freeswitch/src/include/switch_xml.h

/* 
 * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 * Copyright (C) 2005/2006, Anthony Minessale II <anthmct@yahoo.com>
 *
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 *
 * The Initial Developer of the Original Code is
 * Anthony Minessale II <anthmct@yahoo.com>
 * Portions created by the Initial Developer are Copyright (C)
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * 
 * Anthony Minessale II <anthmct@yahoo.com>
 *
 *
 * switch_xml.h -- XML PARSER
 *
 * Derived from EZXML http://ezxml.sourceforge.net
 * Original Copyright
 *
 * Copyright 2004, 2005 Aaron Voisine <aaron@voisine.org>
 *
 * 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.
 */

#ifndef _SWITCH_XML_H
#define _SWITCH_XML_H
#include <switch_types.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <fcntl.h>


///\defgroup xml1 XML Library Functions
///\ingroup core1
///\{
SWITCH_BEGIN_EXTERN_C

#define SWITCH_XML_BUFSIZE 1024 // size of internal memory buffers

typedef enum {
	SWITCH_XML_ROOT =	   (1 << 0), // root
	SWITCH_XML_NAMEM =  (1 << 1), // name is malloced
	SWITCH_XML_TXTM =   (1 << 2), // txt is malloced
	SWITCH_XML_DUP   =  (1 << 3) // attribute name and value are strduped
} switch_xml_flag_t;

/*! \brief A representation of an XML tree */
struct switch_xml {
	/*! tag name */
    char *name;      
	/*! tag attributes { name, value, name, value, ... NULL } */
    char **attr;
	/*! tag character content, empty string if none */
    char *txt;
	/*! tag offset from start of parent tag character content */
    switch_size_t off;
	/*! next tag with same name in this section at this depth */
    switch_xml_t next;
	/*! next tag with different name in same section and depth*/
    switch_xml_t sibling;
	/*! next tag, same section and depth, in original order */
    switch_xml_t ordered;
	/*! head of sub tag list, NULL if none*/
    switch_xml_t child;
	/*! parent tag, NULL if current tag is root tag*/
    switch_xml_t parent;
	/*! flags */
    uint32_t flags;
};

///\brief Given a string of xml data and its length, parses it and creates an switch_xml
///\ structure. For efficiency, modifies the data by adding null terminators
///\ and decoding ampersand sequences. If you don't want this, copy the data and
///\ pass in the copy. Returns NULL on failure.
///\param s a string
///\param len the length of the string
///\return a formated xml node or NULL
SWITCH_DECLARE(switch_xml_t) switch_xml_parse_str(char *s, switch_size_t len);

///\brief A wrapper for switch_xml_parse_str() that accepts a file descriptor. First
///\ attempts to mem map the file. Failing that, reads the file into memory.
///\ Returns NULL on failure.
///\param fd
///\return a formated xml node or NULL
SWITCH_DECLARE(switch_xml_t) switch_xml_parse_fd(int fd);

///\brief a wrapper for switch_xml_parse_fd() that accepts a file name
///\param file a file to parse
///\return a formated xml node or NULL
SWITCH_DECLARE(switch_xml_t) switch_xml_parse_file(const char *file);
    
///\brief Wrapper for switch_xml_parse_str() that accepts a file stream. Reads the entire
///\ stream into memory and then parses it. For xml files, use switch_xml_parse_file()
///\ or switch_xml_parse_fd()
///\param fp a FILE pointer to parse
///\return an xml node or NULL
SWITCH_DECLARE(switch_xml_t) switch_xml_parse_fp(FILE *fp);

///\brief returns the first child tag (one level deeper) with the given name or NULL
///\ if not found
///\param xml an xml node
///\param name the name of the child tag
///\return an xml node or NULL
SWITCH_DECLARE(switch_xml_t) switch_xml_child(switch_xml_t xml, const char *name);

///\brief find a child tag in a node called 'childname' with an attribute 'attrname' which equals 'value'
///\param node the xml node
///\param childname the child tag name
///\param attrname the attribute name
///\param value the value
///\return an xml node or NULL
SWITCH_DECLARE(switch_xml_t) switch_xml_find_child(switch_xml_t node, char *childname, char *attrname, char *value);

