Save instance of an class in another class objective-c

Question

In a class I am establishing a database connection with fmdb

Something like (pseudo code):

// someClass.m
- (void)sameDatabase:(NSString *)database{
    if (database is the same as before)
    {
        // call method and access reference previously saved in class (someClass) in else statement
    } else {
        ...
        [database open]; //FMDB
        // save reference to database in class (someClass)
        // call method and access reference saved in class (someClass)
    }

How would I save the reference to database in the class?

Answer 1

Store the reference in a data member. In Objective-C, this would be something like the following. I’m using a class name of SomeClass and assuming that FMDatabase has a name member.

// someClass.m

@interface SomeClass () // In the .m file, this is for defining private members
{
    FMDatabase* _database; // Convention is to have private data start with _
}
@end

@implementation SomeClass

- (void)sameDatabase:(NSString *)database 
    if ([_database.databasePath isEqualToString:database]) {
        // call method and access reference previously saved in class (someClass) in else statement
    } else {
        ...
        // I can't say what this line should be, so I just used your code.
        // It would depend on the database you are using.
       _database = [FMDatabase databaseWithPath: database];
       [_database open];
    }
}

@end