Hyperledger Foundation Meetups, 27 Feb 2023

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From YouTube: How to Build Web-Based Distributed Applications (DApps) on Hyperledger Fabric

Description

A virtual meetup hosted by Hyperledger Boston on Monday, February 27, 2023 featuring Jim Sullivan from The Blockchain Academy leading an online workshop about using the Ethereum Virtual Machine (EVM) and NodeJS to build web-based distributed applications (DApps) on Hyperledger Fabric. Use your Solidity skills and the EVM tools to develop robust DApps on Hyperledger Fabric.

Prerequisites: Basic Blockchain, Hyperledger Fabic, and EVM knowledge.

More about Hyperledger Fabric can be found at: https://wiki.hyperledger.org/display/fabric/Hyperledger+Fabric

And the previous event Jim ran on Building Hyperledger Fabric Smart Contracts using Solidity and the EVM that he references in this discussion can be found at:

https://www.youtube.com/watch?v=vXYTqKMb5zs&list=PL0MZ85B_96CEmmy0C6NF52ZCMNcY1Wryf&index=24

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License
Creative Commons Attribution license (reuse allowed)

A

Once the live stream is going, yep you were live, yeah feel free to take it away.

B

C

B

Right uh so I want to welcome everybody today um to our session that we're doing on uh running smart contracts on hyper major fabric, which is obviously a very popular topic for I'll call it almost everyone we have over 500 registered attendees we've got more joining all the time, so we'll.

B

So we'll have an excellent session, we're fortunate that Jim Sullivan, who had done the original uh session for us on uh developing d-app contracts on hyper electric fabric, has come back and now we're running smart contracts on hyper electric fabric as well, and so Jim's uh got a long list of certifications on many Technologies, not just hyperledger, but on Smart contracts and everything else, d-apps ethereum, all kinds of stuff. So with that and his experience um I want to get the session started.

B

uh First question though Jim over to you is: how do you want to run this from your perspective? We're going to go through this session? Do you want to hold questions to the end, or how do you want to manage that? Yeah? Let's hold.

A

The questions until the end yeah.

B

That makes sense to me: yeah I think there's a ton to cover here, and it would be better if we just drive through it. First.

A

It's going to be a little review from last time, so everybody if you did not see part one of this which was November 3rd, the video, the YouTube video is still out there. So please do uh We're, Not, Gonna, obviously rehash any of that, but what's in there is, uh is installing the uh chain code that uh for the ebm it is invoking the chain code for the evm and it's substantiating querying, all of which are basic, hyper Ledger uh chain code or whatever chain code fundamentals, so that in and of itself is still worthwhile.

A

So please do take a look at that. We're going to skip all that uh we're gonna, get right to uh working with the EDM and distributed applications.

B

Yeah one thing I will say: Jim you have this: the PDF of the slide deck available for us after the call, so we'll make a connect, it's posted, but then, at the same time um we have these. All of the attendees came through different hyperledger meetup groups and the public sector session as well and I'm, going to make sure that we do Post uh both the current slide deck and even the old slide deck out there again for people.

B

A

With that I'll turn it over to you, Jim, okay, all right great! Well, do you do you have to do this disclaimer anymore,.

B

A

B

I do thank you so much I got my head somewhere else. So two things. First of all, um it's uh hyperledger is uh an open organization and we have competitors uh who are sometimes in these meetings, and we have to make sure that we conduct ourselves according to uh the hyperledger uh rules of conduct on uh competition, that we're uh aware that that we don't want to violate any antitrust laws um for sure uh that are in the US or anywhere else.

B

So, please make sure your comments are appropriate and the other thing is hyperledger is a welcoming and inclusive community at all times. What does that mean? It means we show respect uh for everyone else and professionalism in our conduct and we're happy to have anybody and everyone here attend and contribute uh in this case in the I'll call it q a section, um but the idea being that we are welcoming and uh do want to make sure that all uh interaction is respectful.

B

So there's more information on both handed competition laws, uh as well as the uh antitrust laws on the hyperledger website, as well as the open inclusion uh theme for hyperledger as well. So with that said, I do want to turn it over to Jim Sullivan from blockchain Academy and let him go through running smart contracts on hyperledger fabric thanks.

A

All right great thanks so much Jim Mason, and uh we appreciate everything you do uh for the uh hyper Ledger Fabric and the hyper analytics Foundation uh in general, uh so just very quickly. I just want to refresh everybody's memory at uh where we left off uh so right here we have you're not familiar if you're new I won't go too far into this, but we have. This is hyperledger fabric, as everybody knows, is our uh Enterprise blockchain solution here are our Enterprises and here's a little bit about the uh architecture.

A

Here we have the piers, obviously the ordering Pier. So this would be an example. A very brief, a very simple example of the network. We have our client apps, which, interestingly enough we're going to look at today and all of the data is managed on all these peers. You can see the distributed.

B

Solution right, Jim, I'm, sorry to interrupt, but.

A

Your audio got a little quiet right there, oh okay, how about now? Is it sounding better? Now yeah, yeah? Okay, uh let me get a little closer here, so uh we have our peers here, and this is where all of the the on all the peers is where the Ledger is kept, where The Ledger is, is actually queried, and then we have our ordering peer that orders, the transactions pretty straightforward.

A

uh One thing about this solution is and we're going to talk about this, and there will be a call to the community, so we will need everybody to jump in and say: okay, yes, we understand what needs to be done here is we could see popular solutions that are still out there right now are are using, so this is symbicing I, don't know if anyone's familiar with Simba chain, but if you're not, please take a look at it.

