Neil Hopcroft

A digital misfit

One for the geeks out there – I’m trying to understand how the user agent header and user agent profiles are used, can you help me out?

Leave a comment if you’ve got some thoughts about how these things should all fit together….


Categories: Memories.

/ 12 Comments

12 comments

  1. dan_lane

    I think the results to your poll will be tainted by people not realising the platform you are using.

    Web sites intended for use by web browsers such as Internet Explorer and Mozilla (etc etc) should be standard and not care what client the end user is using.

    HOWEVER, web and wap sites intended for use by mobile phones DO need to depend on the useragent to determine the featureset offered by that handset.

    I didn’t know about UAProf until you mentioned it, a quick google and I’ve just assigned a developer to go take a look at it with a view to replacing our own in-house compatibility list :)

    Reply
    • neilh

      Perhaps – what I’m more interested in is awareness of either or both mechanisms, rather than actually the context in which they are used. UAProf has a bunch of good stuff, but isn’t widely used outside of the WAP space (and even within that space it seems merely supported rather than used). The advantage of UAProf is that you can dynamically support new devices (and new configs of existing devices) without having to update the user agent database – your compatibility list. If it was used well it could be a good thing. Right now, it seems it isn’t used well.

      Reply
      • dan_lane

        being both a Mac and Linux user I’m not a big fan of this current trend of excluding my favorite browsers from websites because they don’t support some obscure feature that isn’t critical to the functionality of the site.

        If UAProf were to transcend into Web space and be used to enable clients rather than exclude, it would prove to be a valuable tool.

        For now we intend to use it to determine what kind of binary content a client can accept.

        Reply
        • neilh

          It has potential, and is almost certainly a better solution than switching on UserAgent, I’ve been playing around with wget sending different UA strings to see how different servers react, there are an awful lot of poorly configured servers out there, and an awful lot of people who can’t tell the difference between a bad server setup and a browser bug.

          Reply
  2. jarkman

    Both are actively used in the MMS world, to support a bit of transcoding of media in messages and a lot of filtering of unsuitable media formats. If that helps.

    Reply
    • neilh

      …and, theoretically, in the WAP world, too, for serving up different content to different terminals.

      I’m trying to figure out how (indeed, whether) they are used in the real world, or are they just another misguided set of standards suffering wapathy?

      Reply
      • jarkman

        They are only spottily observed in the MMS world. And in general we seem to be seeing much less excitement about WAP browsers than MMS clients, which sugests that (in the carrier’s minds, at least) WAP browsing is not getting much use.

        Reply
        • neilh

          Not sure that I’ve ever really had much inclination to use either, I’ve sent one MMS in my life and that was a test to someone in the same car as me. I never bothered again. And WAP, while better over HSCSD (and GPRS, but I gave up with it by then), still isn’t really that useful.

          I think one of the big problems is that a lot of people are thinking “How can we make money out of this?” rather than “What would people find useful?”.

          Reply
          • jarkman

            I actually send a fair few MMS, but mostly to email addresses.

            I agree, that’s the core problem. But I can kind of see how it happens. Apps at this level, MMS and SMS and so on, have to be rolled out across many networks before they really work right, and there has to be a clear economic point for the networks before anyone would bother doing that.

  3. dmh

    Profiles of a user agent’s capabilities = good, kludges based solely on user-agent headers = bad and not a long-term solution. IMHO.

    Reply
  4. neilh

    This, as far as I can tell, is the only valid use of User Agent as a content adaptation, to track (and filter out) buggy user agent implementations….so the string must always be correct (unless you are testing things), whether that leads to your UA being served low quality content or not – thats an issue for the server admin to figure out, not UA.

    Reply

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