gmarkup.h File Reference

__G_MARKUP_H__

Enum GMarkupError

G_MARKUP_ERROR

g_markup_error_quark ( void )

IMPORT_C GQuarkg_markup_error_quark(void)

Enum GMarkupParseFlags

Typedef GMarkupParseContext

typedef struct _GMarkupParseContextGMarkupParseContext

Typedef GMarkupParser

typedef struct _GMarkupParserGMarkupParser

g_markup_parse_context_new ( const GMarkupParser *, GMarkupParseFlags, gpointer, GDestroyNotify )

IMPORT_C GMarkupParseContext *g_markup_parse_context_new(const GMarkupParser *parser,
GMarkupParseFlagsflags,
gpointeruser_data,
GDestroyNotifyuser_data_dnotify
)

g_markup_parse_context_new: : a GMarkupParser : one or more GMarkupParseFlags : user data to pass to GMarkupParser functions : user data destroy notifier called when the parse context is freed

Creates a new parse context. A parse context is used to parse marked-up documents. You can feed any number of documents into a context, as long as no errors occur; once an error occurs, the parse context can't continue to parse text (you have to free it and create a new parse context).

Return value: a new GMarkupParseContext

g_markup_parse_context_free ( GMarkupParseContext * )

IMPORT_C voidg_markup_parse_context_free(GMarkupParseContext *context)

g_markup_parse_context_free: : a GMarkupParseContext

Frees a GMarkupParseContext. Can't be called from inside one of the GMarkupParser functions. Can't be called while a subparser is pushed.

g_markup_parse_context_parse ( GMarkupParseContext *, const gchar *, gssize, GError ** )

IMPORT_C gbooleang_markup_parse_context_parse(GMarkupParseContext *context,
const gchar *text,
gssizetext_len,
GError **error
)

g_markup_parse_context_parse: : a GMarkupParseContext : chunk of text to parse : length of in bytes : return location for a GError

Feed some data to the GMarkupParseContext. The data need not be valid UTF-8; an error will be signaled if it's invalid. The data need not be an entire document; you can feed a document into the parser incrementally, via multiple calls to this function. Typically, as you receive data from a network connection or file, you feed each received chunk of data into this function, aborting the process if an error occurs. Once an error is reported, no further data may be fed to the GMarkupParseContext; all errors are fatal.

Return value: FALSE if an error occurred, TRUE on success

g_markup_parse_context_push ( GMarkupParseContext *, GMarkupParser *, gpointer )

IMPORT_C voidg_markup_parse_context_push(GMarkupParseContext *context,
GMarkupParser *parser,
gpointeruser_data
)

g_markup_parse_context_push: : a GMarkupParseContext : a GMarkupParser : user data to pass to GMarkupParser functions

Temporarily redirects markup data to a sub-parser.

This function may only be called from the start_element handler of a GMarkupParser. It must be matched with a corresponding call to g_markup_parse_context_pop() in the matching end_element handler (except in the case that the parser aborts due to an error).

All tags, text and other data between the matching tags is redirected to the subparser given by . is used as the user_data for that parser. is also passed to the error callback in the event that an error occurs. This includes errors that occur in subparsers of the subparser.

The end tag matching the start tag for which this call was made is handled by the previous parser (which is given its own user_data) which is why g_markup_parse_context_pop() is provided to allow "one last access" to the provided to this function. In the case of error, the provided here is passed directly to the error callback of the subparser and g_markup_parse_context() should not be called. In either case, if was allocated then it ought to be freed from both of these locations.

This function is not intended to be directly called by users interested in invoking subparsers. Instead, it is intended to be used by the subparsers themselves to implement a higher-level interface.

As an example, see the following implementation of a simple parser that counts the number of tags encountered.

|[ typedef struct { gint tag_count; } CounterData;

static void counter_start_element (GMarkupParseContext *context, const gchar *element_name, const gchar **attribute_names, const gchar **attribute_values, gpointer user_data, GError **error) { CounterData *data = user_data;

data->tag_count++; }

static void counter_error (GMarkupParseContext *context, GError *error, gpointer user_data) { CounterData *data = user_data;

g_slice_free (CounterData, data); }

static GMarkupParser counter_subparser = { counter_start_element, NULL, NULL, NULL, counter_error }; ]|

