This article outlines the general outline of the ParkingDAO. For details about this application, look at its source
In order to register as a User, simply call the registerUser function in the ParkingAuthority master contract. This will deploy a User proxy-contract which is owned by the caller. The master contract can validate the application with additional logic, currently this is mocked by accepting all applications.
In order to register an anchor, call the registerParkingAnchor function in the ParkingAuthority master contract. This function takes 2 arguments, an anchorId and a geohash. The anchorId is just a stand-in for any other auxilliary data required to be a ParkingAnchor. The ParkingAuthorty validates the application (currently mocked to accept all applications), then deploys the ParkingAnchor proxy-contract which is owned by the caller. The ParkingAuthority then registers the parking anchor as a Crypto Spatial Coordinate (see CSC.sol) with the Foam Crypto Spatial Registry contract (see FoamCSR.sol).
sequenceDiagram participant Owner participant ParkingAuthority participant FoamCSR Owner->>ParkingAuthority: apply with geohash and anchorId ParkingAuthority->>ParkingAuthority: reject / validate application ParkingAuthority->>FoamCSR: create anchor as csc, register anchor ParkingAuthority->>Owner: transfer ownership to applicant
A zone is defined as a geohash corresponding to a bounded box on the map of a fixed resolution (in this case, a bytestring of length 4 bytes). The FoamCSR contract and CSC standard uses a bytestring of lenghth 8-bytes to represent the coordinates of the ParkingAnchor. Thus, a ParkingAnchor is in a zone if the first 4 bytes of the anchor’s geohash match the zone’s geohash.
A User can apply to the ParkingAuthority for the ability to park in a certain zone using the requestZone function and supplying the desired zone as an argument. The ParkingAuthority validates the application (currently the authority accepts all applications), then updates the User’s set of licensed zones.
sequenceDiagram participant Owner participant User participant ParkingAuthority Owner->>User: send desired zone User->>ParkingAuthority: forward request for zone ParkingAuthority->>ParkingAuthority: reject / validate application ParkingAuthority->>User: update licensedZone list
In order to pay for parking, the owner of a User proxy-contract calls the payForParking function supplying the address of the desired ParkingAnchor as an argument as well payment for parking. Currently the only requirement is that the payment is non-zero. The ParkingAnchor checks that the User is allowed to park in the zone that it occupies, then accepts the funds or denies the request. It then sets state in the User proxy-contract indicating that the User is currently parked there.
sequenceDiagram participant Owner participant User participant ParkingAnchor Owner->>User: call payForParking with nonzero payment User->>User: setPendingAnchor User->>ParkingAnchor: forwardPayment ParkingAnchor->>User: zones? & pendingAnchor? User->>ParkingAnchor: zones & pendingAnchor ParkingAnchor->>ParkingAnchor: reject if not valid ParkingAnchor->>User: set checkIn and clear pendingAnchor