CommandSet

Contains a set of commands and events supported by a commandable object. The CommandSet supports command interceptors and command call chains.

Description

The CommandSet class allows you to create a set of commands and events supported by a commandable object. In addition, it supports command interceptors and command call chains.

Important points

CommandSets can be used as an alternative commandable interface to a business object.
This class can be used to auto generate multiple external services for a business object.

Constructors

Creates an empty CommandSet object.

public constructor()

Instance methods

addCommand

Adds a command to this command set.
See ICommand

public addCommand(command: ICommand): void

command: ICommand - command to add.

addCommandSet

Adds all of the commands and events from a specified command set into this one.

public addCommandSet(commandSet: CommandSet): void

commandSet: CommandSet - CommandSet to add.

addCommands

Adds multiple commands to this command set.
See ICommand

public addCommands(commands: ICommand[]): void

commands: ICommand[] - array of commands to add.

addEvent

Adds an event to this command set.
See IEvent

public addEvent(event: IEvent): void

event: IEvent - event to add.

addEvents

Adds multiple events to this command set.
See IEvent

public addEvents(events: IEvent[]): void

event: IEvent[] - array of events to add.

addInterceptor

Adds a command interceptor to this command set.

public addInterceptor(interceptor: ICommandInterceptor): void

interceptor: ICommandInterceptor interceptor to add.

addListener

Adds a listener to receive notifications on fired events.
See IEventListener

public addListener(listener: IEventListener): void

listener: IEventListener - listener to add.

execute

Executes a command specificed by its name.
See ICommand, Parameters

public execute(correlationId: string, commandName: string, args: Parameters): Promise<any>

correlationId: string - (optional) transaction id used to trace execution through the call chain.
commandName: string - name of the command that is to be executed.
args: Parameters - parameters (arguments) to pass to the command for execution.
returns: Promise<any> - execution result

findCommand

Searches for a command by its name.
See ICommand

public findCommand(commandName: string): ICommand

commandName: ICommand - name of the command to search for.
returns: ICommand - command, whose name matches the provided name.

findEvent

Searches for an event by its name in this command set.

public findEvent(eventName: string): IEvent

eventName: string - name of the event to search for.
returns: IEvent - event, whose name matches the provided name.

getCommands

Gets all commands registered in this command set.
See ICommand

public getCommands(): ICommand[]

returns: ICommand[] - list of commands.

getEvents

Gets all events registred in this command set.
See IEvent

public getEvents(): IEvent[]

returns: IEvent[] - list of events.

notify

Fires an event specified by its name and notifies all registered listeners

public notify(correlationId: string, eventName: string, args: Parameters): void

correlationId: string - (optional) transaction id used to trace execution through the call chain.
eventName: string - name of the event that is to be fired.
args: Parameters - event arguments (parameters).

removeListener

Removes a previosly added listener.
See IEventListener

public removeListener(listener: IEventListener): void

listener: IEventListener - listener to remove.

validate

Validates the args for a command specified by its name using a defined schema. If the validation schema is not defined, then the methods returns no errors. It returns a validation error if the command is not found.

public validate(commandName: string, args: Parameters): ValidationResult[]

commandName: string - name of the command for which the ‘args’ must be validated.
args: Parameters - parameters (arguments) to validate.
returns: ValidationResult[] - array of ValidationResults. If no command is found by the given name, then the returned array of ValidationResults will contain a single entry, whose type will be ValidationResultType.Error.

Examples

export class MyDataCommandSet extends CommandSet {
    private _controller: IMyDataController;
 
    constructor(controller: IMyDataController) { // Any data controller interface
        super();
        this._controller = controller;
        this.addCommand(this.makeGetMyDataCommand());
    }   
 
    private makeGetMyDataCommand(): ICommand {
        return new Command(
          'get_mydata',
          null,
          async (correlationId: string, args: Parameters) => Promise<any> {
              let param = args.getAsString('param');
              return await this._controller.getMyData(correlationId, param);
          }
        );
    }
}