Question

I have a @property listOfSites declared in a class. I am unable to access listOfSites from another class, even tho’ I have done an #import of that class’ .h file. All I did was change an instance of the listOfSites to a property.

This is the code from another class (slTableViewController) where I send message to get listOfSites:

- (void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    if([[segue identifier] isEqualToString:@"viewSitesSegue"])  {
        NSLog(@"viewSitesSegue");

        //  get list of sites
        slSQLite *dbCode = [[slSQLite alloc] init];
        [dbCode getListOfSites];

        //  put site data into array for display
        slSQLite *item = [[slSQLite alloc] init];
        NSLog(@"\n2-The array listOfSites contains %d items", item.listOfSites.count);

Here is the code for listOfSites:

-  (void) getListOfSites {

    FMDatabase *fmdb = [FMDatabase databaseWithPath:databasePath];  // instantiate d/b
    if(![fmdb open])  {
        NSLog(@"\nFailed to open database");
        return;
    }

    NSMutableArray *listOfSites = [[NSMutableArray alloc] init];

    FMResultSet *rs = [fmdb executeQuery: @"SELECT SITE_ID, SITE_DESC, DATE FROM SiteData WHERE SITE_ID <> '0'"];
    while([rs next])  {
        sArray *sa = [[sArray alloc] init];
        sa.sSiteID = [rs stringForColumnIndex:0];
        sa.sJobDesc = [rs stringForColumnIndex:1];
        sa.sJobDate = [rs stringForColumnIndex:2];

        [listOfSites addObject:sa];  //  add class object to array
    }

    NSLog(@"\nThe array listOfSites contains %d items", listOfSites.count);

    [fmdb close];
}

Answer 1

To be able to access listOfSites from other classes, you need to make it a property of that class:

In the MyClass.h file

@interface MyClass : NSObject

// ...

@property (strong, nonatomic) NSMutableArray *listOfSites;

// ...

@end

Then you have to synthesize in the MyClass.m file

@interface MyClass

@synthesize listOfSites;

// ...

@end

Now, if you import MyClass.h in another class, then you can access the property listOfSites. For example in another file OtherClass.m:

#import "MyClass.h"

// ...

- (void)someMethod {
    MyClass *item = [[MyClass alloc] init];
    item.listOfSites = [[NSMutableArray alloc] init];
    // ...
}

---

You are making many mistakes in the posted code. (Even assuming you correctly declared listOfSites as a property).

First, change the line:

NSMutableArray *listOfSites = [[NSMutableArray alloc] init];

into:

listOfSites = [[NSMutableArray alloc] init];

Second, in the following lines:

slSQLite *dbCode = [[slSQLite alloc] init]; // Create an object
[dbCode getListOfSites]; // Generate the content of listOfSites

//  put site data into array for display
slSQLite *item = [[slSQLite alloc] init]; // Create another object
NSLog(@"\n2-The array listOfSites contains %d items", item.listOfSites.count); // Log the length of listOfSites in this new object

you are generating the content of listOfSites for the object dbCode, and checking the length of listOfSites in item which is a different object and for which you didn’t generate the content of listOfSites.

Try the following instead:

slSQLite *dbCode = [[slSQLite alloc] init]; // Create an object
[dbCode getListOfSites]; // Generate the content of listOfSites
NSLog(@"\n2-The array listOfSites contains %d items", dbCode.listOfSites.count); // Log the length of listOfSites in dbCode