/**
* @copyright
* ====================================================================
* 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.
* ====================================================================
* @endcopyright
*
* @file svn_xml.h
* @brief XML code shared by various Subversion libraries.
*/
#ifndef SVN_XML_H
#define SVN_XML_H
#include <apr.h>
#include <apr_pools.h>
#include <apr_hash.h>
#include "svn_types.h"
#include "svn_string.h"
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/** The namespace all Subversion XML uses. */
#define SVN_XML_NAMESPACE "svn:"
/** Used as style argument to svn_xml_make_open_tag() and friends. */
enum svn_xml_open_tag_style {
/** <tag ...> */
svn_xml_normal = 1,
/** <tag ...>, no cosmetic newline */
svn_xml_protect_pcdata,
/** <tag .../> */
svn_xml_self_closing
};
/** Determine if a string of character @a data of length @a len is a
* safe bet for use with the svn_xml_escape_* functions found in this
* header.
*
* Return @c TRUE if it is, @c FALSE otherwise.
*
* Essentially, this function exists to determine whether or not
* simply running a string of bytes through the Subversion XML escape
* routines will produce legitimate XML. It should only be necessary
* for data which might contain bytes that cannot be safely encoded
* into XML (certain control characters, for example).
*/
svn_boolean_t
svn_xml_is_xml_safe(const char *data,
apr_size_t len);
/** Create or append in @a *outstr an xml-escaped version of @a string,
* suitable for output as character data.
*
* If @a *outstr is @c NULL, set @a *outstr to a new stringbuf allocated
* in @a pool, else append to the existing stringbuf there.
*/
void
svn_xml_escape_cdata_stringbuf(svn_stringbuf_t **outstr,
const svn_stringbuf_t *string,
apr_pool_t *pool);
/** Same as svn_xml_escape_cdata_stringbuf(), but @a string is an
* @c svn_string_t.
*/
void
svn_xml_escape_cdata_string(svn_stringbuf_t **outstr,
const svn_string_t *string,
apr_pool_t *pool);
/** Same as svn_xml_escape_cdata_stringbuf(), but @a string is a
* NULL-terminated C string.
*/
void
svn_xml_escape_cdata_cstring(svn_stringbuf_t **outstr,
const char *string,
apr_pool_t *pool);
/** Create or append in @a *outstr an xml-escaped version of @a string,
* suitable for output as an attribute value.
*
* If @a *outstr is @c NULL, set @a *outstr to a new stringbuf allocated
* in @a pool, else append to the existing stringbuf there.
*/
void
svn_xml_escape_attr_stringbuf(svn_stringbuf_t **outstr,
const svn_stringbuf_t *string,
apr_pool_t *pool);
/** Same as svn_xml_escape_attr_stringbuf(), but @a string is an
* @c svn_string_t.
*/
void
svn_xml_escape_attr_string(svn_stringbuf_t **outstr,
const svn_string_t *string,
apr_pool_t *pool);
/** Same as svn_xml_escape_attr_stringbuf(), but @a string is a
* NULL-terminated C string.
*/
void
svn_xml_escape_attr_cstring(svn_stringbuf_t **outstr,
const char *string,
apr_pool_t *pool);
/**
* Return UTF-8 string @a string if it contains no characters that are
* unrepresentable in XML. Else, return a copy of @a string,
* allocated in @a pool, with each unrepresentable character replaced
* by "?\uuu", where "uuu" is the three-digit unsigned decimal value
* of that character.
*
* Neither the input nor the output need be valid XML; however, the
* output can always be safely XML-escaped.
*
* @note The current implementation treats all Unicode characters as
* representable, except for most ASCII control characters (the
* exceptions being CR, LF, and TAB, which are valid in XML). There
* may be other UTF-8 characters that are invalid in XML; see
* http://subversion.tigris.org/servlets/ReadMsg?list=dev&msgNo=90591
* and its thread for details.
*
* @since New in 1.2.
*/
const char *
svn_xml_fuzzy_escape(const char *string,
apr_pool_t *pool);
/*---------------------------------------------------------------*/
/* Generalized Subversion XML Parsing */
/** A generalized Subversion XML parser object */
typedef struct svn_xml_parser_t svn_xml_parser_t;
typedef void (*svn_xml_start_elem)(void *baton,
const char *name,
const char **atts);
typedef void (*svn_xml_end_elem)(void *baton, const char *name);
/* data is not NULL-terminated. */
typedef void (*svn_xml_char_data)(void *baton,
const char *data,
apr_size_t len);
/** Create a general Subversion XML parser */
svn_xml_parser_t *
svn_xml_make_parser(void *baton,
svn_xml_start_elem start_handler,
svn_xml_end_elem end_handler,
svn_xml_char_data data_handler,
apr_pool_t *pool);
/** Free a general Subversion XML parser */
void
svn_xml_free_parser(svn_xml_parser_t *svn_parser);
/** Push @a len bytes of xml data in @a buf at @a svn_parser.
*
* If this is the final push, @a is_final must be set.
*
* An error will be returned if there was a syntax problem in the XML,
* or if any of the callbacks set an error using
* svn_xml_signal_bailout().
*
* If an error is returned, the @c svn_xml_parser_t will have been freed
* automatically, so the caller should not call svn_xml_free_parser().
