context-filter (24oct11)

git-svn-id: svn://tug.org/texlive/trunk@24389 c570f23f-e606-0410-a88d-b1316a301751

2 files changed, 105 insertions, 5 deletions

diff --git a/Master/texmf-dist/doc/context/third/filter/filter.txt b/Master/texmf-dist/doc/context/third/filter/filter.txt
index ab4e9c6f90c..1b03acaaac1 100644
--- a/Master/texmf-dist/doc/context/third/filter/filter.txt
+++ b/Master/texmf-dist/doc/context/third/filter/filter.txt
@@ -106,7 +106,7 @@ Using this filter from within ConTeXt is pretty simple:
 Yes, its that easy! The only thing to note is that TeX macros gobble spaces, so
 we have to manually insert a space after `\externalfilteroutputfile`.
 
-This defines three things:
+This defines four things:
 
 1. An environment
 
@@ -131,6 +131,14 @@ This defines three things:
    The argument to the macro is a filename, which is processed by `pandoc` and
    the output is included back in ConTeXt.
 
+4. A macro
+    
+        \processmarkdownbuffer[...]
+
+   The argument to the macro is the name of a buffer, which is written to an
+   external file, processesd by `pandoc` and the output included back in
+   ConTeXt.
+
 Dealing with slow filters
 -------------------------
 
@@ -339,6 +347,12 @@ I can hide the output of a particular R-environment by
     ...
     \stopR
 
+The macros `\processmarkdownfile` and `\processmarkdownbuffer` also accept user
+options. The usage is
+
+    \processmarkdownfile  [.-.=.-.]{filename}
+    \processmarkdownbuffer[...=...][buffer]
+
 
 A setup to control them all
 ---------------------------
@@ -441,6 +455,50 @@ options:
 
 The options in the `[...]` are the same as those for `\defineexternalfilter`.
 
+Processing Existing Buffers
+---------------------------
+
+Like all macros built on top of buffers, the `\start<filter>` ...
+`\stop<filter>` environment does not work well inside the argument of another
+command. The `\process<filter>buffer` macro is handy for such macros.
+
+Suppose you want to write some markdown text in a footnote. Using
+
+    \footnote{ .... 
+       \startmarkdown
+          ...
+       \stopmarkdown}
+
+gives an error message:
+
+    ! File ended while scanning use of \dododowithbuffer.
+
+    system          > tex > error on line 0 in file : File ended while scanning use
+    of \dododowithbuffer ...
+
+    <empty file>
+
+    <inserted text> 
+                    \par 
+
+To avoid this, define a buffer at the outer level 
+
+    \startbuffer[footnote-markdown]
+       ...
+    \stopbuffer
+
+and then use
+
+    \footnote{... \processmarkdownbuffer[footnote-markdown]}
+
+The `\process<filter>buffer` macro also takes an optional argument for setup
+options:
+
+    \process<filter>buffer[...][...]
+
+The options in the first `[...]` are the same as those for `\defineexternalfilter`.
+
+
 Prepend and append text
 -----------------------
 
diff --git a/Master/texmf-dist/tex/context/third/filter/t-filter.tex b/Master/texmf-dist/tex/context/third/filter/t-filter.tex
index 266c8e182ea..e44550de3ea 100644
--- a/Master/texmf-dist/tex/context/third/filter/t-filter.tex
+++ b/Master/texmf-dist/tex/context/third/filter/t-filter.tex
@@ -1,6 +1,6 @@
 %D \module
 %D   [     file=t-filter,
-%D      version=2011.09.14,
+%D      version=2011.10.22,
 %D        title=\CONTEXT\ User Module,
 %D     subtitle=Filter,
 %D       author=Aditya Mahajan,
@@ -9,7 +9,7 @@
 %D        email=adityam <at> ieee <dot> org,
 %D      license=Simplified BSD License]
 
-\writestatus{loading}{Filter (ver: 2011.09.14)}
+\writestatus{loading}{Filter (ver: 2011.10.22)}
 
 \ifx\undefined\normalexpanded \let\normalexpanded\expanded \fi
 
@@ -111,6 +111,7 @@
     \setvalue {\e!stop#1}{\externalfilter::process_filter}
 
     \setvalue{process#1file}{\dodoubleargument\externalfilter::process_file[#1]}
+    \setvalue{process#1buffer}{\dotripleargument\externalfilter::process_buffer[#1]}
     \setvalue{inline#1}{\dodoubleargument\externalfilter::inline[#1]}
 
 \stoptexdefinition
@@ -132,6 +133,9 @@
 \stoptexdefinition
 
 \starttexdefinition externalfilter::process_file [#1][#2]#3
+    % #1 = filter
+    % #2 = options
+    % #3 = filename
     \begingroup
 
     \edef\externalfilter::name{#1}
@@ -154,12 +158,43 @@
 
     \endgroup
 \stoptexdefinition
+
+\starttexdefinition externalfilter::process_buffer [#1][#2][#3]
+    % #1 = filter
+    % #2 = options
+    % #3 = buffer
+    \begingroup
+
+    \edef\externalfilter::name{#1}
+    \ifthirdargument
+      \setupexternalfilter[#1][\c!name=,#2]
+    \fi
+
+    \externalfilter::set_directory
+    
+    \ifthirdargument
+      \edef\externalfilter::temp_file{#3}
+    \else
+      \edef\externalfilter::temp_file{#2}
+    \fi
+      
+    \externalfilter::set_filenames_extras
+    % In MkII, the above function sets the wrong value of
+    % \type{\externalfilter::input_file}. So, we reset that name here.
+    \doifmode\s!mkii
+        {\edef\externalfilter::input_file {\externalfilter::base_file.\f!temporaryextension}}
+
+    \iftraceexternalfilters \externalfilter::show_filenames \fi
+    
+    \externalfilter::process_filter
+      
+\stoptexdefinition
    
 \starttexdefinition externalfilter::inline [#1][#2]
    \edef\externalfilter::name{#1}
 
    \begingroup % to keep assignments local
-   \setupexternalfilter[#1][\c!name=,\c!before=,\c!after=,#2]
+   \setupexternalfilter[#1][\c!numbering=,\c!name=,\c!before=,\c!after=,#2]
 
    \externalfilter::set_filenames
 
@@ -317,6 +352,13 @@
    \doifsomething{\externalfilterparameter\c!name}
         {\edef\externalfilter::temp_file{\externalfilter::temp_prefix-\externalfilter::name-\externalfilterparameter\c!name}}
 
+
+   \externalfilter::set_filenames_extras
+
+   \iftraceexternalfilters \externalfilter::show_filenames \fi
+\stoptexdefinition
+
+\starttexdefinition externalfilter::set_filenames_extras
    % The following  macros are useful for filter= and filtercommand= options
    % The basename of the external file 
    \edef\externalfilter::base_file  {\jobname-\externalfilter::temp_file}
@@ -337,10 +379,10 @@
 
    % Append directory name to the name of the output file
    \edef\externalfilter::output_file{\externalfilter::get_directory\externalfilterparameter\c!output}
-   \iftraceexternalfilters \externalfilter::show_filenames \fi
 \stoptexdefinition
 
 
+
 %D \subsubject {Process Filter}
 %D
 %D Execute filter, read the output and do book-keeping if needed.