So basically I now have a root UIViewController which has a UINavigationController as a subview; this, in turn, loads a number of UIViewControllers to navigate my items hierarchy.

Today, while working on cosmestic/usability improvements, I realised that something was definitely not working. When moving back and forth in my items, data were not refreshed. This pointed to one culprit, viewWillAppear not being called in the UIViewControllers.

After some googling I found out that if you add a UINavigationController as a subview of a UIViewController subclass, you must explicitly call its viewWillAppear method from its container; otherwise, they won’t be called, and when moving back and forth in the navigation tree, your UIViewControllers’ viewWillAppear: methods won’t be called.

It’s quite simple; assuming that projectNavigationController is a navigation controller added as a a subview of this UIViewController subclass, just make sure you add this simple call:

-(void)viewWillAppear:(BOOL)animated { 
	[super viewWillAppear:animated];
	[projectNavigationController viewWillAppear:animated];
}

Of course the same applies to your other viewWill/Did methods

-(void)viewWillDisappear:(BOOL)animated { 
	[super viewWillDisappear:animated];
	[projectNavigationController viewWillDisappear:animated];
}
-(void)viewDidAppear:(BOOL)animated { 
	[super viewDidAppear:animated];
	[projectNavigationController viewDidAppear:animated];
}
-(void)viewDidDisappear:(BOOL)animated { 
	[super viewDidDisappear:animated];
	[projectNavigationController viewDidDisappear:animated];
}

It’s quite simple, but wasn’t obvious for me at first.

Question

How do I send a tabular report via e-mail in the iPhone SDK?

Short answer

Use a mailto url + stringByAddingPercentEscapesUsingEncoding + HTML.

Longer answer

So far (iPhone OS 2.2) the de facto way to send e-mail on your iPhone application is using a mailto url.²

NSURL *url = [[NSURL alloc] initWithString:
@"mailto:me@me.com?subject=subject&body=Hi"];
[[UIApplication sharedApplication] openURL:url];

Of course you can use a format to include your own dynamic text, but the url string must be url escaped. Cocoa(Touch) provides a nice way to escape URLs, stringByAddingPercentEscapesUsingEncoding:

NSString *encodedBody = [eMailBody stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

The only problem left was representing tabular data. At first I though I’d use \t to create tabs, but I found out they’re not properly supported in e-mail bodies. Then a discussion on the Google Groups gave me the hint, the body parameter of mailto is actually parsed as HTML.
So, amazing as it seems, this code works:

NSString *eMailBody = @"<table>
<tr><td style='text-align:right'><b>Name</b>:</td>
<td>John</td></tr><tr>
<td style='text-align:right'><b>Surname</b>:</td><td>Doe</td></tr>
<tr><td style='text-align:right'>
 <b>Occupation:<b/></td><td>Placeholder</td></tr></table>";
NSString *encodedBody = 
[eMailBody stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; 
NSString *urlString = 
[NSString stringWithFormat:@"mailto:me@me.com?subject=HiPhone&body=%@", encodedBody];
NSURL *url = [[NSURL alloc] initWithString:urlString];
[[UIApplication sharedApplication] openURL:url];

And here’s the result:

Bingo!

A weird downside of this method is that the user will be able to edit the email, but not is formatting: the bold characters will stay bold and so on; this seems to be a feature of the mail app itself.

Device vs Simulator

Since the iPhone simulator does not have a Mail.app, you can use e-mail URLs only in the actual device. As a matter of fact, it’s advisable to use compiler statements to create specific simulator/device code:

#if TARGETIPHONESIMULATOR
    //compiler specific code
#else
    // device specific code
#endif

In my app, I use a UIAlertView in the simulator code, so I can have the email text displayed onscreen. Currently I have a UITextView as its subview, but I plan to use a UIWebView, so I can preview the HTML in the simulator.

(Thanks to Slashzero for his comment)

Notes

1. shush shush, too early to talk about it!
2. Please note that, although the mailto protocol might support attachments, you specify attachment with the sdk. I know, it’s a shame, but so far we’re not allowed to send attachments through mail. The alternative is writing your own smtp server, but refrain from doing it, unless the composed mail is sent without any user intervention, otherwise you’ll also have to write your own mail client.