rename parser/parsers module, add get_parsers() with preference_order

weboob/tools/parsers/__init__.py

@@ -0,0 +1,63 @@
+# -*- coding: utf-8 -*-
+
+"""
+Copyright(C) 2010  Christophe Benz, Romain Bignon
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, version 3 of the License.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+"""
+
+import logging
+
+
+__all__ = ['get_parser', 'NoParserFound']
+
+
+class NoParserFound(Exception): pass
+
+
+def get_parser(preference_order=['lxml', 'html5lib', 'elementtidy', 'builtin'], *args, **kwargs):
+    """
+    Get a parser from a preference order list.
+    This allows Weboob to run on systems without lxml, which is the default parser.
+    Return a parser implementing IParser.
+    """
+    if not isinstance(preference_order, (tuple, list)):
+        preference_order = [preference_order]
+    for kind in preference_order:
+        if kind == 'lxml':
+            try:
+                from .lxmlparser import LxmlHtmlParser
+                return LxmlHtmlParser()
+            except ImportError:
+                logging.debug('%s is not installed.' % kind)
+        elif kind == 'html5lib':
+            try:
+                from .html5libparser import Html5libParser
+                return Html5libParser(*args, **kwargs)
+            except ImportError:
+                logging.debug('%s is not installed.' % kind)
+        elif kind == 'elementtidy':
+            try:
+                from .elementtidyparser import ElementTidyParser
+                return ElementTidyParser()
+            except ImportError:
+                logging.debug('%s is not installed.' % kind)
+        elif kind == 'builtin':
+            try:
+                from .htmlparser import HTMLParser
+                return HTMLParser()
+            except ImportError:
+                logging.debug('%s is not installed.' % kind)
+    raise NoParserFound()