PruneColumnsTransformer implements Transformer
Read onlyYes
FinalYes
Unlike {@see SelectColumnsTransformer}, which throws when a reference is not declared by the schema, prune keeps what is there and silently skips absent references - pruned rows are spilled to storage, where the pruning is opportunistic rather than a contract.
Interfaces
Methods
- __construct() : mixed
- bind() : BoundStep<string|int, Transformer>
- describe() : null|Description
- fromDescription() : static
- transform() : Rows
Methods
__construct()
public
__construct(string|Reference ...$refs) : mixed
Parameters
- $refs : string|Reference
bind()
public
bind(Schema $input) : BoundStep<string|int, Transformer>
Parameters
- $input : Schema
Return values
BoundStep<string|int, Transformer>describe()
public
describe() : null|Description
Return values
null|Description —null when this instance cannot cross a process boundary (a live client, a custom collaborator)
fromDescription()
public
static fromDescription(array<string|int, mixed> $data, Rebuild $rebuild) : static
Parameters
- $data : array<string|int, mixed>
- $rebuild : Rebuild
Return values
statictransform()
public
transform(Rows $rows, Backend $backend) : Rows