So I have some code to grab an item from an index:
NSString *fullUrl = [NSString stringWithFormat:#"%#",[webView.URL absoluteURL]];
NSArray *listItems = [fullUrl componentsSeparatedByString:#"?url="];
NSString *urlString = [listItems objectAtIndex:1];
if (urlString != (id)[NSNull null]) {
NSURL *url = [NSURL URLWithString:urlString];
[[UIApplication sharedApplication] openURL:url];
} else {
//fallback just in case
[self loadBaseURL];
}
It ended up erroring on this line:
NSString *urlString = [listItems objectAtIndex:1];
Which I thought I was checking for in the following line for null. It seems like I need some check beforehand to ensure that the objectAtIndex:1 exists before grabbing it. What's the best format to write this in?
It is an error to say
[listItems objectAtIndex:1]
if there is no such index. So your first step should be to examine listItems.count. If your proposed index is greater than or equal to that number, don’t use it.
Related
I've got a small problem that seems a little bit odd to me. I often used NSString or NSLog while adding NSNumbers into several places:
NSNumber *categoryId = [[NSNumber alloc]initWithInt:0];
NSURL *url = [NSURL URLWithString:#"http://shop.rs/api/json.php?action=getCategoryByCategory&category=%i",[categoryId integerValue]];
Now xcode tells me that I'm too many arguments. What am I doing wrong? Setting up an NSNumber into NSStrings or NSLogs works as I did it above.
Best Regards
What is wrong is on
NSURL *url = [NSURL URLWithString:#"http://shop.rs/api/json.php?action=getCategoryByCategory&category=%i",[categoryId integerValue]];
you are calling URLWithString: and then pass in a string that is not being formatted correctly. If you want to do it all on one line then you need to be using stringWithFormat: like
NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:#"http://shop.rs/api/json.php?action=getCategoryByCategory&category=%i",[categoryId integerValue]]];
Because it is adding a parameter you can't just create a string like you normally would with #"some text" you need to format it using the stringWithFormat: which will return an NSString * with the text held within #"" and the paramters you pass in. So [NSString stringWithFormat:#"My String will come with %#", #"Apples"]; this would provide an NSString with "My String will come with Apples". For more information check out the Apple Documentation for NSString and stringWithFormat:
Try this :
NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:#"http://shop.rs/api/json.phpaction=getCategoryByCategory&category=%i", [categoryId integerValue]]];
Initially code was wrong because of : "categoryId integerValue]" (I forgot a '[').
You can use NSString to form your NSURL. You can then pass it to your URLWithString like below:
NSNumber *categoryId = [NSNumber numberWithInteger:0];
NSString *urlString = [NSString stringWithFormat:#"http://shop.rs/api/json.php?action=getCategoryByCategory&category=%i",[categoryId integerValue]];
NSURL *url = [NSURL URLWithString:urlString];
my url is https://photos.googleapis.com/data/upload/resumable/media/create-session/feed/api/user/111066158452258/albumid/60281009241807
i want to extract the value of user & albumid, i had tried to extract with different methods which i found in stack overflow ,but they didn't work.
Please help me out.
Thank you for your precious time.
You can take your NSURL (or init one from the URL string), and use the method pathComponents which return an array of the words in the URL (separated from the slash /), so:
pathComponents[0] == #"photos.googleapis.com"
pathComponents[1] == #"data"
...etc.
