View source for Creating and loading jigs

After you have simply opened the devtools console at [https://Runcraft.io Runcraft.io], or [[Installing the_run_sdk#Setup|installed and setup Run locally]], you are ready to create and load jigs !

Jigs are interactive objets on Bitcoin. You define a jig with a JavaScript class explaining what the jig can do. Each jig is unique and only the owner can update it, which is secured by bitcoin miners.

= Creating Jigs =

Let's begin with a basic jig that stores a value in a variable. Create a jig called <code>SimpleStore</code>. By extending from <code>Jig</code>, the instances of your class will automatically sync to the blockchain. Every jig has an <code>owner</code>. Any code may read jigs but only its <code>owner</code> can update it. The <code>owner</code> is typically a Bitcoin address, and the private key is required to update it.

In addition to <code>owner</code>, every jig has a <code>location</code>. A jig's <code>location</code> is the pairing of a Bitcoin transaction ID and an output index, and it represents a particular state in time of an object or class on Bitcoin. When you check the <code>location</code> property of a jig, you get its current location. If you wish to get the location where the jig was first deployed, that is called its <code>origin</code>. The <code>origin</code> is unique and will not change, however <code>location</code> changes with every update. After a method call, your jig will have a new <code>location</code> pointing to a Bitcoin transaction containing the last method call.

== Code ==

<syntaxhighlight lang="javascript">
class SimpleStore extends Jig {
  set(value) {
    this.value = value
  }
}

const jig = new SimpleStore()

jig.set('Satoshi Nakamoto')

await jig.sync()

console.log(jig.owner)
console.log(jig.location)
console.log(jig.origin)
</syntaxhighlight>

= Loading Jigs =

The simplest way to load your jigs is to call <code>run.inventory.sync()</code> and then access <code>run.inventory.jigs</code>. <code>run.inventory.sync()</code> will find and load all objects owned by <code>run.owner</code> and place them in the <code>jigs</code> array. Once loaded, you may call methods and use them normally. Alternatively, you may wish to load a particular jig or load a jig in a historical state. To do either, pass the <code>location</code> of the jig you wish to load into <code>run.load()</code>.

If you've loaded a historical location so that your jig is in a previous state, you'll need to first catch up to the latest state before you'll be allowed to make a method call. <code>sync()</code> will handily fast-forward a jig to its latest state on the blockchain without triggering a Bitcoin transaction. In the example on the sidebar, if <code>specificJig</code> was in a historical state, you would call <code>specificJig.sync()</code> and then call <code>specificJig.set('abc')</code>. When you accidentally try to update a jig without the jig being in its latest state, Run will safely abort before publishing a Bitcoin transaction and inform you with an error. In that case, you'll just need to add the preceding <code>sync()</code> call and execute your code again. The best practice is to write code in such a way that jigs are always up-to-date in their latest state. Run manages the heavy lifting for you.

<code>sync()</code> also acts as a debugging tool since it surfaces any errors your jigs have after you've made changes to them. If you notice your app acting funny, a well-placed preceding <code>specificJig.sync()</code> can help you uncover the error. You may also call <code>sync()</code> on your <code>Run</code> instance, like this: <code>run.sync()</code>. That'll help you search out any errors from your entire app in all of the jigs you own.
== Code ==

Loading all jigs

<syntaxhighlight lang="javascript">
await run.inventory.sync()

const simpleStore = run.inventory.jigs.find(x => x instanceof SimpleStore)

simpleStore.set(123)
</syntaxhighlight>

Loading a specific jig

<syntaxhighlight lang="javascript">
const specificJig = await run.load(simpleStore.location)

specificJig.set('abc')

// Fast-forward the jig to its latest state
await specificJig.sync()
</syntaxhighlight>

Remember this:

<code>jig.origin</code> = 1st transaction of this jig<br>
<code>jig.constructor.origin</code> = 1st transaction of the '''code''' of this jig<br>
<br>
<p>Now that you understand the basics, let's [[Jigs|create some more interesting jigs]]</p>
[[Category:Documentation]]