check if an string matches any value in an array? - iphone

Question

Preamble: I'm working with some code I didn't write and I have next to no knowledge of iOS.
The app has a webview which handles most of the app; internal links are loaded in the webview and links to other sites are opened in Safari which is expected. However, embedding a google maps also causes safari to open. I found the relevant controller code, I think, and it looks like this:
// a bit higher up
static NSString *const siteURL = #"http://my.example.com"
if (![request.URL.absoluteString hasPrefix:siteUrl])
{
if ([[UIApplication sharedApplication] canOpenURL:request.URL])
{
[[UIApplication sharedApplication] openURL:request.URL];
}
return NO;
}
Now because 'maps.google.com' doesn't start with 'my.example.com' it farms out to safari - and that makes sense to me. However, I tried modifying this:
static NSString *const googleMaps = #"http://maps.google.com"
if (! ([request.URL.absoluteString hasPrefix:siteUrl] || [request.URL.absoluteString hasPrefix:googleMaps]))
{
if ([[UIApplication sharedApplication] canOpenURL:request.URL])
{
[[UIApplication sharedApplication] openURL:request.URL];
}
return NO;
}
This also works. But I need to add some more URLs. Is my only choice to keep adding 'or' and string constants? Or is there a way to make an array and say "if it matches any of these"? Sorry if this question seems simplistic.
In PHP I'd just do something like in_array('string', $array) as my condition, I guess I'm looking for how to do this in iOS

Answer 1

One solution would be to maintain a NSSet of objects, being all the strings that you want to be handled in your internal webview.
NSSet *internalURLSet = [NSSet setWithObjects:#"http://my.example.com", #"http://maps.google.com", nil];
Use a mutable set if you will be adding to the set over time but you will likely know which URLs you want to handle internally as soon as your app starts and this will not change. If you are adding sets as the app runs then add them to the mutable set as they become known.
When you check a URL, use [internalURLSet containsObject:urlToTest] and it will match any of the strings you have added to the set.
Checking against the set is very efficient. Adding objects to the set is less so, but you will very likely add URLs to the set only once while you check many times.
(Doing indexOfObject: against a NSArray is very inefficient...)

Answer 2

You could try using a predicate. Here's a tutorial link with an example (older, but should still work):
http://arstechnica.com/apple/2009/04/cocoa-dev-the-joy-of-nspredicates-and-matching-strings/
I do a lot of .NET development too and always miss LINQ when I go back to iOS. Predicates help a little, more lines of code but handy since you can do all kinds of searches.

Answer 3

I see your problem. In IOS, don't have a function in_array('string',$array) to check a string is contained in array.
I have a suggestion: you create a array with all urls. And implement 'for' or 'while' loop to get value of array check it. If it's same, you call function OpenUrl.

Answer 4

You could do this by creating an NSArray of your URLS and then using the indexOfObjectPassingTest: method to test your URL against each one in the array. It would go something like this:
NSArray *testURLs = #[ #"http://maps.google.com", #"http://www.example.com" ];
NSString *urlString = request.URL.absoluteString;
BOOL urlMatchedTest = NO;
for ( NSString *testURL in testURLs ) {
if [urlString hasPrefix:testURL] ) {
urlMatchedTest = YES;
}
}
if ( urlMatchedTest ){
// the url contains one of the test URLS
} else {
// it didn't match any of the test URLs
}