CommandableHttpClient

Extends: RestClient

Description

The CommandableHttpClient class allows you to create commandable services. Commandable services are generated automatically for ICommandable objects.

Important points

• Each command is exposed as a POST operation that receives all parameters in the body object.

Configuration parameters

• base_route: base route for a remote URI
• 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
• options:
  • retries: number of retries (default: 3)
  • connect_timeout: connection timeout in milliseconds (default: 10 sec)
  • timeout: invocation timeout in milliseconds (default: 10 sec)

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 a connection

Constructors

Creates a new instance of the client.

public constructor(baseRoute: string)

• baseRoute: string - base route for a remote service.

Instance methods

callCommand

Calls a remote method via the HTTP commadable protocol. The call is made via a POST operation and all parameters are sent in the body object. The complete route to the remote method is defined as baseRoute + “/” + name.

protected callCommand<T>(name: string, correlationId: string, params: any): Promise<T>

• name: string - name of the command to call.
• correlationId: string - (optional) transaction id used to trace execution through a call chain.
• params: any - command parameters.
• returns: Promise<T> - result of the command.

Examples

class MyCommandableHttpClient extends CommandableHttpClient implements IMyClient {
   ...
    public async getData(correlationId: string, id: string): Promise<MyData> {
       return await this.callCommand(
           "get_data",
           correlationId,
           { id: id }
       );        
    }
    ...
}

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

let result = await client.getData("123", "1");
...