Here the snippet of code:
NSURL *url = [NSURL urlWithString:#"https://photos.googleapis.com/data/upload/resumable/media/create-session/feed/api/user/111066158452258/albumid/60281009241807"];
NSString *user = url.pathComponents[9];
NSString *album = url.pathComponents[11];
I give you an example here, NSURL class is your friend. You can use e.g. pathComponents: to get an array of all components and then process this array as you need it:
NSURL *url = [NSURL URLWithString:#"https://photos.googleapis.com/data/upload/resumable/media/create-session/feed/api/user/111066158452258/albumid/60281009241807"];
NSArray *components = [url pathComponents];
NSLog(#"path components: %#", components);
NSLog(#"user: %#", components[9]);
NSLog(#"albumid: %#", components[11]);
NSURL *url = [NSURL URLWithString:#"https://photos.googleapis.com/data/upload/resumable/media/create-session/feed/api/user/111066158452258/albumid/60281009241807"];
NSArray *pathComponentsArray = [url pathComponents];
NSString*userValue;
NSString*albumidValue;
for(int i=0;i<[pathComponentsArray count];i++)
{
if([pathComponentsArray[i] isEqualToString:#"user"])
{
userValue = pathComponentsArray[i+1];
}
if([pathComponentsArray[i] isEqualToString:#"albumid"])
{
albumidValue = pathComponentsArray[i+1];
}
}
In my app, I have a view where user have to fill a form. But, sometime the app crash here, in this function, that simple cacth the value field and built a url to give
-(NSString*)urlToUpload{
NSString *string1 =[[NSString alloc]init];
string1= [NSString stringWithFormat:#"?nombre="];
NSString *string2 = [string1 stringByAppendingString:nameAdded];
//crash here
NSString *string3 = [string2 stringByAppendingString:#"&horario="];
NSString *string4 = [string3 stringByAppendingString:horarioAdded];
NSString *string5 = [string4 stringByAppendingString:#"&info="];
NSString *string6 = [string5 stringByAppendingString:infoAdded];
NSString *string7 = [string6 stringByAppendingString:#"&offerta="];
NSString *string8 = [string7 stringByAppendingString:offertaAdded];
NSString *lat_string = [[[NSString alloc] initWithFormat:#"%f",locationToUpload2.latitude] autorelease];
NSString *lon_string = [[[NSString alloc] initWithFormat:#"%f",locationToUpload2.longitude] autorelease];
NSString *string9 = [string8 stringByAppendingString:#"&latitude="];
NSString *string10 = [string9 stringByAppendingString:lat_string];
NSString *string11 = [string10 stringByAppendingString:#"&longitude="];
NSString *string12 = [string11 stringByAppendingString:lon_string];
NSString *url1 = [NSString stringWithFormat:#"http://myserverside/mysql_up.php"];
NSString *url = [url1 stringByAppendingString:string12];
return url;
}
EDIT:
It seems problem appers on nameAdded when there is a white space into textField(i.e. MisterB not crash, Mister B yes ).
But I am using:
nameAdded =[[nameField.text stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]] stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
and NSLOg give of nameAdded is Mister%20B.
The crash still appearing...
Just use a single stringWithFormat::
- (NSString *)urlToUpload {
NSString *url = [NSString stringWithFormat:#"http://myserverside/mysql_up.php?nombre=%#&horario=%#&info=%#&offerta=%#&latitude=%f&longitude=%f",
[nameAdded stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
[horarioAdded stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
[infoAdded stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
[offertaAdded stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
locationToUpload2.latitude, locationToUpload2.longitude];
return url;
}
Make sure the referenced variables are valid.
In your original code there is no need to alloc/init an NSString then assign another string to the same variable. That's a memory leak (string1).
If you really want to structure your code the way you have it, at least use an NSMutableString and append to that one mutable string. Creating over a dozen NSString variables is the wrong way to do it.
Updated: Ensure each of the strings added to the URL are properly escaped.
It looks like nameAdded may be the cause of your problems. Is it nil at that point?
Also
You are allocating a string, setting it to string1 and then immediately setting string1 to the class function stringWithFormat which allocates another string. Also you are using stringWithFormat but you aren't using any format so you could simply use NSString *string1 = #"?nombre=";
Rather than declaring all of those variables you should just use NSMutableString and build it all in one variabl
I'm building an app that lets you call different service centers from Netherlands. The problem is that some of them have a different commercial format (like 0800-xxxx) and the device can't make the call.
The code looks like this:
if ([[UIApplication sharedApplication] canOpenURL:phoneURL]) {
[[UIApplication sharedApplication] openURL:phoneURL];
}
Do you have any idea how to format the number or to make the phone call, no matter it's format?
