godot/core/io/xml_parser.cpp

/*************************************************************************/
/*  xml_parser.cpp                                                       */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
/*                                                                       */
/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
/*************************************************************************/
#include "xml_parser.h"
#include "print_string.h"
//#define DEBUG_XML

VARIANT_ENUM_CAST(XMLParser::NodeType);

static bool _equalsn(const CharType* str1, const CharType* str2, int len) {
	int i;
	for(i=0; i < len && str1[i] && str2[i] ; ++i)
	     if (str1[i] != str2[i])
		     return false;

	// if one (or both) of the strings was smaller then they
	// are only equal if they have the same lenght
	return (i == len) || (str1[i] == 0 && str2[i] == 0);
}


String XMLParser::_replace_special_characters(const String& origstr) {

	int pos = origstr.find("&");
	int oldPos = 0;

	if (pos == -1)
		return origstr;

	String newstr;

	while(pos != -1 && pos < origstr.length()-2) {
		// check if it is one of the special characters

		int specialChar = -1;
		for (int i=0; i<(int)special_characters.size(); ++i)
		{
			const CharType* p = &origstr[pos]+1;

			if (_equalsn(&special_characters[i][1], p, special_characters[i].length()-1))
			{
				specialChar = i;
				break;
			}
		}

		if (specialChar != -1)
		{
			newstr+=(origstr.substr(oldPos, pos - oldPos));
			newstr+=(special_characters[specialChar][0]);
			pos += special_characters[specialChar].length();
		}
		else
		{
			newstr+=(origstr.substr(oldPos, pos - oldPos + 1));
			pos += 1;
		}

		// find next &
		oldPos = pos;
		pos = origstr.find("&", pos);
	}

	if (oldPos < origstr.length()-1)
		newstr+=(origstr.substr(oldPos, origstr.length()-oldPos));

	return newstr;
}


static inline bool _is_white_space(char c)
{
	return (c==' ' || c=='\t' || c=='\n' || c=='\r');
}


//! sets the state that text was found. Returns true if set should be set
bool XMLParser::_set_text(char* start, char* end) {
	// check if text is more than 2 characters, and if not, check if there is
	// only white space, so that this text won't be reported
	if (end - start < 3)
	{
		char* p = start;
		for(; p != end; ++p)
			if (!_is_white_space(*p))
				break;

		if (p == end)
			return false;
	}

	// set current text to the parsed text, and replace xml special characters
	String s = String::utf8(start, (int)(end - start));
	node_name = _replace_special_characters(s);

	// current XML node type is text
	node_type = NODE_TEXT;

	return true;
}

void XMLParser::_parse_closing_xml_element() {
	node_type = NODE_ELEMENT_END;
	node_empty = false;
	attributes.clear();

	++P;
	const char* pBeginClose = P;

	while(*P != '>')
		++P;

	node_name = String::utf8(pBeginClose, (int)(P - pBeginClose));
#ifdef DEBUG_XML
	print_line("XML CLOSE: "+node_name);
#endif
	++P;
}

void XMLParser::_ignore_definition() {
	node_type = NODE_UNKNOWN;

	char *F=P;
	// move until end marked with '>' reached
	while(*P != '>')
		++P;
	node_name.parse_utf8(F,P-F);
	++P;
}

bool XMLParser::_parse_cdata() {

	if (*(P+1) != '[')
		return false;

	node_type = NODE_CDATA;

	// skip '<![CDATA['
	int count=0;
	while( *P && count<8 )
	{
		++P;
		++count;
	}

	if (!*P)
		return true;

	char *cDataBegin = P;
	char *cDataEnd = 0;

	// find end of CDATA
	while(*P && !cDataEnd) {
		if (*P == '>' &&
		   (*(P-1) == ']') &&
		   (*(P-2) == ']'))
		{
			cDataEnd = P - 2;
		}

		++P;
	}

	if ( cDataEnd )
		node_name = String::utf8(cDataBegin, (int)(cDataEnd - cDataBegin));
	else
		node_name = "";
#ifdef DEBUG_XML
	print_line("XML CDATA: "+node_name);
#endif

	return true;
}

void XMLParser::_parse_comment() {

	node_type = NODE_COMMENT;
	P += 1;

	char *pCommentBegin = P;

	int count = 1;

	// move until end of comment reached
	while(count)
	{
		if (*P == '>')
			--count;
		else
		if (*P == '<')
			++count;

		++P;
	}

	P -= 3;
	node_name = String::utf8(pCommentBegin+2, (int)(P - pCommentBegin-2));
	P += 3;
#ifdef DEBUG_XML
	print_line("XML COMMENT: "+node_name);
#endif

