefaultLogger.hpp>

#include "BaseImporter.h"
#include "IOStream.hpp"

#include <pugixml.hpp>
#include <vector>

namespace Assimp {

/// @brief  Will find a node by its name.
struct find_node_by_name_predicate {
    std::string mName;
    find_node_by_name_predicate(const std::string &name) :
            mName(name) {
        // empty
    }

    bool operator()(pugi::xml_node node) const {
        return node.name() == mName;
    }
};

/// @brief  Will convert an attribute to its int value.
/// @tparam TNodeType The node type.
template <class TNodeType>
struct NodeConverter {
public:
    static int to_int(TNodeType &node, const char *attribName) {
        ai_assert(nullptr != attribName);
        return node.attribute(attribName).to_int();
    }
};

using XmlNode = pugi::xml_node;
using XmlAttribute = pugi::xml_attribute;

/// @brief The Xml-Parser class.
///
/// Use this parser if you have to import any kind of xml-format.
///
/// An example:
/// @code
/// TXmlParser<XmlNode> theParser;
/// if (theParser.parse(fileStream)) {
///     auto node = theParser.getRootNode();
///     for ( auto currentNode : node.children()) {
///         // Will loop over all children
///     }
/// }
/// @endcode
/// @tparam TNodeType
template <class TNodeType>
class TXmlParser {
public:
    /// @brief The default class constructor.
    TXmlParser() :
            mDoc(nullptr),
            mData() {
        // empty
    }

    ///	@brief  The class destructor.
    ~TXmlParser() {
        clear();
    }

    ///	@brief  Will clear the parsed xml-file.
    void clear() {
        if (mData.empty()) {
            mDoc = nullptr;
            return;
        }
        mData.clear();
        delete mDoc;
        mDoc = nullptr;
    }

    ///	@brief  Will search for a child-node by its name
    /// @param  name     [in] The name of the child-node.
    /// @return The node instance or nullptr, if nothing was found.
    TNodeType *findNode(const std::string &name) {
        if (name.empty()) {
            return nullptr;
        }

        if (nullptr == mDoc) {
            return nullptr;
        }

        find_node_by_name_predicate predicate(name);
        mCurrent = mDoc->find_node(predicate);
        if (mCurrent.empty()) {
            return nullptr;
        }

        return &mCurrent;
    }

    /// @brief  Will return true, if the node is a child-node.
    /// @param  name    [in] The name of the child node to look for.
    /// @return true, if the node is a child-node or false if not.
    bool hasNode(const std::string &name) {
        return nullptr != findNode(name);
    }

    /// @brief  Will parse an xml-file from a given stream.
    /// @param  stream      The input stream.
    /// @return true, if the parsing was successful, false if not.
    bool parse(IOStream *stream) {
        if (nullptr == stream) {
            ASSIMP_LOG_DEBUG("Stream is nullptr.");
            return false;
        }

        const size_t len = stream->FileSize();
        mData.resize(len + 1);
        memset(&mData[0], '\0', len + 1);
        stream->Read(&mData[0], 1, len);

        mDoc = new pugi::xml_document();
        pugi::xml_parse_result parse_result = mDoc->load_string(&mData[0], pugi::parse_full);
        if (parse_result.status == pugi::status_ok) {
            return true;
        }

        ASSIMP_LOG_DEBUG("Error while parse xml.", std::string(parse_result.description()), " @ ", parse_result.offset);

        return false;
    }

    /// @brief  Will return truem if a root node is there.
    /// @return true in case of an existing root.
    bool hasRoot() const {
        return nullptr != mDoc;
    }
    /// @brief  Will return the document pointer, is nullptr if no xml-file was parsed.
    /// @return The pointer showing to the document.
    pugi::xml_document *getDocument() const {
        return mDoc;
    }

    /// @brief  Will return the root node, const version.
    /// @return The root node.
    const TNodeType getRootNode() const {
        static pugi::xml_node none;
        if (nullptr == mDoc) {
            return none;
        }
        return mDoc->root();
    }

    /// @brief  Will return the root node, non-const version.
    /// @return The root node.
    TNodeType getRootNode() {
        static pugi::xml_node none;
        if (nullptr == mDoc) {
            return none;
        }
        return mDoc->root();
    }

    /// @brief Will check if a node with the given name is in.
    /// @param node     [in] The node to look in.
    /// @param name     [in] The name of the child-node.
    /// @return true, if node was found, false if not.
    static inline bool hasNode(XmlNode &node, const char *name) {
        pugi::xml_node child = node.find_child(find_node_by_name_predicate(name));
        return !child.empty();
    }

