Added a, perhaps overly simplistic, multipart form handler.
[wrw.git] / wrw / form.py
CommitLineData
b409a338 1import cgi
c21c8713 2import proto
b409a338
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3
4__all__ = ["formdata"]
5
6class formwrap(object):
7 def __init__(self, req):
aba06d86 8 if req.ihead.get("Content-Type") == "application/x-www-form-urlencoded":
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9 self.cf = cgi.parse(environ = req.env, fp = req.env["wsgi.input"])
10 else:
11 self.cf = cgi.parse(environ = req.env)
12
13 def __getitem__(self, key):
14 return self.cf[key][0]
15
16 def get(self, key, default = ""):
17 if key in self:
18 return self.cf[key][0]
19 return default
20
21 def __contains__(self, key):
22 return key in self.cf and len(self.cf[key]) > 0
23
24 def __iter__(self):
25 return iter(self.cf)
26
27 def items(self):
28 def iter():
29 for key, list in self.cf.items():
30 for val in list:
31 yield key, val
32 return list(iter())
33
34 def keys(self):
35 return self.cf.keys()
36
37 def values(self):
38 return [val for key, val in self.items()]
39
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40class badmultipart(Exception):
41 pass
42
43class formpart(object):
44 def __init__(self, form):
45 self.form = form
46 self.buf = ""
47 self.eof = False
48 self.head = {}
49
50 def parsehead(self):
51 pass
52
53 def fillbuf(self, sz):
54 req = self.form.req
55 mboundary = "\r\n--" + self.form.boundary + "\r\n"
56 lboundary = "\r\n--" + self.form.boundary + "--\r\n"
57 while not self.eof:
58 p = self.form.buf.find(mboundary)
59 if p >= 0:
60 self.buf += self.form.buf[:p]
61 self.form.buf = self.form.buf[p + len(mboundary):]
62 self.eof = True
63 break
64 p = self.form.buf.find(lboundary)
65 if p >= 0:
66 self.buf += self.form.buf[:p]
67 self.form.buf = self.form.buf[p + len(lboundary):]
68 self.eof = True
69 self.form.eof = True
70 break
71 self.buf += self.form.buf[:-len(lboundary)]
72 self.form.buf = self.form.buf[-len(lboundary):]
73 if sz >= 0 and len(self.buf) >= sz:
74 break
75 while len(self.form.buf) <= len(lboundary):
76 ret = req.env["wsgi.input"].read(8192)
77 if ret == "":
78 raise badmultipart("Missing last multipart boundary")
79 self.form.buf += ret
80
81 def read(self, limit = -1):
82 self.fillbuf(limit)
83 if limit >= 0:
84 ret = self.buf[:limit]
85 self.buf = self.buf[limit:]
86 else:
87 ret = self.buf
88 self.buf = ""
89 return ret
90
91 def readline(self, limit = -1):
92 last = 0
93 while True:
94 p = self.buf.find('\n', last)
95 if p < 0:
96 if self.eof:
97 ret = self.buf
98 self.buf = ""
99 return ret
100 last = len(self.buf)
101 self.fillbuf(last + 128)
102 else:
103 ret = self.buf[:p + 1]
104 self.buf = self.buf[p + 1:]
105 return ret
106
107 def close(self):
108 self.fillbuf(-1)
109
110 def __enter__(self):
111 return self
112
113 def __exit__(self, *excinfo):
114 return False
115
116 def parsehead(self):
117 def headline():
118 ln = self.readline(256)
119 if ln[-1] != '\n':
120 raise badmultipart("Too long header line in part")
121 return ln.rstrip()
122
123 ln = headline()
124 while True:
125 if ln == "":
126 break
127 buf = ln
128 while True:
129 ln = headline()
130 if not ln[1:].isspace():
131 break
132 buf += ln.lstrip()
133 p = buf.find(':')
134 if p < 0:
135 raise badmultipart("Malformed multipart header line")
136 self.head[buf[:p].strip().lower()] = buf[p + 1:].lstrip()
137
138 val, par = proto.pmimehead(self.head.get("content-disposition", ""))
139 if val != "form-data":
140 raise badmultipart("Unexpected Content-Disposition in form part: %r" % val)
141 if not "name" in par:
142 raise badmultipart("Missing name in form part")
143 self.name = par["name"]
144 self.filename = par.get("filename")
145 val, par = proto.pmimehead(self.head.get("content-type", ""))
146 self.ctype = val
147 self.charset = par.get("charset")
148 encoding = self.head.get("content-transfer-encoding", "binary")
149 if encoding != "binary":
150 raise badmultipart("Form part uses unexpected transfer encoding: %r" % encoding)
151
152class multipart(object):
153 def __init__(self, req):
154 val, par = proto.pmimehead(req.ihead.get("Content-Type", ""))
155 if req.method != "POST" or val != "multipart/form-data":
156 raise badmultipart("Request is not a multipart form")
157 if "boundary" not in par:
158 raise badmultipart("Multipart form lacks boundary")
159 self.boundary = par["boundary"]
160 self.req = req
161 self.buf = "\r\n"
162 self.eof = False
163 self.lastpart = formpart(self)
164 self.lastpart.close()
165
166 def __iter__(self):
167 return self
168
169 def next(self):
170 if not self.lastpart.eof:
171 raise RuntimeError("All form parts must be read entirely")
172 if self.eof:
173 raise StopIteration()
174 self.lastpart = formpart(self)
175 self.lastpart.parsehead()
176 return self.lastpart
177
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178def formdata(req):
179 return req.item(formwrap)