Sample Ethereum Dapp to create your resume on Ethereum.
Follow the steps described below to install, deploy and run the Dapp.
Make that you don't run your tests on the Ethereum's main net otherwise you will spend real ether with no chance to get it back
To build, deploy and test your Dapp locally, you need to install the following tools and frameworks:
-
node.js and npm: https://nodejs.org/en/
- Node.js can be installed from an installation package or through some package managers such as Homebrew on a Mac.
-
Truffle: https://github.com/trufflesuite/truffle
- Create and deploy your Dapp with this build framework for Ethereum.
-
testrpc: https://github.com/ethereumjs/testrpc
- Simulates an Ethereum node.
-
Metamask: https://metamask.io/
- Transforms Chrome into a Dapp browser
git clone https://github.com/chainskills/resumeum
$ cd resumeum
$ npm install
Start testrpc or your private chain. We added a script at the root of the project that starts a testrpc instance with 3 predefined accounts.
$ ./starttestrpc.sh
The first account will be the coinbase, the account that will deploy the contracts.
If you didn't use the starttestrpc.sh script and started your own private chain instead, you should edit the truffle.js file and set the port number according to your Ethereum node.
$ truffle test
$ truffle migrate --reset
You will have to migrate (deploy) your smart contract each time your restart testrpc.
Unlock the Metamask extension in Chrome, and switch it to the network "Localhost 8545".
Import accounts defined in your testrpc Ethereum node.
If you used starttestrpc.sh, here are the 3 private keys defined in the script:
- 0x351494a5ae8f9b70a2a2fd482146ab4578f61d4d796685c597ec6683635a940e
- 0x4cd491f96e6623edb52719a8d4d1110a87d8d83e3fa86f8e14007cb3831c0a2b
- 0xef40e0d6ada046010b6965d73603cabae1a119ca804f5d9e9a9ce866b0bea7d
In Metamask, rename these accounts respectively:
- testrpc-coinbase
- testrpc-account1
- testrpc-account2
$ npm run dev
In your browser, open the following URL: http://localhost:3000
When you switch accounts or networks in Metamask, you have to refresh your page to let your frontend application know about it.
You can publish your resume.
Metamask will ask you to confirm the transaction before publishing your resume.
From your console window in Terminal, you can use the Truffle console to inspect the status of your contract.
Here is a short example:
$ truffle console
truffle(development)>
truffle(development)> Resumeum.deployed().then(function(instance) {app = instance; })
From now on, you can use the app variable to interact with your smart contract.
truffle(development)> web3.eth.accounts
[ '0x00d1ae0a6fc13b9ecdefa118b94cf95ac16d4ab0', '0x1daa654cfbc28f375e0f08f329de219fff50c765', '0xc2dbc0a6b68d6148d80273ce4d6667477dbf2aa7' ]
truffle(development)> app.getPrice.call()
{ [String: '40000000000000000'] s: 1, e: 16, c: [ 400 ] }
truffle(development)> app.setPrice(40000000000000000, {from: web3.eth.accounts[0]})
truffle(development)> web3.fromWei(web3.eth.getBalance(Resumeum.address), "ether").toNumber()
truffle(development)> web3.fromWei(web3.eth.getBalance(web3.eth.accounts[1]), "ether").toNumber()
truffle(development)> var resumeEvent = app.publishResumeEvent({}, {fromBlock: 0,toBlock: 'latest'}).watch(function(error, event) {console.log(event);})
truffle(development)> app.getResume.call()
[ '0x1daa654cfbc28f375e0f08f329de219fff50c765', 'John', 'Doe', 'I’m an Ethereum developer', 'In the past year, I have created a lot of Ethereum smart contracts. My personal projects are available on Github', 'Belgium', 'https://cdn.pixabay.com/photo/2013/07/13/10/07/man-156584_960_720.png' ]
truffle(development)> app.publishResume("John", "Doe", "I’m an Ethereum developer", "In the past year, I have created a lot of Ethereum smart contracts. My personal projects are available on Github", "Belgium", "https://cdn.pixabay.com/photo/2013/07/13/10/07/man-156584_960_720.png", {from: web3.eth.accounts[1], value: web3.toWei(0.02, "ether")} )
truffle(development)> app.publishResume("Jane", "Smith", "I'm an blockchain developer", "This is my summary", "United States", "http://i.pravatar.cc/300", {from: web3.eth.accounts[2], value: web3.toWei(0.02, "ether")})
truffle(development)> app.getConsultants()
[ '0x1daa654cfbc28f375e0f08f329de219fff50c765', '0xc2dbc0a6b68d6148d80273ce4d6667477dbf2aa7' ]
truffle(development)> app.resumes('0x1daa654cfbc28f375e0f08f329de219fff50c765') [ '0x1daa654cfbc28f375e0f08f329de219fff50c765', 'John', 'Doe', 'I\'m a developer', 'This is my summary', 'Belgium', 'http://i.pravatar.cc/300' ]
Only required if you want to "kill" your smart contract:
truffle(development)> app.kill({from: web3.eth.accounts[0]})
- Is Metamask slow ? try to disable and enable the extension. This happens sometimes, especially when we work with a private chain.
- When you switch accounts in Metamask, don't forget to refresh the page to make sure you get the current account set in Metamask.
If you want to know more about all the steps required to install, build and deploy a Dapp, you can subscribe to our course available on Udemy: https://www.udemy.com/getting-started-with-ethereum-solidity-development
Have fun !!!
ChainSkills Team - 2017