IDataObject

What is a Data Object?

Data Object is responsible for managing storage or data structures without containing any business logic. Unlike the Data Manager, which defines how an asset should behave, the Data Object focuses solely on handling the data itself, including encoding, decoding, and executing changes to the asset's state.

Data Objects are entrusted with managing transactions that affect the storage of Data Points. They can receive read() and write() requests from a Data Manager seeking access to a Data Point. Therefore, Data Objects operate based on a gating mechanism provided by a single Data Index.

Fig 1. An operation coming to the Data Object from the Data Index modifies data structures associated with a Data Point.

Interface

When the Data Manager instructs the Data Index to execute an operation, the Data Object will handle the internal storage changes. It must inherit this interface.

Inside the Data Object, we should implement the intrinsic logic required to handle each write() or read() operation coming from a Data Manager. This logic should refer to the specific Data Point for each user or application, ensuring that only the targeted storage is modified.

At this point, the application of logic in the Data Manager or Data Index should look familiar:

    //This method is defined at DataIndex
    function write(address dobj, DataPoint dp, bytes4 operation, bytes calldata data) external onlyApprovedDM(dp) returns (bytes memory) {
        return IDataObject(dobj).write(dp, operation, data);
    }

note

Focus on the use of read() and write() operations.

    //This method is defined at DataManager
    function publicViewMethod1(address arg1, uint256 arg2, bytes argN) public view returns (bool) {
    return
        abi.decode(
            dataObject.read(_datapoint, operation.selector, abi.encode(arg1, arg2, argN)),
            (bool)
        );
    }

Methods

1. read()

function read(DataPoint dp, bytes4 operation, bytes calldata data) external view returns (bytes memory);

Description	Parameters	Returns	Modifiers
Reads stored data	dp: Identifier of the Data Point operation: Read operation to execute on the data data: Operation-specific data	Operation-specific data	external view

2. write()

function write(DataPoint dp, bytes4 operation, bytes calldata data) external returns (bytes memory);

Description	Parameters	Returns	Modifiers
Stores data	dp: Identifier of the Data Point operation: Write operation to execute on the data data: Operation-specific data	Operation-specific data (can be empty)	external

3. setDataIndexImplementation()

function setDataIndexImplementation(DataPoint dp, IDataIndex newImpl) external;

Description	Parameters	Returns	Modifiers
Sets Data Index Implementation	dp: Identifier of the Data Point newImpl: Address of the new Data Index implementation	None	external

note

More details of the storage management in Data Objects functions can be found in the Data Object Reference Implementation.