PriceTracker
code for price tracking based on api
Api
There are two main parts to the system
- Transactor stores and logs the transformations to the database
- Strategy, wraps your custom modules to interact with the transactor
lib/strategies/omega_pricing.ex impliments the contract of strategy
for the omega api. You could extend your own by writing your own modueles
and using Strategy
Strategies expose a make_request() function that will call the api and
merge the changes into the database. By deriving from Strategy,
The Transactor code can be resued verbatim.
You can call make_request at periodic intervals to gather data
for the database. a library such as quantum-elixir
would be perfect for this and could be mounted in a supervision tree.
I did make a few assumptions
- http with get responses. I did add a case statement where a post handler could be added
- The exposed method takes no option. This is to make it easier to mount it in a cron function.
- we want to support multiple companies so I added a company code to the product model
Libraries used
I wasn't sure if phoenix was allowed so I built the test harness with support for ecto and mocking http requests for httpoison myself.
- ecto
- exvcr to mock http requests for testing
- timex for time handling
Running tests
to run the tests, simply run
mix deps.get
mix test