rippled/modules/beast_core/xml/XmlElement.cpp

//------------------------------------------------------------------------------
/*
    This file is part of Beast: https://github.com/vinniefalco/Beast
    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>

    Portions of this file are from JUCE.
    Copyright (c) 2013 - Raw Material Software Ltd.
    Please visit http://www.juce.com

    Permission to use, copy, modify, and/or distribute this software for any
    purpose  with  or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.

    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================

XmlElement::XmlAttributeNode::XmlAttributeNode (const XmlAttributeNode& other) noexcept
    : name (other.name),
      value (other.value)
{
}

XmlElement::XmlAttributeNode::XmlAttributeNode (const String& n, const String& v) noexcept
    : name (n), value (v)
{
   #if BEAST_DEBUG
    // this checks whether the attribute name string contains any illegal characters..
    for (String::CharPointerType t (name.getCharPointer()); ! t.isEmpty(); ++t)
        bassert (t.isLetterOrDigit() || *t == '_' || *t == '-' || *t == ':');
   #endif
}

inline bool XmlElement::XmlAttributeNode::hasName (const String& nameToMatch) const noexcept
{
    return name.equalsIgnoreCase (nameToMatch);
}

//==============================================================================
XmlElement::XmlElement (const String& tag) noexcept
    : tagName (tag)
{
    // the tag name mustn't be empty, or it'll look like a text element!
    bassert (tag.containsNonWhitespaceChars())

    // The tag can't contain spaces or other characters that would create invalid XML!
    bassert (! tag.containsAnyOf (" <>/&"));
}

XmlElement::XmlElement (int /*dummy*/) noexcept
{
}

XmlElement::XmlElement (const XmlElement& other)
    : tagName (other.tagName)
{
    copyChildrenAndAttributesFrom (other);
}

XmlElement& XmlElement::operator= (const XmlElement& other)
{
    if (this != &other)
    {
        removeAllAttributes();
        deleteAllChildElements();

        tagName = other.tagName;

        copyChildrenAndAttributesFrom (other);
    }

    return *this;
}

#if BEAST_COMPILER_SUPPORTS_MOVE_SEMANTICS
XmlElement::XmlElement (XmlElement&& other) noexcept
    : nextListItem      (static_cast <LinkedListPointer <XmlElement>&&> (other.nextListItem)),
      firstChildElement (static_cast <LinkedListPointer <XmlElement>&&> (other.firstChildElement)),
      attributes        (static_cast <LinkedListPointer <XmlAttributeNode>&&> (other.attributes)),
      tagName           (static_cast <String&&> (other.tagName))
{
}

XmlElement& XmlElement::operator= (XmlElement&& other) noexcept
{
    bassert (this != &other); // hopefully the compiler should make this situation impossible!

    removeAllAttributes();
    deleteAllChildElements();

    nextListItem      = static_cast <LinkedListPointer <XmlElement>&&> (other.nextListItem);
    firstChildElement = static_cast <LinkedListPointer <XmlElement>&&> (other.firstChildElement);
    attributes        = static_cast <LinkedListPointer <XmlAttributeNode>&&> (other.attributes);
    tagName           = static_cast <String&&> (other.tagName);

    return *this;
}
#endif

void XmlElement::copyChildrenAndAttributesFrom (const XmlElement& other)
{
    bassert (firstChildElement.get() == nullptr);
    firstChildElement.addCopyOfList (other.firstChildElement);

    bassert (attributes.get() == nullptr);
    attributes.addCopyOfList (other.attributes);
}

XmlElement::~XmlElement() noexcept
{
    firstChildElement.deleteAll();
    attributes.deleteAll();
}

//==============================================================================
namespace XmlOutputFunctions
{
   #if 0 // (These functions are just used to generate the lookup table used below)
    bool isLegalXmlCharSlow (const beast_wchar character) noexcept
    {
        if ((character >= 'a' && character <= 'z')
             || (character >= 'A' && character <= 'Z')
                || (character >= '0' && character <= '9'))
            return true;

        const char* t = " .,;:-()_+=?!'#@[]/\\*%~{}$|";

        do
        {
            if (((beast_wchar) (uint8) *t) == character)
                return true;
        }
        while (*++t != 0);

        return false;
    }

    void generateLegalCharLookupTable()
    {
        uint8 n[32] = { 0 };
        for (int i = 0; i < 256; ++i)
            if (isLegalXmlCharSlow (i))
                n[i >> 3] |= (1 << (i & 7));

