Hyperledger Foundation Hyperledger Composer, 27 Aug 2018

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From YouTube: Hyperledger Composer Intro + Playground Tutorial in 20 Mins

Description

Link to webpage: https://www.srcmake.com/home/composer

Hyperledger Composer is a tool to help easily create blockchain networks. The best way to think about it is: you want to make your own custom blockchain, but it's simple enough that you just need to define who is going to be using the blockchain and what they're going to be trading/creating, then Composer will let you define those people/items and you can have your blockchain ready with minimal code.

Composer is much easier to use than Fabric, but you have less control over the blockchain.

Twitter: https://twitter.com/srcmake
Twitch: https://www.twitch.tv/srcmake
Discord: https://discord.gg/q5vAET3

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Hey there I'm source Mike and welcome to the hyper ledger composer introduction in playground tutorial and in this video we are going to go over what Hyperallergic composer is we're going to go over some key terminology and concepts and hyper legend composer, and this is important because we're going through all over some file types and key words that you need for the programming languages and composer and we'll use an example to you know how all this works. Then we are going to go over some demo code.

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That shows actually how you would make an example block chain using the high polish composer, then we're going to deploy that code onto the playground- and this is going to be all online in the web browser there's going to be no installation in this video, so anyone can follow along, even if you're not really a developer. It's going to be so easy that you can actually do this yourself. So what you're going to do is you're going to watch me.

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Do this video you're going to see me, explain everything and then you're going to click the link to this website and they're, going to be instruction two that you can try this yourself and I wrote this really so that you can follow along I. Do this yourself, so the link to this page, where you can do this yourself, is going to be right here below this video below this video is going to be a link.

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You click it you get to this page and try this yourself and while you down there hit the subscribe button for this YouTube channel Thanks. So this isn't our first rodeo. This isn't our first type of Legend video. We also have a blog post on hypo ledger at roha and we have a blog post and a video on high polish of fabric.

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So if you want to try those go ahead and click those links, but in this video we're going to be doing hypo logic, composer and composer is a tool that helps you easily create block chain Network.

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So it's all about block chain, and the best way to think about composer is that if you want to make your own custom block chain for your own thing, and it's going to be really simple, you really just need to define who's going to be using the block chain and what they're going to be trading or creating on the block chain. Then composes a tool for you, you define those people are items and your block chain can be ready with really minimal code.

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It's so simple and composer is actually much easier to use in fabric personally for fabric. You kind of need to know everything that's going on and you have more control in fabric because of that, but composers just like if you just want a quick start, composer so good for you.

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So that's why it's important to know with that said: let's go over some composer terminology and concepts, and for this we're going to have an example, so we own a fast food and we sell customers, food and the customers buy food from us and maybe there's some other fast-food restaurants on the block chain. Besides, our own restaurant seems simple right, so, let's go through 12 things that you need to know. If you want to use composure, a participant on the blockchain is a person that can own something or perform an action.

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So in our restaurant example, this could be the manager for our restaurant could be a cook that makes the food a cashier that you know. Does the transactions takes money from customers and gives them the food? It could even be the costume yourself that looks from watching that did just something just a person. An asset is just an item of value. Another example. This could be a burger or french fries or even money that you know we just try to model those assets on the blockchain, anything that gets traded.

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Speaking of that, a transaction is when some participants create new assets or they trade assets. So, for example, a customer gives us money and we give them food. That's the transaction or chef makes new burgers, so they bring new burgers into the blockchain system. That's the transaction! That's the great way to think about it now, any time one of those transaction happens.

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Sometimes we want to admit an event so that people know what's going on in the blockchain and avenges broadcast that so everybody knows what's going on and a CTO file now is just a file type with the exception CTO and that's where we declare the models for all of our participants, assets, transactions and events. You need to define what these are and the CTO file is where you do that, and we'll see an example of that. So don't get too scared about that. It's actually really simple.

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You know a transaction function remember that this is all being done on a computer, so you need to write some code. That actually, you know, makes this stuff happen, and some JavaScript code is just what you will write to actually carry out the logic for each transaction. Really simple, we'll be seeing how that works. An ACL file is something we're not going to be doing, but it's necessary. So it's just a file extension, and this is where we put the rules for what our participants can or cannot do or access.

