OpenStep 4.2J (Developer)/os42jdev.iso/NextDeveloper/OpenStepConversion/3.3Headers/eoaccess/EOGenericRecord.h

Text File | 1994-12-06 | 3.5 KB | 89 lines

// EOGenericRecord.h
// Copyright (c) 1994, NeXT Computer, Inc. All rights reserved.

#import    "EOKeyValueCoding.h"

#import <foundation/NSArray.h>
#import <foundation/NSData.h>
#import <foundation/NSDictionary.h>
#import <foundation/NSObject.h>
#import <foundation/NSString.h>

@class EOEntity;

// The EOEntityMapping protocol defines the only method that must be
// implemented on classes which manage their own class to entity mapping.  EOF
// must be able to determine an entity for every enterprise object it creates.
// This is normally accomplished by examining the model.  The EOEntityMapping
// protocol provides an opportunity for classes to implement their own
// mapping.  The entity mapping must not change during the life of the object.
// It must also be the entity that was specifed when the object was created.

@interface NSObject (EOEntityMapping)
- (EOEntity *)entity;
    // Returns the entity with which the receiver is associated.
@end

// The EOClassMapping protocol defines a class method that allows a class
// specified by a particular entity to substitute a different class based on
// it's fetched row or primary key values.  Note that the returned class MUST
// be either a sublass of the original class, have an entity specified in the
// model, or implement the EOEntityMapping informal protocol.  This
// requirement is not checked, but will cause insert, deletes, and updates to
// fail if not met.  If row is nil then a new object is being created,
// probably for insertion.

// The method is called in three situations.
// 1. When a row is fetched.  values will be the fetched row
// 2.  When an object is created by a data source, usually for insertion.
// values will be nil.
// 3.  When an fault creates it's underlying object.  values will be the
// object's primary key.

@interface NSObject (EOClassMapping)
+ (Class)classForEntity:(EOEntity *)entity values:(NSDictionary *)values;
@end

// This informal protocol defines the initialization method which may be
// implemented by enterprise objects.  If this method is not implemented by
// an enterprise object init is used.  The dictionary supplied contains the
// value of the primary key associated with the enterprise object.

@interface NSObject (EOInitialization)
- initWithPrimaryKey:(NSDictionary *)key entity:(EOEntity *)entity;
    // Initializes a newly allocated Enterprise Object.
@end


// EOGenericRecords are associated with EOEntities for which you haven't
// defined custom Enterprise Object classes.  When a record from the entity's
// table is fetched by an database-layer object, an EOGenericRecord is
// instantiated and filled with the data from the row.  Any other enterprise
// object class is uniquely associated with an EOEntity object in a given
// EOModel.  Since EOGenericRecords need to be used for any entity, an
// EOGenericRecord holds the entity with which it's associated.

@interface EOGenericRecord:NSObject
{
    EOEntity *entity;
    NSMutableDictionary *dictionary;
}

- initWithPrimaryKey:(NSDictionary *)key entity:(EOEntity *)entity;
    // Initializes a newly allocated EOGenericRecord, associating it with
    // entity.

- (BOOL)takeValuesFromDictionary:(NSDictionary *)dictionary;
- (NSDictionary *)valuesForKeys:(NSArray *)keys;
    // These are the standard methods for getting data into and out of
    // Enterprise Objects.  See EOKeyValueCoding.h.

- (void)setObject:object forKey:(NSString *)key;
- objectForKey:(NSString *)key;
- (void)removeObjectForKey:(NSString *)key;
    // These are convenience methods for accessing single key-value pairs.

- (EOEntity *)entity;
@end