        String s;
        for (int i = 0; i < 32; ++i)
            s << (int) n[i] << ", ";

        DBG (s);
    }
   #endif

    static bool isLegalXmlChar (const uint32 c) noexcept
    {
        static const unsigned char legalChars[] = { 0, 0, 0, 0, 187, 255, 255, 175, 255, 255, 255, 191, 254, 255, 255, 127 };

        return c < sizeof (legalChars) * 8
                 && (legalChars [c >> 3] & (1 << (c & 7))) != 0;
    }

    static void escapeIllegalXmlChars (OutputStream& outputStream, const String& text, const bool changeNewLines)
    {
        String::CharPointerType t (text.getCharPointer());

        for (;;)
        {
            const uint32 character = (uint32) t.getAndAdvance();

            if (character == 0)
                break;

            if (isLegalXmlChar (character))
            {
                outputStream << (char) character;
            }
            else
            {
                switch (character)
                {
                case '&':   outputStream << "&amp;"; break;
                case '"':   outputStream << "&quot;"; break;
                case '>':   outputStream << "&gt;"; break;
                case '<':   outputStream << "&lt;"; break;

                case '\n':
                case '\r':
                    if (! changeNewLines)
                    {
                        outputStream << (char) character;
                        break;
                    }
                    // Note: deliberate fall-through here!
                default:
                    outputStream << "&#" << ((int) character) << ';';
                    break;
                }
            }
        }
    }

    static void writeSpaces (OutputStream& out, const size_t numSpaces)
    {
        out.writeRepeatedByte (' ', numSpaces);
    }
}

void XmlElement::writeElementAsText (OutputStream& outputStream,
                                     const int indentationLevel,
                                     const int lineWrapLength) const
{
    using namespace XmlOutputFunctions;

    if (indentationLevel >= 0)
        writeSpaces (outputStream, (size_t) indentationLevel);

    if (! isTextElement())
    {
        outputStream.writeByte ('<');
        outputStream << tagName;

        {
            const size_t attIndent = (size_t) (indentationLevel + tagName.length() + 1);
            int lineLen = 0;

            for (const XmlAttributeNode* att = attributes; att != nullptr; att = att->nextListItem)
            {
                if (lineLen > lineWrapLength && indentationLevel >= 0)
                {
                    outputStream << newLine;
                    writeSpaces (outputStream, attIndent);
                    lineLen = 0;
                }

                const int64 startPos = outputStream.getPosition();
                outputStream.writeByte (' ');
                outputStream << att->name;
                outputStream.write ("=\"", 2);
                escapeIllegalXmlChars (outputStream, att->value, true);
                outputStream.writeByte ('"');
                lineLen += (int) (outputStream.getPosition() - startPos);
            }
        }

        if (firstChildElement != nullptr)
        {
            outputStream.writeByte ('>');

            bool lastWasTextNode = false;

            for (XmlElement* child = firstChildElement; child != nullptr; child = child->nextListItem)
            {
                if (child->isTextElement())
                {
                    escapeIllegalXmlChars (outputStream, child->getText(), false);
                    lastWasTextNode = true;
                }
                else
                {
                    if (indentationLevel >= 0 && ! lastWasTextNode)
                        outputStream << newLine;

                    child->writeElementAsText (outputStream,
                                               lastWasTextNode ? 0 : (indentationLevel + (indentationLevel >= 0 ? 2 : 0)), lineWrapLength);
                    lastWasTextNode = false;
                }
            }

            if (indentationLevel >= 0 && ! lastWasTextNode)
            {
                outputStream << newLine;
                writeSpaces (outputStream, (size_t) indentationLevel);
            }

            outputStream.write ("</", 2);
            outputStream << tagName;
            outputStream.writeByte ('>');
        }
        else
        {
            outputStream.write ("/>", 2);
        }
    }
    else
    {
        escapeIllegalXmlChars (outputStream, getText(), false);
    }
}

