Tasks Overview

In this section, we delve into the specifics of the task executor's implementation.

A basic task implementation would appear as follows:

@CommandModel("example-task")
export class ExampleCommand extends TaskCommand {
    @ApiProperty()
    @IsString()
    public name: string
}

@ResponseModel("example-task")
export class ExampleResponse extends TaskResult {
    @ApiProperty()
    @IsString()
    public result: string
}

@Executor("example-task")
export class ExampleExecutor implements TaskExecutor {

    async processTask(exampleCommand: ExampleCommand): Promise<ExampleResponse> {
        return {
            result: `Hello ${exampleCommand.name} !!! `
        }
    }
}

decorator::@Executor

Marks the class as an executor of the task.

@Excutor('example-task')

• Parameters:
  • name: string - The name of the task

interface::TaskExecutor

Tasks decorated as an executor should implement processTask method of TaskExecutor interface. Once a new task execution request is submitted the method will be called with the following params

• command: Any - the input payload of the task passed in the request
• meta: TaskMetadata - meta information about the task. The object can be used to identify the user, user's subscription plan and other info about request context.

@Executor("example-task")
export class ExampleExecutor implements TaskExecutor {
    async processTask(command: ExampleCommand, metadata: TaskMetadata): Promise<ExampleResponse> {
        console.log(`UserId ${metdata.userId}`);
        console.log(`Tier ${metdata.userSubscriptionTier}`);
        return {
            result: `Hello ${command.name}`
        };
    }
}

@CommandModel("example-task")

Marks the class as input payload model for a given task

• name: string - The name of the task
• options
  • description: string - the description of the task appearing in OpenAPI documentation

To apply validation on task input payload you can add decorators from class-validator on model properties

@CommandModel("example-task", {
    description: "Sends greatings to the given name"
})
export class ExampleCommand extends TaskCommand {
    @ApiProperty()
    @IsString()
    public name: string
}

@ResponseModel("example-task")

Marks the class as output payload model for a given task

• name: string - The name of the task

@ResponseModel(Commands.EXAMPLE)
export class ExampleResponse extends TaskResult {
    @ApiProperty()
    @IsString()
    public result: string
}

naming convention

To maintain consistency please keep naming convention of the classes.

• Task Executor class name should end with Executor

• Task input model name should end with Command

• Task output model name should end with Response

• Response result nested model (if any) name should end with Result