///\brief returns the next tag of the same name in the same section and depth or NULL
///\ if not found
///\param xml an xml node
///\return an xml node or NULL
#define switch_xml_next(xml) ((xml) ? xml->next : NULL)

///\brief Returns the Nth tag with the same name in the same section at the same depth
///\ or NULL if not found. An index of 0 returns the tag given.
///\param xml the xml node
///\param idx the index
///\return an xml node or NULL
switch_xml_t switch_xml_idx(switch_xml_t xml, int idx);

///\brief returns the name of the given tag
///\param xml the xml node
///\return the name
#define switch_xml_name(xml) ((xml) ? xml->name : NULL)

///\brief returns the given tag's character content or empty string if none
///\param xml the xml node
///\return the content
#define switch_xml_txt(xml) ((xml) ? xml->txt : "")

///\brief returns the value of the requested tag attribute, or NULL if not found
///\param xml the xml node
///\param attr the attribute
///\return the value
SWITCH_DECLARE(const char *) switch_xml_attr(switch_xml_t xml, const char *attr);

///\brief returns the value of the requested tag attribute, or "" if not found
///\param xml the xml node
///\param attr the attribute
///\return the value
SWITCH_DECLARE(const char *) switch_xml_attr_soft(switch_xml_t xml, const char *attr);

///\brief Traverses the switch_xml sturcture to retrieve a specific subtag. Takes a
///\ variable length list of tag names and indexes. The argument list must be
///\ terminated by either an index of -1 or an empty string tag name. Example: 
///\ title = switch_xml_get(library, "shelf", 0, "book", 2, "title", -1);
///\ This retrieves the title of the 3rd book on the 1st shelf of library.
///\ Returns NULL if not found.
///\param xml the xml node
///\return an xml node or NULL
SWITCH_DECLARE(switch_xml_t) switch_xml_get(switch_xml_t xml, ...);

///\brief Converts an switch_xml structure back to xml. Returns a string of xml data that
///\ must be freed.
///\param xml the xml node
///\return the xml text string
SWITCH_DECLARE(char *) switch_xml_toxml(switch_xml_t xml);

///\brief returns a NULL terminated array of processing instructions for the given
///\ target
///\param xml the xml node
///\param target the instructions
///\return the array
SWITCH_DECLARE(const char **) switch_xml_pi(switch_xml_t xml, const char *target);

///\brief frees the memory allocated for an switch_xml structure
///\param xml the xml node
///\note in the case of the root node the readlock will be lifted
SWITCH_DECLARE(void) switch_xml_free(switch_xml_t xml);
    
///\brief returns parser error message or empty string if none
///\param xml the xml node
///\return the error string or nothing
SWITCH_DECLARE(const char *) switch_xml_error(switch_xml_t xml);

///\brief returns a new empty switch_xml structure with the given root tag name
///\param name the name of the new root tag
SWITCH_DECLARE(switch_xml_t) switch_xml_new(const char *name);

///\brief wrapper for switch_xml_new() that strdup()s name
///\param name the name of the root
///\return an xml node or NULL
#define switch_xml_new_d(name) switch_xml_set_flag(switch_xml_new(strdup(name)), SWITCH_XML_NAMEM)

///\brief Adds a child tag. off is the offset of the child tag relative to the start
///\ of the parent tag's character content. Returns the child tag.
///\param xml the xml node
///\param name the name of the tag
///\param off the offset
///\return an xml node or NULL
switch_xml_t switch_xml_add_child(switch_xml_t xml, const char *name, switch_size_t off);

///\brief wrapper for switch_xml_add_child() that strdup()s name
///\param xml the xml node
///\param name the name of the child
///\param off the offset
#define switch_xml_add_child_d(xml, name, off) \
    switch_xml_set_flag(switch_xml_add_child(xml, strdup(name), off), SWITCH_XML_NAMEM)

///\brief sets the character content for the given tag and returns the tag
///\param xml the xml node
///\param txt the text
///\return an xml node or NULL
switch_xml_t switch_xml_set_txt(switch_xml_t xml, const char *txt);

