API Express is one of the core components in Appery.io platform. API Express allows you to integrate with external enterprise data sources and expose them via REST APIs. API Express also allows to compose advanced services using a visual editor. The REST APIs are then used in a mobile app.
API Express supports connecting and exposing the following data sources via REST APIs:
- Relational database – connect and expose any relational database via REST APIs (automatic CRUD generation)
- SQL query – expose any custom SQL query via a REST API.
- Stored Procedure – expose any store procedure via a REST API.
- REST API – connect to any external REST API.
- SOAP service – connect and expose any SOAP service via REST API.
- Server Code script – invoke any existing Server Code script.
In addition to these services, the visual editor also supports the following components:
- Fork – execute two more more services (from above) at the same time.
- Condition – add if-then like function to the service flow.
- Mapping – map data from one component to another component.
The API Express visual service editor allows to create very advance service flow and logic. Here is one example:
- Start – entry into the service.
- Invoke the SOAP component.
- In parallel (Fork), invoke the REST API component and the SQL component.
- Take the result and process it with the Script component.
- End – set the service response
In the above flow, steps 1-4 are exposed via an API Express REST API. To the client (the mobile app), it is just a simple API. As you can see, the actual service logic can be very advanced.
A REST API can be quickly tested right in the developer console.
A REST API created can also be secured. A user has to login before invoking the service. For authentication, API Express supports LDAP and Appery.io Database.
Another big benefit that API Express provides is a special client SDK that allows to build offline apps. If the app you built with API Express APIs goes offline, you can use the app the same way. When the app (or device) goes back online, any changes will be automatically synced.