In order to allow this parser to be easily used as a subparser, the following interface is provided:

|[ void start_counting (GMarkupParseContext *context) { CounterData *data = g_slice_new (CounterData);

data->tag_count = 0; g_markup_parse_context_push (context, &counter_subparser, data); }

gint end_counting (GMarkupParseContext *context) { CounterData *data = g_markup_parse_context_pop (context); int result;

result = data->tag_count; g_slice_free (CounterData, data);

return result; } ]|

The subparser would then be used as follows:

|[ static void start_element (context, element_name, ...) { if (strcmp (element_name, "count-these") == 0) start_counting (context);

/ else, handle other tags... / }

static void end_element (context, element_name, ...) { if (strcmp (element_name, "count-these") == 0) g_print ("Counted %d tags\n", end_counting (context));

/ else, handle other tags... / } ]|

Since: 2.18

g_markup_parse_context_pop ( GMarkupParseContext * )

IMPORT_C gpointerg_markup_parse_context_pop(GMarkupParseContext *context)

g_markup_parse_context_pop: : a GMarkupParseContext

Completes the process of a temporary sub-parser redirection.

This function exists to collect the user_data allocated by a matching call to g_markup_parse_context_push(). It must be called in the end_element handler corresponding to the start_element handler during which g_markup_parse_context_push() was called. You must not call this function from the error callback -- the is provided directly to the callback in that case.

This function is not intended to be directly called by users interested in invoking subparsers. Instead, it is intended to be used by the subparsers themselves to implement a higher-level interface.

Returns: the user_data passed to g_markup_parse_context_push().

Since: 2.18

g_markup_parse_context_end_parse ( GMarkupParseContext *, GError ** )

IMPORT_C gbooleang_markup_parse_context_end_parse(GMarkupParseContext *context,
GError **error
)

g_markup_parse_context_end_parse: : a GMarkupParseContext : return location for a GError

Signals to the GMarkupParseContext that all data has been fed into the parse context with g_markup_parse_context_parse(). This function reports an error if the document isn't complete, for example if elements are still open.

Return value: TRUE on success, FALSE if an error was set

g_markup_parse_context_get_element ( GMarkupParseContext * )

IMPORT_C G_CONST_RETURN gchar *g_markup_parse_context_get_element(GMarkupParseContext *context)

g_markup_parse_context_get_element: : a GMarkupParseContext Retrieves the name of the currently open element.

If called from the start_element or end_element handlers this will give the element_name as passed to those functions. For the parent elements, see g_markup_parse_context_get_element_stack().

Since: 2.2

Return Value
: the name of the currently open element, or NULL

g_markup_parse_context_get_element_stack ( GMarkupParseContext * )

IMPORT_C G_CONST_RETURN GSList *g_markup_parse_context_get_element_stack(GMarkupParseContext *context)

g_markup_parse_context_get_element_stack: : a GMarkupParseContext

Retrieves the element stack from the internal state of the parser. The returned GSList is a list of strings where the first item is the currently open tag (as would be returned by g_markup_parse_context_get_element()) and the next item is its immediate parent.

This function is intended to be used in the start_element and end_element handlers where g_markup_parse_context_get_element() would merely return the name of the element that is being processed.

Returns: the element stack, which must not be modified

Since: 2.16

g_markup_parse_context_get_position ( GMarkupParseContext *, gint *, gint * )

IMPORT_C voidg_markup_parse_context_get_position(GMarkupParseContext *context,
gint *line_number,
gint *char_number
)

g_markup_parse_context_get_position: : a GMarkupParseContext : return location for a line number, or NULL : return location for a char-on-line number, or NULL

Retrieves the current line number and the number of the character on that line. Intended for use in error messages; there are no strict semantics for what constitutes the "current" line number other than "the best number we could come up with for error messages."

g_markup_parse_context_get_user_data ( GMarkupParseContext * )

IMPORT_C gpointerg_markup_parse_context_get_user_data(GMarkupParseContext *context)

g_markup_parse_context_get_user_data: : a GMarkupParseContext

Returns the user_data associated with . This will either be the user_data that was provided to g_markup_parse_context_new() or to the most recent call of g_markup_parse_context_push().

Returns: the provided user_data. The returned data belongs to the markup context and will be freed when g_markup_context_free() is called.

Since: 2.18

g_markup_escape_text ( const gchar *, gssize )

IMPORT_C gchar *g_markup_escape_text(const gchar *text,
gssizelength
)

g_markup_escape_text: : some valid UTF-8 text : length of in bytes, or -1 if the text is nul-terminated

Escapes text so that the markup parser will parse it verbatim. Less than, greater than, ampersand, etc. are replaced with the corresponding entities. This function would typically be used when writing out a file to be parsed with the markup parser.

