Don’t use NSLog anymore!

By Josh Highland in iPhone app dev, tutorials

NSLog is a convenient way to output logging information from your iPhone app. NSLog is most commonly used by developers for debugging purposes. The problem with adding NSLog statements in your code is that you have to remove them or comment them out before you can submit your application to the app store. Apps that output data via NSLog will not be approved into the app store.

I would like to show you how I handle this delema. Start by opening the “_Prefix.pch” file.

next, add the following lines to the file

#define DEBUG_MODE

#ifdef DEBUG_MODE
#define DebugLog( s, ... ) NSLog( @"<%@:(%d)> %@", [[NSString stringWithUTF8String:__FILE__] lastPathComponent], __LINE__, [NSString stringWithFormat:(s), ##__VA_ARGS__] )
#else
#define DebugLog( s, ... )
#endif

In your code, replace “NSLog” with “DebugLog”. THATS IT!

DebugLog adds some new functionality to NSLog. It will now output the file name and line number of the Debug statement.

The best part of this is that its very easy to disable when its time to create a release build of your code. Simple comment out the “#define DEBUG_MODE” line im the “_Prefix.pch” file.

SQL Server 2008: FIXED “Data has changed since the Results pane was last retrieved”

By Josh Highland in MySQL, Programming, software, tutorials, windows

Today I was trying to edit the value in a table cell through the query browser in Microsoft SQL Server Management Itudio and I kept getting the following error:

Data has changed since the Results pane was last retrieved. Do you want to save your changes now?
(Optimistic Concurrency Control Error)
Click Yes to commit your changes to database anyway.
Click No to discard your change and retrieve the current data for this row.
Click Cancel to continue editing.

I would click “Yes”, and get another error:

No row was updated.
The data in row X was not committed.
Error Source: Microsoft.VisualStudio.DataTools.
Error Message: The row value(s) updated or deleted either do not make the row unique or they alter multiple rows(N rows).
Correct the errors and retry or press ESC to cancel the change(s).

I was killing myself trying to figure out what was wrong. I was the only person working on the database, so the data wasnt being changed behind my back.

After an hour on goolge I came across a Microsoft tech article for MS SQL 2005, http://support.microsoft.com/kb/925719

It stated the issue could occure from one of the following conditions:

  • The table contains one or more columns of the text or ntext data type.
  • The value of one of these columns contains the following characters:
  • Percent sign (%)
  • Underscore (_)
  • Left bracket ([)
  • The table does not contain a primary key.

I double checked the table I was working on and realized it didnt have a primary key. It must have gotten dropped in the data migration from MS SQL 2000 to MS SQL 2008. A simple right click, set primary key and my problem was fixed.

Verify the primary keys! It’s a simple fix to a head breaker of a problem. I hope someone finds this and it fixes their issue.

How To detect an internet connection with the iPhone SDK

By Josh Highland in iPhone, iPhone app dev, Programming, Tech, tutorials

There are several ways to problematically detect if an iPhone has an internet connection, but most of them cant tell you how the iPhone is connected to the internet.

Apple has sample code to accomplish just this task. The Reachability class is not shipped with the SDK, but is part of a sample project of the same name. http://developer.apple.com/iphone/library/samplecode/Reachability/index.html

Using the reachability class:

Set up:

  • Download the reachability project from Apple
  • Copy Reachability.h and Reachability.m to your project.
  • Add the ‘SystemConfiguration’ framework to your project.

Sample Usage:

Reachability *reachability = [Reachability sharedReachability];
 [reachability setHostName:@"www.JoshHighland.com"];
 NetworkStatus remoteHostStatus = [reachability remoteHostStatus];

if(remoteHostStatus == NotReachable) {
 //no internet connection
 }
 else if (remoteHostStatus == ReachableViaWiFiNetwork) {
 //wifi connection found
 }
 else if (remoteHostStatus == ReachableViaCarrierDataNetwork) {
 //EDGE or 3G connection found
 }