RESTful Rails Development

Chapter 12. Consuming Data Streams: Integrating External APIs in Your Application

In this chapter we are going to integrate two external APIs into our Walks application. We are going to see how integrating external services is somewhat similar to integrating an internal API. There are some issues regarding the way we consume and offer external content that need to be considered, however.

Creating a Weather Service

Imagine that our Walks application could be enriched with a weather forecast, or that our Citywalks API could also suggest that users pack an umbrella or sunscreen before leaving the house. If you are thinking what I am thinking right now, you would agree that this would be a nice feature to have.

The problem with this is that you actually need a simple weather forecasting service to implement it—yet you may want to code a way to get weather forecasts in your app yourself. The ideal solution would be a third-party service that you could talk to to get a weather forecast for a particular city or location.

Luckily for us, there are a number of APIs that offer this service on the Web. Most of these also allow your app to make a certain number of calls per day for free, which is our ideal situation since we are just starting with a test project.

I have chosen to use the OpenWeatherMap project, since it adopts an approach to its business and service that is inspired by OpenStreetMap and Wikipedia and involves making its information available to everybody to use. OpenWeatherMap ...