Note that this function doesn't protect whitespace and line endings from being processed according to the XML rules for normalization of line endings and attribute values.

Note also that if given a string containing them, this function will produce character references in the range of  ..  for all control sequences except for tabstop, newline and carriage return. The character references in this range are not valid XML 1.0, but they are valid XML 1.1 and will be accepted by the GMarkup parser.

Return value: a newly allocated string with the escaped text

g_markup_printf_escaped ( const char *, ... )

IMPORT_C gchar *g_markup_printf_escaped(const char *format,
...
)

g_markup_vprintf_escaped ( const char *, va_list )

IMPORT_C gchar IMPORT_C gchar *g_markup_vprintf_escaped(const char *format,
va_listargs
)

g_markup_vprintf_escaped: : printf() style format string : variable argument list, similar to vprintf()

Formats the data in according to , escaping all string and character arguments in the fashion of g_markup_escape_text(). See g_markup_printf_escaped().

Return value: newly allocated result from formatting operation. Free with g_free().

Since: 2.4

Enum GMarkupCollectType

g_markup_collect_attributes ( const gchar *, const gchar **, const gchar **, GError **, GMarkupCollectType, const gchar *, ... )

IMPORT_C gbooleang_markup_collect_attributes(const gchar *element_name,
const gchar **attribute_names,
const gchar **attribute_values,
GError **error,
GMarkupCollectTypefirst_type,
const gchar *first_attr,
...
)

GMarkupCollectType: : used to terminate the list of attributes to collect. : collect the string pointer directly from the attribute_values[] array. Expects a parameter of type (const char **). If G_MARKUP_COLLECT_OPTIONAL is specified and the attribute isn't present then the pointer will be set to NULL. : as with G_MARKUP_COLLECT_STRING, but expects a paramter of type (char **) and g_strdup()s the returned pointer. The pointer must be freed with g_free(). : expects a parameter of type (gboolean *) and parses the attribute value as a boolean. Sets FALSE if the attribute isn't present. Valid boolean values consist of (case insensitive) "false", "f", "no", "n", "0" and "true", "t", "yes", "y", "1". : as with G_MARKUP_COLLECT_BOOLEAN, but in the case of a missing attribute a value is set that compares equal to neither FALSE nor TRUE. G_MARKUP_COLLECT_OPTIONAL is implied. : can be bitwise ORed with the other fields. If present, allows the attribute not to appear. A default value is set depending on what value type is used.

A mixed enumerated type and flags field. You must specify one type (string, strdup, boolean, tristate). Additionally, you may optionally bitwise OR the type with the flag G_MARKUP_COLLECT_OPTIONAL.

It is likely that this enum will be extended in the future to support other types. g_markup_collect_attributes: : the current tag name : the attribute names : the attribute values : a pointer to a GError or NULL : the GMarkupCollectType of the first attribute : the name of the first attribute @...: a pointer to the storage location of the first attribute (or NULL), followed by more types names and pointers, ending with G_MARKUP_COLLECT_INVALID.

Collects the attributes of the element from the data passed to the GMarkupParser start_element function, dealing with common error conditions and supporting boolean values.

This utility function is not required to write a parser but can save a lot of typing.

The , , and parameters passed to the start_element callback should be passed unmodified to this function.

Following these arguments is a list of "supported" attributes to collect. It is an error to specify multiple attributes with the same name. If any attribute not in the list appears in the array then an unknown attribute error will result.

The GMarkupCollectType field allows specifying the type of collection to perform and if a given attribute must appear or is optional.

The attribute name is simply the name of the attribute to collect.

The pointer should be of the appropriate type (see the descriptions under GMarkupCollectType) and may be NULL in case a particular attribute is to be allowed but ignored.

This function deals with issuing errors for missing attributes (of type G_MARKUP_ERROR_MISSING_ATTRIBUTE), unknown attributes (of type G_MARKUP_ERROR_UNKNOWN_ATTRIBUTE) and duplicate attributes (of type G_MARKUP_ERROR_INVALID_CONTENT) as well as parse errors for boolean-valued attributes (again of type G_MARKUP_ERROR_INVALID_CONTENT). In all of these cases FALSE will be returned and will be set as appropriate.

Return value: TRUE if successful

Since: 2.16