///\brief wrapper for switch_xml_set_txt() that strdup()s txt
///\ sets the character content for the given tag and returns the tag
///\param xml the xml node
///\param txt the text
///\return an xml node or NULL
#define switch_xml_set_txt_d(xml, txt) \
    switch_xml_set_flag(switch_xml_set_txt(xml, strdup(txt)), SWITCH_XML_TXTM)

///\brief Sets the given tag attribute or adds a new attribute if not found. A value
///\ of NULL will remove the specified attribute.
///\param xml the xml node
///\param name the attribute name
///\param value the attribute value
SWITCH_DECLARE(void) switch_xml_set_attr(switch_xml_t xml, const char *name, const char *value);

///\ Wrapper for switch_xml_set_attr() that strdup()s name/value. Value cannot be NULL
///\param xml the xml node
///\param name the attribute name
///\param value the attribute value
///\return an xml node or NULL
#define switch_xml_set_attr_d(xml, name, value) \
    switch_xml_set_attr(switch_xml_set_flag(xml, SWITCH_XML_DUP), strdup(name), strdup(value))

///\brief sets a flag for the given tag and returns the tag
///\param xml the xml node
///\param flag the flag to set
///\return an xml node or NULL
SWITCH_DECLARE(switch_xml_t) switch_xml_set_flag(switch_xml_t xml, switch_xml_flag_t flag);


///\brief removes a tag along with all its subtags
///\param xml the xml node
SWITCH_DECLARE(void) switch_xml_remove(switch_xml_t xml);

///\brief open the Core xml root
///\param reload if it's is already open close it and open it again as soon as permissable (blocking)
///\param err a pointer to set error strings
///\return the xml root node or NULL
SWITCH_DECLARE(switch_xml_t) switch_xml_open_root(uint8_t reload, const char **err);

///\brief initilize the core XML backend
///\param pool a memory pool to use
///\param err a pointer to set error strings
///\return SWITCH_STATUS_SUCCESS if successful
SWITCH_DECLARE(switch_status_t) switch_xml_init(switch_memory_pool_t *pool, const char **err);


SWITCH_DECLARE(switch_status_t) switch_xml_destroy(void);

///\brief retrieve the core XML root node
///\return the xml root node
///\note this will cause a readlock on the root until it's released with \see switch_xml_free
SWITCH_DECLARE(switch_xml_t) switch_xml_root(void);

///\brief locate an xml pointer in the core registry
///\param section the section to look in
///\param tag_name the type of tag in that section
///\param key_name the name of the key
///\param key_value the value of the key
///\param root a pointer to point at the root node
///\param node a pointer to the requested node
///\param params optional URL formatted params to pass to external gateways
///\return SWITCH_STATUS_SUCCESS if successful root and node will be assigned
SWITCH_DECLARE(switch_status_t) switch_xml_locate(char *section,
												  char *tag_name,
												  char *key_name,
												  char *key_value,
												  switch_xml_t *root,
												  switch_xml_t *node,
												  char *params);
												 
///\brief open a config in the core registry
///\param file_path the name of the config section e.g. modules.conf
///\param node a pointer to point to the node if it is found
///\param params optional URL formatted params to pass to external gateways
///\return the root xml node associated with the current request or NULL
SWITCH_DECLARE(switch_xml_t) switch_xml_open_cfg(char *file_path, switch_xml_t *node, char *params);

///\brief bind a search function to an external gateway
///\param function the search function to bind
///\param sections a bitmask of sections you wil service
///\return SWITCH_STATUS_SUCCESS if successful
///\note gateway functions will be executed in the order they were binded until a success is found else the root registry will be used
SWITCH_DECLARE(switch_status_t) switch_xml_bind_search_function(switch_xml_search_function_t function, switch_xml_section_t sections);

///\brief parse a string for a list of sections
///\param str a | delimited list of section names
///\return the section mask
SWITCH_DECLARE(switch_xml_section_t) switch_xml_parse_section_string(char *str);

SWITCH_END_EXTERN_C

///\}

#endif // _SWITCH_XML_H

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