}

void XMLParser::_parse_opening_xml_element() {

	node_type = NODE_ELEMENT;
	node_empty = false;
	attributes.clear();

	// find name
	const char* startName = P;

	// find end of element
	while(*P != '>' && !_is_white_space(*P))
		++P;

	const char* endName = P;

	// find attributes
	while(*P != '>')
	{
		if (_is_white_space(*P))
			++P;
		else
		{
			if (*P != '/')
			{
				// we've got an attribute

				// read the attribute names
				const char* attributeNameBegin = P;

				while(!_is_white_space(*P) && *P != '=')
					++P;

				const char* attributeNameEnd = P;
				++P;

				// read the attribute value
				// check for quotes and single quotes, thx to murphy
				while( (*P != '\"') && (*P != '\'') && *P)
					++P;

				if (!*P) // malformatted xml file
					return;

				const char attributeQuoteChar = *P;

				++P;
				const char* attributeValueBegin = P;

				while(*P != attributeQuoteChar && *P)
					++P;

				if (!*P) // malformatted xml file
					return;

				const char* attributeValueEnd = P;
				++P;

				Attribute attr;
				attr.name = String::utf8(attributeNameBegin,
					(int)(attributeNameEnd - attributeNameBegin));

				String s =String::utf8(attributeValueBegin,
					(int)(attributeValueEnd - attributeValueBegin));

				attr.value = _replace_special_characters(s);
				attributes.push_back(attr);
			}
			else
			{
				// tag is closed directly
				++P;
				node_empty = true;
				break;
			}
		}
	}

	// check if this tag is closing directly
	if (endName > startName && *(endName-1) == '/')
	{
		// directly closing tag
		node_empty = true;
		endName--;
	}

	node_name = String::utf8(startName, (int)(endName - startName));
#ifdef DEBUG_XML
	print_line("XML OPEN: "+node_name);
#endif

	++P;
}


void XMLParser::_parse_current_node() {

	char* start = P;
	node_offset = P - data;

	// more forward until '<' found
	while(*P != '<' && *P)
		++P;

	if (!*P)
		return;

	if (P - start > 0)
	{
		// we found some text, store it
		if (_set_text(start, P))
			return;
	}

	++P;

	// based on current token, parse and report next element
	switch(*P)
	{
	case '/':
		_parse_closing_xml_element();
		break;
	case '?':
		_ignore_definition();
		break;
	case '!':
		if (!_parse_cdata())
			_parse_comment();
		break;
	default:
		_parse_opening_xml_element();
		break;
	}
}


uint64_t XMLParser::get_node_offset() const {

	return node_offset;
};

Error XMLParser::seek(uint64_t p_pos) {

	ERR_FAIL_COND_V(!data, ERR_FILE_EOF)
	ERR_FAIL_COND_V(p_pos >= length, ERR_FILE_EOF);

	P = data + p_pos;

	return read();
};

void XMLParser::_bind_methods() {

	ClassDB::bind_method(D_METHOD("read"),&XMLParser::read);
	ClassDB::bind_method(D_METHOD("get_node_type"),&XMLParser::get_node_type);
	ClassDB::bind_method(D_METHOD("get_node_name"),&XMLParser::get_node_name);
	ClassDB::bind_method(D_METHOD("get_node_data"),&XMLParser::get_node_data);
	ClassDB::bind_method(D_METHOD("get_node_offset"),&XMLParser::get_node_offset);
	ClassDB::bind_method(D_METHOD("get_attribute_count"),&XMLParser::get_attribute_count);
	ClassDB::bind_method(D_METHOD("get_attribute_name","idx"),&XMLParser::get_attribute_name);
	ClassDB::bind_method(D_METHOD("get_attribute_value","idx"),(String (XMLParser::*)(int) const) &XMLParser::get_attribute_value);
	ClassDB::bind_method(D_METHOD("has_attribute","name"),&XMLParser::has_attribute);
	ClassDB::bind_method(D_METHOD("get_named_attribute_value","name"), (String (XMLParser::*)(const String&) const) &XMLParser::get_attribute_value);
	ClassDB::bind_method(D_METHOD("get_named_attribute_value_safe","name"), &XMLParser::get_attribute_value_safe);
	ClassDB::bind_method(D_METHOD("is_empty"),&XMLParser::is_empty);
	ClassDB::bind_method(D_METHOD("get_current_line"),&XMLParser::get_current_line);
	ClassDB::bind_method(D_METHOD("skip_section"),&XMLParser::skip_section);
	ClassDB::bind_method(D_METHOD("seek","pos"),&XMLParser::seek);
	ClassDB::bind_method(D_METHOD("open","file"),&XMLParser::open);
	ClassDB::bind_method(D_METHOD("open_buffer","buffer"),&XMLParser::open_buffer);

