Class: Eth::Contract

Inherits:
Object
  • Object
show all
Defined in:
lib/eth/contract.rb

Overview

Provides classes to access smart contracts

Defined Under Namespace

Classes: Error, Event, Function, FunctionInput, FunctionOutput, Initializer

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, bin, abi) ⇒ Contract

Constructor of the Eth::Contract class.

Note, do not use this directly. Use from_abi, from_bin, or from_file!

Parameters:

  • name (String) —

    contract name.

  • bin (String) —

    contract bin string.

  • abi (String) —

    contract abi string.



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# File 'lib/eth/contract.rb', line 38

def initialize(name, bin, abi)

  # The contract name will be the class name and needs title casing.
  _name = name.dup
  _name[0] = name[0].upcase

  @name = _name
  @bin = bin
  @abi = abi
  @constructor_inputs, @functions, @events, @errors = parse_abi(abi)
  @sigs2events = {}
  @events.each do |event|
    @sigs2events[event.signature] = event
  end
end

Instance Attribute Details

#abi ⇒ Object

Returns the value of attribute abi.



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# File 'lib/eth/contract.rb', line 27

def abi
  @abi
end

#address ⇒ Object

Returns the value of attribute address.



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# File 'lib/eth/contract.rb', line 24

def address
  @address
end

#bin ⇒ Object

Returns the value of attribute bin.



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# File 'lib/eth/contract.rb', line 27

def bin
  @bin
end

#class_object ⇒ Object

Returns the value of attribute class_object.



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# File 'lib/eth/contract.rb', line 27

def class_object
  @class_object
end

#constructor_inputs ⇒ Object

Returns the value of attribute constructor_inputs.



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# File 'lib/eth/contract.rb', line 28

def constructor_inputs
  @constructor_inputs
end

#errors ⇒ Object

Returns the value of attribute errors.



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# File 'lib/eth/contract.rb', line 28

def errors
  @errors
end

#events ⇒ Object

Returns the value of attribute events.



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# File 'lib/eth/contract.rb', line 28

def events
  @events
end

#functions ⇒ Object

Returns the value of attribute functions.



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# File 'lib/eth/contract.rb', line 28

def functions
  @functions
end

#gas_limit ⇒ Object

Returns the value of attribute gas_limit.



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# File 'lib/eth/contract.rb', line 26

def gas_limit
  @gas_limit
end

#gas_price ⇒ Object

Returns the value of attribute gas_price.



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# File 'lib/eth/contract.rb', line 26

def gas_price
  @gas_price
end

#key ⇒ Object

Returns the value of attribute key.



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# File 'lib/eth/contract.rb', line 25

def key
  @key
end

#max_fee_per_gas ⇒ Object

Returns the value of attribute max_fee_per_gas.



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# File 'lib/eth/contract.rb', line 26

def max_fee_per_gas
  @max_fee_per_gas
end

#max_priority_fee_per_gas ⇒ Object

Returns the value of attribute max_priority_fee_per_gas.



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# File 'lib/eth/contract.rb', line 26

def max_priority_fee_per_gas
  @max_priority_fee_per_gas
end

#name ⇒ Object

Returns the value of attribute name.



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# File 'lib/eth/contract.rb', line 27

def name
  @name
end

#nonce ⇒ Object

Returns the value of attribute nonce.



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# File 'lib/eth/contract.rb', line 26

def nonce
  @nonce
end

Class Method Details

.from_abi(abi:, address:, name:) ⇒ Eth::Contract::Object

Creates a contract wrapper from ABI and address.

Parameters:

  • abi (String) —

    contract abi string.

  • address (String) —

    contract address.

  • name (String) —

    name of contract.

Returns:

  • (Eth::Contract::Object) —

    Returns the class of the smart contract.

Raises:

  • (JSON::ParserError) —

    if the json format is wrong.

  • (ArgumentError) —

    if ABI, address, or name is missing.



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# File 'lib/eth/contract.rb', line 75

def self.from_abi(abi:, address:, name:)
  abi = abi.is_a?(Array) ? abi : JSON.parse(abi)
  contract = Eth::Contract.new(name, nil, abi)
  contract.build
  contract = contract.class_object.new
  contract.address = address
  contract
end

.from_bin(bin:, abi:, name:) ⇒ Eth::Contract::Object

Creates a contract wrapper from binary and ABI.

Parameters:

  • bin (String) —

    contract bin string.

  • abi (String) —

    contract abi string.

  • name (String) —

    name of contract.

Returns:

  • (Eth::Contract::Object) —

    Returns the class of the smart contract.

Raises:

  • (JSON::ParserError) —

    if the json format is wrong.

  • (ArgumentError) —

    if ABI, binary, or name is missing.



