PATH Documentation > WebObjects 4.5 > EOControl Reference

EOAndQualifier

Inherits from:
EOQualifier : NSObject

Conforms to:
EOQualifierEvaluation

EOQualifierSQLGeneration

Declared in:
EOControl/EOQualifier.h

Class Description

EOAndQualifier is a subclass of EOQualifier that contains multiple qualifiers. EOAndQualifier adopts the EOQualifierEvaluation protocol, which defines the method evaluateWithObject: for in-memory evaluation. When an EOAndQualifier object receives an evaluateWithObject: message, it evaluates each of its qualifiers until one of them returns NO. If one of its qualifiers returns NO, the EOAndQualifier object returns NO immediately. If all of its qualifiers return YES, the EOAndQualifier object returns YES.

Adopted Protocols

EOQualifierEvaluation
- evaluateWithObject:

EOQualifierSQLGeneration (EOAccess)
- sqlStringForSQLExpression:

- schemaBasedQualifierWithRootEntity:

Instance Methods

evaluateWithObject:

- (BOOL)evaluateWithObject:(id)anObject

Returns YES if anObject satisfies the qualifier, NO otherwise. When an EOAndQualifier object receives an evaluateWithObject: message, it evaluates each of its qualifiers until one of them returns NO. If any of its qualifiers returns NO, the EOAndQualifier object returns NO immediately. If all of its qualifiers return YES, the object returns YES. This method can raise one of several possible exceptions if an error occurs. If your application allows users to construct arbitrary qualifiers (such as through a user interface), you may want to write code to catch any exceptions and properly respond to errors (for example, by displaying a panel saying that the user typed a poorly formed qualifier).

initWithQualifierArray:

- initWithQualifierArray:(NSArray *)qualifiers

Initializes the receiver with the qualifiers in qualifiers and returns self. This method is the designated initializer for EOAndQualifier.

initWithQualifiers:

- initWithQualifiers:(EOQualifier *)qualifiers, ...

Initializes the receiver with the nil-terminated list of qualifiers in qualifiers. Works by invoking initWithQualifierArray:. For example, the following code excerpt constructs two qualifiers, qual1 and qual2. It then uses these qualifiers to initialize an EOAndQualifier, andQual. The qualifier andQual is then used to filter an in-memory array.

NSArray *guests;    /* Assume this exists. */
EOQualifier *qual1, *qual2, *andQual;

qual1 = [EOQualifier qualifierWithQualifierFormat:@"lastName = 'Nunez'"];
qual2 = [EOQualifier qualifierWithQualifierFormat:@"firstName = 'Maria'"];
andQual = [[EOAndQualifier alloc] initWithQualifiers:qual1, qual2, nil];
return [guests filteredArrayUsingQualifier:andQual];

qualifiers

- (NSArray *)qualifiers

Returns the receiver's qualifiers.