Mercurial > hg > pyloader

comparison pyloader/factory.py @ 9:ff634cc2e62b

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
unfinished sketch of an abstract factory
author Jeff Hammel <jhammel@mozilla.com>
date Thu, 26 May 2011 18:14:56 -0700
parents
children ba2355d57998
comparison
equal deleted inserted replaced
8:4d3ea44fd813 9:ff634cc2e62b
1 """
2 abstract factories
3 """
4
5 import loader
6
7 class CircularReferenceError(Exception):
8 """factory has detected a circular reference"""
9
10 class PyFactory(object):
11
12 delimeters = ('%(', ')s')
13
14 def __init__(self, config=None, main=''):
15 self.main = main # main section
16 self.seen = set() # already seen apps to note cyclic dependencies
17 self.parsed = {} # instantiated apps
18 self.load(config or {})
19
20 def load(self, config, name=None):
21 name = name or self.main # load main section by default
22 assert name in config, "'%s' not found in config"
23 if name in self.parsed:
24 return self.parsed[name]
25 if name in self.seen:
26 raise CircularReferenceError('Circular reference! : %s' % name)
27 self.seen.add(name)
28
29 # get section
30 section = config['name']
31 assert 'path' in section
32
33 # load object
34 obj = loader.load(section['path'])
35
36 # interpolate arguments
37 args = section.get('args', None)
38 kwargs = section.get('kwargs', None)
39 if args:
40 args = [self.iterpolate(arg) for arg in args]
41 if kwargs:
42 kwargs = dict([(key, self.interpolate(value))
43 for key, value in kwargs.items()])
44
45 # if args and kwargs aren't there, you're done!
46
47 def interpolate(self, value):
48
49 # only interpolate strings
50 if not isinstance(value, basestring):
51 return value