# (c) 2005 Ian Bicking and contributors # This module is part of the Python Paste Project and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php """ This module provides helper routines with work directly on a WSGI environment to solve common requirements. * get_cookies(environ) * parse_querystring(environ) * parse_formvars(environ, all_as_list=False, include_get_vars=True) * construct_url(environ, with_query_string=True, with_path_info=True, script_name=None, path_info=None, querystring=None) * path_info_split(path_info) * path_info_pop(environ) """ import cgi from Cookie import SimpleCookie __all__ = ['get_cookies', 'parse_querystring', 'parse_formvars', 'construct_url', 'path_info_split', 'path_info_pop'] def get_cookies(environ): """ Gets a cookie object (which is a dictionary-like object) from the request environment; caches this value in case get_cookies is called again for the same request. """ header = environ.get('HTTP_COOKIE', '') if environ.has_key('paste.cookies'): cookies, check_header = environ['paste.cookies'] if check_header == header: return cookies cookies = SimpleCookie() cookies.load(header) environ['paste.cookies'] = (cookies, header) return cookies def parse_querystring(environ): """ Parses a query string into a list like ``[(name, value)]``. Caches this value in case parse_querystring is called again for the same request. You can pass the result to ``dict()``, but be aware that keys that appear multiple times will be lost (only the last value will be preserved). """ source = environ.get('QUERY_STRING', '') if not source: return [] if 'paste.parsed_querystring' in environ: parsed, check_source = environ['paste.parsed_querystring'] if check_source == source: return parsed parsed = cgi.parse_qsl(source, keep_blank_values=True, strict_parsing=False) environ['paste.parsed_querystring'] = (parsed, source) return parsed def parse_formvars(environ, all_as_list=False, include_get_vars=True): """ Parses the request, returning a dictionary of the keys. If ``all_as_list`` is true, then all values will be lists. If not, then only values that show up multiple times will be lists. If ``include_get_vars`` is true and this was a POST request, then GET (query string) variables will also be folded into the dictionary. All values should be strings, except for file uploads which are left as FieldStorage instances. """ source = (environ.get('QUERY_STRING', ''), environ['wsgi.input'], environ['REQUEST_METHOD'], all_as_list, include_get_vars) if 'paste.parsed_formvars' in environ: parsed, check_source = environ['paste.parsed_formvars'] if check_source == source: return parsed fs = cgi.FieldStorage(fp=environ['wsgi.input'], environ=environ, keep_blank_values=1) formvars = {} for name in fs.keys(): values = fs[name] if not isinstance(values, list): values = [values] for value in values: if not value.filename: value = value.value if name in formvars: if isinstance(formvars[name], list): formvars[name].append(value) else: formvars[name] = [formvars[name], value] elif all_as_list: formvars[name] = [value] else: formvars[name] = value if environ['REQUEST_METHOD'] == 'POST' and include_get_vars: for name, value in parse_querystring(environ): if name in formvars: if isinstance(formvars[name], list): formvars[name].append(value) else: formvars[name] = [formvars[name], value] elif all_as_list: formvars[name] = [value] else: formvars[name] = value environ['paste.parsed_formvars'] = (formvars, source) return formvars def construct_url(environ, with_query_string=True, with_path_info=True, script_name=None, path_info=None, querystring=None): """ Reconstructs the URL from the WSGI environment. You may override SCRIPT_NAME, PATH_INFO, and QUERYSTRING with the keyword arguments. """ url = environ['wsgi.url_scheme']+'://' if environ.get('HTTP_HOST'): url += environ['HTTP_HOST'].split(':')[0] else: url += environ['SERVER_NAME'] if environ['wsgi.url_scheme'] == 'https': if environ['SERVER_PORT'] != '443': url += ':' + environ['SERVER_PORT'] else: if environ['SERVER_PORT'] != '80': url += ':' + environ['SERVER_PORT'] if script_name is None: url += environ.get('SCRIPT_NAME','') else: url += script_name if with_path_info: if path_info is None: url += environ.get('PATH_INFO','') else: url += path_info if with_query_string: if querystring is None: if environ.get('QUERY_STRING'): url += '?' + environ['QUERY_STRING'] elif querystring: url += '?' + querystring return url def path_info_split(path_info): """ Splits off the first segment of the path. Returns (first_part, rest_of_path). first_part can be None (if PATH_INFO is empty), '' (if PATH_INFO is '/'), or a name without any /'s. rest_of_path can be '' or a string starting with /. """ if not path_info: return None, '' assert path_info.startswith('/'), ( "PATH_INFO should start with /: %r" % path_info) path_info = path_info.lstrip('/') if '/' in path_info: first, rest = path_info.split('/', 1) return first, '/' + rest else: return path_info, '' def path_info_pop(environ): """ 'Pops' off the next segment of PATH_INFO, pushing it onto SCRIPT_NAME, and returning that segment. For instance:: >>> def call_it(script_name, path_info): ... env = {'SCRIPT_NAME': script_name, 'PATH_INFO': path_info} ... result = path_info_pop(env) ... print 'SCRIPT_NAME=%r; PATH_INFO=%r; returns=%r' % ( ... env['SCRIPT_NAME'], env['PATH_INFO'], result) >>> call_it('/foo', '/bar') SCRIPT_NAME='/foo/bar'; PATH_INFO=''; returns='bar' >>> call_it('/foo/bar', '') SCRIPT_NAME='/foo/bar'; PATH_INFO=''; returns=None >>> call_it('/foo/bar', '/') SCRIPT_NAME='/foo/bar/'; PATH_INFO=''; returns='' >>> call_it('', '/1/2/3') SCRIPT_NAME='/1'; PATH_INFO='/2/3'; returns='1' >>> call_it('', '//1/2') SCRIPT_NAME='//1'; PATH_INFO='/2'; returns='1' """ path = environ.get('PATH_INFO', '') if not path: return None while path.startswith('/'): environ['SCRIPT_NAME'] += '/' path = path[1:] if '/' not in path: environ['SCRIPT_NAME'] += path environ['PATH_INFO'] = '' return path else: segment, path = path.split('/', 1) environ['PATH_INFO'] = '/' + path environ['SCRIPT_NAME'] += segment return segment if __name__ == '__main__': import doctest doctest.testmod()