AppleScript to preview the current file in TextWranger in Chrome.

gistfile1.applescript

-- Based on Sam Dutton's  script (http://goo.gl/27XlZ)
-- which was based on Mike Piontek's script (http://goo.gl/SBkkL)
-- This is Chrome specific. See https://gist.github.com/3232318 for a Safari Script

tell application "TextWrangler" to set theFile to file of document 1
tell application "TextWrangler" to save document 1

set appleScriptPath to theFile as text
set currentURL to POSIX path of appleScriptPath
set currentURL1 to POSIX path of appleScriptPath
set currentURL to ("file://" & currentURL)

-- this script will get the <title> tag from the web page for comparison below.
set theTitle to do shell script "grep -i '<title>' " & currentURL1 & "| sed -e 's#<[^>]*>##g' | sed 's/^[ 	]*//;s/[ 	]*$//'"

tell application "Google Chrome"
	activate
	-- using the <title> tag above, we compare to the current open tab. If they are equal, replace the contents, otherwise, open a new tab.
	if (exists window 1) and (title of active tab of window 1 is theTitle) then
		tell window 1 to set URL of active tab to currentURL
	else
		open location currentURL
	end if
end tell