TodoList Dapp
Live demo
Goal
While a TodoList app is not suited to ethereum-based backends, I originally wanted to do one to get my hands on this technology and to have a very simple app actually doing something I am familiar with as a front-end developper.
The goal of this sample app is to help anyone wanting to understand what are ethereum contracts and how they can be used as a distributed back-ends, with its limitations as well.
Required dependencies
A running node
You must run a node on your computer, whether its a real or virtual one. For development speed reasons, the best choice is to use testrpc because you have as much ether as you want and don't need to mine transactions.
Install instructions
Mac & Linux
sudo npm install -g ethereumjs-testrpc
Windows
If you can't afford this, we've covered you with Vagrant. This piece of software allows you to run a lightweight linux virtual machine in the terminal. Thus, it uses much less power than a full VM and you can still enjoy your Windows environment and tools you are used to, while providing you linux compatibility for terminal tools.
To do so, it's as easy as:
- Downloading and installing Vagrant
- Run
vagrant up
in a terminal opened at the project root. It may take some time as it must download an ubuntu ISO the first time it runs. - Then run
vagrant ssh
. If it doesn't work (it probably won't in fact) you can use Git bash if you already have it on your computer. If you don't, follow those instructions.
And that's it ! Now you can run testrpc
and you should see your node running.
Truffle - Compile & Migrate contracts to the blockchain
sudo npm install -g truffle
Note :
npm install -g truffle
on Windows.
Instructions
Setting up the devTools and client dependencies
npm install
Note : If install fails on windows (particularly if node-gyp is the issue), run Powershell as administrator and run
npm install -g windows-build-tools
. It will allow you to install and use native node packages.
Run your ethereum node
With testrpc
In a terminal (or in vagrant ssh on Windows, see above), run testrpc
With Geth
Locally
- Install Ethereum on your machine
npm run geth
to initialize and run the ethereum node with geth consolepersonal.unlockAccount("ACCOUNT_TO_UNLOCK_ADDRESS", "pass")
(see Note if you don't get it)miner.start()
Note : At least the first time, you need to run those commands to create an account to mine on
personal.newAccount("pass")
personal.unlockAccount("ACCOUNT_ADDRESS", "pass")
Note 2: If you need to customize the geth parameters, check the "geth" task in gulpfile.js.
Deploy the smart contracts to the node
In another terminal, run truffle compile
and then truffle migrate --reset
Warning here: You have to re-run those commands when you modify your contracts so that they are re-deployed to the blockchain.
Note : There is an experimental watcher that launch these commands when you save a contract. It may not work but it's worth the shot :
npm run watch-contracts
Running the client app
With your node running and the smart contracts deployed to it, run in terminal npm start
.
You're done !
FAQ
-
Why is there both a truffle.js file and a truffle-config.js file?
Truffle requires the truffle.js file be named truffle-config on Windows machines. Feel free to delete the file that doesn't correspond to your platform.
-
Where is my production build?
The production build will be in the build_webpack folder. This is because Truffle outputs contract compilations to the build folder.
-
Where can I find more documentation?
This project has been created with truffle-box-react which is a marriage of Truffle and a React setup created with create-react-app. Either one would be a great place to start!