A

It is a low code or no code, a smart contract uh developer engine and it uses for this. It uses the solution that we are looking at right now and also for truffle. Those of you that are familiar with truffle uh that this supports exactly the hyperledger fabric, ebm that we are going to look at right now. So there are already two Enterprise tools out here which are using this solution, uh and everybody remembers. If you could. You could probably look pretty closely here, we're installing this evm CC. Hopefully this slide.

A

Isn't that great it's a little further, it's a little zoomed out, but that's what we'll be adding and if you look at our previous uh session, that's where we went ahead and installed it. So you can see that container right there, that Gene code running that's the evmcc that we look to install and last time around. This is the instantiation of that evmcc. So, even if uh your, uh even if you're just looking to get a uh just a kind of a high level, introduction well right here, here's some chain code instantiation with the evmcc.

A

So at least you get a little bit of review. You get a little bit of work with uh the hyper Ledger basic uh chain code, instantiations, queries and so on. So you get up a little bit of everything uh we can see here. We can actually here's here's one of the queries, so we were able to actually install and run this natively right from the pier you can see we're running right from the peer gear.

A

The downside of running in this fashion is it gets a little cryptic and I uh because we're using a hex, all kinds of and getting hex results back, which is not that great, uh uh but that's just running natively. You can see here with the uh so we set a value. uh This was a basic contract, we're going to do a smart contract.

A

That's a little more involved this time around and then we it just it just echoed the value back here, but then we were able to install web 3 and we were able to set a value and then return that value right here. So that's what uh so. You can see the difference here between uh the running uh natively and then running out of what we call web3, which is the protocol for a web. uh What's a Fab three, which is a web 3 provider that is part of the solution.

A

So actually we install something called that rate and that again is in our previous video that that becomes the web 3 provider. So we don't have to use these hexes and uh read the hex data. We can look at just regular old decimal numbers and again truffle, which is a popular, uh very, very popular tool, Suite, those of us that do use it.

A

We want to be able to continue to use it and we want to be able to use it for hyper Ledger Fabric and if you look really close here, I hope this is viewable. You can see Port 5000, we'll see why. That is um why that's significant, because what this solution is giving us here, the the evm running on hyperledger fabric uh is our our web3 provider does run on Port, 5000 and we'll take a quick look exam. We'll look at that example, and.

C

A

Here I'm sure everybody's familiar with remix, so this is where it starts. uh This is where we begin to develop our smart contract that we will Deploy on to hyperledger fabric, so at least this is where I start. This is a good place to start. This is where we're going to look, or at least for our example.

A

um Almost anybody that uh develops for whether it's ethereum or any evm supported, uh distributed, Ledger or blockchain, starts with um remix, just because it's so convenient right and we get out there and we uh uh we start to upload in our data and our functions, and what we are going to have to do is pay attention to the ABI, which is the application, binary interface and the byte code. So we get a little introduction to that and that's fine.

A

uh We that's that's it's all knowledge that uh is is useful to have even good, and it's not it's it's reasonably straightforward and uh we have a book to developing smart contracts on Amazon, so programming and solidity, and that's what we're going to look at. We are looking at the solidity development please if, if you are interested in getting a book, this is learning by examples.

A

You should probably put that in the title, uh but it is, uh it is published on Amazon, uh Kindle Direct publishing, uh which, if any of you have ever done, that um it's quite an interesting Journey.

A

So again, how do we do this? How do we develop distributed? Applications dapps? How do we take our smart contract and create an interface that is, um that is, is a web application and or a mobile application? Well, really. What we're going to be looking at is an API that comes with our user interface. So here we can see uh just this happens to be web3js, which we can use, not a problem, uh but it actually calls our smart contract. So if you take a real quick look here, you can see web3.

A

current provider and we can see what our provider is for web3 now. So this is an interface. This is just regular JavaScript, uh so one thing I we need you to take away from this is this is going to be JavaScript whether it is uh out of the box, JavaScript, web3js or react.js, we're going to look at a react.js example and shortly uh it is. It has an API that calls your smart contracts and returns.

A

Take obviously sends uh inputs from the user to the smart contract uh and then Returns the results back to the user. So you can take you can see here. We are just really taking the results and uh the inputs and sending it to the smart contract and then returning it back to the user, no more difficult than that. So it is an API.

C

A

There are you can see here again the fan three um right: the Fab three provider, the public network. This is the fabric Network here with its uh work with the organization, the peer, the channel, the channels which will actually run on on Piers and the evm chain code, and over here is our App decentralized application. So our decentralized application is building is, is going back to the web 3 provider and building that web page that working with the hyperledger fabric Network. So a relatively simple architecture and right here we'll actually come back to this.

A

But if you want to take this Workshop, uh you can scan this OR look at the registration code. That's right! There uh we'll actually put this up near the end of the session.

A

When we're looking at our example, uh if you scan that QR code, you can get to a registration page where uh everything is there for you, an image, a step-by-step instructions and uh the uh the ability to uh go yeah, go through all the steps or uh really what what we did on the previous session back in November, but but working with that hyperledger uh fabric, the chain code working with it natively and then installing web3 and working your way through calling a smart content, a simple, smart contract.

A

We don't want to get any into anything too complex for your first time out and you'll have the opportunity to uh bring this back up a little bit later, and so let's go ahead. Nobody wants to watch a lot of slides. So let's jump right into this.

C

Drag this out of the way I can.

A

Okay, all right: let's wake this up.

