From datasource config to Service REST API with no proxy/controller classes

[bajtos]

In LoopBack 3, it was very easy to get a fully-featured CRUD REST API with very little code: a datasource configuration for a 3rd party webservice (REST, SOAP, etc.) and an empty model attached to that datasource.

Let's provide the same simplicity to LB4 users too and build on top of the mechanism implemented for models in #2036.

• User creates a datasource using a web-service connector like REST or SOAP. (No change here.)
• User declaratively defines how to expose this service via REST API. At minimum, we need a model name or URL path where to mount the service API.
• @loopback/boot processes this configuration and registers appropriate service proxies & controllers with the app.

Note: having config for multiple services in a single JSON file can quickly become a maintenance nightmare, see strongloop/loopback#1316. It will be better to have one config file per service, e.g. public-services/geocoder.json.

See also

• From model definition to REST API with no repository/controller classes From model definition to REST API with no custom repository/controller classes #2036
• Include related models in "GET /mymodels" results #1889:

  provide a set of extensions in order to keep the simplicity of LB3, without the needed to creat e repository, controller for default CRUD actions (only if we need custom actions) ?

• Declarative Support #565 Declarative Support