:right-sidebar: True MarkupParseContext =================================================================== .. currentmodule:: gi.repository.GLib .. class:: MarkupParseContext(**kwargs) :no-contents-entry: A parse context is used to parse a stream of bytes that you expect to contain marked-up text. See :func:`~gi.repository.GLib.MarkupParseContext.new`, :obj:`~gi.repository.GLib.MarkupParser`\, and so on for more details. Constructors ------------ .. rst-class:: interim-class .. class:: MarkupParseContext :no-index: .. classmethod:: new(parser: ~gi.repository.GLib.MarkupParser, flags: ~gi.repository.GLib.MarkupParseFlags, user_data: ~typing.Any, user_data_dnotify: ~typing.Callable[[~typing.Any], None]) -> ~gi.repository.GLib.MarkupParseContext 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). :param parser: a :obj:`~gi.repository.GLib.MarkupParser` :param flags: one or more :obj:`~gi.repository.GLib.MarkupParseFlags` :param user_data: user data to pass to :obj:`~gi.repository.GLib.MarkupParser` functions :param user_data_dnotify: user data destroy notifier called when the parse context is freed Methods ------- .. rst-class:: interim-class .. class:: MarkupParseContext :no-index: .. method:: end_parse() -> bool Signals to the :obj:`~gi.repository.GLib.MarkupParseContext` that all data has been fed into the parse context with :func:`~gi.repository.GLib.MarkupParseContext.parse`. This function reports an error if the document isn't complete, for example if elements are still open. .. method:: free() -> None Frees a :obj:`~gi.repository.GLib.MarkupParseContext`\. This function can't be called from inside one of the :obj:`~gi.repository.GLib.MarkupParser` functions or while a subparser is pushed. .. method:: get_element() -> str 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 :func:`~gi.repository.GLib.MarkupParseContext.get_element_stack`. .. versionadded:: 2.2 .. method:: get_element_stack() -> list[str] 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 :func:`~gi.repository.GLib.MarkupParseContext.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 :func:`~gi.repository.GLib.MarkupParseContext.get_element` would merely return the name of the element that is being processed. .. versionadded:: 2.16 .. method:: get_position() -> ~typing.Tuple[int, int] 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." .. method:: get_user_data() -> ~typing.Any | None Returns the user_data associated with ``context``\. This will either be the user_data that was provided to :func:`~gi.repository.GLib.MarkupParseContext.new` or to the most recent call of :func:`~gi.repository.GLib.MarkupParseContext.push`. .. versionadded:: 2.18 .. method:: parse(text: str, text_len: int) -> bool Feed some data to the :obj:`~gi.repository.GLib.MarkupParseContext`\. 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 :obj:`~gi.repository.GLib.MarkupParseContext`\; all errors are fatal. :param text: chunk of text to parse :param text_len: length of ``text`` in bytes .. method:: pop() -> ~typing.Any | None Completes the process of a temporary sub-parser redirection. This function exists to collect the user_data allocated by a matching call to :func:`~gi.repository.GLib.MarkupParseContext.push`. It must be called in the end_element handler corresponding to the start_element handler during which :func:`~gi.repository.GLib.MarkupParseContext.push` was called. You must not call this function from the error callback -- the ``user_data`` 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. .. versionadded:: 2.18 .. method:: push(parser: ~gi.repository.GLib.MarkupParser, user_data: ~typing.Any = None) -> None Temporarily redirects markup data to a sub-parser. This function may only be called from the start_element handler of a :obj:`~gi.repository.GLib.MarkupParser`\. It must be matched with a corresponding call to :func:`~gi.repository.GLib.MarkupParseContext.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 ``parser``\. ``user_data`` is used as the user_data for that parser. ``user_data`` 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 :func:`~gi.repository.GLib.MarkupParseContext.pop` is provided to allow "one last access" to the ``user_data`` provided to this function. In the case of error, the ``user_data`` provided here is passed directly to the error callback of the subparser and :func:`~gi.repository.GLib.MarkupParseContext.pop` should not be called. In either case, if ``user_data`` 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. .. code-block:: C :dedent: 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: .. code-block:: C :dedent: 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: .. code-block:: C :dedent: 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... } .. versionadded:: 2.18 :param parser: a :obj:`~gi.repository.GLib.MarkupParser` :param user_data: user data to pass to :obj:`~gi.repository.GLib.MarkupParser` functions