1 """Generic MIME writer. 2 3 This module defines the class MimeWriter. The MimeWriter class implements 4 a basic formatter for creating MIME multi-part files. It doesn't seek around 5 the output file nor does it use large amounts of buffer space. You must write 6 the parts out in the order that they should occur in the final file. 7 MimeWriter does buffer the headers you add, allowing you to rearrange their 8 order. 9 10 """ 11 12 13 import mimetools 14 15 __all__ = ["MimeWriter"] 16 17 import warnings 18 19 warnings.warn("the MimeWriter module is deprecated; use the email package instead", 20 DeprecationWarning, 2) 21 22 class MimeWriter: 23 24 """Generic MIME writer. 25 26 Methods: 27 28 __init__() 29 addheader() 30 flushheaders() 31 startbody() 32 startmultipartbody() 33 nextpart() 34 lastpart() 35 36 A MIME writer is much more primitive than a MIME parser. It 37 doesn't seek around on the output file, and it doesn't use large 38 amounts of buffer space, so you have to write the parts in the 39 order they should occur on the output file. It does buffer the 40 headers you add, allowing you to rearrange their order. 41 42 General usage is: 43 44 f = <open the output file> 45 w = MimeWriter(f) 46 ...call w.addheader(key, value) 0 or more times... 47 48 followed by either: 49 50 f = w.startbody(content_type) 51 ...call f.write(data) for body data... 52 53 or: 54 55 w.startmultipartbody(subtype) 56 for each part: 57 subwriter = w.nextpart() 58 ...use the subwriter's methods to create the subpart... 59 w.lastpart() 60 61 The subwriter is another MimeWriter instance, and should be 62 treated in the same way as the toplevel MimeWriter. This way, 63 writing recursive body parts is easy. 64 65 Warning: don't forget to call lastpart()! 66 67 XXX There should be more state so calls made in the wrong order 68 are detected. 69 70 Some special cases: 71 72 - startbody() just returns the file passed to the constructor; 73 but don't use this knowledge, as it may be changed. 74 75 - startmultipartbody() actually returns a file as well; 76 this can be used to write the initial 'if you can read this your 77 mailer is not MIME-aware' message. 78 79 - If you call flushheaders(), the headers accumulated so far are 80 written out (and forgotten); this is useful if you don't need a 81 body part at all, e.g. for a subpart of type message/rfc822 82 that's (mis)used to store some header-like information. 83 84 - Passing a keyword argument 'prefix=<flag>' to addheader(), 85 start*body() affects where the header is inserted; 0 means 86 append at the end, 1 means insert at the start; default is 87 append for addheader(), but insert for start*body(), which use 88 it to determine where the Content-Type header goes. 89 90 """ 91 92 def __init__(self, fp): 93 self._fp = fp 94 self._headers = [] 95 96 def addheader(self, key, value, prefix=0): 97 """Add a header line to the MIME message. 98 99 The key is the name of the header, where the value obviously provides 100 the value of the header. The optional argument prefix determines 101 where the header is inserted; 0 means append at the end, 1 means 102 insert at the start. The default is to append. 103 104 """ 105 lines = value.split("\n") 106 while lines and not lines[-1]: del lines[-1] 107 while lines and not lines[0]: del lines[0] 108 for i in range(1, len(lines)): 109 lines[i] = " " + lines[i].strip() 110 value = "\n".join(lines) + "\n" 111 line = key + ": " + value 112 if prefix: 113 self._headers.insert(0, line) 114 else: 115 self._headers.append(line) 116 117 def flushheaders(self): 118 """Writes out and forgets all headers accumulated so far. 119 120 This is useful if you don't need a body part at all; for example, 121 for a subpart of type message/rfc822 that's (mis)used to store some 122 header-like information. 123 124 """ 125 self._fp.writelines(self._headers) 126 self._headers = [] 127 128 def startbody(self, ctype, plist=[], prefix=1): 129 """Returns a file-like object for writing the body of the message. 130 131 The content-type is set to the provided ctype, and the optional 132 parameter, plist, provides additional parameters for the 133 content-type declaration. The optional argument prefix determines 134 where the header is inserted; 0 means append at the end, 1 means 135 insert at the start. The default is to insert at the start. 136 137 """ 138 for name, value in plist: 139 ctype = ctype + ';\n %s=\"%s\"' % (name, value) 140 self.addheader("Content-Type", ctype, prefix=prefix) 141 self.flushheaders() 142 self._fp.write("\n") 143 return self._fp 144 145 def startmultipartbody(self, subtype, boundary=None, plist=[], prefix=1): 146 """Returns a file-like object for writing the body of the message. 147 148 Additionally, this method initializes the multi-part code, where the 149 subtype parameter provides the multipart subtype, the boundary 150 parameter may provide a user-defined boundary specification, and the 151 plist parameter provides optional parameters for the subtype. The 152 optional argument, prefix, determines where the header is inserted; 153 0 means append at the end, 1 means insert at the start. The default 154 is to insert at the start. Subparts should be created using the 155 nextpart() method. 156 157 """ 158 self._boundary = boundary or mimetools.choose_boundary() 159 return self.startbody("multipart/" + subtype, 160 [("boundary", self._boundary)] + plist, 161 prefix=prefix) 162 163 def nextpart(self): 164 """Returns a new instance of MimeWriter which represents an 165 individual part in a multipart message. 166 167 This may be used to write the part as well as used for creating 168 recursively complex multipart messages. The message must first be 169 initialized with the startmultipartbody() method before using the 170 nextpart() method. 171 172 """ 173 self._fp.write("\n--" + self._boundary + "\n") 174 return self.__class__(self._fp) 175 176 def lastpart(self): 177 """This is used to designate the last part of a multipart message. 178 179 It should always be used when writing multipart messages. 180 181 """ 182 self._fp.write("\n--" + self._boundary + "--\n") 183 184 185 if __name__ == '__main__': 186 import test.test_MimeWriter 187
