Getting data from Oracles

Users can utilize purchased data from Zap Oracles in their dapps or apps. Zap provides templates for offchain and onchain solutions

Zap Oracles will need to define the data structure they provide in their responses. Users can look up the information in https://admin.zap.org or Oracle's own source if they provide one.

Onchain solution

Dapps can receive data from Zap Oracles by simply implementing callback method that match the data type users expect from the Oracle. Zap platform provides multiple types of responses :

Response method	Response Type	Callback to implement
respondBytes32Array	bytes32[]	callback(id, response)
respondIntArray	int[]	callback(id, response)
respond1	string	callback(id, response1)
respond2	(string, string)	callback(id, response1, 2)
respond3	(string, string, string)	callback(id, response1, 2, 3, 4)
respond4	(string, string, string, string)	callback(id, response1, 2, 3, 4)

Check out Onchain subscriber example for solidity code example of dapps that use data from Zap Oracles

Offchain solution

If User's address is not a contract address, all above response method will automatically emit Event of responses instead of calling callback method. User can listen to Events for each method to receive data offchain. Following table includes all offchain events with response method

Response method	Event
respondBytes32	OffchainResponse
respondIntArray	OffchainResponseInt
respond1	OffchainResult1
respond2	OffchainResult2
respond3	OffchainResult3
respond4	OffchainResult4

Check out Offchain Subscriber Example for code example of receiving offchain responses