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Now, for example, maybe a manager for our restaurant can order some beef from a farm if we're running low on beef or a restaurant, but the cashier doesn't have that permission? You know, that's just something that you declare in the ACL file. Who can do what really simple so can canoeing on the asset of registry is actually the place where or the storage where our data lives. So remember, all of these numbers are the things that are going on, for example, how many burgers does a restaurant have right now?

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You would look that up in the place called the asset registry. That's just a place in the blockchain where all the stuff is stored and basically we use this in transaction function. So next thing is get factory which is just a method of function, and you call this in your code anytime. You want to create a new asset, purchase the transaction and we'll see an example of this. So don't worry too much about it. Just know that it exists and that we're going to be using it in our namespace is a little bit important.

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Basically, it's the way you organize things into groups, so, for example, maybe our restaurant is called source to make a restaurant. So that's what we want our namespace to be, but another restaurant in the system may be hyper ledger. Restaurant would have a different type of namespace or hierarchy of what they would name their self just just for organization purposes. So, for example, the cashiers in our restaurant would be under the name to a source. Make restaurant dot cap shares because that's just you know the hierarchy of they're part of our restaurant and their cashier.

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So that's where they live in this hierarchy, and this is a good way just to organize. You know who can access what and you know how you would do things so next. Our queries and queries are SQL, like statements written to search for how many assets the participant has. Now you have to remember we're talking about things on blockchain. A blockchain are just like knows that live on people's computers and they're spread out and decentralization and all that.

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But what happens if you actually want to look up a value like how many burgers our restaurant has? How would you actually do that you know from outside the blockchain system? Well, you query is basically where you write these SQL statements so that you could look up these values outside for like websites that API is there anywhere else you want to access the blockchain. Remember when you architects, this stuff, you want to access the data. You're gonna write some queries to do that.

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We're not gonna be going over those, but I have this link here that you can. Actually, you know, read yourself if you are actually building your own flock a network and finally, a business network definition is where you take all our models for the assets, participants, transactions and events. You take all our JavaScript files for our transaction functions. You take our a CL file with all our rules and permissions. You take our query files which you're gonna, you know have our queries for whatever we want to access outside of the blocking Network.

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You bundle all those up and that's our business network definition and that creates what's called a business network archive which is just the file type, and once you have that you can you know you have your blocks in, you can deploy it to fabric or you know, browser or anything else like that. It's just you bundle up all these file types and you get your business network definition, because that defines what our blockchain actually is. So that should have been really simple. Hopefully it was. If not you can.

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You know, you'll learn more as you go along, but we're going to look at some demo code just to see how this actually works and continuing on with our restaurant example we're going to define our stuff in this CTL file. So you can see the first thing in our file. Is this namespace and we have so I personally have a restaurant. So that's how this is going to be organized like this, and that's just our namespace for this file.

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Now you can see the first thing that we define is a participant and it's going to be a cook for our restaurant, and you see this identified by employee ID. That means each cook is going to have a unique employee, ID that represents them, and you can see two fields here. Two strings and one field is the employee ID, which again is going to do it. Every employees gonna have their own ID and we're also going to have a string that defines the first name of that employee.

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So the next thing you see is an asset which is just going to be for our purposes of Burger asset and it's going to be identified by the outside ID, which you know just each type of our burger is gonna. Have our own ID, for example, I cheese birds are going to have the asset ID of cheeseburger. It's just a string that defines what the asset is going to be.

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You know defined by and we're going to have a quantity which is an integer that just represents how many burgers of this type of cow at any given time, and then we have this little weird arrow thing here and, let's think about this, for a second, do you know in like other programming languages, how there are classes and objects and a class is really just. You know a definition, a template, a blueprint for an object. So anytime, you want to have a specific object.

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You would instantiate over of that class and that object is an instance of the class like, for example, you have an animal class and you instantiate an object of like a giraffe there's nothing like that. This is kind of similar. So you see we have this definition of a participant cook, but when we actually have our blockchain we're going to take this kind of template and we're going to actually create a cook and we're gonna give them employee, ID and a first-name.

