RestService

Abstract service that receives remove calls via HTTP/REST protocol.

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

_dependencyResolver

Dependency resolver.

protected _dependencyResolver: DependencyResolver

_logger

Logger.

protected _logger: CompositeLogger = CompositeLogger()

_counters

Performance counters.

protected _counters: CompositeCounters = CompositeCounters()

_debug

Boolean that set debugging to True or False.

protected _debug: boolean = false

_baseRoute

Base route.

protected _baseRoute: string

_endpoint

HTTP endpoint that exposes this service.

protected _endpoint: HttpEndpoint

_tracer

Tracer.

protected _tracer: CompositeTracer = CompositeTracer()

_config

Service’s configuration paramters.

protected _config: ConfigParams

_swaggerService

Swagger service.

protected _swaggerService: ISwaggerService

_swaggerEnable

Boolean that defines if the Swagger sevice is enabled or not.

protected _swaggerEnable: boolean = false

_swaggerRoute

Swagger’s route.

protected _swaggerRoute: string = ‘swagger’

Instance methods

close

Closes a component and frees used resources.

public close(correlationId: string): Promise<void>

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

configure

Configures a component by passing its configuration parameters.

public configure(config: ConfigParams): void

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

getCorrelationId

Returns correlationId from a request

protected getCorrelationId(req: any): string

  • req: any - an HTTP request
  • returns: string - the correlation id from request.

instrument

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

protected instrument(correlationId: string, name: string): InstrumentTiming

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

isOpen

Checks if the component is open.

public isOpen(): boolean

  • returns: boolean - True if the component has been opened and False otherwise.

open

Opens the component.

public open(correlationId: string): Promise<void>

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

registerInterceptor

Registers a middleware for a given route in HTTP endpoint.

protected registerInterceptor(route: string, action: (req: any, res: any, next: () => void) => void): void

  • route: string - command route. Base route will be added to this route
  • action: (req: any, res: any, next: () => void) => void - action function that is called when middleware is invoked.

registerOpenApiSpec

Registers the open api spec.

protected registerOpenApiSpec(content: string)

  • content: string - response header content

registerOpenApiSpecFromFile

Registers the open api spec from a file.

protected registerOpenApiSpecFromFile(path: string)

  • path: string - path to the file

registerRoute

Registers a route in HTTP endpoint.

protected registerRoute(method: string, route: string, schema: Schema, action: (req: any, res: any) => void): void

  • 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: (req: any, res: any) => void - action function that is called when an operation is invoked.

registerRouteWithAuth

Registers a route with authorization in HTTP endpoint.

protected registerRouteWithAuth(method: string, route: string, schema: Schema, authorize: (req: any, res: any, next: () => void) => void, action: (req: any, res: any) => void): void

  • 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: (req: any, res: any, next: () => void) => void - authorization interceptor
  • action: (req: any, res: any) => void - 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.

protected sendCreatedResult(req: any, res: any, result: any): void

  • req: any - an HTTP request
  • res: any - an HTTP response
  • result: any - an IReferences object, containing references to a logger, counters, and a connection resolver.

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.

protected sendDeletedResult(req: any, res: any, result: any): void

  • req: any - an HTTP request
  • res: any - an HTTP response
  • result: any - body object to result.

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.

protected sendError(req: any, res: any, error: any): void

  • req: any - an HTTP request
  • res: any - an HTTP response
  • error: any - error object to be sent.

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.

protected sendResult(req: any, res: any, result: any): void

  • req: any - an HTTP request
  • res: any - an HTTP response
  • result: any - body object to result.

setReferences

Sets references to dependent components.

public setReferences(references: IReferences): void

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

unsetReferences

Unsets (clears) previously set references to dependent components.

public unsetReferences(): void

Abstract methods

register

Registers all service routes in a HTTP endpoint.

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

abstract register(): void

Examples

class MyRestService extends RestService {
   private _controller: IMyController;
   ...
   public constructor() {
      base();
      this._dependencyResolver.put(
          "controller",
          new Descriptor("mygroup","controller","*","*","1.0")
      );
   }
   public setReferences(references: IReferences): void {
      base.setReferences(references);
      this._controller = this._dependencyResolver.getRequired<IMyController>("controller");
   }
   public register(): void {
       registerRoute("get", "get_mydata", null, (req, res) => {
           let correlationId = req.param("correlation_id");
           let id = req.param("id");
           let promise = this._controller.getMyData(correlationId, id);
           this.sendResult(req, res, promise);
       });
       ...
   }
}

let service = new MyRestService();
service.configure(ConfigParams.fromTuples(
    "connection.protocol", "http",
    "connection.host", "localhost",
    "connection.port", 8080
));

service.setReferences(References.fromTuples(
   new Descriptor("mygroup","controller","default","default","1.0"), controller
));

await service.open("123");
console.log("The REST service is running on port 8080");

See also