A

Okay, great so here we are on our image. Hopefully everybody can see this and it's clear. uh Hopefully, I've made this a little bit bigger, but this is our uh we have running here remix and we have a smart contract here. That is going to be a roster type of solution for uh for our smart contract. So we will add, we have a Constructor here which is going to run this create student function which assigns a well, let's see if we look up here a little bit. Let's first look at, we have a.

A

We have a struct which is kind of like those of you that aren't familiar with it kind of like a class uh astute. What does a student have? What are the properties or attributes a student has well in our case, this is really simple: a student has an ID, a student has a name which we're calling content and the students either present or present true or present false.

A

Then we have a mapping where we take all of these students with different IDs, different content, obviously and different uh present status, and we can stack those up in a data structure, and uh so you know just like an array vector or anything else. It's called it's called a mapping uh here that that we're using we're going to write an event to the log- and you can see here these two events we're going to write to the log. We have our Constructor, where we're going to create some students out of the box.

A

Sorry about that I should probably close my email, so we have again our create student where we're increasing that student count we're using that for our.

C

A

And we are passing in here.

C

A

Student count that we just calculated up here their content, which gets passed in here and we're going to initialize their status as false, so their present status is false, uh I actually for our example. We're going to change that initially to true so, uh but for this demo here uh when we take a look at our our actual running example, we change this to true, and then we mark them as absence, and then we have a way to toggle uh that they are present.

A

So whatever their status is we have our little uh the bang symbol there. So we're going to flip it to the opposite of uh before we're going to pass in a student ID and whatever their current status is it becomes the opposite and then so, if they're uh initialized as as apps, and we uh make that status, uh we we change that to true, so they become present.

A

Now of those of you that are not familiar with remix. First thing: we're going to do is click this, what they call the compile module here, that little and we're going to compile this contract and hooray right. We gotta we gotta clean, compile so, and one thing that's important is we're going to look at the ABI, so the ABI is like a Json uh Json schema we'll. We will take a look at it.

A

I promise you where we, we can only copy it right here and the byte code, so anytime we're working with solidity or the ebm. It works in a virtual environment. So all of this code here now has been compiled to a byte code, so maybe I have a little example here. um Here is the byte code. Oh boy, that's small!

A

uh At the very tip top I promise you we will take a look at it and uh it's not all this down here and if we look here at a at a different example, we can also see the ABI, which is right here. So this is the ABI and it is a Json type of schema and we can see here our present Boolean. If you look closely here, you can see some elements, so we need both of these uh for to deploy our smart contract uh onto hyper ledger.

A

So there are no tools right now out of the box. That uh that that do a lot of this for us, some of this we still have to do manually so uh I'll be I'll, be copying pasting a little bit because obviously those are long, particularly the bike code. Those are long uh strings and you don't want to assume uh mess that up as far as as far as typing, everything in or entering anything in.

A

So let's take a quick look at this, so we'll go here, we'll click on our deploy, module and we'll deploy this smart contract and we're just deploying this right now to our our environment and what this does. It gives us a little what's good thing, if you, if you're not familiar with remix, is it gives us this little user interface here for free and that's fantastic? So we know we have four four students out of the box. We can click here on student counts and it returns.

A

Four, hopefully that's visible and uh we can say hey give me uh give me the details on student one. So we enter student one, we click there and we can see student. One is Tim Baker and we can put in student two and we can see the student is, is Rob Sims and we can also create a new student.

A

So from here we can enter.

A

We may have to enter here just so. You can see what this does. So we can do all kinds of uh testing here at this level make sure everything works as needed. Quick transact that was successful, fantastic. Our student account should go up to five, it did and then so. Let's look at the detail here on student five, so that's Ryan, Williams and Ryan is right now initialized as as follows as far as being absent.

A

uh So right now, uh Ryan is marked as as um as absent, but we go up here to our toggle present, we'll put in a five here and click that button and that was successful and then we'll click on student. Five again, we should see this boss of data to True, which it was great, okay, good, so pretty straightforward. We could also do this for the other uh student number.

A

Two I don't want to do too much of this, because you'll get bored watching me do this, but uh student number two here was initialized as false is now initialized as true, so that so this is our smart contract that we are going to be working with now a little a little more uh involved than what we saw last time around, but exact same steps.

A

So first thing we want to do is we want to hop here into our hyper Ledger, one of our back to our Network and everybody's, probably familiar with hyperledging hyperledger directory, where we keep all of our chain code? Let me try. I've I've made this a little bit bigger. So let me see if I can resize this just a slight bit, so everybody can see. What's moving on, I will clear this as needed, because the screens do get a little messy.

A

And I will be copying and pasting a little bit, so you don't have to watch me fumble with with the keyboard so first thing that we need to do so. We have the chain code in vote, so we're not gonna and we've already built Fab three. So that's already running uh what we're going to do right before we get into is we're going to install web 3..

A

So this is the command pretty straightforward, we're going to install with three and then our.

A

Okay, great so we have web 3 installed now.

C

A

To run node I believe it's weird.

A

Okay, so- uh and the next thing that we are actually going to do, is we're going to set up our we're going to require web3, so we're going to have our web3 provider, and so, let's put.

C

A

Then I want to show everybody again to refresh everybody's memory where require web 3. great and that worked. um But let's go back here and let's take a look at.

A

So if you look here localhost on 5000. and let's just make this a little bit bigger, so we have Fab three running on Port 5000. and if we look here at our let's just come in here, I'm sorry.

A

Sometimes these are.

A

Oh great, it's here and let me make this a little bigger, no matter how many you can see here. We are running Fab three and it's returning this information Fab three and it is running on Port 5000 and that is running and.

