apr_xml.h

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/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 APR_XML_H
#define APR_XML_H

#include "apr_pools.h"
#include "apr_tables.h"
#include "apr_file_io.h"

#include "apu.h"
#if APR_CHARSET_EBCDIC
#include "apr_xlate.h"
#endif

#ifdef __cplusplus
extern "C" {
#endif

/* -------------------------------------------------------------------- */

/* ### these will need to move at some point to a more logical spot */

typedef struct apr_text apr_text;

struct apr_text {
    const char *text;
    struct apr_text *next;
};

typedef struct apr_text_header apr_text_header;

struct apr_text_header {
    apr_text *first;
    apr_text *last;
};

APU_DECLARE(void) apr_text_append(apr_pool_t *p, apr_text_header *hdr,
                                  const char *text);


/* --------------------------------------------------------------------
**
** XML PARSING
*/

/*
** Qualified namespace values
**
** APR_XML_NS_DAV_ID
**    We always insert the "DAV:" namespace URI at the head of the
**    namespace array. This means that it will always be at ID==0,
**    making it much easier to test for.
**
** APR_XML_NS_NONE
**    This special ID is used for two situations:
**
**    1) The namespace prefix begins with "xml" (and we do not know
**       what it means). Namespace prefixes with "xml" (any case) as
**       their first three characters are reserved by the XML Namespaces
**       specification for future use. mod_dav will pass these through
**       unchanged. When this identifier is used, the prefix is LEFT in
**       the element/attribute name. Downstream processing should not
**       prepend another prefix.
**
**    2) The element/attribute does not have a namespace.
**
**       a) No prefix was used, and a default namespace has not been
**          defined.
**       b) No prefix was used, and the default namespace was specified
**          to mean "no namespace". This is done with a namespace
**          declaration of:  xmlns=""
**          (this declaration is typically used to override a previous
**          specification for the default namespace)
**
**       In these cases, we need to record that the elem/attr has no
**       namespace so that we will not attempt to prepend a prefix.
**       All namespaces that are used will have a prefix assigned to
**       them -- mod_dav will never set or use the default namespace
**       when generating XML. This means that "no prefix" will always
**       mean "no namespace".
**
**    In both cases, the XML generation will avoid prepending a prefix.
**    For the first case, this means the original prefix/name will be
**    inserted into the output stream. For the latter case, it means
**    the name will have no prefix, and since we never define a default
**    namespace, this means it will have no namespace.
**
** Note: currently, mod_dav understands the "xmlns" prefix and the
**     "xml:lang" attribute. These are handled specially (they aren't
**     left within the XML tree), so the APR_XML_NS_NONE value won't ever
**     really apply to these values.
*/
#define APR_XML_NS_DAV_ID       0       
#define APR_XML_NS_NONE         -10     
#define APR_XML_NS_ERROR_BASE   -100    
#define APR_XML_NS_IS_ERROR(e)  ((e) <= APR_XML_NS_ERROR_BASE)

typedef struct apr_xml_attr apr_xml_attr;
typedef struct apr_xml_elem apr_xml_elem;
typedef struct apr_xml_doc apr_xml_doc;

struct apr_xml_attr {
    const char *name;
    int ns;

    const char *value;

    struct apr_xml_attr *next;
};

struct apr_xml_elem {
    const char *name;
    int ns;
    const char *lang;

    apr_text_header first_cdata;
    apr_text_header following_cdata;

    struct apr_xml_elem *parent;        
    struct apr_xml_elem *next;  
    struct apr_xml_elem *first_child;
    struct apr_xml_attr *attr;          

    /* used only during parsing */
    struct apr_xml_elem *last_child;
    struct apr_xml_ns_scope *ns_scope;

    /* used by modules during request processing */
    void *priv;
};

#define APR_XML_ELEM_IS_EMPTY(e) ((e)->first_child == NULL && \
                                  (e)->first_cdata.first == NULL)

struct apr_xml_doc {
    apr_xml_elem *root; 
    apr_array_header_t *namespaces;
};

typedef struct apr_xml_parser apr_xml_parser;

APU_DECLARE(apr_xml_parser *) apr_xml_parser_create(apr_pool_t *pool);

APU_DECLARE(apr_status_t) apr_xml_parse_file(apr_pool_t *p,
                                             apr_xml_parser **parser,
                                             apr_xml_doc **ppdoc,
                                             apr_file_t *xmlfd,
                                             apr_size_t buffer_length);


APU_DECLARE(apr_status_t) apr_xml_parser_feed(apr_xml_parser *parser,
                                              const char *data,
                                              apr_size_t len);

APU_DECLARE(apr_status_t) apr_xml_parser_done(apr_xml_parser *parser,
                                              apr_xml_doc **pdoc);

APU_DECLARE(char *) apr_xml_parser_geterror(apr_xml_parser *parser,
                                            char *errbuf,
                                            apr_size_t errbufsize);


APU_DECLARE(void) apr_xml_to_text(apr_pool_t *p, const apr_xml_elem *elem,
                                  int style, apr_array_header_t *namespaces,
                                  int *ns_map, const char **pbuf,
                                  apr_size_t *psize);

/* style argument values: */
#define APR_XML_X2T_FULL         0      
#define APR_XML_X2T_INNER        1      
#define APR_XML_X2T_LANG_INNER   2      
#define APR_XML_X2T_FULL_NS_LANG 3      
APU_DECLARE(const char *) apr_xml_empty_elem(apr_pool_t *p,
                                             const apr_xml_elem *elem);

APU_DECLARE(const char *) apr_xml_quote_string(apr_pool_t *p, const char *s,
                                               int quotes);

APU_DECLARE(void) apr_xml_quote_elem(apr_pool_t *p, apr_xml_elem *elem);

/* manage an array of unique URIs: apr_xml_insert_uri() and APR_XML_URI_ITEM() */

APU_DECLARE(int) apr_xml_insert_uri(apr_array_header_t *uri_array,
                                    const char *uri);

#define APR_XML_GET_URI_ITEM(ary, i) (((const char * const *)(ary)->elts)[i])

#if APR_CHARSET_EBCDIC

APU_DECLARE(apr_status_t) apr_xml_parser_convert_doc(apr_pool_t *p,
                                                     apr_xml_doc *pdoc,
                                                     apr_xlate_t *convset);
#endif

#ifdef __cplusplus
}
#endif

#endif /* APR_XML_H */