CommandService

Description

The methods of this service are primarily used to manipulate the command table.

In the example for the method below, assume you import the CommandModule into your module as follows:

import { CommandModule } from "@mbc-cqrs-serverless/core";
import { Module } from "@nestjs/common";

import { CatDataSyncRdsHandler } from "./handler/cat-rds.handler";
import { CatController } from "./cat.controller";
import { CatService } from "./cat.service";

@Module({
  imports: [
    CommandModule.register({
      tableName: "cat",
      dataSyncHandlers: [CatDataSyncRdsHandler],
    }),
  ],
  controllers: [CatController],
  providers: [CatService],
})
export class CatModule {}

Then, the CommandService and DataService will be ready for injection into other services for your use.

Methods

async publish(input: CommandInputModel, opts: ICommandOptions)

Utilize this method to publish a full command, as it will insert the data directly into the command table.

For example, you can publish a new cat command as bellow:

import {
  generateId,
  getCommandSource,
  VERSION_FIRST,
} from "@mbc-cqrs-serverless/core";

// ...

const catCommand = new CatCommandDto({
  pk: catPk,
  sk: catSk,
  tenantCode,
  id: generateId(catPk, catSk),
  code,
  type: "CAT",
  name: attributes.name,
  version: VERSION_FIRST,
  attributes,
});

const commandSource = getCommandSource(
  basename(__dirname),
  this.constructor.name,
  "createCatCommand"
);

const item = await this.commandService.publish(catCommand, {
  source: commandSource,
  invokeContext,
});

The method returns the command data.

async publishPartialUpdate( input: CommandPartialInputModel, opts?: ICommandOptions)

This method allows you to create new command data based on the previous command.

For example, you want to update cat's name:

import {
  generateId,
  getCommandSource,
  VERSION_FIRST,
} from '@mbc-cqrs-serverless/core'

// ...

  const catCommand = new CatCommandDto({
    pk: catPk,
    sk: catSk,
    tenantCode,
    id: generateId(catPk, catSk),
    code,
    type: 'CAT',
    name: attributes.name,
    version: VERSION_FIRST,
    attributes,
  })
  
  const commandSource = getCommandSource(
    basename(__dirname),
    this.constructor.name,
    'createCatCommand',
  )
  
  const item = await this.commandService.publish(catCommand,{
    source: commandSource,
    invokeContext,
  })

The method returns the command data.

async reSyncData()

If you want to reapply the data sync handler, this method is designed for you to use. You only need to call the function as follows:

await this.commandService.reSyncData();