class RMail::StreamHandler
Overview¶ ↑
An RMail::StreamHandler
documents the set of methods a RMail::StreamParser
handler must implement. See RMail::StreamParser.parse
. This is a low level interface to the RMail
message parser.
Order of Method Calls (Grammar)¶ ↑
Calls to the methods of this class follow a specific grammar, described informally below. The words in all caps are productions in the grammar, while the lower case words are method calls to this object.
- MESSAGE
-
mbox_from
-
*(
header_field
)
( BODY / MULTIPART_BODY )
-
- BODY
-
*body_begin *(
body_chunk
)body_end
- MULTIPART_BODY
-
multipart_body_begin
*(preamble_chunk
) *(part_begin
MESSAGEpart_end
) *(epilogue_chunk
)multipart_body_end
Order of Method Calls (English)¶ ↑
If the grammar above is not clear, here is a description in English.
The parser begins calling header_field
, possibly calling mbox_from
for the first line. Then it determines if the message was a MIME multipart message.
If the message is a not a MIME multipart, the parser calls body_begin
once, then body_chunk
any number of times, then body_end
.
If the message header is a MIME multipart message, then multipart_body_begin
is called, followed by any number of calls to preamble_chunk
. Then for each part parsed, part_begin
is called, followed by a recursive set of calls described by the “MESSAGE” production above, and then part_end
. After all parts are parsed, any number of calls to epilogue_chunk
are followed by a single call to multipart_body_end
.
The recursive nature of MIME multipart messages is represented by the recursive invocation of the “MESSAGE” production in the grammar above.
Public Instance Methods
This method is called before a non-multipart message body is about to be parsed.
# File lib/rmail/parser.rb, line 100 def body_begin end
This method is called with a string chunk of data from a non-multipart message body. The string does not necessarily begin or end on any particular boundary.
# File lib/rmail/parser.rb, line 106 def body_chunk(chunk) end
This method is called after all of the non-multipart message body has been parsed.
# File lib/rmail/parser.rb, line 111 def body_end end
This method is called with a chunk of data from a multipart message body’s epilogue. The epilogue is any text that appears after the last part of the multipart message body.
# File lib/rmail/parser.rb, line 136 def epilogue_chunk(chunk) end
This method is called when a header field is parsed. The field
is the full text of the field, the name
is the name of the field and the value
is the field’s value with leading and trailing whitespace removed. Note that both field
and value
may be multi-line strings.
# File lib/rmail/parser.rb, line 95 def header_field(field, name, value) end
This method is called for Unix MBOX “From ” lines in the message header, it calls this method with the text.
# File lib/rmail/parser.rb, line 87 def mbox_from(line) end
This method is called before a multipart message body is about to be parsed.
# File lib/rmail/parser.rb, line 116 def multipart_body_begin end
This method is called after a multipart message body has been completely parsed.
The delimiters
is an Array of strings, one for each boundary string found in the multipart body. The boundary
is the boundary string used to delimit each part in the multipart body. You can normally ignore both delimiters
and boundary
if you are concerned only about message content.
# File lib/rmail/parser.rb, line 147 def multipart_body_end(delimiters, boundary) end
This method is called when a part of a multipart body begins.
# File lib/rmail/parser.rb, line 126 def part_begin end
This method is called when a part of a multipart body ends.
# File lib/rmail/parser.rb, line 130 def part_end end
This method is called with a chunk of data from a multipart message body’s preamble. The preamble is any text that appears before the first part of the multipart message body.
# File lib/rmail/parser.rb, line 122 def preamble_chunk(chunk) end