(www server-utils form-2-form) module provides a procedure to
parse a string in ‘multipart/form-data’ format.
Parse raw-data (an integer) bytes from the current input port, as raw form response data of enctype ‘multipart/form-data’ and return an alist. For backward compatibility, raw-data can also be a string.
type is a form:
((multipart . MINOR) [PARAMETER...])
where minor is a downcased symbol (usually
and each parameter is a pair with CAR a downcased
symbol and CDR a string. It is an error if one of these
parameters is not
For backward compatibility,
type may also be a string,
the unparsed value of the
Each element of the alist has the form
(name . value),
where name is a string and value is either a string or
a (four-element) list of:
A string, or
A string representing the MIME type of the uploaded file.
A string, including all eol CRLF chars. Incidentally, the type should be (redundantly) visible in one of the headers.
A procedure that takes one arg abr (standing for access byte
range). If abr is
#f, then internal references to the
uploaded file’s data are dropped. Otherwise, abr should be a
procedure that takes three arguments: a string, a beginning index
(integer, inclusive), and an ending index (integer, exclusive).
If there is no type information, value is a simple non-empty string, and no associated information (filename, raw-headers, squeeze) is kept.
parse-form ignores degenerate uploads, that is those parts
raw-data where the part header specifies no filename and the
part content-length is zero or unspecified.
The squeeze interface can help reduce data motion. Consider a common upload scenario: client uploads file(s) for local (server-side) storage.
classic squeeze * * 0. (current-input-port) * * 1. Guile-WWW string (for parsing purposes) * 2. your substring (image/jpeg) * * 3. filesystem
You can achieve the same effect as the “classic” approach by specifying
substring (or something like it) as the access-byte-range proc, but
you don’t have to. You could, instead, call squeeze with a
procedure that writes the byte range directly to the filesystem.