MIME API from LittleShoot on Google App Engine

July 23, 2009

The other day I needed to add an HTML form to the LittleShoot site to upload files directly to Amazon S3. S3’s “browser-based uploads” allow you to send files directly into S3 using hidden form fields to sign the request as opposed to sending files through your server. Nice and efficient.

Everything was going along fine until I realized one glaring problem: how the heck could I set the Content-Type on the file? S3 requires you to do this in the initial request, in this case using another hidden form field, but how could I determine the MIME type at all? Cut past 30 minutes of digging around, and it turns out you can, of course do the following:

  1. Attach to the form submit event. In JQuery, this is just:
    $("#myForm").submit(function() {...});
  2. Lookup the MIME type in JavaScript (somehow – pay attention to this one)
  3. Dynamically add a hidden “Content-Type” form field just before the upload.

The only problem? To do this, you need to include a full JavaScript library to lookup all MIME types in the submit function above, another 40K+ of JavaScript code. That seems a little excessive for a call you’ll only make every once in awhile.

Now comes the beauty of Google App Engine (GAE). With App Engine, you can fire up a site in a matter of minutes that will scale to millions. With a little help from my favorite App Engine Patch, you can run it all on Django. The speed and ease of deployment are breathtaking: 1 hour to deploy a REST API for MIME lookups, all for free.

The result is http://www.mimeapi.org/.  It’s a trivial, ridiculously simple API that basically just exposes the Python “mimetypes” module. It’s the simplest, silliest, and most trivial REST API I’ve ever seen or written, and that’s the whole point. Google App Engine annihilates the barrier to creating this type of API on the only two scales that really matter in this case: time and cost.

I predict we’ll see a lot of similarly trivial services continuing to pop up because they’re so easy. They seem almost stupid at first. Simple building blocks like these are the secret sauce in building any truly powerful platform, however, and with tools like GAE, the web is getting more powerful by leaps and bounds.

If you ever run into the obscure case where you need to lookup a MIME type via an API, check out mimeapi. I built it because it makes more sense than cramming another JavaScript library down my user’s pipes. Maybe it’ll help you too.

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Google App Engine Full Text Search From App Engine Patch Team

July 1, 2009

Waldemar Kornewald and the rest of the Google App Engine Patch team have just released the first full text search implementation for Google App Engine (GAE).  LittleShoot has been using App Engine Patch since the early days of App Engine, and we can’t recommend it highly enough.  Its seamless Django integration has saved us countless hours, and features like its tool for combining and compressing all of your JavaScript and CSS using the YUI compressor are just stellar.

While we don’t have an immediate need for full text search over at LittleShoot, we can tell you the team behind GAE full text search is rock solid and battle tested.  Given the various limitations of the GAE datastore API, it’s also quite a technical feat.

If you need full text search, and you’re running on App Engine using python, GAE search will save you a great deal of pain.  Go get it.