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This arrow here means that this resource is going to be related to a specific instance of a cook. So, for example, we're gonna be defining a cook named Billy, and that means any time we have a burger asset for our restaurant they're going to be, you know, related to one specific cook, not just this abstract function, but the actual cook on the blockchain who actually owns them and in our case is going to be chef, Billy who's going to be owning all of our burger assets. So keep that in mind.

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That's what these are functions means it means it's going to be related to a specific instance of a definition, not just the actual. You know code next, you'll see we have this transaction defined here called make burgers and again it's going to be related to a specific burger asset. It's going to be related to our cheeseburgers in our example. So every time we have a cheeseburgers we're going to define a new burger count and we're going to see how this transaction function works, we're just going to define what we need to make this transaction happen.

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It's gonna be easier in the demo, don't worry about it and, finally, an event anytime. We make fresh burgers. We want to emit an event and let people know hey, there are more burgers on the system and this is going to be related to a specific burger asset. Maybe we have more cheeseburgers in the system.

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Maybe we will have more I, don't know chicken burgers on the system, so you have to relate that to a specific type of burger to let people know- and we have two integers here- how many burgers there were before how many burgers there are down so I know. That's a lot to take in we'll see how that works later. We're going to look at just a specific transaction function that we have, and you see the first thing here is we define that we're going to look for this? This transaction function is an ASIC JavaScript function.

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They make burgers that's going to trick-taking this transaction object, but it's related to cob that source make restaurant that make burgers. So remember, this parameter is going to say: hey, okay, we're going to look at the namespace comm source, make restaurant and we're going to look at this specific transaction to see what this transaction object is going to have. So these things are related. This parameter is going to be related to this specific model and in this transaction function.

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What we're going to do is we're going to look at the old burger count and we're going to update that quantity for the old burger count with a new burger count, which again is something that we define right here in the transaction. So so we're going to be passing this number into the transaction.

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It's going to use that to update the burger count, and then we are going to update the asset registry because remember all this stuff, all these numbers live in the asset registry, so we need to update it there, so the function is going to do that and then we're going to emit an event just just to let everyone know that hey there are some new cheeseburgers or some type of burger in the system. Let everyone know that this happened and you know that's just good practice, so you should know how that works.

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So that's kind of I know that was a little vague and maybe it doesn't make sense, but we're gonna go through the online playground right now to show you how this works. So let me just make this into like two files right here, so we have like this I.

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Don't know why that B says like this and I just want to keep this tab open and what we're going to do is we're going to click this link to go to the playground to toriel online, the playground- you know, I'm, sorry, the composer online playground and we're going to load this page just taking a second to load, but it's taking a while to load come on come on load, okay, here it is so we're gonna click, lyft blockchain and it's a little bit hard to see.

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Let me make it a bit bigger we're going to click this deploy a new network. They have this example here, but we're gonna make our own network with it. Just so you know. What's going on now we're gonna name this business network? So let's make restaurant network like that, and all this other stuff is fine. You can see that there are some example templates right here that you can go through if you want to see more examples, but we're gonna create an empty business network and fill this in ourselves.

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For our example, we're gonna click deploy, and now you see that a show right here, because it's a source to make restaurant network so we're gonna click. The connect Now button- and we can see right here- is where we're going to be playing a little bit of playing with. So here's where a readme file would be- and the first thing that we want to do is actually go to our model file.

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Now they have this blank model file, but we want to delete this and we want to add our own model file that we defined right here. So I'm gonna copy this in copy paste it in and everything looks good. We went over this code already. The next thing that we need to do is define our transaction function, because this transaction exists here, but we need to add our JavaScript code right. So we're going to add a file, and you can see right here.

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It's going to be a script file, JavaScript file, I'm, going to click this Add button and we're going to delete this and we're going to add our custom code that we have right here and you'll be doing this yourself after you watch me. Do this in the video so make sure you continue watching, and you should try this yourself since it's so simple, so everything looks good and right here.

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There's this access file, that's already defined for us, so you know we don't need to do anything, we're gonna click, this deploy changes, button and that actually deploys our blockchain. So for all intents and purposes, I've actually just deployed out onto the world. So what we want to do now is we want to test it, because, obviously, you have to test to see if it works, so we're gonna click, this test tab does the define tab.

