Loading a thumbnail image into a UITableView from JSON - ios

Question

I'm having issue trying to load a thumbnail from JSON into a UITableView cell. The cell's UI is a xib file. I'm not able to parse the thumbnail part of the JSON and display it in the table view. It's been a while since I did this (I tend to work on more games than typical iOS apps), and the last time I did it was a slightly different implementation.
JSON:
{
"data" :
[
{
"user_id" : "3",
"username" : "Alex Perez",
"avatar_url" : "http://mywebsite.com/images/alex_avatar.png",
"message" : "Hello there?"
},
{
"user_id" : "4",
"username" : "Jon Doe",
"avatar_url" : "http://mywebsite.com/images/john_avatar.png",
"message" : "I'm here now"
},
{
"user_id" : "2",
"username" : "Sam Givens",
"avatar_url" : "http://mywebsite.com/images/sam_avatar.png",
"message" : "Can we have a meeting around 2?"
},
....
And the data in the Data.h:
#import <Foundation/Foundation.h>
#interface Data : NSObject
#property (nonatomic, readwrite) int user_id;
#property (nonatomic, strong) NSString *username;
#property (nonatomic, strong) NSString *avatar_url;
#property (nonatomic, strong) NSString *message;
- (void)loadWithDictionary:(NSDictionary *)dict;
#end
Data.m:
#import "Data.h"
#implementation Data
- (void)loadWithDictionary:(NSDictionary *)dict {
self.user_id = [[dict objectForKey:#"user_id"] intValue];
self.username = [dict objectForKey:#"username"];
self.avatar_url = [dict objectForKey:#"avatar_url"];
self.message = [dict objectForKey:#"message"];
}
#end
Here is I'm running into issues when declaring the property and assigning the property to the data, so then it can then be passed to the View Controller that is going to display it. I'm getting the compiler warning Incompatible pointer types assigning to UIImage * from NSString*. I don't understand why Xcode isn't complaining about the other properties like the UILabel and the UITextView.
Cell.m
#import "Cell.h"
#interface Cell ()
#property (nonatomic) int userID;
// UIImageView property created from Interface Builder
#property (strong, nonatomic) IBOutlet UIImageView *avatarImage;
#property (nonatomic, strong) IBOutlet UILabel *usernameLabel;
#property (nonatomic, strong) IBOutlet UITextView *messageTextView;
#end
#implementation Cell
- (void)loadWithData:(Data *)data {
self.userID = data.user_id;
// Here I get "Incompatible pointer types assigning to UIImage * from NSString*
self.avatarImage.image = data.avatar_url;
self.usernameLabel.text = data.username;
self.messageTextView.text = data.message;
}
#end
Finally the MessagesViewController where it is displayed:
#interface MessagesViewController ()
#property (nonatomic, strong) IBOutlet UITableView *tableView;
#property (nonatomic, strong) NSMutableArray *loadedChatData;
#end
#implementation MessagesViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.loadedChatData = [[NSMutableArray alloc] init];
[self loadJSONData];
}
- (void)loadJSONData {
NSString *filePath = [[NSBundle mainBundle] pathForResource:#"data" ofType:#"json"];
NSError *error = nil;
NSData *rawData = [NSData dataWithContentsOfFile:filePath options:NSDataReadingMappedIfSafe error:&error];
id JSONData = [NSJSONSerialization JSONObjectWithData:rawData options:NSJSONReadingAllowFragments error:&error];
[self.loadedChatData removeAllObjects];
if ([JSONData isKindOfClass:[NSDictionary class]]) {
NSDictionary *jsonDict = (NSDictionary *)JSONData;
NSArray *loadedArray = [jsonDict objectForKey:#"data"];
if ([loadedArray isKindOfClass:[NSArray class]])
{
for (NSDictionary *chatDict in loadedArray)
{
Data *chatData = [[Data alloc] init];
[chatData loadWithDictionary:chatDict];
[self.loadedChatData addObject:chatData];
}
}
}
[self.tableView reloadData];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *cellIdentifier = #"Cell";
Cell *cell = nil;
if (cell == nil) {
NSArray *nib = [[NSBundle mainBundle] loadNibNamed:cellIdentifier owner:self options:nil];
cell = (Cell *)[nib objectAtIndex:0];
}
Data *data = [self.loadedChatData objectAtIndex:[indexPath row]];
[cell loadWithData:data];
return cell;
}

Answer 1

U have to modify the error line and use it as :
self.avatarImage.image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:data.avatar_url]]];

Answer 2

Create a custom class for the nib and then place the certain code in it to load the image from direct URL ... this works
var stringUrl = "http://mywebsite.com/images/alex_avatar.png"
var url: NSURL = NSURL(string: stringUrl)!;
self.imageView1.sd_setImageWithURL(url, placeholderImage: UIImage(named: "no_image_small.png"));

Answer 3

Try the Below code, it may help you.
NSURL *url = [NSURL URLWithString:#"http://mywebsite.com/images/alex_avatar.png"];
UIImage *thumbnail = [UIImage imageWithData: [NSData dataWithContentsOfURL:url]];
if (thumbnail == nil) {
thumbnail = [UIImage imageNamed:#"noimage.jpg"] ; //if no image get from url mean show a dummy one
}
CGSize itemSize = CGSizeMake(80, 80); //your own size can replace with 80
UIGraphicsBeginImageContext(itemSize);
CGRect imageRect = CGRectMake(0.0, 0.0, itemSize.width, itemSize.height);
[thumbnail drawInRect:imageRect];
cell.thumbnailImageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();