Class: NSFetchRequestExpression

Inherits:
NSExpression show all

Overview

Instances of NSFetchRequestExpression represent expressions which evaluate to the result of executing a fetch request on a managed object context.

Class Method Summary (collapse)

Instance Method Summary (collapse)

Methods inherited from NSExpression

#arguments, #collection, #constantValue, #expressionBlock, expressionForAggregate:, expressionForBlock:arguments:, expressionForConstantValue:, expressionForEvaluatedObject, expressionForFunction:arguments:, expressionForFunction:selectorName:arguments:, expressionForIntersectSet:with:, expressionForKeyPath:, expressionForMinusSet:with:, expressionForSubquery:usingIteratorVariable:predicate:, expressionForUnionSet:with:, expressionForVariable:, #expressionType, #expressionValueWithObject:context:, expressionWithFormat:, expressionWithFormat:argumentArray:, expressionWithFormat:arguments:, #function, #initWithExpressionType:, #keyPath, #leftExpression, #operand, #predicate, #rightExpression, #variable

Methods inherited from NSObject

#!, #!=, #!~, #, #==, #===, #=~, #Rational, #__callee__, #__method__, #__send__, #__type__, `, alloc, allocWithZone:, #autoContentAccessingProxy, autoload, autoload?, autorelease_pool, #awakeAfterUsingCoder:, binding, block_given?, caller, cancelPreviousPerformRequestsWithTarget:, cancelPreviousPerformRequestsWithTarget:selector:object:, catch, class, classFallbacksForKeyedArchiver, #classForCoder, #classForKeyedArchiver, classForKeyedUnarchiver, #clone, conformsToProtocol:, #copy, copyWithZone:, #dealloc, #define_singleton_method, description, display, #doesNotRecognizeSelector:, #dup, #enum_for, #eql?, #equal?, #extend, fail, #finalize, format, #forwardInvocation:, #forwardingTargetForSelector:, framework, #freeze, #frozen?, getpass, gets, global_variables, #init, initialize, #initialize_clone, #initialize_copy, #initialize_dup, #inspect, instanceMethodForSelector:, instanceMethodSignatureForSelector:, #instance_eval, #instance_exec, #instance_of?, #instance_variable_defined?, #instance_variable_get, #instance_variable_set, #instance_variables, instancesRespondToSelector:, isSubclassOfClass:, #is_a?, iterator?, #kind_of?, lambda, load, load_bridge_support_file, load_plist, local_variables, loop, #method, #methodForSelector:, #methodSignatureForSelector:, #methods, #mutableCopy, mutableCopyWithZone:, new, #nil?, open, p, #performSelector:onThread:withObject:waitUntilDone:, #performSelector:onThread:withObject:waitUntilDone:modes:, #performSelector:withObject:afterDelay:, #performSelector:withObject:afterDelay:inModes:, #performSelectorInBackground:withObject:, #performSelectorOnMainThread:withObject:waitUntilDone:, #performSelectorOnMainThread:withObject:waitUntilDone:modes:, print, printf, #private_methods, proc, #protected_methods, #public_method, #public_methods, #public_send, putc, puts, raise, rand, readline, readlines, #replacementObjectForCoder:, #replacementObjectForKeyedArchiver:, require, resolveClassMethod:, resolveInstanceMethod:, #respond_to?, #respond_to_missing?, select, #send, setVersion:, #singleton_methods, sprintf, srand, superclass, #taint, #tainted?, #tap, test, throw, #to_plist, #to_s, trace_var, trap, #trust, #untaint, untrace_var, #untrust, #untrusted?, version

Constructor Details

This class inherits a constructor from NSObject

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class NSObject

Class Method Details

+ (NSExpression) expressionForFetch(fetch, context:context, countOnly:countFlag)

Returns an expression which will evaluate to the result of executing a fetch request on a context.

Parameters:

  • fetch (NSExpression) —

    An expression that evaluates to an instance of NSFetchRequest.

  • context (NSExpression) —

    An expression that evaluates to an instance of NSManagedObjectContext.

  • countFlag (Boolean) —

    If YES, when the new expression is evaluated the managed object context (from context) will perform countForFetchRequest:error: with the fetch request (from fetch). If NO, when the new expression is evaluated the managed object context will perform executeFetchRequest:error: with the fetch request.

Returns:

  • (NSExpression) —

    An expression which will evaluate to the result of executing a fetch request (from fetch) on a managed object context (from context).

Instance Method Details

- (NSExpression) contextExpression

Returns the expression for the receiver’s managed object context.

Returns:

- (Boolean) isCountOnlyRequest

Returns a Boolean value that indicates whether the receiver represents a count-only fetch request.

If this method returns NO, the managed object context (from the contextExpression) will perform executeFetchRequest:error

with the requestExpression; if this method returns YES, the managed object context will perform countForFetchRequest:error: with the requestExpression.

Returns:

  • (Boolean) —

    YES if the receiver represents a count-only fetch request, otherwise NO.

- (NSExpression) requestExpresson

Returns the expression for the receiver’s fetch request.

Returns:

  • (NSExpression) —

    The expression for the receiver’s fetch request. Evaluating the expression must return an NSFetchRequest object.