KeyExtractor (nf-bids 0.3.0 API)

nfneuro.channel.operations.keys.KeyExtractor

```
@groovy.util.logging.Slf4j
@groovy.transform.CompileStatic
class KeyExtractor
extends java.lang.Object
```
Utility class for extracting and comparing keys from channel items using closures. This class provides centralized logic for closure-based key extraction with proper error handling, validation, and support for composite (multi-part) keys.
Authors:
Alex Valcourt Caron

Constructor Summary

Constructors
Constructor and description
`KeyExtractor()`

Methods Summary

Methods
Type Params	Return Type	Name and description
	`static java.lang.Object`	`extractKey(java.lang.Object item, groovy.lang.Closure keyExtractor, java.lang.String operatorName)` Extract a key from an item using a closure, with error handling.
	`static boolean`	`keysEqual(java.lang.Object key1, java.lang.Object key2)` Compare two keys for equality.
	`static void`	`validateKeyExtractor(groovy.lang.Closure keyExtractor, java.lang.String operatorName)` Validate that a keyExtractor closure has the correct arity (parameter count).

Inherited Methods Summary

Inherited Methods
Methods inherited from class	Name
`class java.lang.Object`	`java.lang.Object#equals(java.lang.Object), java.lang.Object#toString(), java.lang.Object#hashCode(), java.lang.Object#getClass(), java.lang.Object#notify(), java.lang.Object#notifyAll(), java.lang.Object#wait(long), java.lang.Object#wait(long, int), java.lang.Object#wait()`

- Constructor Detail
  - KeyExtractor()
- Method Detail
  - static java.lang.Object extractKey(java.lang.Object item, groovy.lang.Closure keyExtractor, java.lang.String operatorName)
    
    Extract a key from an item using a closure, with error handling. This method safely invokes the keyExtractor closure on the item, handling null returns and exceptions appropriately. List keys are automatically wrapped in CompositeKey for proper equality semantics.
    throws:
    IllegalStateException if the keyExtractor throws an exception
    
    Parameters:
    item - The channel item to extract a key from
    keyExtractor - The closure that extracts the key
    operatorName - The name of the calling operator (for error messages)
    Returns:
    The extracted key, or null if extraction failed or returned null
  - static boolean keysEqual(java.lang.Object key1, java.lang.Object key2)
    
    Compare two keys for equality.
    Parameters:
    key1 - The first key
    key2 - The second key
    Returns:
    true if the keys are equal, false otherwise
  - static void validateKeyExtractor(groovy.lang.Closure keyExtractor, java.lang.String operatorName)
    
    Validate that a keyExtractor closure has the correct arity (parameter count). A valid keyExtractor must accept at least one parameter (the channel item). Closures with more than 2 parameters will generate a warning as they may indicate incorrect usage.
    throws:
    IllegalArgumentException if the closure is invalid
    
    Parameters:
    keyExtractor - The closure to validate
    operatorName - The name of the calling operator (for error messages)

Summary:
Constructor
Method

| Detail:
Constructor
Method

Groovy Documentation

[Groovy] Class KeyExtractor

Constructor Summary

Methods Summary

Inherited Methods Summary

Constructor Detail

KeyExtractor()

Method Detail

static java.lang.Object extractKey(java.lang.Object item, groovy.lang.Closure keyExtractor, java.lang.String operatorName)

static boolean keysEqual(java.lang.Object key1, java.lang.Object key2)

static void validateKeyExtractor(groovy.lang.Closure keyExtractor, java.lang.String operatorName)