Mercurial > fife-parpg

comparison engine/extensions/pychan/attrs.py @ 0:4a0efb7baf70

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
* Datasets becomes the new trunk and retires after that :-)
author mvbarracuda@33b003aa-7bff-0310-803a-e67f0ece8222
date Sun, 29 Jun 2008 18:44:17 +0000
parents
children ec653fde64d3
comparison
equal deleted inserted replaced
-1:000000000000 0:4a0efb7baf70
1 # coding: utf-8
2
3 """
4 Simple error checking attributes.
5
6 This module defines a set of Attribute classes
7 which you can use to define possible values
8 an attribute of an object accepts.
9
10 Usage::
11 class SomeObject:
12 nameAttr, posAttr = [ Attr("name"), PointAttr("pos") ]
13
14 obj = SomeObject()
15 obj.nameAttr.set(obj,"newName")
16 obj.posAttr.set(obj,"89,89")
17
18 This is most useful for error checking parsing and defining
19 accepted attributes in classes and is used by pychan internally.
20
21 """
22
23 from exceptions import ParserError
24
25 class Attr(object):
26 """
27 A simple text attribute.
28 """
29 def __init__(self,name):
30 self.name = name
31
32 def set(self,obj,value):
33 """
34 Parses the given value with the L{parse} method
35 and sets it on the given instance with C{setattr}.
36 """
37 value = self.parse(value)
38 setattr(obj,self.name,value)
39
40 def parse(self,value):
41 """
42 Parses a value and checks for errors.
43 Override with specialiced behaviour.
44 """
45 return str(value)
46
47 class PointAttr(Attr):
48 def parse(self,value):
49 try:
50 x,y = tuple(map(int,str(value).split(',')))
51 return x,y
52 except:
53 raise ParserError("Expected a comma separated list of two integers.")
54
55 class ColorAttr(Attr):
56 def parse(self,value):
57 try:
58 r,g,b = tuple(map(int,str(value).split(',')))
59 except:
60 raise ParserError("Expected an color.")
61 for c in (r,g,b):
62 if not 0 <= c < 256: raise ParserError("Expected a color (Failed: 0 <= %d <= 255)" %c)
63 return r,g,b
64
65 class IntAttr(Attr):
66 def parse(self,value):
67 try:
68 return int(value)
69 except:
70 raise ParserError("Expected a single integer.")
71
72 class BoolAttr(Attr):
73 def parse(self,value):
74 try:
75 value = int(value)
76 if value not in (0,1):
77 raise ParserError("Expected a 0 or 1.")
78 return value
79 except:
80 raise ParserError("Expected a 0 or 1.")