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Will you define the network and then this test tab will you're actually testing that and we'll see right here can I make it a little bigger whew. Here it is so there are three tabs here: the participants, tab, the assets tab and the transactions tab, which we care about. You see right here that we are in the participant tab and we define that there is a cook asset right. So what we want to do is we want to create our own custom cook.

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We, maybe we hired someone, we want to add them to the blockchain, because now we have a cook in our restaurant. So we're going to copy this right here and I have this on the webpage. You can you'll be following the instructions yourself, but what we do is we click. This button create a new participant, we're gonna, we're going to delete this and we're going to add our custom code and let's look at it really quickly. We are saying that this cook belongs to a source, make restaurant the cook namespace.

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We talked about that we're going to give him an employee ID of 1 1 1 1. His first name is chef bill. If that just happens to be his name, so he used to cook for our restaurant. You can see that right here we're going to press the. Let me make this a little bit. Smaller, we're going to press create new button, and now the cook exists on our network. Chef bill is successfully added to our block chain.

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Well now that he's here, we need to make some burgers and chef bill is really good at making cheeseburgers. So we're going to just copy this code right here, this JSON a little script, that's going to define a burger, offset I'm going to click the assets tab now and we're going to have chef Billy, create some cheeseburgers, so we're going to create a new asset and just to initialize a cheeseburger we're basically gonna write it on the menu of a boy to let people know that they can buy cheeseburgers for myself.

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So this is going to belong to comm source. Make restaurant Burger asset, that's going to be the namespace. The asset ID is the string. That's going to be cheeseburger because what this is going to represent our cheeseburgers and remember, we defined an owner for this. Remember that arrow function that we had before so this owner is going to belong to the resource.

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We're gonna actually have to look up the resource here and it's going to belong to the cook whose ID number is 1: 1, 1, 1 1, which we know is chef, Billy, we're accessing it by his unique employee ID, which is good for us. So so we need to know that we're gonna start out with 5 cheeseburgers that we have in the restaurant, so we're gonna click create you, and now we have a restaurant with a cook named chef Billy, and we have these cheeseburgers and we have 5 of them.

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But let's say we want to make chef Billy make more burgers. Let's say we want to have that transaction happen and we want to let people know well. We can submit a new transaction by clicking that button and there's only one transaction type that we have to find right now.

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That's to make burgers so we're going to copy this JSON right here from here we're going to delete what's here and copy our custom JSON, and you can see right here that the transaction that we're going to be doing is column sourced to make a restaurant make burgers because that's named face. You need to have that syntax down, packed the burger type that we're going to have remember.

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This was also an Arab function, so we're making we're talking about a specific burger instance, and in this case we're looking at source, make restaurants burger and the ID is the cheeseburgers, because that's the one that we're going to be making and the new burger count after we have everything all set down is ten, so chef Billy is whipping up five new burgers because that's the Ricky does it at and there's going to be ten burgers at the end of everything.

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So what we want to do is we want to press submit and the transaction happens. You see that this number updated to ten and if you look at all transactions, you can go right here and you review the record and you see the historian is going to keep track of all transactions for our blockchain and we see that this transaction did happen.

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We have a timestamp and tried to action ID, we see all the details and we can even see that the event was emitted because that's what we defined on code and I, like that, we basically did everything for botching you, you test your network on this. You know the playground and you set up your custom. You know models for your participants, assets, transactions, events and you write your transaction functions to update everything in the asset registry and emit your events and update any assets that you need to and that's it using composer.

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You know we have on blockchain for our restaurant and, of course it gets a little more complex, maybe in future videos we will be doing some. You know I want to do another. Video on native fabric, development versus composer development and I want to make more Creek complex network with more participants as such transactions. But if you can do this, if you do the stuff yourself, you can play with composer yourself and make your own blockchain, like literally like that.

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It's that simple, so that's been composer I'm source to make and make sure you subscribe to this YouTube channel so that you can see more videos like this make sure you like this video, so that I know that this is the type of content. You like comments telling me what you want to see in the future. If you have any questions, let me know I'll try to answer them and that's type of legend composer. You can do it yourself now. So, thanks for watching make sure you do subscribe and yeah happy composing.