Jigs

Jigs are interactive objects on Bitcoin. You define a jig with a JavaScript class and that class determines exactly what the jig can do. All of your jigs are unique. Each one has an owner and only that owner can update the jig. How is that secured? Bitcoin! Let's explore how you create a jig.

Creating

Let's create a new class of jigs called Post to represent comments on a message board. In JavaScript, your class initializer is called constructor, but for jigs, this method is called init. Think of them the same way. If init throws an exception, the jig will never be created, just like constructors. You create jigs with the new keyword, just as you would with normal JavaScript objects, and they get deployed onto the Bitcoin network. Pretty cool.

Code

class Post extends Jig { 
    init(message) {
        this.message = message
    }
}

new Post('Hello, world')

Updating

Jigs are updated by calling methods. In fact, this is the only way to update jigs. Your jig class defines the ways that your jig instances may evolve, so be sure to think ahead. When you call a method, Run publishes a Bitcoin transaction with data in an op_return that includes the method name and its arguments. The state may be recomputed simply by playing back every update one-by-one. For more information about how it works, see How It Works.

Code

class EditablePost extends Post {
    edit(message) {
        this.message = message
    }
}

const editablePost = new EditablePost('Hello, world')

editablePost.edit('Hello, BitCoin')

Sending

Jigs may be sent to someone else by changing the owner property of a jig in a method. You can set the owner to a Bitcoin address, a public key, or a custom Lock. The new owner will be able to update the jig starting in the next transaction.

Code

class Dragon extends Jig {
  send(to) {
    this.owner = to
  }
}

new Dragon().send(address)

Syncing

Code

Wait for updates to complete

class LoyaltyCard extends Jig {
    init() { this.stamps = 0 }
    stamp() { this.stamps +=1 }
}

const card = new LoyaltyCard()
await card.sync()

card.stamp()
await card.sync()

Sync a jig from its origin to its latest state

const card2 = await run.load(card.origin)

await card2.sync()

Interactivity

Code

class Event extends Jig {
  createTicket() { return new Ticket(this) }
}

class Ticket extends Jig {
  init(event) { this.event = event }
}

Event.deps = { Ticket }

Destroying

Code

Destroy a jig

giftCard.destroy()

Override destroy to finalize a jig

class GiftCard extends Jig {
  init(value) {
    this.value = value
  }

  destroy() {
    super.destroy()
    this.value = 0
  }
}

Backing

Code

class Tip extends Jig {
  init(message, pubkey, amount) {
    this.message = message
    this.owner = pubkey
    this.satoshis = amount
  }

  withdraw() {
    this.satoshis = 0
  }
}

new Tip('I like your videos', pubkey, 100000)

Checking Parameters

Code

Attaching an item

class Hat extends Jig { }

class Person extends Jig {
  wear(item) {
    expect(item).toBeInstanceOf(Hat)

    this.item = item
  }
}

Person.deps = { Hat, expect: Run.extra.expect }

Attaching Media

Code

class DinoPet extends Jig { }

DinoPet.metadata = {
  emoji: '🦖',
  image: 'b://55e2c09672355e009e4727c2365fb61d12c69add91215ee3e9f50aa76c808536'
}

new DinoPet()