XMLUtilities.h

//
//  Copyright (C) 2017, Alexander Stukowski and Paul Erhart
//
//  This file is part of atomicrex.
//
//  Atomicrex is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 3 of the License, or
//  (at your option) any later version.
//
//  Atomicrex is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
//

#pragma once

#include "../../Atomicrex.h"

#include <libxml/tree.h>
#include <libxml/parser.h>
#include <libxml/xinclude.h>
#include <libxml/xmlschemastypes.h>
#ifndef LIBXML_XINCLUDE_ENABLED
    #error "Program requires libxml2 with XInclude support."
#endif
#ifndef LIBXML_SCHEMAS_ENABLED
    #error "Program requires libxml2 with XSD Schema support."
#endif

namespace atomicrex {
namespace XML {

struct Context {
    Context() {
        ::xmlInitParser();
        LIBXML_TEST_VERSION
    }
    ~Context() {
        ::xmlCleanupParser();
    }
};

template<class T, class D>
static std::unique_ptr<T, D> make_scoped(T* const ptr, D deleter) {
    return std::unique_ptr<T, D>(ptr, deleter);
}

inline FPString toFPString(const xmlChar* s) { return (const char*)s; }

class OElement;     // Defined below.

class Element
{
public:

    Element(xmlNodePtr e = nullptr) : _el(e) {}

    FPString textContent() const;

    int parseIntParameterElement(const char* tagName) const;

    int parseOptionalIntParameterElement(const char* tagName, int defaultValue) const;

    double parseFloatParameterElement(const char* tagName) const;

    double parseOptionalFloatParameterElement(const char* tagName, double defaultValue) const;

    FPString parseStringParameterElement(const char* tagName) const;

    FPString parseOptionalStringParameterElement(const char* tagName, const FPString& defaultValue = FPString()) const;

    FPString parsePathParameterElement(const char* tagName) const;

    FPString parseOptionalPathParameterElement(const char* tagName, const FPString& defaultValue = FPString()) const;

    double parseFloatParameterAttribute(const char* attributeName) const;

    double parseOptionalFloatParameterAttribute(const char* attributeName, double defaultValue) const;

    int parseIntParameterAttribute(const char* attributeName) const;

    int parseOptionalIntParameterAttribute(const char* attributeName, int defaultValue) const;

    FPString parseStringParameterAttribute(const char* attributeName) const;

    FPString parseOptionalStringParameterAttribute(const char* attributeName, const FPString& defaultValue = FPString()) const;

    FPString parsePathParameterAttribute(const char* attributeName) const;

    bool parseBooleanParameterAttribute(const char* attributeName) const;

    bool parseOptionalBooleanParameterAttribute(const char* attributeName, bool defaultValue) const;

    Element firstChildElement() const;

    Element firstChildElement(const char* tagName) const;

    Element expectChildElement(const char* tagName) const;

    explicit operator bool() const noexcept { return _el != nullptr; }

    bool tagEquals(const char* tagName) const;

    void expectTag(const char* tagName) const;

    bool hasAttribute(const char* attrName) const;

    int lineNumber() const;

    Element nextSibling() const;

    Element nextSibling(const char* tagName) const;

    const char* tag() const { return (const char*)_el->name; }

    explicit operator xmlNodePtr() const noexcept { return _el; }

    Element createIntParameterElement(const char* tagName, int value);

    Element createFloatParameterElement(const char* tagName, double value);

    Element createStringParameterElement(const char* tagName, const FPString& value);

    int attributeCount() const;

    void appendChild(OElement& element);

    void appendChild(OElement&& element);

    void setAttribute(const char* attr, const FPString& value);

    void setTagName(const FPString& tagName);

    void setTextContent(const FPString& text);

protected:

    FPString resolveFilename(const FPString& filename) const;

    xmlNodePtr _el;
};

class OElement : public std::unique_ptr<xmlNode, void(*)(xmlNodePtr)>, public Element
{
public:

    OElement() : std::unique_ptr<xmlNode, void(*)(xmlNodePtr)>(nullptr, xmlFreeNode) {}

    OElement(const char* name);

    explicit operator bool() const noexcept { return _el != nullptr; }
};

} // End of namespace
} // End of namespace