String XmlElement::createDocument (const String& dtdToUse,
                                   const bool allOnOneLine,
                                   const bool includeXmlHeader,
                                   const String& encodingType,
                                   const int lineWrapLength) const
{
    MemoryOutputStream mem (2048);
    writeToStream (mem, dtdToUse, allOnOneLine, includeXmlHeader, encodingType, lineWrapLength);

    return mem.toUTF8();
}

void XmlElement::writeToStream (OutputStream& output,
                                const String& dtdToUse,
                                const bool allOnOneLine,
                                const bool includeXmlHeader,
                                const String& encodingType,
                                const int lineWrapLength) const
{
    using namespace XmlOutputFunctions;

    if (includeXmlHeader)
    {
        output << "<?xml version=\"1.0\" encoding=\"" << encodingType << "\"?>";

        if (allOnOneLine)
            output.writeByte (' ');
        else
            output << newLine << newLine;
    }

    if (dtdToUse.isNotEmpty())
    {
        output << dtdToUse;

        if (allOnOneLine)
            output.writeByte (' ');
        else
            output << newLine;
    }

    writeElementAsText (output, allOnOneLine ? -1 : 0, lineWrapLength);

    if (! allOnOneLine)
        output << newLine;
}

bool XmlElement::writeToFile (const File& file,
                              const String& dtdToUse,
                              const String& encodingType,
                              const int lineWrapLength) const
{
    TemporaryFile tempFile (file);

    {
        FileOutputStream out (tempFile.getFile());

        if (! out.openedOk())
            return false;

        writeToStream (out, dtdToUse, false, true, encodingType, lineWrapLength);
    }

    return tempFile.overwriteTargetFileWithTemporary();
}

//==============================================================================
bool XmlElement::hasTagName (const String& possibleTagName) const noexcept
{
    const bool matches = tagName.equalsIgnoreCase (possibleTagName);

    // XML tags should be case-sensitive, so although this method allows a
    // case-insensitive match to pass, you should try to avoid this.
    bassert ((! matches) || tagName == possibleTagName);

    return matches;
}

String XmlElement::getNamespace() const
{
    return tagName.upToFirstOccurrenceOf (":", false, false);
}

String XmlElement::getTagNameWithoutNamespace() const
{
    return tagName.fromLastOccurrenceOf (":", false, false);
}

bool XmlElement::hasTagNameIgnoringNamespace (const String& possibleTagName) const
{
    return hasTagName (possibleTagName) || getTagNameWithoutNamespace() == possibleTagName;
}

XmlElement* XmlElement::getNextElementWithTagName (const String& requiredTagName) const
{
    XmlElement* e = nextListItem;

    while (e != nullptr && ! e->hasTagName (requiredTagName))
        e = e->nextListItem;

    return e;
}

//==============================================================================
int XmlElement::getNumAttributes() const noexcept
{
    return attributes.size();
}

const String& XmlElement::getAttributeName (const int index) const noexcept
{
    const XmlAttributeNode* const att = attributes [index];
    return att != nullptr ? att->name : String::empty;
}

const String& XmlElement::getAttributeValue (const int index) const noexcept
{
    const XmlAttributeNode* const att = attributes [index];
    return att != nullptr ? att->value : String::empty;
}

bool XmlElement::hasAttribute (const String& attributeName) const noexcept
{
    for (const XmlAttributeNode* att = attributes; att != nullptr; att = att->nextListItem)
        if (att->hasName (attributeName))
            return true;

    return false;
}

//==============================================================================
const String& XmlElement::getStringAttribute (const String& attributeName) const noexcept
{
    for (const XmlAttributeNode* att = attributes; att != nullptr; att = att->nextListItem)
        if (att->hasName (attributeName))
            return att->value;

    return String::empty;
}

String XmlElement::getStringAttribute (const String& attributeName, const String& defaultReturnValue) const
{
    for (const XmlAttributeNode* att = attributes; att != nullptr; att = att->nextListItem)
        if (att->hasName (attributeName))
            return att->value;

    return defaultReturnValue;
}

int XmlElement::getIntAttribute (const String& attributeName, const int defaultReturnValue) const
{
    for (const XmlAttributeNode* att = attributes; att != nullptr; att = att->nextListItem)
        if (att->hasName (attributeName))
            return att->value.getIntValue();

    return defaultReturnValue;
}

double XmlElement::getDoubleAttribute (const String& attributeName, const double defaultReturnValue) const
{
    for (const XmlAttributeNode* att = attributes; att != nullptr; att = att->nextListItem)
        if (att->hasName (attributeName))
            return att->value.getDoubleValue();

    return defaultReturnValue;
}

bool XmlElement::getBoolAttribute (const String& attributeName, const bool defaultReturnValue) const
{
    for (const XmlAttributeNode* att = attributes; att != nullptr; att = att->nextListItem)
    {
        if (att->hasName (attributeName))
        {
            const beast_wchar firstChar = *(att->value.getCharPointer().findEndOfWhitespace());

