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/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:expandtab:shiftwidth=4:tabstop=4:
*/
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* This interface allows any module to access the routine
* for MIME header parameter parsing (RFC 2231/5987)
*/
#include "nsISupports.idl"
[scriptable, uuid(9c9252a1-fdaf-40a2-9c2b-a3dc45e28dde)]
interface nsIMIMEHeaderParam : nsISupports {
/**
* Given the value of a single header field (such as
* Content-Disposition and Content-Type) and the name of a parameter
* (e.g. filename, name, charset), returns the value of the parameter.
* The value is obtained by decoding RFC 2231/5987-style encoding,
* RFC 2047-style encoding, and converting to UniChar(UTF-16)
* from charset specified in RFC 2231/2047 encoding, UTF-8,
* <code>aFallbackCharset</code>, the locale charset as fallback if
* <code>TryLocaleCharset</code> is set, and null-padding as last resort
* if all else fails.
*
* <p>
* This method internally invokes <code>getParameterInternal</code>,
* However, it does not stop at decoding RFC 2231 (the task for
* <code>getParameterInternal</code> but tries to cope
* with several non-standard-compliant cases mentioned below.
*
* <p>
* Note that a lot of MUAs put RFC 2047-encoded parameters. Unfortunately,
* this includes Mozilla as of 2003-05-30. Even more standard-ignorant MUAs,
* web servers and application servers put 'raw 8bit characters'. This will
* try to cope with all these cases as gracefully as possible. Additionally,
* it returns the language tag if the parameter is encoded per RFC 2231 and
* includes lang.
*
* <p>
* Note that GetParameterHTTP skips some of the workarounds used for
* mail (MIME) header fields, and thus SHOULD be used from non-mail
* code.
*
*
* @param aHeaderVal a header string to get the value of a parameter
* from.
* @param aParamName the name of a MIME header parameter (e.g.
* filename, name, charset). If empty, returns
* the first (possibly) _unnamed_ 'parameter'.
* @param aFallbackCharset fallback charset to try if the string after
* RFC 2231/2047 decoding or the raw 8bit
* string is not UTF-8
* @param aTryLocaleCharset If set, makes yet another attempt
* with the locale charset.
* @param aLang If non-null, assigns it to a pointer
* to a string containing the value of language
* obtained from RFC 2231 parsing. Caller has to
* free it.
* @return the value of <code>aParamName</code> in Unichar(UTF-16).
*/
AString getParameter(in ACString aHeaderVal,
in string aParamName,
in ACString aFallbackCharset,
in boolean aTryLocaleCharset,
out string aLang);
/**
* Like getParameter, but disabling encodings and workarounds specific to
* MIME (as opposed to HTTP).
*/
AString getParameterHTTP(in ACString aHeaderVal,
in string aParamName,
in ACString aFallbackCharset,
in boolean aTryLocaleCharset,
out string aLang);
/**
* Given the value of a header field parameter using the encoding
* defined in RFC 5987, decode the value into a Unicode string, and extract
* the optional language parameter.
*
* <p>
* This function is purposefully picky; it will abort for all (most?)
* invalid inputs. This is by design. In particular, it does not support
* any character encodings other than UTF-8, in order not to promote
* non-interoperable usage.
*
* <p>
* Code that parses HTTP header fields (as opposed to MIME header fields)
* should use this function.
*
* @param aParamVal a header field parameter to decode.
* @param aLang will be set to the language part (possibly
* empty).
* @return the decoded parameter value.
*/
AString decodeRFC5987Param(in ACString aParamVal,
out ACString aLang);
/**
* Given the value of a single header field (such as
* Content-Disposition and Content-Type) and the name of a parameter
* (e.g. filename, name, charset), returns the value of the parameter
* after decoding RFC 2231-style encoding.
* <p>
* For <strong>internal use only</strong>. The only other place where
* this needs to be invoked is |MimeHeaders_get_parameter| in
* mailnews/mime/src/mimehdrs.cpp defined as
* char * MimeHeaders_get_parameter (const char *header_value,
* const char *parm_name,
* char **charset, char **language)
*
* Otherwise, this method would have been made static.
*
* @param aHeaderVal a header string to get the value of a parameter from.
* @param aParamName the name of a MIME header parameter (e.g.
* filename, name, charset). If empty, returns
* the first (possibly) _unnamed_ 'parameter'.
* @param aCharset If non-null, it gets assigned a new pointer
* to a string containing the value of charset obtained
* from RFC 2231 parsing. Caller has to free it.
* @param aLang If non-null, it gets assigned a new pointer
* to a string containing the value of language obtained
* from RFC 2231 parsing. Caller has to free it.
* @return the value of <code>aParamName</code> after
* RFC 2231 decoding but without charset conversion.
*/
[noscript]
string getParameterInternal(in string aHeaderVal,
in string aParamName,
out string aCharset,
out string aLang);
/**
* Given a header value, decodes RFC 2047-style encoding and
* returns the decoded header value in UTF-8 if either it's
* RFC-2047-encoded or aDefaultCharset is given. Otherwise,
* returns the input header value (in whatever encoding)
* as it is except that RFC 822 (using backslash) quotation and
* CRLF (if aEatContinuation is set) are stripped away
* <p>
* For internal use only. The only other place where this needs to be
* invoked is <code>MIME_DecodeMimeHeader</code> in
* mailnews/mime/src/mimehdrs.cpp defined as
* char * Mime_DecodeMimeHeader(char *header_val, const char *charset,
* bool override, bool eatcontinuation)
*
* @param aHeaderVal a header value to decode
* @param aDefaultCharset MIME charset to use in place of MIME charset
* specified in RFC 2047 style encoding
* when <code>aOverrideCharset</code> is set.
* @param aOverrideCharset When set, overrides MIME charset specified
* in RFC 2047 style encoding with <code>aDefaultCharset</code>
* @param aEatContinuation When set, removes CR/LF
* @return decoded header value
*/
[noscript]
ACString decodeRFC2047Header(in string aHeaderVal,
in string aDefaultCharset,
in boolean aOverrideCharset,
in boolean aEatContinuation);
/**
* Given a header parameter, decodes RFC 2047 style encoding (if it's
* not obtained from RFC 2231 encoding), converts it to
* UTF-8 and returns the result in UTF-8 if an attempt to extract
* charset info. from a few different sources succeeds.
* Otherwise, returns the input header value (in whatever encoding)
* as it is except that RFC 822 (using backslash) quotation is
* stripped off.
* <p>
* For internal use only. The only other place where this needs to be
* invoked is <code>mime_decode_filename</code> in
* mailnews/mime/src/mimehdrs.cpp defined as
* char * mime_decode_filename(char *name, const char *charset,
* MimeDisplayOptions *opt)
*
* @param aParamValue the value of a parameter to decode and convert
* @param aCharset charset obtained from RFC 2231 decoding in which
* <code>aParamValue</code> is encoded. If null,
* indicates that it needs to try RFC 2047, instead.
* @param aDefaultCharset MIME charset to use when aCharset is null and
* cannot be obtained per RFC 2047 (most likely
* because 'bare' string is used.) Besides, it
* overrides aCharset/MIME charset obtained from
* RFC 2047 if <code>aOverrideCharset</code> is set.
* @param aOverrideCharset When set, overrides MIME charset specified
* in RFC 2047 style encoding with
* <code>aDefaultCharset</code>
* @return decoded parameter
*/
[noscript]
ACString decodeParameter(in ACString aParamValue,
in string aCharset,
in string aDefaultCharset,
in boolean aOverrideCharset);
};