objectpub.py

from paste.request import parse_formvars

class ObjectPublisher(object):
    def __init__(self, root):
        self.root = root

    def __call__(self, environ, start_response):
        fields = parse_formvars(environ)
        obj = self.find_object(self.root, environ)
        response_body = "as per usual"
        if obj:
            try:
                response_body = obj(**fields.mixed())
                start_response('200 OK', [('content-type', 'text/html')])
            except:
                start_response('400 Bad Request', [('content-type', 'text/html')])
        else:
            start_response('400 Bad Request', [('content-type', 'text/html')])
        return response_body

    def find_object(self, obj, environ):
        path_info = environ.get('PATH_INFO', '')
        if not path_info or path_info == '/':
            # We've arrived!
            return obj

        # PATH_INFO always starts with a /, so we'll get rid of it:
        path_info = path_info.lstrip('/')

        # Then split the path into the "next" chunk, and everything after it
        # ("rest"):
        parts = path_info.split('/', 1)
        next = parts[0]
        if len(parts) == 1:
            rest = ''
        else:
            rest = '/' + parts[1]

        # Hide private methods/attributes:
        assert not next.startswith('_')

        # Now we get the attribute; getattr(a, 'b') is equivalent to a.b...
        try:
            next_obj = getattr(obj, next)
        except:
            return None

        # Now fix up SCRIPT_NAME and PATH_INFO...
        environ['SCRIPT_NAME'] += '/' + next
        environ['PATH_INFO'] = rest

        # and now parse the remaining part of the URL...
        return self.find_object(next_obj, environ)