D

A

To have this running on our hyper Ledger uh Network and we can't close it. We always and then we can always double check to make sure it's running by going to localhost 5000, and you can see that and we will be coming back to this browser uh in a little bit. So just let me close that down. So we have that now we have that connection between this web three object and we have our web3 provider and let's now uh create another object here. Web3 object.

A

Where we actually call out the five thousand so remember, I said a little bit earlier. That was important, so we've got to set that, and you can I can imagine this. This certainly can be scripted uh again. If you take a look here, what we do have to do is also set a default account uh if you look at the documentation. This part, for me at least, and again, this is for me, my network. My network might not be that great.

A

um We are I. I only seem to be able to run one account, so this is a little bit different. uh We should have more than one account, but for whatever reason, I have this so uh well. We actually have to do now is uh get this from into the buffer, because now we have to set a default account.

A

Yeah, okay, never mind I got it, get the get the command to set the default account, so I gotta copy that into the buffer and I apologize here. But watching me bumble with this is not what you're all paying for. So, that's why all this is done ahead of time and again, if you take, if you go and take our workshop online on this, uh this is all also available. You can uh run these exact same steps right, there's nothing like running them for yourself all right great, so you can see here this.

A

This ends in in feb8 and feb8. So we see that our uh account is. uh Is that.

A

D

A

What we have to do is we have to set that ABI code, so I already have that set in here. You can see our our Boolean our present, that ABI code that we got out of remix. So you can see here. This is white and API code and it's important to go to get all of it. So um and if everybody remembers here from remix in order to copy it to the buffer, we have to go back to the compile here, just uh click ABI and then it it goes into the buffer.

A

But for our example here we're going to need a.

C

A

So we're going to need to do some setting so we're going to need to set this whole thing.

A

So what we're going to we're going to call this simple right right here, simple storage, API code- and this is the API code that comes right out of remix right here.

A

So again, this is something you're going to use. Alpha Four make sure you get everything.

A

So this is our smart contract.

A

That's going to run out of our web3 provider and we've got to get everything, or else it's not going to work copy.

C

Come back in here.

A

That runs and we scroll back up- and you know this at least we can see it right. We can see their our presence. The contents right you can see all of these items here that we set in our smart contract create student which I abbreviated, to create for the example. Just because uh uh when I did this, things were getting a little longer, but you can.

C

A

Here these simple storage API is right here.

A

And if everything goes right, we should end in that square bracket and enter oh great. That worked okay, because sometimes these big operations can be a little tricky now. The next thing we have to do- and this is another tricky item- is we've- got to set the simple storage byte code. So again, this is the byte code, so this is very, very similar.

A

Those of you that are familiar with java.net that bytecode right that runs virtually so what we need to do here is we need to start at the very beginning of the string and go to the end and again copy that into the buffer, ing on.

A

And then we paste it in.

A

Touch long right and then it's got to be obviously quotes and boom. Oh great, that worked so that that point can be a little frustrating. No question about that. Now we take this simple storage. Avi we create another object, just simply called simple storage.

A

So we're taking that ABI code we're putting it to work for us.

A

That work great again, all this could be uh scripted, and then we take the byte code. We have to create the deployed contract object for that with the byte code passed in, so you can see if you look closely here on this parameter, we are passing in the byte, the simple storage byte code as our data, so we have now that object called and we gotta you might have to run it one more time. Sometimes sometimes this runs a little slow with the byte code and bear with bear with me here for one second,.

A

So that part, if you do get an endorser error, uh try to work with it, there seems to be a little web 3 issue, at least on my network. uh It works fine, natively but uh stuff. Occasionally that does pop up that uh at least I've I've been having it now. The last thing we have to do this, we we are uh match still manually doing this uh I, don't think this. This part can really be scripted.

C

A

We've got to get the address of the smart contract, so here we're going to query the smart contract address and we're going to create this object called my contract and that's going to be now. This is important because this is how, when we set up our user interface or our web page, uh we we're going to have to call on an object. So in our JavaScript now you don't have to use my contract right.

A

That's probably that may or may not be a great uh great uh object name to use, but we're gonna have to make our calls on that, and so we're going to take a quick example or take a look at a quick example about how those calls are made, and now we have to get the contract aggress and in our case we're just gonna put it here in the bumper. So we have to scroll up here.

A

And where it says, transaction hash address and then right before ABI, that is our smart contract address and we've got really no choice. Right. You've got a copy unless you want to type it in which that's not for me and.

C

A

We just kind of put it right here on our little list here of commands.

C

A

We're going we're going to add these simple storage uh and we have to give it here so.

C

A

Ends in 129 ends in 129, okay good, so it looks like we are uh all set to go so now, let's create again, let's update the my contract object with the smart contract address.

A

Okay, that's a smart contract address, so we're going to update this. My contract object, okay, good, so that seems to have fun all right good. Now. What we have to do is now we're going now. We have to get some ideas for calling our smart contract.

A

So if, if you remember, if we jump back here into remix, we have what functions create students. We also have a a mapping called students right here with the lowercase s's. So let's, let's make some calls and just make sure we're able to see Tim Baker, Rob, Sims Johnny case Rob Thomas. We want to make sure we're able to see.

C

A

So what what we'll do here is we'll call my my contract and see if we can get that dot.

A

Students and we gotta pass in one.

A

Oh look at that great Tim Baker that that Tim Baker came back all right to Baker all right. Well, he looks like he's student one. That's that's for darn sure so looks like we got the you know. If if we don't, if we don't believe it, we can come back in here and type in student one and run it and there it is Tim Baker, and we have the he's he's student one, that's his name.

