JBDelegateMetadataHelper

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Contract to create Juicebox delegate metadata

Metadata are built as:

• 32B of reserved space for the protocol
• a lookup table delegateId: offset, defining the offset of the metadata for each delegate. The offset fits 1 bytes, the ID 4 bytes. This table is padded to 32B.
• the metadata for each delegate, padded to 32B each

+-----------------------+ offset: 0
| 32B reserved          |
+-----------------------+ offset: 1 = end of first 32B
| (delegate1 ID,offset1)|
| (delegate2 ID,offset2)|
| 0's padding           |
+-----------------------+ offset: offset1 = 1 + number of words taken by the padded table
| delegate 1 metadata1  |
| 0's padding           |
+-----------------------+ offset: offset2 = offset1 + number of words taken by the metadata1
| delegate 2 metadata2  |
| 0's padding           |
+-----------------------+

This contract is intended to expose the library functions as a helper for frontends.

Functions

getMetadata

Parse the metadata to find the metadata for a specific delegate

Returns false and an empty bytes if no metadata is found

function getMetadata(bytes4 _id, bytes calldata _metadata)
    public
    pure
    returns (bool _found, bytes memory _targetMetadata);

Parameters

Name	Type	Description
_id	bytes4	The delegate id to find
_metadata	bytes	The metadata to parse

Returns

Name	Type	Description
_found	bool	Whether the metadata was found
_targetMetadata	bytes	The metadata for the delegate

createMetadata

Create the metadatas for a list of delegates

Intended for offchain use

function createMetadata(bytes4[] calldata _ids, bytes[] calldata _metadatas)
    public
    pure
    returns (bytes memory _metadata);

Parameters

Name	Type	Description
_ids	bytes4[]	The list of delegate ids
_metadatas	bytes[]	The list of metadatas

Returns

Name	Type	Description
_metadata	bytes	The packed metadata for the delegates

addToMetadata

Add a delegate to an existing metadata

function addToMetadata(bytes4 _idToAdd, bytes calldata _dataToAdd, bytes calldata _originalMetadata)
    public
    pure
    returns (bytes memory _newMetadata);

Parameters

Name	Type	Description
_idToAdd	bytes4	The id of the delegate to add
_dataToAdd	bytes	The metadata of the delegate to add
_originalMetadata	bytes	The original metadata

Returns

Name	Type	Description
_newMetadata	bytes	The new metadata with the delegate added

Errors

LENGTH_MISMATCH

error LENGTH_MISMATCH();

METADATA_TOO_LONG

error METADATA_TOO_LONG();