jmoody

def navbar_visible?
  !query('navigationBar').empty?
end

def navbar_has_back_button?
  !query("navigationItemButtonView").empty?
end

def navbar_should_have_back_button
  unless navbar_has_back_button?

prabirshrestha

@synthesize firstName = _firstName;
@synthesize txtFirstName = _txtFirstName;

[RACAbleSelf(self.firstName) subscribeNext:^(id x) { [self firstNameChanged:x]; }];
[self rac_bind:RAC_KEYPATH_SELF(self.firstName) to:self.txtFirstName.rac_textSubscribable];

- (void) firstNameChanged:(id)firstName {
    NSLog(@"changed: %@", firstName);
}

mattt

Howdy howdy, NSHipsters!

If you alloc init an NSCalendar, you'll notice that New Year's Eve falls on a Monday this year, a.k.a. "the day NSHipster is published every week". What fun!

So in celebration of the upcoming year++, I thought it'd be fun to compile a list of some of your favorite tips and tricks of the trade. Submit your favorite piece of Objective-C trivia, framework arcana, hidden Xcode feature, or anything else you think is cool, and you could have it featured in the year-end blowout article. Just comment on this gist below!

Here are a few examples of the kind of things I'd like to see:

• StaticObjcMethods from [Apple]((http://developer.apple.com/library/mac/#samplecode/CocoaTipsAndTricks/Introduction/Intro.html): Demonstrates how to use static Objective-C m

twobitlabs

// http://cocoawithlove.com/2009/10/ugly-side-of-blocks-explicit.html has a nice breakdown of the syntax--it helps to think of the ^ as similar to a pointer dereference symbol *

// block typedef:

    typedef void(^Block)();
    typedef void(^ConditionalBlock)(BOOL);
    typedef NSString*(^BlockThatReturnsString)();
    typedef NSString*(^ConditionalBlockThatReturnsString)(BOOL);

// block property with typedef:

krzysztofzablocki

expr -- (void)printf("[%s, %s]\n",(char *) object_getClassName(*(long*)($esp+4)), (char *) *(long *)($esp+8) )

dergachev

OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

tibo

@implementation NSURLRequest (printCurlRequest)

-(NSString *)curlRequest
{
    __block NSString *curlstr = [NSString stringWithFormat:@"curl -k -X %@ --dump-header -",self.HTTPMethod];
    
    [[self allHTTPHeaderFields] enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
        curlstr = [curlstr stringByAppendingFormat:@" -H \"%@: %@\"",key, obj];
    }];
    

steipete

// Taken from the commercial iOS PDF framework http://pspdfkit.com.
// Copyright (c) 2014 Peter Steinberger, PSPDFKit GmbH. All rights reserved.
// Licensed under MIT (http://opensource.org/licenses/MIT)
//
// You should only use this in debug builds. It doesn't use private API, but I wouldn't ship it.

// PLEASE DUPE rdar://27192338 (https://openradar.appspot.com/27192338) if you would like to see this in UIKit.

#import <objc/runtime.h>
#import <objc/message.h>

steipete

KEYWORDS="TODO:|FIXME:|\?\?\?:|\!\!\!:"
find "${SRCROOT}" \( -name "*.h" -or -name "*.m" \) -print0 | xargs -0 egrep --with-filename --line-number --only-matching "($KEYWORDS).*\$" | perl -p -e "s/($KEYWORDS)/ warning: \$1/"

calebd

extension Array {
    
    func first() -> Element? {
        if isEmpty {
            return nil
        }
        return self[0]
    }
    
    func last() -> Element? {