Changing documentInteractionController URL if app chosen is Instagram
<p>In the photo app I'm developing I've got a documentInteractionController that enables people to send the photo to various apps which works great.</p>

<p>When sending to Instagram however the image doesn't fill the square in Instagram as it's resized by Instagram, so I create a special Instagram square image for this purpose.</p>

<p>The image creation is all fine, but when I try and alter the docController.URL property after checking is they've chosen Instagram, the app crashes, with no useful error message.</p>

<p>Here's the code I'm using for switching the URL:</p>

<pre><code>- (void)documentInteractionController:(UIDocumentInteractionController *)controller willBeginSendingToApplication:(NSString *)application {

if ([application isEqualToString:@"com.burbn.instagram"]) {


    controller.URL =[self createInstagramFormatURL];

}
</code></pre>

<p>}</p>

<p>Anyone got any ideas where I'm going wrong?</p>

<p>Thanks.</p>