A

Tim Baker and currently set well well I shouldn't say currently set the false, because these are two different, actually they're running two different places, but you can see here it's it's set to false here from Tim Baker Let's, uh maybe bring back student uh three. So.

A

And again, we have this little issue that oh there, it is in feedback, so student, three here's three Johnny case and set the false again just Soldier through. If you get this um endorser uh I, think it's I believe that it is um there's either a bug with the web. 3 provider or just my network is set up to be running a little slow, so um foreign.

A

So there are some few issues with that uh so and also let's get so, we can see their status here. Let's take a look at running a one of these functions, so, let's, first of all, let's, let's add a uh or yeah, let's add a new student, so we want to run this create student and create student. We just passed in the student name as a. We have to pass it in as a string, so that means quotes and then automatically gets uh gets. A student account gets that added, because student account we are obviously.

C

A

Each time and then gets initialized as false, so let's slower that we have to call the object. My contract Dot create student, oh boy, that comes out for us and again.

A

Okay, good, so that came back so there's there's the the transaction ID so far and we should be able to return. It was student count and if we look here, student count is okay, it has a capital c.

A

So let's go back in here. My contract, Dot student count. Look at that and.

A

You can see it in here, it doesn't look like it returned it, but let's do this.

A

Are uh where I was successfully uh added there, so we can see our students count right there at five. So this is what we'll be doing. Oh and let's also do this.

A

And we want to do toggle, toggle, present and.

C

A

Notice it says there on Ryan false. Let's set that, uh let's set that to true, so we have to pass in the five there.

C

A

It's not cooperating, but keep going until it cooperates. That's it and then let's bring back uh the details on on student, five.

A

And there it is so now that's set to trip. So again, it's seems to be in a bad mood right here. I promise, you I have a uh a version that is already running.

A

That is not returning the error uh so when we take a look at the depth, so right now this, so this is what we have to and we could do the exact same thing again uh with.

A

Do that work? Oh yeah, take a look at that, so we can also run this two string, which also returns it instead of being in this big number format. It'll do five it'll just do the name. I'll just do the true, so the two string uh function there um and uh this interface actually helped me help me out that if you notice it just uh added that on there, so that's that's helpful as well, and probably when we do the student count, we probably should have done two numbers foreign.

A

So right now for the student count, uh but uh figure out a way to to bring that it is there obviously, but we've got to figure out a way to return that all right. So uh so, let's now we have a good idea of how our smart contracts should be running from web3 right. So we can see here we're able to call these functions.

A

We're able to call these functions get this data back once this data comes back, we format it to a web page and have it uh and then have some Logic for the web page. So we can see here we have this this true right here, which means that for our for our dap that we're going to do our web page we're going to show uh when this, when, when this item is true here, when this data is true, the person's name will appear when it's false, their person's name will appear.

A

So we'll have to think of some logic up for that. So now, let's take a look here at our at how we are then now providing.

A

And let me make this a little bit bigger.

A

So let's take a look at the API, so we have our our web page that set up right here that that's going to use our smart contract. Now our smart contract is compiled into this project. This is using. uh You can use node.js. uh You can also use uh react.js. This is going to be a react.js. React.Js seems to be a lot friendlier, at least for me. It is anyway.

C

A

But I'm not a react. Js expert by any means I'm just learning it maybe like a lot of you are learning it too, uh but the pro we can see the project here we have the node modules, which can be a little bit of, uh can cause us a little bit of uh of a headache because sometimes the dependencies get uh deprecated, which can be a pain in the neck to manage those.

A

uh But if we go into the source folder here we see here they give us the source folder, which has all the JavaScript for our project. So if we take a quick look here at let's just cap, this very quickly, I don't want to bore anybody with looking at source code.

A

But we can see down here we are calling we have the API inside of here for our smart contract. So you can see here we have that that Dom, that virtual Dom, that react.js creates for us and we're able to uh build in that that API for uh calling our smart contract- and this is something you're- probably going to notice. I've I've reused part of this from a different uh well from different exercise. We had set up so let's go into the components.

A

As everybody knows, react.js has these components which will be part of our web pages. So again, if we look here, let me just cat this briefly. I, don't want you to walk away with.

A

Saying, oh I have to know all of the source code. I have to know all of the JS. You don't, uh but you do have what what we do want to know is uh we see here we have an absent button on here and it it on here it adds a learner. Okay. Now this this is important. We will add a new learner when uh or I'm sorry. It will delete a learner on here. So the delete is up here. So we delete this ID.

A

So you can see this delete I'm right here so and that when we want to Mark somebody as absent click, the absent button, it calls this delete which deletes an ID. So sorry, if I confused you there um and that so that's the most important thing here is the learner is removed. It calls the delete, so you can see.

C

A

That this is our API for our smart contract and then let's do a quick, clear this, and a lot of this is just getting comfortable with using this API. That calls our functions for our smart contract and it can be, it can be a little much in the beginning, but it doesn't take too long. uh So, let's cat here, the.

A

The create and what I do is I use this one for adding a new learn. So we can see here. We create them now. Remember that create uh the the create function uh create student, I called it well, I called it create when I was I, probably should have been. I was a little sloppy there. Unfortunately, I just called it create anyway creates a new learner.

A

Then we were able to add that on an input form, so that's really it and they appear on the screen, and you can attribute you.

C

A

We have a plate, a BLT that just enter a learner name, uh the the value is, and on change we uh load the the uh the new learner. So then you can kind of see on here the create learner we bring in. All of these, we import from react. Pretty straightforward learner right all that so uh so this is so now. At this point we want to run our our depth.

