# ConsumerBase smart contract

This contract can be imported by any smart contract wishing to include off-chain data or data from a different network within it.

The consumer initiates a data request by forwarding the request to the Router smart contract, from where the data provider(s) pick up and process the data request, and forward it back to the specified callback function.

# Functions:

# Function constructor(address _router, address _xfund) internal

Contract constructor. Accepts the address for the router smart contract, and a token allowance for the Router to spend on the consumer's behalf (to pay fees).

The Consumer contract should have enough tokens allocated to it to pay fees and the Router should be able to use the Tokens to forward fees.

# Parameters:

  • _router: address of the deployed Router smart contract

  • _xfund: address of the deployed xFUND smart contract

# Function _setRouter(address _router) internal -> bool

No description

# Parameters:

  • _router: address of the deployed Router smart contract

# Function _increaseRouterAllowance(uint256 _amount) internal -> bool

No description

# Parameters:

  • _amount: uint256 amount to increase allowance by

# Function _requestData(address _dataProvider, uint256 _fee, bytes32 _data) internal -> bytes32

_requestData - initialises a data request. forwards the request to the deployed Router smart contract.

# Parameters:

  • _dataProvider: payable address of the data provider

  • _fee: uint256 fee to be paid

  • _data: bytes32 value of data being requested, e.g. PRICE.BTC.USD.AVG requests average price for BTC/USD pair

# Return Values:

  • requestId bytes32 request ID which can be used to track or cancel the request

# Function rawReceiveData(uint256 _price, bytes32 _requestId) external

rawReceiveData - Called by the Router's fulfillRequest function in order to fulfil a data request. Data providers call the Router's fulfillRequest function The request is validated to ensure it has indeed been sent via the Router.

The Router will only call rawReceiveData once it has validated the origin of the data fulfillment. rawReceiveData then calls the user defined receiveData function to finalise the fulfilment. Contract developers will need to override the abstract receiveData function defined below.

# Parameters:

  • _price: uint256 result being sent

  • _requestId: bytes32 request ID of the request being fulfilled has sent the data

# Function receiveData(uint256 _price, bytes32 _requestId) internal

receiveData - should be overridden by contract developers to process the data fulfilment in their own contract.

# Parameters:

  • _price: uint256 result being sent

  • _requestId: bytes32 request ID of the request being fulfilled

# Function getRouterAddress() external -> address

getRouterAddress returns the address of the Router smart contract being used

Last Updated: 4/21/2021, 1:09:18 PM