X-Git-Url: http://git.chise.org/gitweb/?p=elisp%2Fgnus.git-;a=blobdiff_plain;f=texi%2Femacs-mime.texi;h=08cd7fae15a51834eb6b9418af9b50f3f9c96442;hp=122f5132a2bf1fa3d3c6d923f3562ce8e385c8ea;hb=c8b25eebe2bfccd8b707d8c9e8ffa0d88d4a20af;hpb=3744aa624a1af97f360196755fdeeb6382da8aca diff --git a/texi/emacs-mime.texi b/texi/emacs-mime.texi index 122f513..08cd7fa 100644 --- a/texi/emacs-mime.texi +++ b/texi/emacs-mime.texi @@ -17,7 +17,7 @@ This file documents the Emacs MIME interface functionality. -Copyright (C) 1996 Free Software Foundation, Inc. +Copyright (C) 1998,99 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice @@ -48,7 +48,7 @@ into another language, under the above conditions for modified versions. @page @vskip 0pt plus 1filll -Copyright @copyright{} 1998 Free Software Foundation, Inc. +Copyright @copyright{} 1998,99 Free Software Foundation, Inc. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice @@ -89,6 +89,7 @@ read at least RFC2045 and RFC2047. * Interface Functions:: An abstraction over the basic functions. * Basic Functions:: Utility and basic parsing functions. * Decoding and Viewing:: A framework for decoding and viewing. +* Composing:: MML; a language for describing MIME parts. * Standards:: A summary of RFCs and working documents used. * Index:: Function and variable index. @end menu @@ -165,6 +166,12 @@ Returns the value of the attribute. @result{} "b980912.gif" @end example +@item mail-header-encode-parameter +@findex mail-header-encode-parameter +Takes a parameter string and returns an encoded version of the string. +This is used for parameters in headers like @code{Content-Type} and +@code{Content-Disposition}. + @item mail-header-remove-comments @findex mail-header-remove-comments Return a comment-free version of a header. @@ -191,9 +198,9 @@ and comments is preserved. Return the last comment in a header. @example -(mail-header-get-comment +(mail-header-get-comment "Gnus/5.070027 (Pterodactyl Gnus v0.27) (Finnish Landrace)") -@result{} "Finnish Landrace" +@result{} "Finnish Landrace" @end example @item mail-header-parse-address @@ -269,8 +276,8 @@ Decode the encoded words in the string and return the result. @end table Currently, @code{mail-parse} is an abstraction over @code{ietf-drums}, -@code{rfc2047} and @code{rfc2231}. These are documented in the -subsequent sections. +@code{rfc2047}, @code{rfc2045} and @code{rfc2231}. These are documented +in the subsequent sections. @@ -284,6 +291,7 @@ on. High-level functionality is dealt with in the next chapter (@pxref{Decoding and Viewing}). @menu +* rfc2045:: Encoding @code{Content-Type} headers. * rfc2231:: Parsing @code{Content-Type} headers. * ietf-drums:: Handling mail headers defined by RFC822bis. * rfc2047:: En/decoding encoded words in headers. @@ -297,6 +305,24 @@ on. High-level functionality is dealt with in the next chapter @end menu +@node rfc2045 +@section rfc2045 + +RFC2045 is the ``main'' @sc{mime} document, and as such, one would +imagine that there would be a lot to implement. But there isn't, since +most of the implementation details are delegated to the subsequent +RFCs. + +So @file{rfc2045.el} has only a single function: + +@table @code +@item rfc2045-encode-string +@findex rfc2045-encode-string +Takes a parameter and a value and returns a @samp{PARAM=VALUE} string. +@var{value} will be quoted if there are non-safe characters in it. +@end table + + @node rfc2231 @section rfc2231 @@ -326,7 +352,7 @@ elements. @example (rfc2231-parse-string - "application/x-stuff; + "application/x-stuff; title*0*=us-ascii'en'This%20is%20even%20more%20; title*1*=%2A%2A%2Afun%2A%2A%2A%20; title*2=\"isn't it!\"") @@ -336,9 +362,14 @@ elements. @item rfc2231-get-value @findex rfc2231-get-value -Takes one of the lists on the format above and return +Takes one of the lists on the format above and returns the value of the specified attribute. +@item rfc2231-encode-string +@findex rfc2231-encode-string +Encode a parameter in headers likes @code{Content-Type} and +@code{Content-Disposition}. + @end table @@ -428,11 +459,11 @@ This is an alist of encoding / function pairs. The encodings are The @code{Q} encoding isn't quite the same for all headers. Some headers allow a narrower range of characters, and that is what this variable is for. It's an alist of header regexps / allowable character -ranges. +ranges. @item rfc2047-encoded-word-regexp @vindex rfc2047-encoded-word-regexp -When decoding words, this library looks for matches to this regexp. +When decoding words, this library looks for matches to this regexp. @end table @@ -711,9 +742,11 @@ other programs to do things based on the list of @dfn{handles} that are returned as a result of this analysis. @menu -* Dissection:: Analyzing a @sc{mime} message. -* Handles:: Handle manipulations. -* Display:: Displaying handles. +* Dissection:: Analyzing a @sc{mime} message. +* Handles:: Handle manipulations. +* Display:: Displaying handles. +* Customization:: Variables that affect display. +* New Viewers:: How to write your own viewers. @end menu @@ -810,7 +843,364 @@ Offer to pipe the part to some process. Prompt for a mailcap method to use to view the part. @end table - + + +@node Customization +@section Customization + +@table @code + +@item mm-inline-media-tests +This is an alist where the key is a @sc{mime} type, the second element +is a function to display the part @dfn{inline} (i.e., inside Emacs), and +the third element is a form to be @code{eval}ed to say whether the part +can be displayed inline. + +This variable specifies whether a part @emph{can} be displayed inline, +and, if so, how to do it. It does not say whether parts are +@emph{actually} displayed inline. + +@item mm-inlined-types +This, on the other hand, says what types are to be displayed inline, if +they satisfy the conditions set by the variable above. It's a list of +@sc{mime} media types. + +@item mm-automatic-display +This is a list of types that are to be displayed ``automatically'', but +only if the above variable allows it. That is, only inlinable parts can +be displayed automatically. + +@item mm-attachment-override-types +Some @sc{mime} agents create parts that have a content-disposition of +@samp{attachment}. This variable allows overriding that disposition and +displaying the part inline. (Note that the disposition is only +overridden if we are able to, and want to, display the part inline.) + +@item mm-discouraged-alternatives +List of @sc{mime} types that are discouraged when viewing +@samp{multipart/alternative}. Viewing agents are supposed to view the +last possible part of a message, as that is supposed to be the richest. +However, users may prefer other types instead, and this list says what +types are most unwanted. If, for instance, @samp{text/html} parts are +very unwanted, and @samp{text/richtech} parts are somewhat unwanted, +then the value of this variable should be set to: + +@lisp +("text/html" "text/richtext") +@end lisp + +@item mm-inline-large-images-p +When displaying inline images that are larger than the window, XEmacs +does not enable scrolling, which means that you cannot see the whole +image. To prevent this, the library tries to determine the image size +before displaying it inline, and if it doesn't fit the window, the +library will display it externally (e.g. with @samp{ImageMagick} or +@samp{xv}). Setting this variable to @code{t} disables this check and +makes the library display all inline images as inline, regardless of +their size. + + +@end table + + +@node New Viewers +@section New Viewers + +Here's an example viewer for displaying @code{text/enriched} inline: + +@lisp +(defun mm-display-enriched-inline (handle) + (let (text) + (with-temp-buffer + (mm-insert-part handle) + (save-window-excursion + (enriched-decode (point-min) (point-max)) + (setq text (buffer-string)))) + (mm-insert-inline handle text))) +@end lisp + +We see that the function takes a @sc{mime} handle as its parameter. It +then goes to a temporary buffer, inserts the text of the part, does some +work on the text, stores the result, goes back to the buffer it was +called from and inserts the result. + +The two important helper functions here are @code{mm-insert-part} and +@code{mm-insert-inline}. The first function inserts the text of the +handle in the current buffer. It handles charset and/or content +transfer decoding. The second function just inserts whatever text you +tell it to insert, but it also sets things up so that the text can be +``undisplayed' in a convenient manner. + + +@node Composing +@chapter Composing +@cindex Composing +@cindex MIME Composing +@cindex MML +@cindex MIME Meta Language + +Creating a @sc{mime} message is boring and non-trivial. Therefore, a +library called @code{mml} has been defined that parses a language called +MML (@sc{mime} Meta Language) and generates @sc{mime} messages. + +@findex mml-generate-mime +The main interface function is @code{mml-generate-mime}. It will +examine the contents of the current (narrowed-to) buffer and return a +string containing the @sc{mime} message. + +@menu +* Simple MML Example:: An example MML document. +* MML Definition:: All valid MML elements. +* Advanced MML Example:: Another example MML document. +* Conversion:: Going from @sc{mime} to MML and vice versa. +@end menu + + +@node Simple MML Example +@section Simple MML Example + +Here's a simple @samp{multipart/alternative}: + +@example +<#multipart type=alternative> +This is a plain text part. +<#part type=text/enriched> +