Not able to compare responseString in objective c - objective-c

NSString *responseString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSLog(#"the response string is %#",responseString);
if ([responseString isEqualToString:#"No Data Available"] )
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Message"
message:#"No data Avilable in server"delegate:self cancelButtonTitle:nil otherButtonTitles:
#"OK", nil];
[alert show];
[alert release];
}
in my connectiondidfinishloadin delegate method i have the above code. when the server replies there is no data , it does not go into the if loop for some reason. not sure why. any hint will be greatly appreciated.
Thank You.

ResponseString is probably null/nil and runtime knows that that if statement will b false because of this, so skips it. You should see this with your NSLog(#"the response string is %#",responseString);
On a side note, Charles is a good debugging tool for this- you can see the http info as it goes out and comes in.

Related

No visible #interface for 'UIAlertView' declares the selector :NSString stringWithUTF8String

i have an error which i donno how to fix it it's making me crazy. i have searched about the solution a lot but didn't find anything which works here .
here is the code and you can see the error in the picture .
thanks
UIAlertView *alert = [[UIAlertView alloc]
initWithTitle:[NSString stringWithUTF8String:title]
message:[NSString stringWithUTF8String:body]
delegate:nil
cancleButtonTitle:[NSString stringWithUTF8String:cancleLable]
otherButtonTitles:[NSString stringWithUTF8String:firstLable],
[NSString stringWithUTF8String:secondLable], nil];
[alert show];

CloudKit Query Time

I've just started trialling CloudKit and am having some pretty slow query times. Here is some sample code I am using:
//CLOUDKIT
CKContainer *container = [CKContainer defaultContainer];
CKDatabase *privateDatabase = [container privateCloudDatabase];
NSPredicate *predicate = [NSPredicate predicateWithFormat:#"TRUEPREDICATE"];
CKQuery *query = [[CKQuery alloc] initWithRecordType:#"FlightLog" predicate:predicate];
[privateDatabase performQuery:query inZoneWithID:nil completionHandler:^(NSArray *results, NSError *error) {
//SUCCESS
if (!error)
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"SUCCESS" message:#"IT WORKED" delegate:self cancelButtonTitle:#"dismiss" otherButtonTitles:nil];
[alert show];
NSLog(#"%#", #"fetchFlights success!");
NSLog(#"%#", self.fetchedRecords);
self.fetchedRecords = results;
[self.tableView reloadData];
}
//ERROR
else
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"error" message:error.localizedDescription delegate:self cancelButtonTitle:#"dismiss" otherButtonTitles:nil];
[alert show];
NSLog(#"%#", error);
}
}];
I get the private database, and query for all records. There is just four simple ones I added in the dashboard.
Upon calling this code, I can see from my console log that the success message gets called almost immediately, with a null results array. Then moments later, the results are returned, as seen in the log. However, the alert view isn't shown and results displayed in my table for about 3-4 more seconds.
What's going on?
This is resolved. As Edwin mentions, I didn't know that the callback is on a background thread. So when I call [self.tableView reloadData] in the completion block, it is also running on the background thread.
By putting it back on the main thread, the table view reloads within about a second. Vs taking about 4-5 seconds if running on the same thread as the callback.
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
dispatch_async(dispatch_get_main_queue(), ^{
[self.tableView reloadData];
});
});
Let me know if I have misunderstood, but I think that's what has happened.

Randomizing Alert view text for Objective C

I am new to programming. I am having trouble finding out what all is wrong with this. It is an alert view that i am trying to randomize the text displayed in the message.
-(void)alert:(id)sender{
int randomNumber;
randomNumber = (randomNumber() %3 + 1);
NSLog(#"%i", randomNumber);
if (randomNumber == 1) {
self.YouWin.text = [NSString stringWithFormat:#"You Win"];
}
else if (randomNumber == 2) {
self.YouWin.text = [NSString stringWithFormat:#"You Lose"];
}
else if (randomNumber == 3) {
self.YouWin.text = [NSString stringWithFormat:#"Tie"];
}
NSLog(#"%#",YouWin);
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Hello" message:[NSString stringWithFormat:#"%#",YouWin] delegate:self cancelButtonTitle:#"Ok" otherButtonTitles: nil];
[alert show];
button.hidden = YES;
Try this one:
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Hello"
message:self.YouWin.text
delegate:self
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
You needed text-value stored in YouWin, but you passed the YouWin object itself.
*Note: you can use arc4random() for generating random numbers.
There are many good suggestions; I agree with AKB8085.
Replacing the randomNumber() with arc4random() will help at compile time.
But you might want to re-think implementing a random number generator. The reason is in fairness to your user. I pose the question, “Is it fair to assume you want your user to guess a number with this large of a number range?”
Did you Know?
Using the arc4random(3), rand(3), or random(3) you are using a C function.
You are asking the user to guess a number with the following ranges:
arc4random(3) = 0 to 4294967296
rand(3) and random(3) that top out at a RAND_MAX of 0x7fffffff (214748647)
To help in answering your question, answer the following requirement questions:
Is there a min/max range restraint?
What type of compelling delays will happen
by using arc4random(3), rand(3), or random(3)?
Is using NSArray like in the Fisher–Yates_shuffle a better answer?
SUGGESTION:
Read an article on random numbers and NSArray.
NOTE:
Random numbers tend to task the compiler and your user experience will be hindered.
As Anoop noted you are using stringWithFormat but you're not providing a format string at all.
You should do
[NSString stringWithFormat:#"%#", #"You Win"];
but that's extremely redundant, although correct, and it's totally equivalent to just using #"You Win".
Also an advice for the general approach on the problem. Instead of having a big if-else statement, it's better to store all your string into a data structure and then randomly access to it.
In code this would translate to
NSArray * outcomes = #[ #"You Win", #"You lose", #"Tie" ];
int randomIndex = arc4random_uniform(outcomes.count);
NSString * randomOutcome = outcomes[randomIndex];
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Hello"
message:randomOutcome
delegate:self
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
[alert show];
button.hidden = YES;
Note the usage of arc4random_uniform() that gives you back a random number between 0 and the argument provided, excluded.
Replace
randomNumber = (randomNumber() %3 + 1);
with
randomNumber = arc4random() %3 + 1;
Also use this...
if (randomNumber == 1) {
self.YouWin.text = [NSString stringWithFormat:#"You Win"];
}
else if (randomNumber == 2) {
self.YouWin.text = [NSString stringWithFormat:#"You Lose"];
}
else if (randomNumber == 3) {
self.YouWin.text = [NSString stringWithFormat:#"Tie"];
}
NSLog(#"%#",YouWin);
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Hello"
message:self.YouWin.text
delegate:self
cancelButtonTitle:#"Ok"
otherButtonTitles:nil];
[alert show];
button.hidden = YES;