            return firstChar == '1'
                || firstChar == 't'
                || firstChar == 'y'
                || firstChar == 'T'
                || firstChar == 'Y';
        }
    }

    return defaultReturnValue;
}

bool XmlElement::compareAttribute (const String& attributeName,
                                   const String& stringToCompareAgainst,
                                   const bool ignoreCase) const noexcept
{
    for (const XmlAttributeNode* att = attributes; att != nullptr; att = att->nextListItem)
        if (att->hasName (attributeName))
            return ignoreCase ? att->value.equalsIgnoreCase (stringToCompareAgainst)
                              : att->value == stringToCompareAgainst;

    return false;
}

//==============================================================================
void XmlElement::setAttribute (const String& attributeName, const String& value)
{
    if (attributes == nullptr)
    {
        attributes = new XmlAttributeNode (attributeName, value);
    }
    else
    {
        for (XmlAttributeNode* att = attributes; ; att = att->nextListItem)
        {
            if (att->hasName (attributeName))
            {
                att->value = value;
                break;
            }

            if (att->nextListItem == nullptr)
            {
                att->nextListItem = new XmlAttributeNode (attributeName, value);
                break;
            }
        }
    }
}

void XmlElement::setAttribute (const String& attributeName, const int number)
{
    setAttribute (attributeName, String (number));
}

void XmlElement::setAttribute (const String& attributeName, const double number)
{
    setAttribute (attributeName, String (number, 20));
}

void XmlElement::removeAttribute (const String& attributeName) noexcept
{
    for (LinkedListPointer<XmlAttributeNode>* att = &attributes;
         att->get() != nullptr;
         att = &(att->get()->nextListItem))
    {
        if (att->get()->hasName (attributeName))
        {
            delete att->removeNext();
            break;
        }
    }
}

void XmlElement::removeAllAttributes() noexcept
{
    attributes.deleteAll();
}

//==============================================================================
int XmlElement::getNumChildElements() const noexcept
{
    return firstChildElement.size();
}

XmlElement* XmlElement::getChildElement (const int index) const noexcept
{
    return firstChildElement [index].get();
}

XmlElement* XmlElement::getChildByName (const String& childName) const noexcept
{
    for (XmlElement* child = firstChildElement; child != nullptr; child = child->nextListItem)
        if (child->hasTagName (childName))
            return child;

    return nullptr;
}

void XmlElement::addChildElement (XmlElement* const newNode) noexcept
{
    if (newNode != nullptr)
        firstChildElement.append (newNode);
}

void XmlElement::insertChildElement (XmlElement* const newNode,
                                     int indexToInsertAt) noexcept
{
    if (newNode != nullptr)
    {
        removeChildElement (newNode, false);
        firstChildElement.insertAtIndex (indexToInsertAt, newNode);
    }
}

XmlElement* XmlElement::createNewChildElement (const String& childTagName)
{
    XmlElement* const newElement = new XmlElement (childTagName);
    addChildElement (newElement);
    return newElement;
}

bool XmlElement::replaceChildElement (XmlElement* const currentChildElement,
                                      XmlElement* const newNode) noexcept
{
    if (newNode != nullptr)
    {
        if (LinkedListPointer<XmlElement>* const p = firstChildElement.findPointerTo (currentChildElement))
        {
            if (currentChildElement != newNode)
                delete p->replaceNext (newNode);

            return true;
        }
    }

    return false;
}

void XmlElement::removeChildElement (XmlElement* const childToRemove,
                                     const bool shouldDeleteTheChild) noexcept
{
    if (childToRemove != nullptr)
    {
        firstChildElement.remove (childToRemove);

        if (shouldDeleteTheChild)
            delete childToRemove;
    }
}

bool XmlElement::isEquivalentTo (const XmlElement* const other,
                                 const bool ignoreOrderOfAttributes) const noexcept
{
    if (this != other)
    {
        if (other == nullptr || tagName != other->tagName)
            return false;

        if (ignoreOrderOfAttributes)
        {
            int totalAtts = 0;

            for (const XmlAttributeNode* att = attributes; att != nullptr; att = att->nextListItem)
            {
                if (! other->compareAttribute (att->name, att->value))
                    return false;

