PNObject/Example/Pods/JRSwizzle/README.markdown

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# JRSwizzle
## Description
JRSwizzle is source code package that offers a single, easy, correct+consistent interface for exchanging Objective-C method implementations ("method swizzling") across many versions of Mac OS X, iOS, Objective-C and runtime architectures.
More succinctly: *JRSwizzle wants to be your one-stop-shop for all your method swizzling needs.*
## Download
$ cd /path/to/top/of/your/project
$ git submodule add git://github.com/rentzsch/jrswizzle.git JRSwizzle
$ git submodule init && git submodule update
# OPTIONAL: Execute the following commands if you want to explicitly peg
# to a certain version. Otherwise `git submodule update` will keep you
# current with HEAD.
$ cd JRSwizzle
$ git checkout v1.0
## Reasons for Existence
* **Easy:** Just do this: `[SomeClass jr_swizzle:@selector(foo) withMethod:@selector(my_foo) error:&error];` Voila.
* **Correct:** There's a subtle interaction between method swizzling and method inheritance. Following in Kevin Ballard's footsteps, this package Does The Right Thing.
* **Compatible:** JRSwizzle should Just Work on any version of Mac OS X and iOS you care about. Here's the exhaustive compatibility list:
* Mac OS X v10.3/ppc (Ballard implementation)
* Mac OS X v10.4/ppc (Ballard implementation)
* Mac OS X v10.4/i386 (Ballard implementation)
* Mac OS X v10.5/ppc (method_exchangeImplementations+Ballard implementation)
* Mac OS X v10.5/i386 (method_exchangeImplementations+Ballard implementation)
* Mac OS X v10.5/ppc64 (method_exchangeImplementations+Ballard implementation)
* Mac OS X v10.5/x86_64 (method_exchangeImplementations+Ballard implementation)
* iOS 2.0+ (method_exchangeImplementations+Ballard implementation)
* **Robust:** All parameters are checked and JRSwizzle returns an optional `NSError` with high-quality diagnostics.
## Support
Please use [JRSwizzle's GitHub Issues tab](https://github.com/rentzsch/jrswizzle/issues) to [file bugs or feature requests](https://github.com/rentzsch/jrswizzle/issues/new).
To contribute, please fork this project, make+commit your changes and then send me a pull request.
## Comparison
There's at least four swizzling implementations floating around. Here's a comparison chart to help you make sense of how they relate to each other and why JRSwizzle exists.
<table>
<tr>
<th>Scenario</th>
<th>Swizzle Technology</th>
<th>Method Implementation</th>
<th>Correct Behavior</th>
<th>10.4</th>
<th>64-bit</th>
</tr>
<tr>
<td>1</td>
<td>Classic</td>
<td>Direct</td>
<td>YES</td>
<td>YES</td>
<td>NO</td>
</tr>
<tr>
<td>2</td>
<td>Classic</td>
<td>Inherited</td>
<td>NO</td>
<td>YES</td>
<td>NO</td>
</tr>
<tr>
<td>3</td>
<td>Ballard</td>
<td>Direct</td>
<td>YES</td>
<td>YES</td>
<td>NO</td>
</tr>
<tr>
<td>4</td>
<td>Ballard</td>
<td>Inherited</td>
<td>YES</td>
<td>YES</td>
<td>NO</td>
</tr>
<tr>
<td>5</td>
<td>Apple</td>
<td>Direct</td>
<td>YES</td>
<td>NO</td>
<td>YES</td>
</tr>
<tr>
<td>6</td>
<td>Apple</td>
<td>Inherited</td>
<td>NO</td>
<td>NO</td>
<td>YES</td>
</tr>
<tr>
<td>7</td>
<td>JRSwizzle</td>
<td>Direct</td>
<td>YES</td>
<td>YES</td>
<td>YES</td>
</tr>
<tr>
<td>8</td>
<td>JRSwizzle</td>
<td>Inherited</td>
<td>YES</td>
<td>YES</td>
<td>YES</td>
</tr>
</table>
* *Classic* is the canonical `MethodSwizzle()` implementation as described in [CocoaDev's MethodSwizzling page](http://www.cocoadev.com/index.pl?MethodSwizzling).
* *Ballard* is [Kevin Ballard's improved implementation](http://kevin.sb.org/2006/12/30/method-swizzling-reimplemented/) which solves the inherited method problem.
* *Apple* is 10.5's new `method_exchangeImplementations` API.
* *JRSwizzle* is this package.
## License
The source code is distributed under the nonviral [MIT License](http://opensource.org/licenses/mit-license.php). It's the simplest most permissive license available.
## Version History
* **v1.0:** Mar 2 2012
* [NEW] iOS Support. ([Anton Serebryakov](https://github.com/rentzsch/jrswizzle/commit/60ccb350a3577e55d00d3fdfee8b3c0390b8e852]))
* [NEW] Class method swizzling. ([outis](https://github.com/rentzsch/jrswizzle/pull/1))
* **v1.0d1:** May 31 2009
* [FIX] Soothe valgrind by nulling out `hoisted_method_list->obsolete`, which it apparently reads. ([Daniel Jalkut](http://github.com/rentzsch/jrswizzle/commit/2f677d063202b443ca7a1c46e8b67d67ea6fc88e))
* [FIX] Xcode 3.2 apparently now needs `ARCHS` set explicitly for 10.3 targets. ([rentzsch](http://github.com/rentzsch/jrswizzle/commit/4478faa40e4fdb322201da20f24d3996193ea48b))
* **v1.0d0:** Apr 09 2009
* Moved to github.
* **v1.0d0:** Dec 28 2007
* Under development.