| Class | RMail::StreamHandler |
| In: |
lib/rmail/parser.rb
|
| Parent: | Object |
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.
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 MESSAGE part_end) *( epilogue_chunk ) multipart_body_end |
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.
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.
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.
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.
This method is called for Unix MBOX "From " lines in the message header, it calls this method with the text.
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.