How to directly return to rootViewController? UIStoryboard (or update tableview)

There are some questions I have found but the answers don't work with my code, therefore I ask a question of my own.
My objective is reloading a table view from a detailviewcontroller. I tap a cell, go to the detail and when I return to the table I want it updated. The thing is it doesn't update. So I decided it would be better to go back to the rootviewcontroller when certain thing happens on the detailviewcontroller but it still didn't work.
I am open to suggestions and advice feel free to comment!!
I download a video and when the video is downloaded I update the tableView.
Here is the code I am using:
I use MKNetworkKit btw.
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *cachesDirectory = [paths objectAtIndex:0];
NSString *downloadPath = [cachesDirectory stringByAppendingPathComponent:videoName];
self.downloadOperation = [ApplicationDelegate.mainDownloader downloadVideoFrom:finalAddress
toFile:downloadPath];
[self.downloadOperation onDownloadProgressChanged:^(double progress) {
//DLog(#"%.2f", progress*100.0);
//self.downloadProgressBar.progress = progress;
}];
[self.downloadOperation onCompletion:^(MKNetworkOperation* completedRequest) {
//THIS DOES NOT WORK, dismissModalViewControllerAnimated.
[[ApplicationDelegate.window rootViewController] dismissModalViewControllerAnimated:YES];
DLog(#"COMPLETED REQUEST: %#", completedRequest);
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:#"Download completed"
message:#"The file is in your photo and video Library"
delegate:nil
cancelButtonTitle:NSLocalizedString(#"Thank you WebSurg!!", #"")
otherButtonTitles:nil];
[alert show];
// THIS IS WHAT I PREVIOUSLY TRIED.
// NSDictionary *tableSecData = ApplicationDelegate.videoLibraryController.tableSectionData;
// NSMutableArray *tempValuesDownloaded = [tableSecData objectForKey:#"Downloaded videos"];
// NSMutableArray *tempValuesUndownloaded = [tableSecData objectForKey:#"Undownloaded videos"];
// for (NSArray *videoArray in tempValuesUndownloaded) {
// if ([[videoArray objectAtIndex:0] isEqualToString:self.videoDetailTitle.text]) {
// [tempValuesUndownloaded removeObject:videoArray];
// [tempValuesDownloaded addObject:videoArray];
// }
// }
// [ApplicationDelegate.videoLibraryController.tableSectionData removeAllObjects];
// ApplicationDelegate.videoLibraryController.tableSectionData = [NSMutableDictionary dictionaryWithObjectsAndKeys:tempValuesDownloaded, #"Downloaded videos", tempValuesUndownloaded, #"Undownloaded videos", nil];
// [ApplicationDelegate.videoLibraryController.mainTableView reloadData];
}
onError:^(NSError* error) {
DLog(#"%#", error);
[[[UIAlertView alloc] initWithTitle:#"Download failed" message:#"The download failed because of a connection error please try again" delegate:nil cancelButtonTitle:NSLocalizedString(#"Dismiss", #"") otherButtonTitles:nil] show];
}];
} else {
UIAlertView *failureAlert=[[UIAlertView alloc] initWithTitle:#"Download status" message:#"Download failed, not enough free space." delegate:self cancelButtonTitle:#"Ok" otherButtonTitles:nil, nil, nil];
[failureAlert show];
}

No object pairs in plist reading data from a server

I am trying to read a plist from a server. I know for a fact that the plist is valid since when I go to the URL i get the plist downloaded and the plist editor shows me my array properly. Now when I use the following code I get now array populated. I see the data is in there. In debugger i see that plistData has value however the array petListArray has no data at all. What is wrong?
- (void)getPetListRequestFinished:(ASIHTTPRequest *)request
{
NSData *plistData = [request responseData];
NSError *error = nil;
NSPropertyListFormat format = NSPropertyListBinaryFormat_v1_0;
NSArray *petListArray = (NSArray *)[NSPropertyListSerialization propertyListWithData:plistData
options:(NSPropertyListReadOptions)NSPropertyListImmutable format:&format error:(NSError **)error];
if(error){
UIAlertView * alert = [[UIAlertView alloc] initWithTitle:#"GetPetListError" message:[NSString stringWithFormat:#"getPettListRequestFinished_new deserialization error: error = %#", error]
delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil];
[alert show];
[alert release];
return;
}
----snip-------
You are passing the wrong type of argument for the error: slot of - NSPropertyListSerialization propertyListWithData:options:format:error:. Try:
[NSPropertyListSerialization propertyListWithData: plistData
options: (NSPropertyListReadOptions) NSPropertyListImmutable
format: &format
error: &error]
(edited after checking docs)