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README.md
embark-vyper
Embark wrapper for the Vyper compiler
Step 1. Install the Embark Vyper plugin
Installing the Embark Vyper plugin in our ÐApp is extremely simple:
- Add the
embark-vyper
package to your ÐApp:
yarn add embark-vyper
# OR
npm i embark-vyper
- Add the
embark-vyper
plugin toembark.json
:
// embark.json
// ...
"plugins": {
"embark-ipfs": {},
"embark-swarm": {},
"embark-whisper-geth": {},
"embark-geth": {},
"embark-parity": {},
"embark-profiler": {},
"embark-graph": {},
"embark-vyper": {} // <====== add this!
},
// ...
Step 2. Add a Vyper contract to your ÐApp
For the purposes of this guide, let's delete the existing SimpleStorage
Solidity contract that comes with the Embark Demo by default if it exists:
rm -rf contracts/simple_storage.sol
Next, let's create a Vyper contract in the contracts
folder of our ÐApp, ie contract/SimpleStorage.vy
(case is important):
# contracts/SimpleStorage.vy
storedData: public(int128)
@public
def __init__(_x: int128):
self.storedData = _x
@public
def set(_x: int128):
self.storedData = _x
The function of this contract is simple: upon creation (deployment), it will store the value we initially give it during deployment. We also have access to a set()
that will allow to set the value stored in the contract.
Changing the contract filename
Because Vyper's constructor is called __init__
, Embark must take the contract class name from the file name. If you'd prefer to change the name of your contract file to something else like contracts/simple_storage.vy
, you'll need to update config/contract.js
to allow Embark to match a contract configuration to a contract file:
// config/contracts.js
module.exports = {
default: {
// ...
deploy: {
simple_storage: {
fromIndex: 0,
args: [100]
}
}
// ...
}
}
Please see the Embark smart contract configuration documentation for more information on how to configure contracts in Embark.
Step 3. Run Embark
Now that we have installed and configured everything, let's run Embark and watch the magic!
embark run --nodashboard --nobrowser
Assuming we kept the file name SimpleStorage.vy
from step 4, we should see the following output in the console:
compiling Vyper contracts...
deploying contracts
Deploying SimpleStorage with 144379 gas at the price of 2000000000 Wei. Estimated cost: 288758000000000 Wei (txHash: 0x370a864b12b1785b17180b2a10ec2f941a15638eeffadfecf5bbe68755a06f14)
SimpleStorage deployed at 0x5Baf4D88bC454537C51CEC7568a1E23400483abc using 135456 gas (txHash: 0x370a864b12b1785b17180b2a10ec2f941a15638eeffadfecf5bbe68755a06f14)
Troubleshooting
There are a few common issues you may experience when Embark attempts to compile and deploy your Vyper contracts.
Vyper is not installed on your machine
Vyper is not installed on your machine
You can install it by visiting: https://vyper.readthedocs.io/en/latest/installing-vyper.html
This means that the binary vyper
cannot be found on your machine. If you're running *nix, you can verify this by running:
which vyper
# expected output: path/to/virtual-env/bin/vyper
# actual output: vyper not found
If vyper
was installed in a virtual environment, you may have forgotten to active the environment, ie:
source path/to/vyper-env/bin/activate
If vyper
was not installed in a virual environment, it means either your PATH
environment variable needs to be updated to point to the directory where the vyper
binary is installed. You can inspect your PATH
environment variable by:
echo $PATH
And update it with the path to the directory containing the vyper
binary using:
export PATH=/path/to/vyper/dir:$PATH
Error deploying contract
SimpleStorage has no code associated
did you mean "simple_storage"?
deploying contracts
Error deploying contract simple_storage
[simple_storage]: Invalid number of parameters for "constructor". Got 0 expected 1!
Error deploying contracts. Please fix errors to continue.
This means that the contract simple_storage
is a file in contracts/
and expected to be deployed by Embark, but is not configured for deploy in the contracts configuration. This could be the result of changing the filename of the Vyper contract to simple_storage.vy
, but not updating the contracts configuration, as outlined in step 2.
Visit framework.embarklabs.io to get started with Embark.