[ui] Prepare for better rst parsing and displaying

beat/web/ui/templatetags/markup.py

@@ -95,6 +95,64 @@ def markdown(value, arg=''):
                     ))
 
 
+def get_rst_errors(s, config):
+    """Catch errors and syntax warnings and returns them
+    """
+
+    import docutils.utils
+    import docutils.parsers
+    import docutils.frontend
+
+    class SilentReporter(docutils.utils.Reporter):
+      """
+      Silent reporter
+
+      All warnings and errors will be stored and can be used subsequently
+      through the reporter instance
+      """
+
+      def __init__(self, *args, **kwargs):
+          self.messages = []
+          docutils.utils.Reporter.__init__(self, *args, **kwargs)
+
+      def system_message(self, level, message, *children, **kwargs):
+          self.messages.append((level, message, children, kwargs))
+
+    parser = docutils.parsers.rst.Parser()
+
+    defaults = docutils.frontend.OptionParser().get_default_values()
+    for key, val in config.items(): setattr(defaults, key, val)
+    defaults.tab_width = 4
+    defaults.pep_references = None
+    defaults.rfc_references = None
+    defaults.report_level = 1 #info
+    defaults.halt_level = 4 #severe
+    defaults.debug = 0 #don't debug
+
+    reporter = SilentReporter(
+        None,
+        defaults.report_level, #info
+        defaults.halt_level, #severe
+        stream=defaults.warning_stream,
+        debug=defaults.debug, #no debug
+        encoding=defaults.error_encoding,
+        error_handler=defaults.error_encoding_error_handler,
+    )
+
+    document = docutils.utils.new_document(None, defaults)
+    document.reporter = reporter
+
+    try:
+        parser.parse(s, document)
+    except AttributeError:
+        pass
+    except TypeError:
+        # Catch ``TypeError`` to avoid problems with local roles
+        # NOTE: Is this still necessary ?
+        pass
+    return reporter.messages
+
+
 @register.filter(is_safe=True)
 @stringfilter
 def restructuredtext(value, full=False):
@@ -107,6 +165,7 @@ def restructuredtext(value, full=False):
     else:
         docutils_settings = getattr(settings, "RESTRUCTUREDTEXT_FILTER_SETTINGS", {})
         parts = publish_parts(source=force_bytes(value), writer_name="html4css1", settings_overrides=docutils_settings)
+        #errors = get_rst_errors(value, docutils_settings)
         if full:
             return mark_safe(force_text(parts["html_body"])) #with h1 title
         else: