Image is not fetching from database

Question

I stored some images in my server. I used JSON for fetch remote data from server. When i was storing images in local database it was working. When i use json url it's not working. Im getting EXC_BAD_ACCESS error.

code:

Mysof.h file:

@interface Mysof : NSObject{
    NSInteger sofaId;
    NSString *sofa;
    NSString *rating;
    UIImage *photo;
}

@property (nonatomic,retain)NSString *sofa;
@property (nonatomic, assign) NSInteger sofaId;
@property (nonatomic, retain)NSString *rating;
@property (nonatomic, retain) UIImage *photo;

@end

Mysof.m file:

@implementation Mysof

@synthesize sofId;
@synthesize sofa;
@synthesize rating;
@synthesize photo;

@end

Sofalistsql.h file:

@interface Sofalistsql : NSObject

{
    sqlite3 *db;
}

- (NSMutableArray *) getMysofas;

@end

.m file:

 @implementation Sofalistsql

    - (NSMutableArray *) getMysofas{


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

    NSFileManager *fileMgr = [NSFileManager defaultManager];
    NSError *err;

    NSString *bundlePath = [[NSBundle mainBundle] pathForResource:@"Empty" ofType:@"sqlite"];
    //NSLog(@"bundlePath %@", bundlePath);


    //call update function to check any data updated,
    //if there is a version difference
    //update the data base with all the required fileds.



    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    //NSLog(@"docs dir is %@", documentsDirectory);

    NSString *appFile = [documentsDirectory stringByAppendingPathComponent:@"App6.sqlite"];

    [fileMgr copyItemAtPath:bundlePath toPath:appFile error:&err];


    NSURL *URL = [NSURL URLWithString:@"http://server.net/projects/mobile/jsonstring.php"];

    NSLog(@"URL is %@", URL);


     NSError *error;
     NSString *stringFromFileAtURL = [[NSString alloc]
     initWithContentsOfURL:URL
     encoding:NSUTF8StringEncoding
     error:&error];

     //NSLog(@"response is %@", stringFromFileAtURL);

     NSString *path = [documentsDirectory stringByAppendingPathComponent:@"App6.sqlite"];


     NSArray *userData = [stringFromFileAtURL JSONValue];

     // NSArray *skarray = [[NSArray alloc]init];



    NSLog(@"userdata is %@", userData);

   // int  i = 0;
    BOOL notExist = TRUE;


     for (NSArray *skarray in userData) {

     for (NSDictionary *tuser in skarray) {


           //if already exists in data base id then overwrite the name 

         if (sqlite3_open([path UTF8String], &db) == SQLITE_OK) {


      const char *sql = [[NSString stringWithFormat:@"SELECT id FROM categories where id = '%@'",[tuser objectForKey:@"id"]] cStringUsingEncoding:NSUTF8StringEncoding];     

     //NSLog(@"check stmt is %s", sql);

     sqlite3_stmt *sqlStatement,*addStmt;

     if (sqlite3_prepare_v2(db, sql, -1, &sqlStatement, NULL) == SQLITE_OK) {

       notExist = TRUE;

     while (sqlite3_step(sqlStatement) == SQLITE_ROW) {

        notExist = FALSE;


     Mysof *Mylist = [[Mysof alloc]init];
     Mylist.sofaId = sqlite3_column_int(sqlStatement, 0);
     Mylist.sofa = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement,1)];
     Mylist.rating = [NSString stringWithUTF8String:(char *) sqlite3_column_text(sqlStatement, 2)];
     const char *raw = sqlite3_column_blob(sqlStatement, 3);
     int rawLen = sqlite3_column_bytes(sqlStatement, 3);
     NSData *data = [NSData dataWithBytes:raw length:rawLen];
     Mylist.photo = [[UIImage alloc] initWithData:data];
     [sofArray addObject:Mylist];



     }

         if(notExist){
             //NSLog(@"cat id does not exist");

             const char *sqlInsert = [[NSString stringWithFormat:@"insert into categories (id, cat_name,order_by) values ('%@', '%@', '%@')", [tuser objectForKey:@"id"], [tuser objectForKey:@"cat_name"],[tuser objectForKey:@"order_by"]] cStringUsingEncoding:NSUTF8StringEncoding];
             //NSLog(@"stmt is %s", sqlInsert);

             if(sqlite3_prepare_v2(db, sqlInsert, -1, &addStmt, NULL) != SQLITE_OK)
                 NSAssert1(0, @"Error while creating add statement. '%s'", sqlite3_errmsg(db));

             if(SQLITE_DONE != sqlite3_step(addStmt))
                 NSAssert1(0, @"Error while inserting data. '%s'", sqlite3_errmsg(db));

         }


     }

     }

     }

     }

    return sofArray;


}

   @end

In viewController.m file:

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.


    Sofalistsql * mysofs =[[Sofalistsql alloc] init];
    self.sofas = [mysofs getMysofas];



}

Button click to display images from server:

-(void)click:(id)sender{


 scrollview=[[UIScrollView alloc]initWithFrame:CGRectMake(0,500,320,200)];

        scrollview.showsVerticalScrollIndicator=NO;
          scrollview.showsHorizontalScrollIndicator=NO;

      scrollview.scrollEnabled=YES;

        int Width = 0;      

     //   Width = Width + 20+(i*74);


  for (int i = 0; i<[self.sofas count]; i++ ) {
            NSLog(@"index %d",i);



          //  imgView1=[[UIButton alloc]initWithFrame:CGRectMake(20+(i*74), 500, 72, 72)];

            imgView1=[[UIButton alloc]initWithFrame:CGRectMake(20+(i*74), 0, 72, 72)];

            Width = Width + 20+(i*74);

            [imgView1 setTag:i+1];

            [imgView1 addTarget:self action:@selector(dbsofaClicked:) forControlEvents:UIControlEventTouchUpInside];

            [imgView1 setImage:((Mysof *)[self.sofas objectAtIndex:i]).photo forState:UIControlStateNormal];

            [scrollview addSubview:imgView1];

          //  [myScroll addSubview:imgView1];



        }

        [scrollview setContentSize:CGSizeMake(Width,imgView1.frame.size.height+20)];

        [self.view addSubview:scrollview];



}

jsonstring.php file:

<?php 
    require_once('database_connection.php');
    $i = 0;
    $j = 0;
    $k = 0;
    $l = 0;
    mysql_query('SET CHARACTER SET utf8') or die("MYSQL character set error: ".mysql_error());
    $result = array();
        $sql=mysql_query("SELECT * FROM categories ORDER BY id ASC") or die(mysql_error());
        if(mysql_num_rows($sql) > 0) {
            while($res=mysql_fetch_array($sql, MYSQL_ASSOC)){
                $result[0][$i] = $res;

                $art_sql=mysql_query("SELECT * FROM product WHERE cat_id=" .$res['id']. " ORDER BY id ASC") or die(mysql_error());
                if (mysql_num_rows($art_sql) > 0){
                    while($art_res=mysql_fetch_array($art_sql, MYSQL_ASSOC)){
                        //$art_res['art_details'] = (utf8_encode(htmlentities($art_res['art_details'])));
                        //$art_res['art_details'] = htmlentities($art_res['art_details']);
                        //echo $art_res['art_details'];
                        $result[1][$k] = $art_res;
                        //print_r($art_res);    
                        $k = $k+1;  
                    }   
                }
                $i= $i+1;
            }
            $version_sql = mysql_query("SELECT * FROM version_app order by product_id desc limit 1") or die(mysql_error());
            $row = mysql_fetch_array($version_sql);
            $last_version = $row['product_id'];
            $result['2'][$l] = array('product_id' => $last_version);
            $l = $l+1;
        }


        /*echo "<pre>";
            print_r($result);
        echo "</pre>";exit;*/

    $str_enc = json_encode($result);
    //print_r($str_enc); exit;
    $str=str_replace('\r','',$str_enc);
    $str=str_replace('\t','',$str);
    $str=str_replace('\n','',$str);
    $str = stripslashes($str);
    //$str_renc = json_encode(json_decode($str));

    echo $str;

mysql_close();
?>

NSLog:

userdata is (
        (
                {
            "cat_name" = Table1;
            id = 1;
            "order_by" = 1;
        },
                {
            "cat_name" = Table2;
            id = 2;
            "order_by" = 2;
        },
                {
            "cat_name" = test;
            id = 3;
            "order_by" = 3;
        }
    ),
        (
                {
            "cat_id" = 1;
            id = 2;
            "order_by" = 1;
            "product_image" = "img.png";
        },
                {
            "cat_id" = 1;
            id = 3;
            "order_by" = 2;
            "product_image" = "img1.png";
        },
                {
            "cat_id" = 1;
            id = 4;
            "order_by" = 3;
            "product_image" = "img2.png";
        },
                {
            "cat_id" = 1;
            id = 5;
            "order_by" = 4;
            "product_image" = "img3.png";
        },
                {
            "cat_id" = 1;
            id = 6;
            "order_by" = 5;
            "product_image" = "img4.png";
        },
                {
            "cat_id" = 1;
            id = 7;
            "order_by" = 6;
            "product_image" = "img5.png";
        },

    )
)


array (
)
2013-08-16 13:19:53.044 App[3395:c07] scroll is <UIScrollView: 0x9de7cb0; frame = (0 300; 320 200); clipsToBounds = YES; gestureRecognizers = <NSArray: 0x9de60e0>; layer = <CALayer: 0x9de4bc0>; contentOffset: {0, 0}>

I stored same Table name in local database. And used overwrite database. In local database i stored images in BLOB type. But in my array i got nothing displaying. App is working. But images are not displaying from database.

Answer 1

Now that you've included your JSON sample, I can see another problem: Your JSON is an array of three arrays, an array of categories, an array of products, and an array of versions. That is a questionable structure (usually an array would be of homogeneous items of the same type). Rather than an array of arrays, I'd make it a dictionary of arrays.

This confusing structure in your JSON manifests itself in your Objective-C code. You're trying to iterate through the userdata array, but you can't, because each of the three item is different.

So let me suggest two possible fixes. First you if you stick with your array of arrays (which I'm not crazy about), you cannot iterate through that array with a for loop, but you could extract the three arrays it contains like so:

NSArray *categories = userdata[0];
NSArray *products = userdata[1];
NSArray *versions = userdata[2];

Now you can iterate through each of those three arrays.

Personally, I'd take this a step further and change that PHP that generates the JSON to generate a top level dictionary, e.g.

<?php 
    require_once('database_connection.php');
    $i = 0;
    $j = 0;
    $k = 0;
    $l = 0;
    mysql_query('SET CHARACTER SET utf8') or die("MYSQL character set error: ".mysql_error());
    $result = array();
        $sql=mysql_query("SELECT * FROM categories ORDER BY id ASC") or die(mysql_error());
        if(mysql_num_rows($sql) > 0) {
            while($res=mysql_fetch_array($sql, MYSQL_ASSOC)){
                $result['categories'][$i] = $res;

                $art_sql=mysql_query("SELECT * FROM product WHERE cat_id=" .$res['id']. " ORDER BY id ASC") or die(mysql_error());
                if (mysql_num_rows($art_sql) > 0){
                    while($art_res=mysql_fetch_array($art_sql, MYSQL_ASSOC)){
                        $result['products'][$k] = $art_res;
                        $k = $k+1;  
                    }   
                }
                $i= $i+1;
            }
            $version_sql = mysql_query("SELECT * FROM version_app order by product_id desc limit 1") or die(mysql_error());
            $row = mysql_fetch_array($version_sql);
            $last_version = $row['product_id'];
            $result['versions'][$l] = array('product_id' => $last_version);
            $l = $l+1;
        }

    $str_enc = json_encode($result);

    // note, these str_replace lines are not needed

    // $str=str_replace('\r','',$str_enc);
    // $str=str_replace('\t','',$str);
    // $str=str_replace('\n','',$str);

    // this stripslashes is a really bad idea, though

    // $str = stripslashes($str);

    // you echoed `$str`, but I'll obviously echo @str_enc    
    echo $str_enc;

    mysql_close();
?>

And if you did that, you could then retrieve your three arrays with

NSArray *categories = userdata[@"categories"];
NSArray *products = userdata[@"products"];
NSArray *versions = userdata[@"versions"];

It's not a mission critical change, but it's a more logical representation for three heterogeneous items. But the idea is the same: Extract your three arrays from your JSON, and now you can iterate through them, respectively.

---

A couple of SQLite-related issues leap out at me

1. One issue is that you have a line of SQL that says:

   SELECT id FROM categories where cat_id = '%@'
   

   But you then proceed to try to read four columns worth of data (even though you only returned one). And even if you changed your SQL to actually return four columns of data, you should really check the sqlite3_column_blob and sqlite3_column_bytes calls to make sure there was something to populate the NSData.

   As an aside, it's generally safer to not use stringWithFormat when building a SQL statement, but rather use ? placeholders instead of printf-formatters and then use sqlite3_bind_xxx functions.

2. You getMysofas is repeatedly opening the database, but never closing it. Have one sqlite3_close for every sqlite3_open call. Likewise, you should have one sqlite3_finalize statement for each sqlite3_prepare_v2 line.

---

Beyond that you have to identify the source of the crash by either using an exception breakpoint, single-stepping through this code in the debugger, or putting a bunch of NSLog statements in there. See Ray Wenderlich's series My App Crashed, Now What?. But you really need to identify the line of code that is causing the problem.