	BIND_CONSTANT( NODE_NONE );
	BIND_CONSTANT( NODE_ELEMENT );
	BIND_CONSTANT( NODE_ELEMENT_END );
	BIND_CONSTANT( NODE_TEXT );
	BIND_CONSTANT( NODE_COMMENT );
	BIND_CONSTANT( NODE_CDATA );
	BIND_CONSTANT( NODE_UNKNOWN );

};



Error XMLParser::read() {

	// if not end reached, parse the node
	if (P && (P - data) < length - 1 && *P != 0)
	{
		_parse_current_node();
		return OK;
	}

	return ERR_FILE_EOF;
}

XMLParser::NodeType XMLParser::get_node_type() {

	return node_type;
}
String XMLParser::get_node_data() const {

	ERR_FAIL_COND_V( node_type != NODE_TEXT, "");
	return node_name;
}

String XMLParser::get_node_name() const {
	ERR_FAIL_COND_V( node_type == NODE_TEXT, "");
	return node_name;
}
int XMLParser::get_attribute_count() const {

	return attributes.size();
}
String XMLParser::get_attribute_name(int p_idx) const {

	ERR_FAIL_INDEX_V(p_idx,attributes.size(),"");
	return attributes[p_idx].name;
}
String XMLParser::get_attribute_value(int p_idx) const {

	ERR_FAIL_INDEX_V(p_idx,attributes.size(),"");
	return attributes[p_idx].value;
}
bool XMLParser::has_attribute(const String& p_name) const {

	for(int i=0;i<attributes.size();i++) {
		if (attributes[i].name==p_name)
			return true;
	}

	return false;
}
String XMLParser::get_attribute_value(const String& p_name) const {

	int idx=-1;
	for(int i=0;i<attributes.size();i++) {
		if (attributes[i].name==p_name) {
			idx=i;
			break;
		}
	}

	if (idx<0) {
		ERR_EXPLAIN("Attribute not found: "+p_name);
	}
	ERR_FAIL_COND_V(idx<0,"");
	return attributes[idx].value;

}

String XMLParser::get_attribute_value_safe(const String& p_name) const {

	int idx=-1;
	for(int i=0;i<attributes.size();i++) {
		if (attributes[i].name==p_name) {
			idx=i;
			break;
		}
	}

	if (idx<0)
		return "";
	return attributes[idx].value;

}
bool XMLParser::is_empty() const {

	return node_empty;
}

Error XMLParser::open_buffer(const Vector<uint8_t>& p_buffer) {

	ERR_FAIL_COND_V(p_buffer.size()==0,ERR_INVALID_DATA);

	length = p_buffer.size();
	data = memnew_arr( char, length+1);
	copymem(data,p_buffer.ptr(),length);
	data[length]=0;
	P=data;
	return OK;

}

Error XMLParser::open(const String& p_path) {

	Error err;
	FileAccess * file = FileAccess::open(p_path,FileAccess::READ,&err);

	if (err) {
		ERR_FAIL_COND_V(err!=OK,err);
	}

	length = file->get_len();
	ERR_FAIL_COND_V(length<1, ERR_FILE_CORRUPT);

	data = memnew_arr( char, length+1);
	file->get_buffer((uint8_t*)data,length);
	data[length]=0;
	P=data;

	memdelete(file);

	return OK;

}

void XMLParser::skip_section() {

	// skip if this element is empty anyway.
	if (is_empty())
		return;

	// read until we've reached the last element in this section
	int tagcount = 1;

	while(tagcount && read()==OK)
	{
		if (get_node_type() == XMLParser::NODE_ELEMENT &&
			!is_empty())
		{
			++tagcount;
		}
		else
		if (get_node_type() == XMLParser::NODE_ELEMENT_END)
			--tagcount;
	}

}

void XMLParser::close() {

	if (data)
		memdelete_arr(data);
	data=NULL;
	length=0;
	P=NULL;
	node_empty=false;
	node_type=NODE_NONE;
	node_offset = 0;
}

int XMLParser::get_current_line() const {

	return 0;
}

XMLParser::XMLParser() {

	data=NULL;
	close();
	special_characters.push_back("&amp;");
	special_characters.push_back("<lt;");
	special_characters.push_back(">gt;");
	special_characters.push_back("\"quot;");
	special_characters.push_back("'apos;");


}
XMLParser::~XMLParser() {


	if (data)
		memdelete_arr(data);
}