Objective-c iPhone percent encode a string?

I would like to get the percent encoded string for these specific letters, how to do that in objective-c?

Reserved characters after percent-encoding
!   *   '   (   )   ;   :   @   &   =   +   $   ,   /   ?   #   [   ]
%21 %2A %27 %28 %29 %3B %3A %40 %26 %3D %2B %24 %2C %2F %3F %23 %5B %5D

Percent-encoding wiki

Please test with this string and see if it do work:

myURL = @"someurl/somecontent"

I would like the string to look like:

myEncodedURL = @"someurl%2Fsomecontent"

I tried with the stringByAddingPercentEscapesUsingEncoding: NSASCIIStringEncoding already but it does not work, the result is still the same as the original string. Please advice.

iphone objective-c

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1 Answer

If you are using ASI HttpRequest library in your objective-c program, which I cannot recommend highly enough, then you can use the "encodeURL" helper API on its ASIFormDataRequest object. Unfortunately, the API is not static so maybe worth creating an extension using its implementation in your project.

The code, copied straight from the ASIFormDataRequest.m for encodeURL implementation, is:

- (NSString*)encodeURL:(NSString *)string
{
    NSString *newString = NSMakeCollectable([(NSString *)CFURLCreateStringByAddingPercentEscapes(kCFAllocatorDefault, (CFStringRef)string, NULL, CFSTR(":/?#[]@!$ &'()*+,;=\"<>%{}|\\^~`"), CFStringConvertNSStringEncodingToEncoding([self stringEncoding])) autorelease]);
    if (newString) {
        return newString;
    }
    return @"";
}

As you can see, it is essentially a wrapper around CFURLCreateStringByAddingPercentEscapes that takes care of all the characters that should be properly escaped.

answered 2011-09-01T16:13:00.587

Objective-c iPhone percent encode a string?

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