NSSpecifierTest Class Reference

Inherits from	NSScriptWhoseTest : NSObject
Conforms to	NSCoding (NSScriptWhoseTest) NSObject (NSObject)
Framework	/System/Library/Frameworks/Foundation.framework
Availability	Available in Mac OS X v10.0 and later.
Companion guide	Cocoa Scripting Guide
Declared in	NSScriptWhoseTests.h

Overview

Instances of this class represent a Boolean expression; they evaluate an object specifier and compare the resulting object to another object using a given comparison method. For more information on NSSpecifierTest, see the method description for its sole public method, its initializer, initWithObjectSpecifier:comparisonOperator:testObject:.

When an NSSpecifierTest object is properly initialized, it holds two objects:

A “value” or “test” object used as the basis of the comparison; this object can be a regular object or object specifier (such as “blue” in “words whose color is blue”).
An object specifier evaluating to the container (“words”).

The instance also encapsulates a selector identifying the method performing this comparison. The informal protocol NSComparisonMethods defines a set of comparison methods useful for this purpose, while NSScriptingComparisonMethods describes additional methods you may need to use for scripting.

The test object is compared, using the selector, against each object in the container. Specifiers in these tests usually have containerIsObjectBeingTested invoked on their topmost container.

You should rarely need to subclass NSSpecifierTest.

Tasks

Initializing a Specifier Test

Instance Methods

initWithObjectSpecifier:comparisonOperator:testObject:

Returns a specifier test initialized to evaluate a test object against an object specified by an object specifier using a given comparison operation.

- (id)initWithObjectSpecifier:(NSScriptObjectSpecifier *)obj1 comparisonOperator:(NSTestComparisonOperation)compOp testObject:(id)obj2

Parameters

obj1: An object specifier.
compOp: The comparison operation.
obj2: The object against which to evaluate the object specified by obj1.

Return Value

A specifier test initialized to evaluate (obj2) against an object specified by obj1 using the comparison operation compOp.

Availability

Available in Mac OS X v10.0 and later.

Declared In

NSScriptWhoseTests.h

Constants

NSTestComparisonOperation

These are passed to initWithObjectSpecifier:comparisonOperator:testObject: to specify the comparison operator.

typedef enum {
   NSEqualToComparison = 0,
   NSLessThanOrEqualToComparison,
   NSLessThanComparison,
   NSGreaterThanOrEqualToComparison,
   NSGreaterThanComparison,
   NSBeginsWithComparison,
   NSEndsWithComparison,
   NSContainsComparison
} NSTestComparisonOperation;