Truffle DappChain Example

This simple example shows how you can use Truffle and the Loom Truffle Provider to build a simple Web UI that interacts with the Basechain.

Requirements

Make sure the following requirements are met and then follow the steps in the next section:

Node >= 8
yarn or npm

Install

First, let's clone this repository. Open a terminal, cd into the directory where you store your projects, and run the following command:

git clone https://github.com/loomnetwork/truffle-dappchain-example

Next, cd into truffle-dappchain-example:

cd truffle-dappchain-example

and run:

yarn install

Run against Extdev Testnet

Generate the Loom private key

The following command will download the loom binary and generate the private key for you:

yarn gen:extdev-key

The Loom private key will be saved into a file called extdev_private_key.

Deploy to Extdev Testnet

As an example, we will deploy and run our application against Extdev.

Run the following command:

yarn deploy:extdev

The above command will compile and then deploy our smart contract to Extdev

Test

Run this command below to send transactions to the smart contract deployed to Extdev:

yarn test:extdev

If everything looks good, let's spin up a web server and interact with our smart contract.

Start the web interface

The web interface is built with React and Webpack. Open a new terminal and run the following command:

yarn serve:extdev

The web interface is available on http://localhost:8080.

Run against local Loom chain

First, you have to generate a private key using:

yarn gen:extdev-key

Spin up Loom Chain

In a new terminal, run:

yarn loom-init

Deploy the smart contract

To deploy, run the following command:

yarn deploy

You will see something like this:

Starting migrations...
======================
> Network name:    'loom_dapp_chain'
> Network id:      13654820909954
> Block gas limit: 0

Copy the Network id paste it into a text file. We'll use it later.

Test

yarn test

Web interface

Open the src/contract.js file in your text editor of choice and go to line 87.

Now, say your Network id is 13654820909954. Replace

return Promise.resolve('default')

with

return Promise.resolve('13654820909954')

We're ready to start the web server. In a new terminal, run:

yarn serve

Useful information

  1. In order to correctly redeploy the contracts, there's a command yarn deploy:reset.

  2. Also is possible to call truffle command directly with yarn truffle.

  3. We're not versioning the build directory for this particular example, although is recommended to versioning, the limitation can be removed by editing the .gitignore file.

Current limitations

  • Events declared on smart contracts should have an named parameter like NewValueSet(uint _value) in the contract SimpleStore.sol. Also, it helps in dealing with events.

Loom Network

https://loomx.io

License

BSD 3-Clause License

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