EDIT: This is how the phoneNumber is created:
NSString *phoneNumberString = phoneNumber; // dynamically assigned
NSString *phoneURLString = [NSString stringWithFormat:#"telprompt:%#", phoneNumberString];
NSURL *phoneURL = [NSURL URLWithString:phoneURLString];
I used this code and it worked:
NSString *cleanedString = [[phoneNumber componentsSeparatedByCharactersInSet:[[NSCharacterSet characterSetWithCharactersInString:#"0123456789-+()"] invertedSet]] componentsJoinedByString:#""];
NSString *escapedPhoneNumber = [cleanedString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSString *phoneURLString = [NSString stringWithFormat:#"telprompt:%#", escapedPhoneNumber];
NSURL *phoneURL = [NSURL URLWithString:phoneURLString];
if ([[UIApplication sharedApplication] canOpenURL:phoneURL]) {
[[UIApplication sharedApplication] openURL:phoneURL];
}
NSString *strm = (NSString *) CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)mob, NULL, CFSTR(":/?#[]#!$&’()*+,;="), kCFStringEncodingUTF8);
NSString *strMob = [[NSString alloc] initWithFormat:#"tel://%#",strm];
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:strMob]];
try this code . This works perfectly for any kind of format.It will convert into perfect calling URL .
I have a string
https://gdata.youtube.com/feeds/api/videos?q=4s-PbMuNooo
I want to get string 4s-PbMuNooo. How do I parse a NSString?
Short answer :
NSString *myString = #"https://gdata.youtube.com/feeds/api/videos?q=4s-PbMuNooo";
NSArray *components = [myString componentsSeparatedByString:#"="];
NSString *query = [components lastObject];
Problems :
1) What if the bit after the q= contains another =
2) What if the q= bit is missing?
A better answer is for you to read the documentation - there are lots of helper methods on NSString that will get you substrings. Look for rangeOfString to find out where the equals would be and subStringWithRange to get the bit you want.
EDIT: Thomas has raised a fair point about URL parsing - see his answer here
A slightly longer but more complete answer. Hope this helps:
NSURL *url = [NSURL URLWithString: #"https://gdata.youtube.com/feeds/api/videos?param1=yeah¶m2="];
NSArray *listItems = [[url query] componentsSeparatedByString:#"&"];
NSMutableDictionary *keyValues = [NSMutableDictionary dictionaryWithCapacity:listItems.count];
for (NSString *item in listItems) {
NSArray *keyValue = [item componentsSeparatedByString:#"="];
NSAssert(keyValue.count == 2, #"Key value pair mismatch");
[keyValues setObject:[keyValue objectAtIndex:1] forKey:[keyValue objectAtIndex:0]];
}
NSLog(#"1: %#", [keyValues objectForKey:#"param1"]);
NSLog(#"2: %#", [keyValues objectForKey:#"param2"]);
Like this:
NSArray *listItems = [yourString componentsSeparatedByString:#"="];
NSString *myFinalString=[NSString stringWithString:[listItems objectAtIndex:1]];
I wanted to try this a bit, so here is my code that handles more than one parameters:
NSURL *url = [NSURL URLWithString:#"https://gdata.youtube.com/feeds/api/videos?p=123123&q=234"];
NSArray *queryArray = [[url query] componentsSeparatedByString:#"&"];
for (NSString *queryString in queryArray) {
NSArray *queryComponents = [queryString componentsSeparatedByString:#"="];
if ([[queryComponents objectAtIndex:0] isEqualToString:#"q"]) {
NSLog(#"Found q: %#", [queryString substringFromIndex:2]);
} else {
NSLog(#"Did not find q.");
}
}
The question and its title are badly chosen - the answers are generally right for the more general task of splitting ANY string up, but bad for splitting up URLs as this question is actually about.
Here's how to properly get the values from a URL:
To break up a URL string, first do this:
NSURL *url = [NSURL URLWithString:urlString];
Then retrieve the parameters (the part past the "?") like this:
NSString *query = [url query];
Now you can go ahead and split that query string up using componentsSeparatedByString:#"&" as shown in the other answers.