August 2019
Intermediate to advanced
486 pages
13h 52m
English
Content preview from Mastering Blockchain Programming with Solidity
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The Approval event
The Approval event is triggered when the approval of a token is given or changed.
The event takes three arguments:
- owner: The address of the approver who is the owner of the token
- approved: The address that will be approved for the given token
- tokenId: The tokenId of the NFT for which the approval is initiated
All of the preceding arguments are indexed in the event, which would allow the client applications to filter out the events:
event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
The Approval event is triggered only from the approve() function of the ERC721 implementation.
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