Appengine: Transaction Safe Reference Properties with Ancestor Queries

This is a quick article on transactions with “one to many” relationship queries within a single by utilizing entity groups and ancestor queries. If you find it helpful, please feel free to link to it and help spread the google juice. Special thanks to co-worker Robert Kluin for helping me figure this out last week. My Problem My initial problem was that I was working inside a...

Appengine Files Api – part 1: Storing/Fetching remote images in Blobstore using Django

Here is a quick tutorial on how to fetch remote images with the new Files API on Google Appengine 1.4.3 released March 30th. These examples use Django. Before we begin, read up on how to write files to blobstore using the Files API. Prior to the 1.4.3 release of the SDK, the only way to get files into the blobstore (and thus leverage things like BlobInfo) was to upload them via a POST request. To...

Appengine: getCurrentUser() is None but app.yaml login:admin Allows Access?

Today, while working on Google AppEngine code, I discovered a bug in AppEngine, but it just turned out to be a typo. I spent a good few hours googling before tearing things apart and solving the tricky issue. As such, I am sharing my finds to help others’ save some time and stress. Short version is to check your regular expressions in the app.yaml file when adding security to an entire...

Appengine Django/GQL – Ensuring Uniqueness of Model Type on Edit – Not Equals Filters

Edit 2009-02-02 - Added note about inequality query complexity. Spoiler – inequalities are 2 queries under the hood. In my further adventures in Google AppEngine land, I wanted to ensure uniqueness of an email field while still allowing the user to change their email address. Since, Google App Engine’s BigTable doesn’t allow you to custom define unique indexes, this poses a...

New Phone – an Android Even!

For my birthday, my awesome girlfriend bought me a new phone – a MyTouch Google Android phone! App development, here I come! Historically, I have not been a huge phone connoisseur. Before I had a phone, I remember my old roommate Jin and I outside of night classes surrounded by lots of people standing around talking on their phone rather than each other. We used to hold our hands up to our...