How to make API call in UITableVIewCell - ios

Question

I have a Scenario in which I have to make a API request to update UILables in TableViewCell .
The problem is that for each cell I have to make a Unique API request. The API url is same but the parameter is different.
Currently I am making calls in cellForRowAtIndex and In success block I am using dispatch_async to update the array and reloading the UITableView.
My cellForRowAtIndexMethod :
if(!apiResponded) //Bool value to check API hasn't responded I have to make API request
{
cell.authorLabel.text = #"-------";// Set Nil
NSString *userId =[CacheHandler getUserId];
[self.handleAPI getAuthorList:userId]; //make API Call
}
else
{
cell.authorLabel.text = [authorArray objectAtIndex:indexPath.row];// authorArray is global Array
}
My success Block of API Request :
numOfCallsMade = numOfCallsMade+1; //To track how manny calls made
apiResponded = YES; // to check API is reponded and I have to update the UILables
dispatch_async(kBgQueue, ^{
if(!authorArray)
authorArray = [[NSMutableArray alloc]init];
NSArray *obj = [responseData valueForKey:#"aName"];
if(obj == nil)
{
[authorArray addObject:#"N/A"];
}
else
{
[authorArray addObject:[obj valueForKey:#"authorName"]];
}
dispatch_async(dispatch_get_main_queue(), ^{
if(numOfCallsMade == [self.mCarsArray count]) // this is to check if I have 10 rows the 10 API request is made then only update
[self.mTableView reloadData];
});
});
When I run this code I am getting Same Value for each Label. I don't know my approach is good or not. Please any one suggest how can Achieve this.

Answer 1

From your code, I’m not really sure what you want to achieve. All I know is that you want to make a request per each cell, and display received data. Now I don’t know how you’d like to store your data, or how you’ve setup things, but I’ll give you a simple suggestion of how you could set this up, and then you can modify as needed.
I assume you only need to make this request once per cell. For simplicity, we could therefore store a dictionary for the received data (author names?).
#property (nonatomic, strong) NSMutableDictionary *authorNames;
We need to instantiate it before usage, inside init or ViewDidLoad, or wherever you see fit (as long as it's before TableView calls cellForRowAtIndexPath:).
authorNames = [[NSMutableDictionary alloc] init];
Now in cellForRowAtIndexPath, you could do the following:
NSInteger index = indexPath.row
cell.authorLabel.text = nil;
cell.tag = index
NSString *authorName = authorNames[#(index)];
if (authorName) { // Check if name has already exists
cell.authorLabel.text = authorName;
} else {
// Make request here
}
In your requests completion block (inside CellForRowAtIndexPath:), you add this:
NSString *authorName = [responseData valueForKey:#“aName”];
authorNames[#(index)] = authorName; // Set the name for that index
if (cell.index == index) { // If the cell is still being used for the same index
cell.authorLabel.text = authorName;
}
When you scroll up and down in a TableView, it will reuse cell that are scrolled outside of the screen. That means that when a request has finished, the cell could have been scrolled offscreen and reused for another index. Therefore, you want to set the cell tag, and when the request has completed, check if the cell is still being used for the index you made the request for.
Potential issues: When scrolling up and down fast, when your requests are still loading, it could potentially make multiple requests for each cell. You'll have to add some way to just make each request once.

Answer 2

You can declare a method in your custom cell and then call it from cellForRowAtIndex , the method will call the API and update the label present only in that cell.
So for each cell you will have separate method calls & each success block will update the particular cell Label text only.