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Three small tools to help you meet Xcode halfway.
branch: master

Merge pull request #13 from fabb/master

replace disallowed characters '@' and '-' in method names
latest commit 0d977c614e
@puls puls authored


We love Xcode 5. It's been adding way cool features at a really fast pace, and adopting these features is the quickest way to bliss in life.

(Or at least iOS development bliss.)

But sometimes these boss new features don't quite get all the way. In the interest of meeting the tools halfway, we present three small code generators to improve your life in subtle ways.


Xcode 5 has an awesome new feature called "asset catalogs", allowing you to specify all of your image variants and resizable cap insets in a single place.

Unfortunately, to get the full benefits, you have to set your deployment target to iOS 7; otherwise, Xcode will dutifully put all of the images into your app bundle but totally ignore all of your resizable insets with only a build warning.

And even if you're targeting iOS 7, you'll still have to deal with typing string filenames correctly. And everybody knows that stringly-typed code is bad. (While you're at it, consider replacing your stringly-typed key paths with a macro to check them at compile time!)

But shucks! The important and awesome part is the editor, and it puts all of the data out in super-readable JSON. We should be able to do a poor man's version that reads in the data and spits out some code to give you most of the benefits.


Call objc-assetgen with the .xcassets paths as arguments from the directory into which it should output the code.

For an asset catalog named "Foo" containing image sets "Bar" and "Baz", you'll get FooCatalog.h and FooCatalog.m, with class methods + (UIImage *)barImage and + (UIImage *)bazImage. Put them in your DerivedSources folder and you're good to go.


On Mac OS X, the standard system color picker has a tab for palette-based colors:

System color picker

One little-known feature of this color picker tab is that you can create your own palettes and fill them with the custom colors for your app.

In the spirit of Once and Only Once, once you've used these colors in your storyboards and nib files, you won't want to have to define them again for that rare occasion you're using them in code. Luckily, your custom color palettes are just files in ~/Library/Colors, and we can read them and give your app access to them.

Running the tool will also install the palette into your system color picker, so the other developers on your team can use your colors in their storyboards.


Call objc-colordump with the .clr paths as arguments from the directory into which it should output the code.

For a color palette named "Foo" colors named "Bar" and "Baz", you'll get FooColorList.h and FooColorList.m, with class methods + (UIColor *)barColor and + (UIColor *)bazColor. Put them in your DerivedSources folder and you're good to go.


Storyboards are great. They let you visually lay out your interface and define the interactions between different screens in a way that's much more compact than writing a ton of view code.

At least I think so. But if you go and search for more information on storyboards, one of the first things you'll find is this Stack Overflow answer:

Storyboard haters

We already fixed the part about code reuse with objc-colordump, and now we can fix the parts about failures at runtime. If we generate some code to turn your string identifiers—and that's any kind of string identifier, be it a view controller identifier, a segue identifier, or a cell reuse identifier—into compiler-checked constants, we can avoid a whole class of problems.


Call objc-identifierconstants with the .storyboard paths as arguments from the directory into which it should output the code.

For a storyboard named "Foo" with view controller identifier "Bar" and segue identifier "Baz" somewhere in it, you'll get FooStoryboardIdentifiers.h and FooStoryboardIdentifiers.m with extern NSString *const FooStoryboardBarIdentifier and extern NSString *const FooStoryboardBazIdentifier in it. Put them in your DerivedSources folder and you're good to go.

Command-line options (common to all three tools)


  • objc-assetgen [-6] [-o <path>] [-f <path>] [-p <prefix>] [<paths>]
  • objc-colordump [-6] [-o <path>] [-f <path>] [-p <prefix>] [<paths>]
  • objc-identifierconstants [-6] [-o <path>] [-f <path>] [-p <prefix>] [<paths>]


Target iOS 6 in addition to iOS 7
-o <path>
Output files at <path>
-f <path>
Search for input files starting from <path>
-p <prefix>
Use <prefix> as the class prefix in the generated code
Print this help and exit
Input files; this and/or `-f` are required.


We're glad you're interested in codegenutils, and we'd love to see where you take it.

Any contributors to the master codegenutils repository must sign the Individual Contributor License Agreement (CLA). It's a short form that covers our bases and makes sure you're eligible to contribute.

When you have a change you'd like to see in the master repository, send a pull request. Before we merge your request, we'll make sure you're in the list of people who have signed a CLA.

Thanks, and happy generating!

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