Dapple is a Solidity developer multitool designed to manage the growing complexity of interconnected smart contract systems.

Its core functionality encompasses three main areas:

• Package management
• Contract building
• Deployment scripting

These concepts are related in a way unique to the smart contract ecosystem, due to each blockchain's universal singleton nature.

The central data model for Dapple is the dappfile, whose definition will normally reference IPFS objects and Ethereum contract addresses.

Installation

The normal way to install Dapple is through npm:

$ npm install -g dapple
$ dapple --help

Ubuntu 14.04 or above

If you're on Ubuntu 14.04 or above and don't have Node.js or the Solidity compiler, try following these steps to install them:

Install Node.js:

apt-get install -y curl
curl -sL https://deb.nodesource.com/setup_6.x | bash
apt-get update
apt-get install -y nodejs

Install Solidity:

apt-get install -y software-properties-common
add-apt-repository ppa:ethereum/ethereum
add-apt-repository ppa:ethereum/ethereum-qt
apt-get update
apt-get install -y cpp-ethereum

Install Dapple:

apt-get install -y git build-essential python
git clone https://github.com/nexusdev/dapple
cd dapple
npm link

Docker

If you can't or don't want to install Dapple and the Solidity compiler on your host machine, you can use the dapple-docker wrapper script to run the whole toolchain inside a Docker container. This script can be used instead of dapple but must be installed separately:

$ make docker-install
$ dapple-docker help

The current directory is automatically mounted into the containers. Note: If you're on OS X, this only works in your home directory.

Basic usage

Use dapple init to generate a project skeleton:

mkdir foo; cd foo; dapple init

By default, build/ is where the output of dapple build gets put, and contracts/ is where Dapple looks for your contract source files. Both of these are configured in your dappfile and can be overridden.

Now try writing a contract and a test (see Dapple test harness docs):

$ vim contracts/dapp.sol
$ vim contracts/dapp_test.sol
$ dapple test

Finally, try building your project:

$ dapple build

By default, dapple build builds the entire contracts/ tree, and emits the following:

• cached build objects
• classes.json — a list of type definitions
• js_module.js — a JavaScript module which wraps classes.json and adds Contract objects instantiated from web3.js for each object in the dappfile

FAQ

Can I use TestRPC with dapple?

If you are using TestRPC, remember that dapple run has a default block confirmation time of one block. To prevent a deadlock you need to turn off the confirmation time testrpc environment:

environments:
    test:
        confirmationBlocks: 0

Example packages

• Dappsys — a contract system framework (Nexus's "standard library")
• Feedbase — a simple paid feed app
• stringutils — string manipulation library

More information

• Basic VM tests
• Testing exceptions
• Testing events
• Installing and publishing packages
• Deployment scripting
• Logging

Not yet documented

• Aliasing and imports
• Environments and object linking
• Ignore/add