< p align = "center" >
< img src = "./exw3_logo.jpg" / >
< / p >
## Installation
def deps do
[{:exw3, "~> 0.1.1"}]
end
## Overview
ExW3 is a wrapper around ethereumex to provide a high level, user friendly json rpc api. It currently only supports Http. The primary feature it provides is a handy abstraction for working with smart contracts.
## Usage
Ensure you have an ethereum node to connect to at the specified url in your config. An easy local testnet to use is ganache-cli:
```
ganache-cli
```
Make sure your config includes:
```elixir
config :ethereumex,
url: "http://localhost:8545"
```
Currently, ExW3 supports a handful of json rpc commands. Mostly just the useful ones. If it doesn't support a specific commands you can always use the [Ethereumex ](https://github.com/exthereum/ethereumex ) commands.
Check out the [documentation ](https://hexdocs.pm/exw3/ExW3.html )
```elixir
iex(1)> accounts = ExW3.accounts()
["0xb5c17637ccc1a5d91715429de76949fbe49d36f0",
"0xecf00f60a29acf81d7fdf696fd2ca1fa82b623b0",
"0xbf11365685e07ad86387098f27204700d7568ee2",
"0xba76d611c29fb25158e5a7409cb627cf1bd220cf",
"0xbb209f51ef097cc5ca320264b5373a48f7ee0fba",
"0x31b7a2c8b2f82a92bf4cb5fd13971849c6c956fc",
"0xeb943cee8ec3723ab3a06e45dc2a75a3caa04288",
"0x59315d9706ac567d01860d7ede03720876972162",
"0x4dbd23f361a4df1ef5e517b68e099bf2fcc77b10",
"0x150eb320428b9bc93453b850b4ea454a35308f17"]
iex(2)> ExW3.balance(Enum.at(accounts, 0))
99999999999962720359
iex(3)> ExW3.block_number()
835
iex(4)> simple_storage_abi = ExW3.load_abi("test/examples/build/SimpleStorage.abi")
%{
"get" => %{
"constant" => true,
"inputs" => [],
"name" => "get",
"outputs" => [%{"name" => "", "type" => "uint256"}],
"payable" => false,
"stateMutability" => "view",
"type" => "function"
},
"set" => %{
"constant" => false,
"inputs" => [%{"name" => "_data", "type" => "uint256"}],
"name" => "set",
"outputs" => [],
"payable" => false,
"stateMutability" => "nonpayable",
"type" => "function"
}
}
iex(5)> ExW3.Contract.start_link(SimpleStorage, abi: simple_storage_abi)
{:ok, #PID < 0.239.0 > }
iex(6)> {:ok, address} = ExW3.Contract.deploy(SimpleStorage, bin: ExW3.load_bin("test/examples/build/SimpleStorage.bin"), options: %{gas: 300000, from: Enum.at(accounts, 0)})
{:ok, "0xd99306b81bd61cb0ecdd3f2c946af513b3395088"}
iex(7)> ExW3.Contract.at(SimpleStorage, address)
:ok
iex(8)> ExW3.Contract.call(SimpleStorage, :get)
{:ok, 0}
iex(9)> ExW3.Contract.send(SimpleStorage, :set, [1], %{from: Enum.at(accounts, 0)})
{:ok, "0xb7e9cbdd2cec8ca017e675059a3af063d754496c960f156e1a41fe51ea82f3b8"}
iex(10)> ExW3.Contract.call(SimpleStorage, :get)
{:ok, 1}
```
