Amazingly, Shelf is still fun to work on. Hence version 0.0.10. Read the release notes.

These version numbers are just jumping around randomly now. Well, ok, they're not, but not every version escapes to the world. Anyway, download the new Shelf - this one has an icon! And it now includes Sparkle, so it'll update itself automatically from now on - you can stop visiting my blog every 10 minutes to see if I've released a new version now.

Incidentally, Sparkle is <i>stupidly</i> easy to install - everyone should use it. It's awesome.

I'm going to start keeping a proper ChangeLog now, because I have no idea what's in this version. Better cacheing? I think it'll also use AddressBook.app as a source of Clues, so if you're having trouble getting the app to do anything, just open Address Book and look at a card - you're guaranteed to see something.

Right, Shelf has now reached version 0.0.6 - download it (there are newer versions out now - get those). It's good enough that I'm running it full time now. Thanks to Mark Fowler, it can now pull clues from Firefox, which is a relief. I've also added Address Book and iChat support, although the iChat stuff is a little hokey - it assumes you're not using tabbed chats, and that you speak English. Sorry. The iChat AppleScript dictionary is lousy.

Musings

It's been suggested that I could work out twitter feed and Flickr photostream URLs about people based on their name / nick / email. I'm currently shying away from deriving too many things about a person magically. For instance, I could work out (and cache, obviously) a Flickr username for a person from their email address. Quite apart from the horrible privacy implications of sending the email addresses of everyone you read mail from to Flickr, I just don't like the approach. I'd much rather encourage a rich address book with lots of data in it. This has the side-effect that Shelf will also recognise my Flickr page as belonging to me.

Ruby turned out to be a bit of a pain for Shelf - I needed many external libraries and the Ruby bridge does a fairly bad job of packaging them all. I've ported the thing to Python now and it seems better - in fact, it's better enough that I can actually produce a binary! Check out the downloadable action! - MacOS 10.5 only, and this is very unlikely to change. Deal with it.

It'll pull context from Safari, NetNewsWire, Mail.app, Adium and Twitterific. Adding new apps is easy, I just haven't yet. It'll display only the person's name, email addresses, and street address. And there will be errors if the street address is incomplete. It's a PROOF OF CONCEPT. Jeez. Quit whining. There is code to fetch the recent feeds of their pages, but it's disabled because the app blocks while it's doing it, making it practically unusable.

Update: [Version 0.0.2 now available](http://2lmc.org/files/jerakeen/Shelf-0.0.2.zip) - it's a little smarter, and tries to parse microformats in the source of the current Safari tab now.Another Update: Hmm, packaging things is _hard_. Never mind, try [version 0.0.5](http://2lmc.org/files/jerakeen/Shelf-0.0.5.zip) - it actually _works_, and does RSS feeds and Flickr photos and twitter messages and threading and things. I'm getting happier and happier with this..

Rather than me updating this page all the time, just go to the Shelf project page and get the most recent binary from there.

I really miss Dashboard. It was an effort to display some context around whatever person you were interacting with at any given moment - look at an email from Paul, or open an IM chat with him and you'd see things that he'd blogged or uploaded to Flickr recently. Genius. From the screenshots, it looks practically magic, tying into incoming SMS messages, IM conversations, the RSS feed reader, etc.

Alas, I never had a fully working Dashboard setup locally, mostly because applications had to actively participate in the process - they sent things called 'cluepackets' to the dashboard application containing hints about the current context. Because of this design, every app involved needed its source code patched and a recompile. This was a complete pain. Obviously, had everything gone to plan, the patches would have been merged and everyone would have been happy. I presume that Dashboard failed because the bootstrapping process was so hard that no-one used it.

Anyway, inspired by both Dashboard and Aaron's obsession with the address book, I've had a stab at doing it again, but worse.

Shelf

Shelf will look at the current foreground application, and try to figure out if what you're looking at corresponds to a person in your Address Book. Then it'll tell you things about them.

Update 2008/01/08: I have downloadable versions of Shelf now. Go to the project page and download one.

It's for MacOS. Because on MacOS, I have OSA - I can interrogate most (well-written) applications about their state in a beautiful, language-agnostic and fast manner. I can ask Mail.app for the email address of the current mail. I can ask Safari what the URL of the foreground window is. I can ask Adium for the account details of the current chat. I can ask NetNewsWire for the homepage URL of the current subscription. And I can ask the system what app is in the foreground. I can also interrogate the system address book via the Cocoa bindings for same and find out what users have got that email address, or URL, or AIM screen name. And then I can take all the other information about them in their address book entry, and figure out some context. Oh, and the thing's written in Ruby, because the Ruby scripting bridge is a thing of serious beauty and should be played with by everyone.

Good thing

So, advantages. I don't have the bootstrapping problem, because most MacOS applications already have enough of a scripting interface that I can extract information from them. Firefox is proving to be a serious problem, alas, but I've hit no other apps I can't get something useful out of.

Once I have an Addressbook record as context, I can update the interface with a picture of the person and their name/company (direct from the address book, so easy). As a 'will this work?' experiment, I'm parsing every referenced URL in the address book card for RSS feeds, and displaying those as context. And (because I work there) I have special-case Dopplr support that tells me where the person is in the world and where they're going next. This means that when someone IMs me, a window pops up and tells me where they are, when they're back, and what they've blogged recently. Awesome.

The system address book is great - it has multiple email address and URLs for people, so I'm indicating things like Dopplr username by just putting the url to my traveller page in my address book entry. I can parse the username out later and use it to call the API with. This has the advantage that if I visit my Dopplr page in Safari, hey, wow, that URL is in the address book, and it knows that it's me again. Flickr is the next obvious choice for special-casing, but the principle extends to anything.