A

We should be able to run uh I already have a running copy, just in case something we get, those errors that doesn't have it because I prepared ahead of time. But let's try to run this. Hopefully everything will run okay.

A

So right here again we're using react.js. So it is yarn start.

A

Now, the oh great, that's right, sometimes the level that I run I get the you know up now. It says uh that something's already running on the same port right, Port 3000, is being used and what's cool about this, it says you know, do I want to run out of a different port. I'll say yes, so it's doing that. So, while it's doing this, let me pause.

A

uh Let me pause this for one second, while that's running and coming up again, let's put this back up for everybody, because uh until slow starting and I'll resume share. So if you want to, if you can, let's do the uh slideshow here account slide and then oh boy.

A

Display settings and swap so you can go in here and again you can take your screenshot or you can scan that QR code. If you want to give everyone and.

C

Everybody will.

A

Get these slides or you can just navigate to this URL.

A

Let's see how we did here.

A

Oh okay: let's.

A

Just let me put this back up here for one second here.

A

C

A

A little while to start up.

A

Okay, I think it's finally up and running.

A

Let's resume share, let me put this down and the browser is too big. So let's take this down a little bit.

A

Okay, so hopefully everybody can see this so here's our Tim Baker, Rob, Sims, John, Kays and I just set up this little pagination Rob Thomas now. Is that consistent again with our remix remix, which is right here, is uh Tim Baker, Rob, Sims Johnny case and Rob Thomas in this, so you notice now how this is running out of port three, three thousand and one.

A

So let's go back here to Baker Robinson.

A

So, although well they.

C

A

Got creative, so that's that's fantastic, so one component here is the end. This component does nothing because uh this is just something I wanted to maybe reuse, possibly for later. If we were running it, but it doesn't do anything right now. uh You can see your enter learner name. Hopefully this is big enough for everybody to see. Maybe we'll try to click it up. One more level and the uh pagination is another component and then add Ed marking the students as apps. So we have the ad learner. Oh no I'm, sorry!

A

um This is all part of the paginations all part of the the ad learner, so the ad learner and the page nation is all part of the same. It's all part of one component, so we promised we would add Ryan Williams.

C

C

A

And again this does pagenation, so we'll probably have to go to page two, but there's Ryan Williams at it. So now what this did is it took that that attribute that was set up as we added the learner, but they get added as true. So do you remember when, in our original smart contract we initialized the false, that's a little difficult, you don't want to add somebody, but not have them show up, so we needed to go in and change this initial initialization here false. That's.

C

A

I just changed the create to create students, just I guess so. I can type Plus now here when I click, when we click on the absent button, that's where they're present their absent present status becomes false and they get removed. So let's get rid of Johnny here.

A

And that goes away uh so uh and then we still should have one more person on the second page. Yet so.

C

A

Gone and let's also remove Rob, so let's say Rob is absent.

A

And you can see here my uh my background is terrible. My buttons are terrible and all that so um I've I've got something to work on here. The good news is, you can reuse a lot of these uh react.js's, so that is what we want to do. We want to develop the smart contract. We want to start off developing it with remix and.

C

Understand and.

A

Obviously, test all of our uh functions and once we're comfortable with all of that, we want to go back in and we want to establish. You got to think how, in the world.

C

A

We going to call this or create, or so we want to go into uh or into web3, and hopefully you don't get something like these errors here. If you do, you can get these back to your web page, which is a kind of a drag, uh and it's very frustrating believe me. I've worked through this like half the weekend and I was so I'm just lucky. You see how it didn't. Do it that time.

A

um So uh now you might not get this. It could be my hyperledger network here, which is just running out of a VM uh which is not really cooperating so, um but uh so, but this is what we want to learn. How do we call that, and then finally is maybe this is a little bit uh clear out of these slides.

A

If we go back here, how do we actually call this from uh from or either react.js or from whichever our favorite is foreign.

A

We make these calls the exact same way. I was just calling them, so you just make the call and you pass well, you can see pass in the web, the provider, but then you call the functions just like I was calling them and you essentially just build the web page. It's just as simple as that. I guess with react. I would say, react is probably a better way to go because, oh you can even see here the Local Host right. Oh my gosh, there's more here than I. Sometimes I.

A

Look at this and I just say everything that we passed in by hand we're seeing again here, so that even really makes our.

A

So you can see here the web 3, the provider, the provider here where, where uh web3 is running so that's important so now, um but uh so yeah that that's really it so we want to be. We want to figure out how we're going to call this and get how the the API learning the apis a little bit. uh That is, uh there are obviously uh did uh we will.

C

A

Have a a course that goes over calling smart contract or especially evm API from a um uh from either react, probably react.js or one with three. We actually have something right now on uh by using uh node.js, oh, but uh setting up the environment sometimes could be. You know a little a little bit just because you have to install node.js, but uh all of that uh taken care of for you so, but uh that is how we will uh actually build web-based distributed.

A

Applications on hyperledger and uh a few things that uh in in before we start to take questions, few items here, a little bit of housekeeping is this where we want to be yeah. This is where we want to be. uh Where are we now? As far as uh as far as using this now, you're, probably familiar with the I'm sure, everybody on here is familiar with the hyperledger family.

A

Okay, uh as you can see on here, what what we're using, which is hyperledger burrow, is not here. You know: where is it well, let's take a quick look. All right, we're not it is. We are uh hyper Ledger Bay Zoo is an ethereum client, no question about it, but it is not what we are doing.

