RestService

Implements: IConfigurable, IReferenceable, IOpenable, IUnreferenceable, IRegisterable

Description

The RestService class allows you to create REST services that receive remote calls via the HTTP/REST protocol.

Configuration parameters

• base_route: base route for remote URI
• dependencies:
  • endpoint: override for HTTP Endpoint dependency
  • controller: override for Controller dependency
• connection(s):
  • discovery_key: (optional) key to retrieve the connection from IDiscovery
  • protocol: connection protocol (http or https)
  • host: host name or IP address
  • port: port number
  • uri: resource URI or connection string with all parameters in it
• credential: the HTTPS credentials:
  • ssl_key_file: SSL private key in PEM
  • ssl_crt_file: SSL certificate in PEM
  • ssl_ca_file: certificate authorities (root cerfiticates) in PEM

References

• *:logger:*:*:1.0 - (optional) ILogger components to pass log messages
• *:counters:*:*:1.0 - (optional) ICounters components to pass collected measurements
• *:traces:*:*:1.0 - (optional) ITracer components to record traces
• *:discovery:*:*:1.0 - (optional) IDiscovery services to resolve connection
• *:endpoint:http:*:1.0 - (optional) HttpEndpoint reference

Fields

Instance methods

close

Closes a component and frees used resources.

@override

Future close(String? correlationId)

• correlationId: String? - (optional) transaction id used to trace execution through the call chain.

configure

Configures a component by passing its configuration parameters.

@override

void configure(ConfigParams config)

• config: ConfigParams - configuration parameters, containing a “connection(s)” section.

instrument

Adds instrumentation to log calls and measure call time. It returns a Timing object that is used to end the time measurement.

InstrumentTiming instrument(String? correlationId, String name)

• correlationId: String? - (optional) transaction id used to trace execution through the call chain.
• name: String - method name.
• returns: InstrumentTiming - CounterTiming object used to end the time measurement.

getCorrelationId

Returns correlationId from request

String? getCorrelationId(shelf.Request req)

• req: shelf.Request - http request
• returns: String? - returns correlationId from request

isOpen

Checks if the component is open.

@override

bool isOpen()

• returns: bool - true if the component is open and false otherwise.

open

Opens the component.

@override

Future open(String? correlationId)

• correlationId: String? - (optional) transaction id used to trace execution through the call chain.

register

Registers all service routes in a HTTP endpoint.

This method is called by the service and must be overriden in child classes.

@override

void register()

registerInterceptor

Registers a middleware for a given route in HTTP endpoint.

void registerInterceptor(String route, Function(shelf.Request req) action)

• route: String - command route. Base route will be added to this route
• action: Function(shelf.Request req) - action function that is called when middleware is invoked.

registerOpenApiSpecFromFile

Registers openapi specification from file

void registerOpenApiSpecFromFile(String path)

• path: String - file path

registerOpenApiSpec_

Registers openapi specification from string

void registerOpenApiSpec_(String content)

• content: String - openapi content

registerRoute

Registers a route in HTTP endpoint.

void registerRoute(String method, String route, Schema? schema, FutureOr<shelf.Response> Function(shelf.Request req) action)

• method: String - HTTP method: “get”, “head”, “post”, “put”, “delete”
• route: String - command route. The base route will be added to this route
• schema: Schema? - validation schema to validate received parameters.
• action: Function(shelf.Request req) - action function that is called when an operation is invoked.

registerRouteWithAuth

Registers a route with authorization in HTTP endpoint.

void registerRouteWithAuth(String method, String route, Schema schema, Future Function(shelf.Request req, Function next) authorize, Future Function(shelf.Request req) action)

• method: String - HTTP method: “get”, “head”, “post”, “put”, “delete”
• route: String - command route. The base route will be added to this route
• schema: Schema - validation schema to validate received parameters.
• authorize: Future Function(shelf.Request req, Function next) - authorization interceptor
• action: Future Function(shelf.Request req) - action function that is called when an operation is invoked.

sendCreatedResult

Creates a callback function that sends a newly created object as JSON. The callack function call be called directly or passed as a parameter to business logic components.

If the object is not null, it returns 200 status code. For null results it returns 204 status code. If an error occurs, it sends ErrorDescription with the approproate status code.

FutureOr<shelf.Response> sendCreatedResult(shelf.Request req, result)

• req: shelf.Request - HTTP request context
• err: dynamic - execution error
• result: dynamic - execution result
• returns: FutureOr<shelf.Response> - HTTP response context

sendDeletedResult

Creates a callback function that sends deleted object as JSON. That callack function call be called directly or passed as a parameter to business logic components.

If object is not null it returns 200 status code. For null results it returns 204 status code. If error occur it sends ErrorDescription with approproate status code.`

FutureOr<Response> sendDeletedResult(Request req, result)

• req: shelf.Request - HTTP request context
• result: dynamic - body object to result.
• returns: FutureOr<Response> - HTTP response context

sendError

Sends an error serialized as ErrorDescription object and the appropriate HTTP status code. If status code is not defined, it uses 500 status code.

void sendError(shelf.Request req, error)

• req: shelf.Request - HTTP request context
• error: dynamic - error object to be sent.
• returns: FutureOr<Response> - HTTP response context

sendResult

Creates a callback function that sends a result as a JSON object. The callack function call be called directly or passed as a parameter to business logic components.

If the object is not null it returns 200 status code. For null results, it returns 204 status code. If an error occurs, it sends ErrorDescription with the approproate status code.

FutureOr<shelf.Response> sendResult(shelf.Request req, result)

• req: shelf.Request - HTTP request context
• error: dynamic - error object to be sent.
• result: dynamic - body object to result.
• returns: FutureOr<shelf.Response> - HTTP response context

setReferences

Sets references to dependent components.

@override

void setReferences(IReferences references)

• references: IReferences - references to locate the component dependencies.

unsetReferences

Unsets (clears) previously set references to dependent components.

@override

void unsetReferences()

Examples

class MyRestService extends RestService {
    IMyController _controller;
   ...
   MyRestService(): base() {
      dependencyResolver.put(
          'controller',
          Descriptor('mygroup','controller','*','*','1.0')
      );
   }
   void setReferences(references: IReferences) {
      base.setReferences(references);
      _controller = dependencyResolver.getRequired<IMyController>('controller');
   }
   void register() {
       registerRoute('get', 'get_mydata', null, (req, res)  {
           var correlationId = req.param('correlation_id');
           var id = req.param('id');
           var result = await _controller.getMyData(correlationId, id);
           sendResult(req, res, null, result);
       });
       ...
   }
}

var service = MyRestService();
service.configure(ConfigParams.fromTuples([
    'connection.protocol', 'http',
    'connection.host', 'localhost',
    'connection.port', 8080
]));

service.setReferences(References.fromTuples([
   Descriptor('mygroup','controller','default','default','1.0'), controller
]));

await service.open('123');
print('The REST service is running on port 8080');

See also

• RestClient