*/
svn_error_t *
svn_xml_parse(svn_xml_parser_t *svn_parser,
const char *buf,
apr_size_t len,
svn_boolean_t is_final);
/** The way to officially bail out of xml parsing.
*
* Store @a error in @a svn_parser and set all expat callbacks to @c NULL.
*/
void
svn_xml_signal_bailout(svn_error_t *error,
svn_xml_parser_t *svn_parser);
/*** Helpers for dealing with the data Expat gives us. ***/
/** Return the value associated with @a name in expat attribute array @a atts,
* else return @c NULL.
*
* (There could never be a @c NULL attribute value in the XML,
* although the empty string is possible.)
*
* @a atts is an array of c-strings: even-numbered indexes are names,
* odd-numbers hold values. If all is right, it should end on an
* even-numbered index pointing to @c NULL.
*/
const char *
svn_xml_get_attr_value(const char *name,
const char *const *atts);
/* Converting between Expat attribute lists and APR hash tables. */
/** Create an attribute hash from @c va_list @a ap.
*
* The contents of @a ap are alternating <tt>char *</tt> keys and
* <tt>char *</tt> vals, terminated by a final @c NULL falling on an
* even index (zero-based).
*/
apr_hash_t *
svn_xml_ap_to_hash(va_list ap,
apr_pool_t *pool);
/** Create a hash that corresponds to Expat xml attribute list @a atts.
*
* The hash's keys and values are <tt>char *</tt>'s.
*
* @a atts may be NULL, in which case you just get an empty hash back
* (this makes life more convenient for some callers).
*/
apr_hash_t *
svn_xml_make_att_hash(const char **atts,
apr_pool_t *pool);
/** Like svn_xml_make_att_hash(), but takes a hash and preserves any
* key/value pairs already in it.
*/
void
svn_xml_hash_atts_preserving(const char **atts,
apr_hash_t *ht,
apr_pool_t *pool);
/** Like svn_xml_make_att_hash(), but takes a hash and overwrites
* key/value pairs already in it that also appear in @a atts.
*/
void
svn_xml_hash_atts_overlaying(const char **atts,
apr_hash_t *ht,
apr_pool_t *pool);
/* Printing XML */
/** Create an XML header and return it in @a *str.
*
* Fully-formed XML documents should start out with a header,
* something like <pre>
* \<?xml version="1.0" encoding="UTF-8"?\>
* </pre>
*
* This function returns such a header. @a *str must either be @c NULL, in
* which case a new string is created, or it must point to an existing
* string to be appended to. @a encoding must either be NULL, in which case
* encoding information is omitted from the header, or must be the name of
* the encoding of the XML document, such as "UTF-8".
*
* @since New in 1.7.
*/
void
svn_xml_make_header2(svn_stringbuf_t **str,
const char *encoding,
apr_pool_t *pool);
/** Like svn_xml_make_header2(), but does not emit encoding information.
*
* @deprecated Provided for backward compatibility with the 1.6 API.
*/
SVN_DEPRECATED
void
svn_xml_make_header(svn_stringbuf_t **str,
apr_pool_t *pool);
/** Store a new xml tag @a tagname in @a *str.
*
* If @a *str is @c NULL, set @a *str to a new stringbuf allocated
* in @a pool, else append to the existing stringbuf there.
*
* Take the tag's attributes from varargs, a NULL-terminated list of
* alternating <tt>char *</tt> key and <tt>char *</tt> val. Do xml-escaping
* on each val.
*
* @a style is one of the enumerated styles in @c svn_xml_open_tag_style.
*/
void
svn_xml_make_open_tag(svn_stringbuf_t **str,
apr_pool_t *pool,
enum svn_xml_open_tag_style style,
const char *tagname,
...);
/** Like svn_xml_make_open_tag(), but takes a @c va_list instead of being
* variadic.
*/
void
svn_xml_make_open_tag_v(svn_stringbuf_t **str,
apr_pool_t *pool,
enum svn_xml_open_tag_style style,
const char *tagname,
va_list ap);
/** Like svn_xml_make_open_tag(), but takes a hash table of attributes
* (<tt>char *</tt> keys mapping to <tt>char *</tt> values).
*
* You might ask, why not just provide svn_xml_make_tag_atts()?
*
* The reason is that a hash table is the most natural interface to an
* attribute list; the fact that Expat uses <tt>char **</tt> atts instead is
* certainly a defensible implementation decision, but since we'd have
* to have special code to support such lists throughout Subversion
* anyway, we might as well write that code for the natural interface
* (hashes) and then convert in the few cases where conversion is
* needed. Someday it might even be nice to change expat-lite to work
* with apr hashes.
*
* See conversion functions svn_xml_make_att_hash() and
* svn_xml_make_att_hash_overlaying(). Callers should use those to
* convert Expat attr lists into hashes when necessary.
*/
void
svn_xml_make_open_tag_hash(svn_stringbuf_t **str,
apr_pool_t *pool,
enum svn_xml_open_tag_style style,
const char *tagname,
apr_hash_t *attributes);
/** Store an xml close tag @a tagname in @a str.
*
* If @a *str is @c NULL, set @a *str to a new stringbuf allocated
* in @a pool, else append to the existing stringbuf there.
*/
void
svn_xml_make_close_tag(svn_stringbuf_t **str,
apr_pool_t *pool,
const char *tagname);
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* SVN_XML_H */