@c $Id: tm-view-ch=en.texi,v 1.1.1.1 1996/12/18 22:43:52 steve Exp $

@node content-header, content-body, content-subject, MIME display
@comment  node-name,  next,  previous,  up
@subsubsection content-header
@cindex content-header

A content header shows the header portion of a content in the preview
buffer.

When the function @code{mime-viewer/header-visible-p} returns @code{t}
for content-number of a content, content-header is displayed. This
judge function returns @code{t} when a content is root or content-type
of its parent is a member of the variable
@code{mime-viewer/childrens-header-showing-Content-Type-list}.

If you want to change this condition, please redefine it.

When content-header is displayed, content-header are formated by
content-header-filter. Content-header-filter is searched from variable
@code{mime-viewer/content-header-filter-alist}. Its key is major-mode
of the article buffer. If not found, function
@code{mime-viewer/default-content-header-filter} is called.


@defvar mime-viewer/childrens-header-showing-Content-Type-list

List of content-type. If content-type of parent of a content is a
member of this variable, its content-header is displayed. Default
value is "message/rfc822".

This variable is referred by the function
@code{mime-viewer/header-visible-p}.
@end defvar


@deffn{Function} mime-viewer/header-visible-p rcnum cinfo &optional ctype

Returns @code{t} if a content is displayed.

@var{cnum} is content-number. @var{cinfo} is content-info. If you know 
content-type, you can specify by @var{ctype}.
@end deffn


@defvar mime-viewer/content-header-filter-alist

Association-list whose key is major-mode of a article buffer, value is
content-header-filter.
@end defvar


@deffn{Function} mime-viewer/default-content-header-filter

It is called when content-header-filter is not found in variable
@code{mime-viewer/content-header-filter-alist}.
@end deffn


@defvar mime-viewer/ignored-field-list

List of regular expression to represent invisible fields.

Variable @code{mime-viewer/ignored-field-regexp} is created from it.

Please use function @code{tm:add-fields} or @code{tm:delete-fields} to 
set it.
@end defvar