Bad thing

Disadvantages. Firstly, urgh, I'm polling. Every 2 seconds, I ask the system for the foreground application, then ask that application (if I know how) for context. This is probably a little heavy (is it? I'm guessing..). Secondly, I have to do explicit work for every app out there. The huge advantages of Dashboard's cluepacket approach over mine were that packets were pushed instantly on a change of context, and that a new application was responsible for sending its own cluepackets.

Actually, this is easy. My app should have a 'change context' OSA method that other applications can call. Smart apps can tell me when their context changes, and I'll just poll everyone else. Once I've taken over the world, everyone will be pushing messages to me, and I can deprecate the poll interface. Genius.

Recently, most of the crazy apps I've put here have been labelled as 'proof of concept'. This one is different. This one probably won't even build on your computer. I'm putting things up here as a was of musing about technique. For instance, Dashboard had a far better design than this app. It had a nice pipeline thing going for it, whereas I just have a class per foreground application, this class must produce an Address Book record, then I just interrogate every context producer for information and display it. This is silly - if I'm looking at Paul's Flickr photos page, I don't need my app showing me the thumbnails again, I might be much more interested in where he is right now. Hell, in a perfect world, it would work out the dates of the photos I'm looking at, and show me where he was at that time.

Future

Clever things I could (and want to) do:

• If the foreground URL doesn't belong to a user, look for hcard markup in the source HTML and try to derive a person from that. Right now, for instance, I'll only recognise your Flickr page as belonging to you if it's one of the URLs against your address book card. But Flickr pages are marked up with enough hcard that I should be just able to figure it out.

• More intelligence around context - as above, if I'm looking at a blog of a friend, I want to see other things, not their blog again.

• Remembering connections - if I figure out a local person from a Flickr page via hcard markup rather than an Address Book URL, why not remember their Flickr username and display their photos when they email me?

Many of these features are difficult, mostly because of my core design right now - I derive an Address Book entry from the current application, then derive context from that entry. This hampers cleverness somewhat - I really need to pass around a lot more information about how I derived this person, and keep a local cache of conclusions about them. Maybe the person isn't in my address book - I get email from people I don't know! But their email address might correspond to a Gravatar so I could show a picture of them. Maybe the mail has some URLs in the .sig and I could find their blog. Maybe they've commented on my blog in the past and I'd like links to the comments. Likewise, if I find, via hcard in the source of a page, that a page is about someone I know, should I update Address Book and add URLs for them? Probably not a good idea. So I need a local store of connections as well.

Now what?

I don't know. It's very tempting to rewrite the thing in Python before it gets any more complex. Partially this is because the Ruby feedparser dependencies are a bugger, but mostly it's because I don't want my python sk1llz to atrophy down to nothing. Recently everything I do is in Ruby, and I don't like that. Shelf also desperately needs some work done to make it asynchronous, and cache things - when I look at an email right now, it'll hang for 5 minutes while it goes off and fetches 20 RSS feeds, every time I change the person I'm looking at. Not exactly pleasant. But the 'find out about a person' is really just a trivial example of the sort of things you can do once you know who they are. The 'derive context from current machine state' side of things is much more interesting.

Today, the spool died. We've been meaning to do this for a while - not living in the same house any more has severely curtailed the 2lmc bile-level, and it barely seems worth keeping up any more. Plus, I really want the memory back on the colo - it's a rails application, and not exactly frugal. I don't intend to let any links go stale - I'll bake the whole thing out to a tree of static pages and leave it up, I just don't need it to be dynamic any more.

We had good moments, and if they were more frequent, I'd leave the thing going. But because the spool was based on turning IRC chattery directly into postings, it required a very high level of active channel participation and anger. It didn't work unless there were two or three people in channel, awake, and paying attention. This was easy to guarantee when the rest of the house was on the sofa over there. It's much much harder now.

I did toy for a while with concepts for some sort of bile-condenser. Something that would let me take several minutes / hours of IRC-based conversation and condense it into a spool post might have worked. But the logistics are nasty - you have to log everything, edit it down when you think there's been a rant about something good, then get the approval of everyone involved that they're happy with the edited version. Paul talked me out of it. We're capable of ranting on our own little sites.

It led me to the realization that too much of my link-finding, musing and ranting goes into an IRC channel, where it's wasted on 2lmc. If more of my rambling was in the form of blog entries I'd feel that it was more worthwhile. But I'd get less feedback from 2lmc. Meh, they can just use the comment form.

13:12  * jerakeen tries to turn that into a blog post.

DuckCall didn't work work under Leopard. Noone really noticed, so I assume noone uses it. Which is probably a Good Thing. But if you were sitting on the edge of your seat, waiting for a compatibility release, you can now relax. DuckCall-0.0.3.zip is now available.

It's also 80k zipped, as opposed to the 3 megs of version 0.0.2. Hurray for bundled PyObjC. This means that this version will only work under Leopard. But there are no other changes between it and 0.0.2, so all you laggards don't need to feel left out.

Had this sitting around in my 'things to think about' file for a bit now.

In the early days of the SNMP, which does use ASN.1, the same issues arose. In the end, the working group agreed that the use of ASN.1 for SNMP was axiomatic, but not because anyone thought that ASN.1 was the most efficient, or the easiest to explain, or even well liked. ASN.1 was given axiomatic status because the working group decided it was not going to spend the next three years explaining an alternative encoding scheme to the developer community.

rfc3117