add-new-skills.md

Add new skills

The coolest part about Laika is that it’s extremely easy to add new skills. Just use the NestJS modules/services system. Start with the commands below:

cd server
yarn nest generate module skills/my-awesome-skill
yarn nest generate service skills/my-awesome-skill

NestJS will create the directory skills/my-awesome-skill, containing a module and a service, and will inject the new module into the facilities of skills.module.ts. All we need to do after is to edit our my-awesome-skill.service.ts file.

Lastly, import the @MessageHandler decorator from src/core to teach Laika a new function. Copy and paste the example below into your my-awesome-skill.service.ts file:

import { Injectable } from "@nestjs/common";

import { MessageHandler } from "src/core";

@Injectable()
export class MyAwesomeSkillService {
  /**
   * Example 1
   * The @MessageHandler decorator is used to inform the core
   * to add the phrase and that function to message processing.
   * In that case, when you say "this is a test",
   * Laika will answer "It works!"
   */
  @MessageHandler("This is a test")
  testing() {
    return `It works!`;
  }
}

Save the file and the server will automatically restart, learning the new features. Then, return to the browser and test the new function.

You can add multiple functions in the same class, just use the @MessageHandler decorator and Laika will learn them. Try copying and pasting the code below into your my-awesome-skill.service for more examples.

import { Injectable } from "@nestjs/common";
import { range, of } from "rxjs";
import { delay, concatMap } from "rxjs/operators";

import { MessageHandler, MessageText, TrimEntity } from "src/core";

@Injectable()
export class MyAwesomeSkillService {
  /**
   * Example 1
   * The @MessageHandler decorator is used to inform the core
   * to add the phrase and that function to message processing.
   * In that case, when you say "this is a test",
   * Laika will answer "It works!"
   */
  @MessageHandler("This is a test")
  testing() {
    return `It works!`;
  }

  /**
   * Example 2
   * You can train multiple sentences for the same function.
   */
  @MessageHandler(["Say my message", "Repeat my message"])
  repeatMessage(
    // Use the @MessageText decorator to inject your own message
    @MessageText() myMessage: string
  ) {
    // Returning an array, a random response will be chosen.
    return [`You said: ${myMessage}`, `Your message was "${myMessage}"`];
  }

  /**
   * Example 3
   * You can return an object containing the text and a function
   * to create more complex dialogues
   */
  @MessageHandler("Say my name")
  sayMyName() {
    return {
      text: `What's your name?`,
      nextCallback: (text: string) => `Your name is ${text}`,
    };
  }

  /**
   * Example 4
   * This is a slightly more complex example
   * In this case, if you say "Count from 1 to 10" Laika will
   * reply with a stream of 10 messages.
   */
  @MessageHandler("Count from %n1% to %n2%")
  count(
    // You can extract data with the @TrimEntity decorator
    @TrimEntity("n1", { between: ["from", "to"] }) n1?: string,
    @TrimEntity("n2", { after: "to" }) n2?: string
  ) {
    const fromNumber = parseInt(n1, 10) || 0;
    const toNumber = parseInt(n2, 10) || 0;
    const response$ = range(fromNumber, 1 + toNumber - fromNumber).pipe(
      concatMap((n) => of(n).pipe(delay(500)))
    );

    // Return an Observable <string> to create a message stream
    return response$;
  }
}

Save the file and the server will automatically restart, learning the new features. Then, return to the browser and test some of the phrases.

Now you're ready to start creating your own personal assistant!

Take a look at the other directories in src / skills for more examples.