Class: RMail::StreamHandler

Inherits:
Object
  • Object
show all
Defined in:
lib/rmail/parser.rb

Overview

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 MESSAGE #part_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.

Direct Known Subclasses

Parser::Handler

Instance Method Summary collapse

Instance Method Details

#body_beginObject

This method is called before a non-multipart message body is about to be parsed.


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# File 'lib/rmail/parser.rb', line 100

def body_begin
end

#body_chunk(chunk) ⇒ Object

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.


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# File 'lib/rmail/parser.rb', line 106

def body_chunk(chunk)
end

#body_endObject

This method is called after all of the non-multipart message body has been parsed.


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# File 'lib/rmail/parser.rb', line 111

def body_end
end

#epilogue_chunk(chunk) ⇒ Object

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.


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# File 'lib/rmail/parser.rb', line 136

def epilogue_chunk(chunk)
end

#header_field(field, name, value) ⇒ Object

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.


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# File 'lib/rmail/parser.rb', line 95

def header_field(field, name, value)
end

#mbox_from(line) ⇒ Object

This method is called for Unix MBOX “From ” lines in the message header, it calls this method with the text.


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# File 'lib/rmail/parser.rb', line 87

def mbox_from(line)
end

#multipart_body_beginObject

This method is called before a multipart message body is about to be parsed.


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# File 'lib/rmail/parser.rb', line 116

def multipart_body_begin
end

#multipart_body_end(delimiters, boundary) ⇒ Object

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.


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# File 'lib/rmail/parser.rb', line 147

def multipart_body_end(delimiters, boundary)
end

#part_beginObject

This method is called when a part of a multipart body begins.


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# File 'lib/rmail/parser.rb', line 126

def part_begin
end

#part_endObject

This method is called when a part of a multipart body ends.


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# File 'lib/rmail/parser.rb', line 130

def part_end
end

#preamble_chunk(chunk) ⇒ Object

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.


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# File 'lib/rmail/parser.rb', line 122

def preamble_chunk(chunk)
end