EOQualifierVariable

Inherits from:

NSObject

Conforms to:

NSCoding

EOKeyValueArchiving

Declared in:

EOControl/EOQualifier.h

Class Description

EOQualifierVariable defines objects that serve as placeholders in the qualifier. When you create a qualifier programmatically, you typically do something like this:

aQual = EOQualifier.qualifierWithQualifierFormat("dateReleased = %@", aDate);

where aDate is a variable that contains the actual date you want to query upon. When you store the qualifier in an EOModel, there is no way to know the actual value to query upon or the variable that will contain that value. The EOQualifierVariable object acts as a placeholder for the actual variable that will represent the right side of the expression. You specify an EOQualifierVariable by using a $, as in the following:

dateReleased = $aDate

Variable values must be substituted for using qualifierWithBindings:requiresAllVariables:.

Constants

In EOQualifier.h, EOControl defines the following NSString constant as the type of exception that's raised when an EOQualifierVariable object requires bindings for all its variables and one or more variable is missing from the bindings (see qualifierWithBindings:requiresAllVariables: in the EOQualifier class specification):

• EOQualifierVariableSubstitutionException

Adopted Protocols

NSCoding

- initWithCoder:

- encodeWithCoder:

EOKeyValueArchiving

- initWithKeyValueUnarchiver:

- encodeWithKeyValueArchiver:

Class Methods

variableWithKey:

+ (id)variableWithKey:(NSString *)key

Instance Methods

initWithKey:

- (id)initWithKey:(NSString *)key

key

- (NSString *)key