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# File 'lib/eth/contract.rb', line 92

def self.from_bin(bin:, abi:, name:)
  abi = abi.is_a?(Array) ? abi : JSON.parse(abi)
  contract = Eth::Contract.new(name, bin, abi)
  contract.build
  contract.class_object.new
end

.from_file(file:, contract_index: 0) ⇒ Eth::Contract::Object

Creates a contract wrapper from a Solidity file.

Parameters:

  • file (String) —

    solidity file path.

  • contract_index (Number) (defaults to: 0) —

    specify contract.

Returns:

  • (Eth::Contract::Object) —

    Returns the class of the smart contract.

Raises:

  • (ArgumentError) —

    if the file path is empty or no contracts were compiled.



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# File 'lib/eth/contract.rb', line 60

def self.from_file(file:, contract_index: 0)
  raise ArgumentError, "Cannot find the contract at #{file.to_s}!" if !File.exist?(file.to_s)
  contracts = Eth::Contract::Initializer.new(file).build_all
  raise ArgumentError, "No contracts compiled." if contracts.empty?
  contracts[contract_index].class_object.new
end

Instance Method Details

#build ⇒ Object

Create meta classes for smart contracts.



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# File 'lib/eth/contract.rb', line 160

def build
  class_name = @name
  parent = self
  class_methods = Class.new do
    extend Forwardable
    def_delegators :parent, :key, :key=
    def_delegators :parent, :name, :abi, :bin
    def_delegators :parent, :gas_limit, :gas_price, :gas_limit=, :gas_price=, :nonce, :nonce=
    def_delegators :parent, :max_fee_per_gas, :max_fee_per_gas=, :max_priority_fee_per_gas, :max_priority_fee_per_gas=
    def_delegators :parent, :events, :errors
    def_delegators :parent, :address, :address=
    def_delegator :parent, :functions
    def_delegator :parent, :function
    def_delegator :parent, :error
    def_delegator :parent, :decode_error
    def_delegator :parent, :decode_log
    def_delegator :parent, :constructor_inputs
    define_method :parent do
      parent
    end
  end
  Eth::Contract.send(:remove_const, class_name) if Eth::Contract.const_defined?(class_name, false)
  Eth::Contract.const_set(class_name, class_methods)
  @class_object = class_methods
end

#decode_error(rpc_error) ⇒ String

Decodes a custom error returned by an RPC error using the contract ABI.

Parameters:

  • rpc_error (RpcError) —

    the RPC error containing revert data.

Returns:

  • (String) —

    a human readable error message.



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# File 'lib/eth/contract.rb', line 141

def decode_error(rpc_error)
  data = rpc_error.data
  return rpc_error.message if data.nil? || errors.nil?

  signature = data[0, 10]
  if (err = errors.find { |e| e.signature == signature })
    values = err.decode(data)
    args = values&.map { |v| v.is_a?(String) ? v : v.inspect }&.join(",")
    args ||= ""
    "execution reverted: #{err.name}(#{args})"
  elsif signature == "0x08c379a0"
    reason = Abi.decode(["string"], "0x" + data[10..])&.first
    "execution reverted: #{reason}"
  else
    rpc_error.message
  end
end

#decode_log(topics, data) ⇒ Hash

Decodes an event log by looking up the event signature in the contract ABI.

Parameters:

  • topics (Array<String>) —

    the list of log topics, including the event selector.

  • data (String) —

    the log data containing non-indexed parameters.

Returns:

  • (Hash) —

    a hash of decoded event parameters.

Raises:

  • (ArgumentError) —

    if the event is not part of the contract ABI.



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# File 'lib/eth/contract.rb', line 194

def decode_log(topics, data)
  sig = Eth::Util.remove_hex_prefix(topics[0])
  event = @sigs2events[sig]
  raise ArgumentError, "this event does not exist!" if event.nil?
  event.decode_params(topics, data)
end

#error(name, args: nil) ⇒ Eth::Contract::Error

Finds an error by name.

Parameters:

  • name (String) —

    error name.

  • args (Integer, nil) (defaults to: nil) —

    number of arguments of an error.

Returns:

Raises:

  • (ArgumentError) —

    if error not found.



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# File 'lib/eth/contract.rb', line 131

def error(name, args: nil)
  errors.find do |e|
    e.name == name && (args.nil? || args == e.inputs.size)
  end || raise(ArgumentError, "this error does not exist!")
end

#function(name, args: nil) ⇒ Eth::Contract::Function

Finds a function by name.

Parameters:

  • name (String) —

    function name.

  • args (Integer, nil) (defaults to: nil) —

    number of arguments of a function.

Returns:

Raises:

  • (ArgumentError) —

    if function not found.



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# File 'lib/eth/contract.rb', line 119

def function(name, args: nil)
  functions.find do |f|
    f.name == name && (args.nil? || args == f.inputs.size)
  end || raise(ArgumentError, "this function does not exist!")
end