    /// @brief Will check if an attribute is part of the XmlNode.
    /// @param xmlNode  [in] The node to search in.
    /// @param name     [in} The attribute name to look for.
    /// @return true, if the was found, false if not.
    static inline bool hasAttribute(XmlNode &xmlNode, const char *name) {
        pugi::xml_attribute attr = xmlNode.attribute(name);
        return !attr.empty();
    }

    /// @brief Will try to get an unsigned int attribute value.
    /// @param xmlNode  [in] The node to search in.
    /// @param name     [in] The attribute name to look for.
    /// @param val      [out] The unsigned int value from the attribute.
    /// @return true, if the node contains an attribute with the given name and if the value is an unsigned int.
    static inline bool getUIntAttribute(XmlNode &xmlNode, const char *name, unsigned int &val) {
        pugi::xml_attribute attr = xmlNode.attribute(name);
        if (attr.empty()) {
            return false;
        }

        val = attr.as_uint();
        return true;
    }

    /// @brief Will try to get an int attribute value.
    /// @param xmlNode  [in] The node to search in.
    /// @param name     [in] The attribute name to look for.
    /// @param val      [out] The int value from the attribute.
    /// @return true, if the node contains an attribute with the given name and if the value is an int.
    static inline bool getIntAttribute(XmlNode &xmlNode, const char *name, int &val) {
        pugi::xml_attribute attr = xmlNode.attribute(name);
        if (attr.empty()) {
            return false;
        }

        val = attr.as_int();
        return true;
    }

    /// @brief Will try to get a real attribute value.
    /// @param xmlNode  [in] The node to search in.
    /// @param name     [in] The attribute name to look for.
    /// @param val      [out] The real value from the attribute.
    /// @return true, if the node contains an attribute with the given name and if the value is a real.
    static inline bool getRealAttribute(XmlNode &xmlNode, const char *name, ai_real &val) {
        pugi::xml_attribute attr = xmlNode.attribute(name);
        if (attr.empty()) {
            return false;
        }
#ifdef ASSIMP_DOUBLE_PRECISION
        val = attr.as_double();
#else
        val = attr.as_float();
#endif
        return true;
    }

    /// @brief Will try to get a float attribute value.
    /// @param xmlNode  [in] The node to search in.
    /// @param name     [in] The attribute name to look for.
    /// @param val      [out] The float value from the attribute.
    /// @return true, if the node contains an attribute with the given name and if the value is a float.
    static inline bool getFloatAttribute(XmlNode &xmlNode, const char *name, float &val) {
        pugi::xml_attribute attr = xmlNode.attribute(name);
        if (attr.empty()) {
            return false;
        }

        val = attr.as_float();
        return true;
    }

    /// @brief Will try to get a double attribute value.
    /// @param xmlNode  [in] The node to search in.
    /// @param name     [in] The attribute name to look for.
    /// @param val      [out] The double value from the attribute.
    /// @return true, if the node contains an attribute with the given name and if the value is a double.
    static inline bool getDoubleAttribute(XmlNode &xmlNode, const char *name, double &val) {
        pugi::xml_attribute attr = xmlNode.attribute(name);
        if (attr.empty()) {
            return false;
        }

        val = attr.as_double();
        return true;
    }

    /// @brief Will try to get a std::string attribute value.
    /// @param xmlNode  [in] The node to search in.
    /// @param name     [in] The attribute name to look for.
    /// @param val      [out] The std::string value from the attribute.
    /// @return true, if the node contains an attribute with the given name and if the value is a std::string.
    static inline bool getStdStrAttribute(XmlNode &xmlNode, const char *name, std::string &val) {
        pugi::xml_attribute attr = xmlNode.attribute(name);
        if (attr.empty()) {
            return false;
        }

        val = attr.as_string();
        return true;
    }

    /// @brief Will try to get a bool attribute value.
    /// @param xmlNode  [in] The node to search in.
    /// @param name     [in] The attribute name to look for.
    /// @param val      [out] The bool value from the attribute.
    /// @return true, if the node contains an attribute with the given name and if the value is a bool.
    static inline bool getBoolAttribute(XmlNode &xmlNode, const char *name, bool &val) {
        pugi::xml_attribute attr = xmlNode.attribute(name);
        if (attr.empty()) {
            return false;
        }

