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objective-cnsurl

Is the | pipe character making URLWithString: fail?

I have this very simple code:

PO(URLString);
url = [NSURL URLWithString:URLString];
PO(url);
NSData * data=[NSData dataWithContentsOfURL:url];

(PO() is my macro to print stuff.)

It works most of the time. Here is the output:

2012-10-08 11:39:28.187 BadgerNew[2475:5007] <0x1f5321f0 BGCRBusinessForDisplay.m:(113)> URLString: http://id.openrice.com/UserPhoto/photo/0/U/0005Z29E131A230CBA4A42n.jpg

2012-10-08 11:39:28.193 BadgerNew[2475:5007] <0x1f5321f0 BGCRBusinessForDisplay.m:(115)> url: http://id.openrice.com/UserPhoto/photo/0/U/0005Z29E131A230CBA4A42n.jpg

2012-10-08 11:39:30.191 BadgerNew[2475:6b03] <0x1f529f00 BGCRBusinessForDisplay.m:(113)> URLString: http://maps.googleapis.com/maps/api/staticmap?&zoom=16&size=160x160&maptype=roadmap&sensor=true&center=-6.187900,106.775429&markers=size:small|color:blue|-6.187900,106.775429

2012-10-08 11:39:30.196 BadgerNew[2475:6b03] <0x1f529f00 BGCRBusinessForDisplay.m:(115)> url: (null)

As you see, it works fine for http://id.openrice.com/UserPhoto/photo/0/U/0005Z29E131A230CBA4A42n.jpg and it fails on http://maps.googleapis.com/maps/api/staticmap?&zoom=16&size=160x160&maptype=roadmap&sensor=true&center=-6.187900,106.775429&markers=size:small|color:blue|-6.187900,106.775429

Perhaps the issue is the | in the Google URL. So what should I do with it?

Solution

  • You're right, the | (the "pipe") is the problem.

    The Apple docs for URLWithString: say that the relevant external docs are RFCs 2396 and 1738. According to them, | is an "unsafe" character and must always be encoded in a URL. The encoding for it is %7C.

    You can correct the pipes in your string manually (if it is a hard-coded string), but the better solution would be to replace them and any other problematic characters using -[NSString stringByAddingPercentEscapesUsingEncoding:].