A

We are running the ethereum virtual machine on hyperledger fabric and where we have a web 3 provider- and we are obviously running web three and we are interacting- and you probably saw the error right- we're we're interacting with the hyperledger network and but we're using the ethereum version hyperledger base. It was not the same thing. High blood your base is brilliant ethereum node that you can set up uh privately.

A

Let's close this for right now, uh but here we could see that the current product that we have this is our community call to action. It's. It is in an archive state right now, so this is right right here. This is the EDM chain code. It.

C

A

An archive State, meaning that it is no longer being maintained, you can still use it just like we still used it. You go through all the steps and run it as a matter of fact. We know people that are using identity applications uh using it right from using this solution for Active Solutions for their business, uh and we saw uh we saw Simba chain is referencing. This solution right here again the EDM chin code.

A

um So I don't have any information on the replacement for this. We are. We want a replacement for it. Obviously, uh so we can go back to doing just what we were doing right, take being also taking our skills for solidity, our skills for the ethereum virtual machine and using it on hyperledger fabric. What does that mean? That means not only applications like we had. uh It means that working with Enterprise level tools like sympa chain like truffle. uh What else? What else does it mean?

A

It means smart contracts to create uh nfts smart contracts to create well fungible tokens might be somewhat Limited in hyperledger fabric, but we have all of those ERC standards for tokenization for certificates that there are certainly many use cases for even on the Enterprise blockchain, so uh I. uh So we have that this call to the community here and we certainly will be advocating for a replacement uh and.

C

A

Rather than later for um for the ethereum virtual machine or the evm running on hyperledger fabric, but we need everybody on this call to uh just make their voices heard, that to the to the development uh community, that we need to get a replacement for this and um build it right back into the hypoledger fabric, because we want to obviously reuse our skills. It's one thing uh to know how to use uh invoke all the chain code and all that we don't have a problem with that.

A

But you know in order to take advantage of what's available in the community, uh we really do need to add this product back to hyperledger fabric. So it's really all I had I, don't know Jim Mason. Are you uh available again.

A

We'll take some questions. I can look at the chat with Jim Mason. Isn't there.

A

Okay, so let's see let's go in here and let's take a look at a couple of the questions. Oh do I know why the the fabric chain code, EDM, was archived I've heard a few different stories, but I don't have I'm, not sure.

A

I have the exact reason why the uh the the the the hyper Ledger of ebm chain code was archived, maybe the community, the maintainers thought that they achieved I heard actually that they achieved what they wanted to achieve, and then they just said: oh okay, we achieve what we want to achieve and now we're done.

A

um So that is uh that that's what I heard I don't know why you would then not turn it back and on uh and give it to the rest of the community. I I can't really answer that.

A

um But uh yeah we've got to it's one thing that it was our contact, but it was uh something else that it was that it's it's um you know we we've got to figure out what the replacement will be and we have a hand raised uh Bobby. Can you uh just speak up Bobby.

D

Yeah sure hi, it's Bobby, um I, think one of the reasons why it was um depreciated was because there was no one maintaining it. It worked and no one was actively doing reports to the technical steering committee or actively engaged in. um So there was no company behind it anymore. It works and everyone's using it fine, but there was nobody supporting the back end of the project and I guess.

D

If anybody wants to uh bring that project back, um you know reach out to me and I'll see you know what how and if people are interested in supporting it uh from an Enterprise perspective. That would be awesome.

A

Thanks, oh great so right there. So there is a voice in the community and Bobby obviously has a loud voice in the community and uh well I shouldn't say: maybe a strong voice, I should say in the community right yeah thanks the person that can uh that that's certainly somebody to uh help us out uh solidity gives us access to ERC capabilities like erc20 fungible tokens, the ERC uh 720 nfts. Absolutely so one of the big advantages are well plungible. I I think is somewhat limited.

C

A

Hyper Ledger, but nft certainly could be something that we could take advantage of, but no question about that. um So what are the advantages of using solidity over using the go or node chain code? Not the only the the advantages is you have the ability to use your solidity knowledge, your solidity skills, the solidity tools, uh the community for solidity and the evm is very, very big. So obviously we are able to take advantage of all of that. We can still use. Go, that's not a problem.

A

You can still do that, uh but you have so you have so many apis written so many books written it really. Is it really would help the the developer community so much if we're able to support all of the ebm functionality also over to hyper Ledger fabric? It's I'm not going to say it's better than go, uh but there's many many more resources available. I would argue, then, what's there. So if that makes sense,.

A

And Bobby got a lot of thumbs up, but you all can probably see that so so that's interesting uh there was nobody to maintain it so uh but yeah. So maybe we can start a movement here in the community uh to and I'm not saying, tag anybody's it or anything like that. Please don't don't take that away, but you know we. We should think about these things uh because again it can give us a um well all of those advantages of that community of that EDM community, which is being used by a lot of distributed.

A

Ledgers right, it's not just ethereal hedera uses it I even understand quarter using cord is one of our competitors uh here in the hyperledger Indiana. um So there's a lot that are algorithm.

A

A

And exactly for those reasons, you know you have your own native way to do it, but sometimes developers you know, developers get sometimes you know we don't want to learn something new when I started to develop in some of those other ones. I was just like. Oh my gosh I got a reason to earn all this I was clumsy. I was only doing basic things where I had known solidity. I I became so uh I I, I I, just my uh Knowledge and Skills got so much better. I just felt hey I.

A

Could uh you know I could do much better if I could just develop on the evm on these um uh well on these black on these Networks?

A

Okay, so another question: uh are there uh any documented videos explaining the differences between the hyperledger projects? Oh yeah, there are. There are edx courses, uh you can go in and look at um I think one of the out of the box ones just really explains uh the hyper Ledger family, and that is a uh that course is offered I'm, not sure who offers it. But uh if you go out to the Linux Foundation under education, you can look at it's.