        val = attr.as_bool();
        return true;
    }

    /// @brief Will try to get the value of the node as a string.
    /// @param node     [in] The node to search in.
    /// @param text     [out] The value as a text.
    /// @return true, if the value can be read out.
    static inline bool getValueAsString(XmlNode &node, std::string &text) {
        text = std::string();
        if (node.empty()) {
            return false;
        }

        text = node.text().as_string();

        return true;
    }

    /// @brief Will try to get the value of the node as a float.
    /// @param node     [in] The node to search in.
    /// @param text     [out] The value as a float.
    /// @return true, if the value can be read out.
    static inline bool getValueAsFloat(XmlNode &node, ai_real &v) {
        if (node.empty()) {
            return false;
        }

        v = node.text().as_float();

        return true;
    }

    /// @brief Will try to get the value of the node as an integer.
    /// @param node     [in] The node to search in.
    /// @param text     [out] The value as a int.
    /// @return true, if the value can be read out.
    static inline bool getValueAsInt(XmlNode &node, int &v) {
        if (node.empty()) {
            return false;
        }

        v = node.text().as_int();

        return true;
    }

    /// @brief Will try to get the value of the node as an bool.
    /// @param node     [in] The node to search in.
    /// @param text     [out] The value as a bool.
    /// @return true, if the value can be read out.
    static inline bool getValueAsBool(XmlNode& node, bool& v)
    {
        if (node.empty()) {
            return false;
        }

        v = node.text().as_bool();

        return true;
    }

private:
    pugi::xml_document *mDoc;
    TNodeType mCurrent;
    std::vector<char> mData;
};

using XmlParser = TXmlParser<pugi::xml_node>;

///	@brief  This class declares an iterator to loop through all children of the root node.
class XmlNodeIterator {
public:
    /// @brief The iteration mode.
    enum IterationMode {
        PreOrderMode, ///< Pre-ordering, get the values, continue the iteration.
        PostOrderMode ///< Post-ordering, continue the iteration, get the values.
    };
    ///	@brief  The class constructor
    /// @param  parent      [in] The xml parent to to iterate through.
    /// @param  mode        [in] The iteration mode.
    explicit XmlNodeIterator(XmlNode &parent, IterationMode mode) :
            mParent(parent),
            mNodes(),
            mIndex(0) {
        if (mode == PreOrderMode) {
            collectChildrenPreOrder(parent);
        } else {
            collectChildrenPostOrder(parent);
        }
    }

    ///	@brief  The class destructor.
    ~XmlNodeIterator() {
        // empty
    }

    ///	@brief  Will iterate through all children in pre-order iteration.
    /// @param  node    [in] The nod to iterate through.
    void collectChildrenPreOrder(XmlNode &node) {
        if (node != mParent && node.type() == pugi::node_element) {
            mNodes.push_back(node);
        }
        for (XmlNode currentNode : node.children()) {
            collectChildrenPreOrder(currentNode);
        }
    }

    ///	@brief  Will iterate through all children in post-order iteration.
    /// @param  node    [in] The nod to iterate through.
    void collectChildrenPostOrder(XmlNode &node) {
        for (XmlNode currentNode = node.first_child(); currentNode; currentNode = currentNode.next_sibling()) {
            collectChildrenPostOrder(currentNode);
        }
        if (node != mParent) {
            mNodes.push_back(node);
        }
    }

    ///	@brief  Will iterate through all collected nodes.
    /// @param  next    The next node, if there is any.
    /// @return true, if there is a node left.
    bool getNext(XmlNode &next) {
        if (mIndex == mNodes.size()) {
            return false;
        }

        next = mNodes[mIndex];
        ++mIndex;

        return true;
    }

    ///	@brief  Will return the number of collected nodes.
    /// @return The number of collected nodes.
    size_t size() const {
        return mNodes.size();
    }

    ///	@brief  Returns true, if the node is empty.
    /// @return true, if the node is empty, false if not.
    bool isEmpty() const {
        return mNodes.empty();
    }

    ///	@brief  Will clear all collected nodes.
    void clear() {
        if (mNodes.empty()) {
            return;
        }

        mNodes.clear();
        mIndex = 0;
    }

private:
    XmlNode &mParent;
    std::vector<XmlNode> mNodes;
    size_t mIndex;
};

} // namespace Assimp

#endif // !! INCLUDED_AI_IRRXML_WRAPPER