add cgit commit-filter example

public-inbox has search functionality, so take advantage of
good commit messages with proper titles to lookup discussion.

diff --git a/examples/cgit-commit-filter.lua b/examples/cgit-commit-filter.lua
new file mode 100644 (file)
index 0000000..4b90125
--- /dev/null
+++ b/examples/cgit-commit-filter.lua
@@ -0,0 +1,44 @@
+-- Copyright (C) 2015 all contributors <meta@public-inbox.org>
+-- License: GPLv2 or later (https://www.gnu.org/licenses/gpl-2.0.txt)
+-- This commit filter maps a subject line to a search URL of a public-inbox
+-- disclaimer: written by someone who does not know Lua.
+--
+-- This requires cgit linked with Lua
+-- Usage (in your cgitrc(5) config file):
+--
+--   commit-filter=lua:/path/to/this/script.lua
+--
+-- Example: http://bogomips.org/public-inbox.git/
+
+local urls = {}
+urls['public-inbox.git'] = 'http://public-inbox.org/meta/'
+-- additional URLs here...
+
+function filter_open(...)
+       lineno = 0
+       buffer = ""
+       subject = ""
+end
+
+function filter_close()
+       if lineno == 1 and string.find(buffer, "\n") == nil then
+               u = urls[os.getenv('CGIT_REPO_URL')]
+               if u == nil then
+                       html(buffer)
+               else
+                       html('<a href="' .. u .. '?x=t&q=')
+                       html_url_arg('"' .. buffer .. '"')
+                       html('"><tt>')
+                       html_txt(buffer)
+                       html('</tt></a>')
+               end
+       else
+               html(buffer)
+       end
+       return 0
+end
+
+function filter_write(str)
+       lineno = lineno + 1
+       buffer = buffer .. str
+end