Skip to main content

In Which I Refute Web3S's Critiques Thusly

So the other shoe has dropped, and Yaron Goland has just given some background on Microsoft's draft Web3S protocol, while Dare comments.  Which seems at first glance kind of interesting and certainly could expand the field of REST based services in a big way.  At the same time, I'm confused by some of the stated rationales for not extending APP the way GData does.  I think there are some straightforward answers to each of the gaps he identifies:

Hierarchy

Turtles all the way down:

<entry>
...
    <content type="application/atom+xml">
        <feed> ... it's turtles all the way down! ... </feed>
     </content>
</entry>  

Merging

I think this is orthogonal, but there's already a proposed extension to APP: Partial Updates.  Which uses (revives?) PATCH rather than inventing a new verb or overloading PUT on the same resource.  I'm neutral on the PATCH vs. POST or PUT thing, except to note that it's useful to be able to 'reset' a resource's state, so having the ability to allow this via either two verbs or two URIs is useful too.  I'm a little confused though since Yaron says that they're using PUT for merging but they're also defining UPDATE as a general purpose atomic delta -- so why do you need to overload PUT?

I need to think about the implications of extending the semantics of ETags to cover children of containers as well as the container. 

I do like Web3S's ability to address sub-elements individually via URIs; APP provides this out of the box for feeds and entries, but not for fields within an entry.  It's not difficult to imagine an extension for doing so that would fit seamlessly within APP though.

I think it'd be interesting to look at an APP+3S  (APP plus 2-3 extensions) to see how it would compare against Web3S, and whether the advantages of a stable, standard base do or do not outweigh the disadvantages of starting from something not tailored for your solution.  Certainly the issues raised by Yaron are fairly generic and do need solutions; they're not new; and the thinking of the APP WG has pretty much been that these sorts of things are best dealt with via extensions.

Popular posts from this blog

Personal Web Discovery (aka Webfinger)

There's a particular discovery problem for open and distributed protocols such as OpenID, OAuth, Portable Contacts, Activity Streams, and OpenSocial.  It seems like a trivial problem, but it's one of the stumbling blocks that slows mass adoption.  We need to fix it.  So first, I'm going to name it:

The Personal Web Discovery Problem:  Given a person, how do I find out what services that person uses?
This does sound trivial, doesn't it?  And it is easy as long as you're service-centric; if you're building on top of social network X, there is no discovery problem, or at least only a trivial one that can be solved with proprietary APIs.  But what if you want to build on top of X,Y, and Z?  Well, you write code to make the user log in to each one so you can call those proprietary APIs... which means the user has to tell you their identity (and probably password) on each one... and the user has already clicked the Back button because this is complicated and annoying.

XAuth is a Lot Like Democracy

XAuth is a lot like democracy:  The worst form of user identity prefs, except for all those others that have been tried (apologies to Churchill).  I've just read Eran's rather overblown "XAuth - a Terrible, Horrible, No Good, Very Bad Idea", and I see that the same objections are being tossed around; I'm going to rebut them here to save time in the future.

Let's take this from the top.  XAuth is a proposal to let browsers remember that sites have registered themselves as a user's identity provider and let other sites know if the user has a session at that site.  In other words, it has the same information as proprietary solutions that already exist, except that it works across multiple identity providers.  It means that when you go to a new website, it doesn't have to ask you what your preferred services are, it can just look them up.  Note that this only tells the site that you have an account with Google or Yahoo or Facebook or Twitter, not what the…
Twister is interesting.  It's a decentralized "microblogging" system based on putting together existing protocols:  Bitcoin, distributed hash tables, and Bittorrent.  The most interesting part for me is using Bitcoin for user registration and spam control.  Federated systems handle this with federated trust, which is at least conceptually simple.  The Twister/Bitcoin mechanism looks intriguing though I don't know enough about Bitcoin to really comment.  Need to read further.