A

It's not instructor-led, it's it's 100 asynchronous, but it's a pretty straightforward course, and uh it goes over by the hyperledger family fabric being one product in the hyper Ledger family.

A

Any other questions: okay, all right.

A

Oh Bobby's, getting a lot of thanks again.

A

And Jim Mason's: are you still out there yeah.

D

I want to thank you Jen. This was a great presentation. Thank you so much. Oh.

A

Good I'm glad you liked it I didn't I know the web page was not that great looking, but I was never a great at um I. Coming up with, with the very nice looking uh I.

D

Thought the colors were very spring yeah.

A

The cup yeah well I, guess you could say yeah. If anything, they were that, yes, this is being recorded, so there should be a YouTube out there. uh It's also being live streamed right now, but there should be a YouTube shortly and uh also I will put in the chat. uh Our previous just bear with me here. One second, let me so you don't have to see me uh going into Google. Let me pause share here for one second.

C

A

I'll put the link in the chat for our previous presentation, where it was just the bare bones: uh EDM.

A

So let me so here it is here. This is what we did uh last November, and this is where you want to start, um but let me put this in the chat for everybody, so this is intro.

A

A

So this is not today's. This is this: is the prior one right, Jim yeah? This was the prior one that I just put in so, but.

C

A

On this is obviously the very beginning, so.

A

Okay, uh anything uh any other questions or would anybody is uh our session? Any other session hosts available right now, yeah I'm here, Jim, oh great great, so uh anything in wrap up Jim Mason, no.

B

Just the fact that uh I can't tell you how good these two sessions you've done have been uh bad news is the other side of that is probably I'll, be asking you for more ideas on better sessions, given how good these two were. I think the key thing is, we do have the live streams for both sessions. It'll um David will get out um this week on to the ones already out on the YouTube channel.

B

The second one will go out this week as well, um which is already running I, guess, uh but we'll have that organized on the hyperledger um Channel cleanly with annotations and stuff. We'll get your um boat slide decks redistributed, if you will, through the meetups, as well as the public, hyperledger and public sector Wiki as well, um and then uh anything that you have that you think for getting the slide decks for a second anything that you think is important or critical from a q, a perspective that we didn't address.

B

You know if you want to add that along I'll make sure that gets distributed as well.

A

All right, fantastic uh yeah, if I, if I, think of anything and again, you know, we've already heard feedback that uh the the product was uh archived because there was no maintenance, uh whatever I I I, don't uh but Jim Mason. Possibly we could send out some information. How do we begin a community movement uh to look for a new, uh uh a new repository or a new uh I? Don't know what we would call it: a new sponsor or an incubator uh for uh the EDM on hyper electric Fabrics yeah.

B

That's actually a big deal um to figure that out. So it's been done. You know obviously I think you know you've. What you've done is created a ton of interest in it. Let's put it that way, which is very, very useful and you're right. We do need to figure out how to build a sponsor for that runtime capability. So my argument, actually is you know in I'll call it my I'll call it job roles, I'm, looking at platforms, and certainly um you know, fabric has been a great platform for a lot of solutions.

B

I've delivered, but the other side of it is having the ability to uh build and run DX directly and fabric is good. uh There's a lot of good things that have also been done in straight fabric on trying to I'll call it operationalize that nicely um and actually I should probably do more to push some of those sessions. So some of the kubernetes stuff they've done nicely. That's you know, platform neutral kind of deal in that cloud.

B

Specific um they've got some pretty good things there that we should focus more on, but I do think that um trying to figure out properly how to uh benefit from what I call more automation, as you were showing so what's really great about your sessions. They get me to the point that I can actually understand. What's going on, they're dirt, critical yeah I'll say, but if you're a large organization, you're saying okay I, don't really want to be doing that. You know at the command line all the time.

B

I've got to figure out ways to automate that and that's where that sponsorship comes back in again. The idea that we've got a start like fabric itself, that whole project is moving forward with automation, work and so on, but the stuff that you've shown us. We want to be able to drive that as well. Yeah.

A

It's going to be, obviously it's going to remove a lot of friction from uh onboarding, a lot of a lot of Internet, a lot of solution providers, a lot of integrators and obviously a lot of developers, that's for sure, uh yeah. If we could somehow, through the community again I, don't want to sound like I'm, saying tag you're it to anybody. I'm not, but you know it's got to rise up in the community.

A

We have to say we need a new home for uh what was called micro measure for our own, what new name it would have if any yeah.

B

Yeah anyway, so right, we're not going to answer that here, but I definitely want to follow up with you on that, because that's a big deal uh to figure out how we move that forward, which is important because ethereum itself and the Technologies you've been showing are also moving forward all the time. So you can't just say: okay I got his labs. This will be good for the next five years.

B

It won't be right, so yeah yeah, it's important in a sense, as you say, find a way to sponsor this thing properly, uh so that it stays current for sure. So anyway, with that I do want to say that you know these sessions. You've done have been absolutely fantastic and the community is really gonna has obviously benefited and I think today's will be a real value as well.

B

So thank you again and everybody I want to thank you for attending today and look forward to um you know the the handouts that we're going to distribute on the meetups as well as we're going to have them linked over on the YouTube channel as well. So with that, thank you again everybody and uh have a good day and thanks again, Jim. Oh.

A

You're welcome Jim Mason and thank you for being our session host and thanks Bobby for your contributions. It was very helpful.

B

Thanks everyone bye foreign.