High level PHP library for Amazon SWF deciders to check state of activity tasks

Question

I'm writing PHP for fairly simple workflow for Amazon SWF. I've found myself starting to write a library to check if certain actions have been started or completed. Essentially looping over the event list to check how things have progressed, and then starting an appropriate activity if its needed. This can be a bit faffy at times as the activity type and input information isn't in every event, it seems to be in the ActivityTaskScheduled event. This sort of thing I've discovered along the way, and I'm concerned that I could be missing subtle things about event lists.

It makes me suspect that someone must have already written some sort of generic library for finding the current state of various activities. Maybe even some sort of more declarative way of coding up the flowcharts that are associated with SWF. Does anything like this exist for PHP?

(Googling hasn't come up with anything)

Answer 1

I'm not aware of anything out there that does what you want, but you are doing it right. What you're talking about is coding up the decider, which necessarily has to look at the entire execution state (basically loop through the event list) and decide what to do next.

Here's an example written in python ( Using Amazon SWF To communicate between servers ) that looks for events of type 'ActivityTaskCompleted' to then decide what to do next, and then, yes, looks at the previous 'ActivityTaskScheduled' entry to figure out what the attributes for the previous task were.

If you write a php framework that specifies the workflow in a declarative way then a generic decider that implements it, please consider sharing it :)

Answer 2

I've since found https://github.com/cbalan/aws-swf-fluent-php which looks promising, but not really used it, so can't speak to the whether it works or not.

I've forked it and started a bit of very light refactoring to allow some testing, available at https://github.com/michalc/aws-swf-fluent-php