                ++totalAtts;
            }

            if (totalAtts != other->getNumAttributes())
                return false;
        }
        else
        {
            const XmlAttributeNode* thisAtt = attributes;
            const XmlAttributeNode* otherAtt = other->attributes;

            for (;;)
            {
                if (thisAtt == nullptr || otherAtt == nullptr)
                {
                    if (thisAtt == otherAtt) // both 0, so it's a match
                        break;

                    return false;
                }

                if (thisAtt->name != otherAtt->name
                     || thisAtt->value != otherAtt->value)
                {
                    return false;
                }

                thisAtt = thisAtt->nextListItem;
                otherAtt = otherAtt->nextListItem;
            }
        }

        const XmlElement* thisChild = firstChildElement;
        const XmlElement* otherChild = other->firstChildElement;

        for (;;)
        {
            if (thisChild == nullptr || otherChild == nullptr)
            {
                if (thisChild == otherChild) // both 0, so it's a match
                    break;

                return false;
            }

            if (! thisChild->isEquivalentTo (otherChild, ignoreOrderOfAttributes))
                return false;

            thisChild = thisChild->nextListItem;
            otherChild = otherChild->nextListItem;
        }
    }

    return true;
}

void XmlElement::deleteAllChildElements() noexcept
{
    firstChildElement.deleteAll();
}

void XmlElement::deleteAllChildElementsWithTagName (const String& name) noexcept
{
    for (XmlElement* child = firstChildElement; child != nullptr;)
    {
        XmlElement* const nextChild = child->nextListItem;

        if (child->hasTagName (name))
            removeChildElement (child, true);

        child = nextChild;
    }
}

bool XmlElement::containsChildElement (const XmlElement* const possibleChild) const noexcept
{
    return firstChildElement.contains (possibleChild);
}

XmlElement* XmlElement::findParentElementOf (const XmlElement* const elementToLookFor) noexcept
{
    if (this == elementToLookFor || elementToLookFor == nullptr)
        return nullptr;

    for (XmlElement* child = firstChildElement; child != nullptr; child = child->nextListItem)
    {
        if (elementToLookFor == child)
            return this;

        if (XmlElement* const found = child->findParentElementOf (elementToLookFor))
            return found;
    }

    return nullptr;
}

void XmlElement::getChildElementsAsArray (XmlElement** elems) const noexcept
{
    firstChildElement.copyToArray (elems);
}

void XmlElement::reorderChildElements (XmlElement** const elems, const int num) noexcept
{
    XmlElement* e = firstChildElement = elems[0];

    for (int i = 1; i < num; ++i)
    {
        e->nextListItem = elems[i];
        e = e->nextListItem;
    }

    e->nextListItem = nullptr;
}

//==============================================================================
bool XmlElement::isTextElement() const noexcept
{
    return tagName.isEmpty();
}

static const String beast_xmltextContentAttributeName ("text");

const String& XmlElement::getText() const noexcept
{
    bassert (isTextElement());  // you're trying to get the text from an element that
                                // isn't actually a text element.. If this contains text sub-nodes, you
                                // probably want to use getAllSubText instead.

    return getStringAttribute (beast_xmltextContentAttributeName);
}

void XmlElement::setText (const String& newText)
{
    if (isTextElement())
        setAttribute (beast_xmltextContentAttributeName, newText);
    else
        bassertfalse; // you can only change the text in a text element, not a normal one.
}

String XmlElement::getAllSubText() const
{
    if (isTextElement())
        return getText();

    MemoryOutputStream mem (1024);

    for (const XmlElement* child = firstChildElement; child != nullptr; child = child->nextListItem)
        mem << child->getAllSubText();

    return mem.toUTF8();
}

String XmlElement::getChildElementAllSubText (const String& childTagName,
                                              const String& defaultReturnValue) const
{
    if (const XmlElement* const child = getChildByName (childTagName))
        return child->getAllSubText();

    return defaultReturnValue;
}

XmlElement* XmlElement::createTextElement (const String& text)
{
    XmlElement* const e = new XmlElement ((int) 0);
    e->setAttribute (beast_xmltextContentAttributeName, text);
    return e;
}

void XmlElement::addTextElement (const String& text)
{
    addChildElement (createTextElement (text));
}

void XmlElement::deleteAllTextElements() noexcept
{
    for (XmlElement* child = firstChildElement; child != nullptr;)
    {
        XmlElement* const next = child->nextListItem;

        if (child->isTextElement())
            removeChildElement (child, true);

        child = next;
    }
}