Send Track Info to a Web Page, part 1

Frequent visitors to this site may have noticed that occasionally you will see a little blurb in the left column that says "Doug's iTunes is now playing such-and-such by so-and-so". It's what the iTunes on the "kMac"—my wife Natalie's name for the kitchen Mac—is currently playing.

This is acomplished with a Stay-Open AppleScript applet that monitors iTunes and writes the information about the current track to a local text file which is then FTP'd to my website via Fetch 3.0.3. The excellent trackReporter by Bret Van Horn does that very thing in OS X using the UNIX curl program to FTP the file. Unfortunately, OS 9 has no such ability, so what follows describes how I modified trackReporter to use the very scriptable Fetch instead.

First, by way of explaination: This site uses PHP to serve webpages and with PHP you can use include files (Perl CGIs can also use include files). An include file is just a text file that contains info that you wish to keep seperate from a page, but which can be loaded by that page. A common use for include files is when a site uses the same text and links in a footer; every page calls the one include file that has the footer info so that the same info needn't be written to every single page on the site.

Thus, every page on this site has a little piece of code that calls the "itunesisplaying.inc" include file. Whenever you load or refresh a page, the contents of the include file is displayed in the left column.

But before any of that happens we have to create the include file locally. So let's start scripting.

Our script will consist of two parts: an implicit run handler and an idle handler. (I explain how to create Stay-Open applets with idle handlers here, so pardon me if I gloss over any details.) The routines in the implicit run handler will run once, when the script is first activated, setting up variables for later use. The routines in the idle handler are run every few seconds by virtue of setting the idle handler's final return value to a number of seconds. The routines in the idle handler will check iTunes for a playing track. Whenever the track changes, the name and artist will be written to a text string. Here's how that looks:

-- declare variables for later use
global sample_frequency -- how often we should check iTunes
global itunes_active -- if iTunes is active or not
global dbid -- stores current track's database id

-- implicit run handler, runs at startup only
-- initialize variables
set sample_frequency to 15 -- seconds between checking iTunes
set dbid to ""

-- start of monitoring section
on idle
	-- check if itunes is running
	set itunes_active to false
	tell application "Finder" -- "System Events" in OS X
		if (get name of every process) contains "iTunes" then set itunes_active to true
	end tell
	-- if itunes is running then we are go
	if itunes_active then
		tell application "iTunes"
			if player state is playing then
				try
					tell application "iTunes"
						set d to database ID of current track
						if d is dbid then -- if current track hasn't changed
							return sample_frequency -- check again shortly
						end if
						set dbid to d -- re-init dbid with current track's id
						set theTitle to name of current track
						set theArtist to artist of current track
					end tell
					set theMessage to ("Doug's iTunes is now playing \"" & theTitle & "\" by " & theArtist)
				end try
			else
				-- itunes is active but not playing so check back later 
				set idle_time to 60
			end if
		end tell
		set idle_time to sample_frequency
	else
		-- itunes is not currently active so wait before checking again
		set idle_time to 360
	end if
	return idle_time
end idle

[upm] click to open in Script Editor

One would save that as an Application with "Stay-Open" checked in the Save dialog.

All it does so far is create a string called theMessage everytime the current track changes. We want to write that string to a text file. Here's a sub-routine from trackReporter that works very nicely:

--function to write a text string to text file
on write_to_file(this_data, target_file)
	try
		set the target_file to the target_file as text
		set the open_target_file to open for access file target_file with write permission
		set eof of the open_target_file to 0 -- erase current contents
		write this_data to the open_target_file
		close access the open_target_file
		return true
	on error error_message number error_number
		return error_message
	end try
end write_to_file

[upm] click to open in Script Editor

Paste that into the script after what we've already written. We'll want to call this function in a couple of places in the script (you'll see where in the next section), like so:

my write_to_file(theMessage, data_file)

We'll also have to declare the global variable data_file and initialize it in the run handler. The data_file is the path to the text file that we are updating. The top of our script will look like this:

-- declare variables for later use
global sample_frequency -- how often we should check iTunes
global itunes_active -- if iTunes is active or not
global dbid -- stores current track's database id
global data_file -- path to text file to update

-- implicit run handler, runs at startup only
-- initialize variables
set sample_frequency to 15 -- seconds between checking iTunes
set dbid to ""
set data_file to "path:to:itunesisplaying.inc"

[upm] click to open in Script Editor

The path to the text file should be written as a string, like "Macintosh HD:Documents:itunesisplaying.inc".

Next, the routine that ships the text file off to your website using Fetch, and the finished script...