/* -------------------------------------------------------------------------- */
/* Copyright 2002-2011, OpenNebula Project Leads (OpenNebula.org) */
/* */
/* Licensed under the Apache License, Version 2.0 (the "License"); you may */
/* not use this file except in compliance with the License. You may obtain */
/* a copy of the License at */
/* */
/* http://www.apache.org/licenses/LICENSE-2.0 */
/* */
/* Unless required by applicable law or agreed to in writing, software */
/* distributed under the License is distributed on an "AS IS" BASIS, */
/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */
/* See the License for the specific language governing permissions and */
/* limitations under the License. */
/* -------------------------------------------------------------------------- */
#ifndef OBJECT_XML_H_
#define OBJECT_XML_H_
#include <string>
#include <vector>
#include <libxml/tree.h>
#include <libxml/parser.h>
#include <libxml/xpath.h>
#include <libxml/xpathInternals.h>
using namespace std;
/**
* This class represents a generic Object supported by a xml document.
* The class provides basic methods to query attributes, and get xml nodes
*/
class ObjectXML
{
public:
// ---------------------- Constructors ------------------------------------
ObjectXML():xml(0),ctx(0){};
/**
* Constructs an object using a XML document
*/
ObjectXML(const string &xml_doc);
/**
* Constructs an object using a XML Node. The node is copied to the new
* object
*/
ObjectXML(const xmlNodePtr node);
virtual ~ObjectXML();
/**
* Access Object elements using Xpath
* @param xpath_expr the Xpath of the element
* @return a vector with the elements
*/
vector<string> operator[] (const char * xpath_expr);
/**
* Gets and sets a xpath attribute, if the attribute is not found a default
* is used
* @param value to set
* @param xpath_expr of the xml element
* @param def default value if the element is not found
*
* @return -1 if default was set
*/
int xpath(string& value, const char * xpath_expr, const char * def);
/**
* Gets and sets a xpath attribute, if the attribute is not found a default
* is used
* @param value to set
* @param xpath_expr of the xml element
* @param def default value if the element is not found
*
* @return -1 if default was set
*/
int xpath(int& value, const char * xpath_expr, const int& def);
/**
* Gets and sets a xpath attribute, if the attribute is not found a default
* is used
* @param value to set
* @param xpath_expr of the xml element
* @param def default value if the element is not found
*
* @return -1 if default was set
*/
int xpath(unsigned int& value, const char * xpath_expr,
const unsigned int& def);
/**
* Gets and sets a xpath attribute, if the attribute is not found a default
* is used
* @param value to set
* @param xpath_expr of the xml element
* @param def default value if the element is not found
*
* @return -1 if default was set
*/
int xpath(time_t& value, const char * xpath_expr, const time_t& def);
/**
* Gets the value of an element from an xml string
* @param value the value of the element
* @param xml the xml string
* @param xpath the xpath of the target element
*
* @return -1 if the element was not found
*/
static int xpath_value(string& value, const char *xml, const char *xpath);
/**
* Get xml nodes by Xpath
* @param xpath_expr the Xpath for the elements
* @param content nodes for the given Xpath expression. The nodes are
* returned as pointers to the object nodes.
* @return the number of nodes found
*/
int get_nodes(const char * xpath_expr, vector<xmlNodePtr>& content);
/**
* Frees a vector of XMLNodes, as returned by the get_nodes function
* @param content the vector of xmlNodePtr
*/
void free_nodes(vector<xmlNodePtr>& content)
{
vector<xmlNodePtr>::iterator it;
for (it = content.begin(); it < content.end(); it++)
{
xmlFreeNode(*it);
}
};
/**
* Updates the object representation with a new XML document. Previous
* XML resources are freed
* @param xml_doc the new xml document
*/
int update_from_str(const string &xml_doc);
/**
* Updates the object representation with a new XML document. Previous
* XML resources are freed
* @param xml_doc the new xml document
*/
int update_from_node(const xmlNodePtr node);
// ---------------------------------------------------------
// Lex & bison parser for requirements and rank expressions
// ---------------------------------------------------------
/**
* Evaluates a requirement expression on the given host.
* @param requirements string
* @param result true if the host matches the requirements
* @param errmsg string describing the error, must be freed by the
* calling function
* @return 0 on success
*/
int eval_bool(const string& expr, bool& result, char **errmsg);
/**
* Evaluates a rank expression on the given host.
* @param rank string
* @param result of the rank evaluation
* @param errmsg string describing the error, must be freed by the
* calling function
* @return 0 on success
*/
int eval_arith(const string& expr, int& result, char **errmsg);
/**
* Function to write the Object in an output stream
*/
friend ostream& operator<<(ostream& os, ObjectXML& oxml)
{
xmlChar * mem;
int size;
xmlDocDumpMemory(oxml.xml,&mem,&size);
string str(reinterpret_cast<char *>(mem));
os << str;
xmlFree(mem);
return os;
};
private:
/**
* XML representation of the Object
*/
xmlDocPtr xml;
/**
* XPath Context to access Object elements
*/
xmlXPathContextPtr ctx;
/**
* Parse a XML documents and initializes XPath contexts
*/
void xml_parse(const string &xml_doc);
};
#endif /*OBJECT_XML_H_*/