akosma edited this page Aug 2, 2011 · 4 revisions
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nib2objc - NIB to Objective-C converter

This suite of utilities converts NIB files (or XIB ones) into Objective-C code, including all the properties of each instance, the documented constructor calls, and also the view hierarchy. It uses the output of the ibtool utility bundled with the Xcode tools. For more information about ibtool, please check the ibtool man page.


The project is placed in the public domain. See the License page for details.


The last version of the binaries is available for download in Github. The latest version includes the GUI executables and all the other tools, ready to use.


Check out the Build Instructions page.


Compile and put the utility in your path, and then call

nib2objc yourfile.xib > code.m

This will generate a file with the output of the conversion, similar to this (check out the included sample.m file for the full version):

// ...
UIView *view6 = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, 320.0, 460.0)];
view6.frame = CGRectMake(0.0, 0.0, 320.0, 460.0);
view6.alpha = 1.000;
view6.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
view6.backgroundColor = [UIColor colorWithWhite:0.750 alpha:1.000];
view6.clearsContextBeforeDrawing = NO;
// ...

UIButton *button9 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
button9.frame = CGRectMake(167.0, 65.0, 72.0, 37.0);
button9.adjustsImageWhenDisabled = YES;
button9.adjustsImageWhenHighlighted = YES;
button9.alpha = 1.000;
button9.autoresizingMask = UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleBottomMargin;
button9.clearsContextBeforeDrawing = NO;
button9.clipsToBounds = NO;
button9.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;
// ...
[button9 setTitleShadowColor:[UIColor colorWithWhite:0.000 alpha:1.000] forState:UIControlStateSelected];

// ...
[view6 addSubview:button9];
// ...

You can also generate code that uses method calls instead of properties, this way:

nib2objc yourfile.xib 2 > code.m

The generated code takes into account the real class hierarchies in the UIKit, and it outputs the correct constructors and/or method calls for each object, depending on its class, including the enum values corresponding to the properties using them.

Mac OS X GUI Application

The “GUI” folder contains a Mac OS X application that can be used to open several nib files and to see their contents as Objective-C code.

The GUI application uses the Fragaria library as a submodule, to provide syntax highlighting of the generated Objective-C code. Prior to compilation, please do the following:

$ git submodule init
$ git submodule update

The application features setting buttons that allow to customize the output, either using properties or classic setters:


You can save the contents of the window as a file, just by hitting Command-S or by selecting the “File / Export” menu.

Mac OS X Service

A secondary project in the “Convert with nib2objc” folder creates an Automator action, that can be used to create Mac OS X services with Automator. The “Convert with nib2objc.zip” file contains an example of such a service, ready to be installed in ~/Library/Services, and which can be called from the Finder after selecting a nib file. The result of the conversion will be placed in the clipboard for pasting into any application.


  • For the moment this utility only works for UIKit views (iPhone), but it should be easy to extend to those of the AppKit too.
  • It cannot output the values of UIImage, NSLocale or NSTimeZone properties, because ibtool does not support them.
  • It does not distinguishes default values for properties, and as such, it outputs all the information it can find about a particular instance.


This project includes the nibs2objc.pl Perl script by Rudi Farkas, which allows users to perform batch transformations of nib files in a folder. Thanks Rudi for the contribution!