The **Derived Data** folder contains all the intermediate build information, debug- and release-built targets, as well as your project&#39;s index. It&#39;s *helpful* to delete the derived data when you have odd index problems (code completion not working right, constant re-indexing, or even just a slow project). Deleting the entire folder nukes this information for *all* projects Xcode 4 knows about.

The **Archives** folder (a sibling of Derived Data) contains the archived form of your targets. That is, a release build as well as dSYM data for later debugging. This you *should not* delete if you want to be able to debug deployed versions of your application.

You can nuke the derived data for a given project by opening the Organizer window and selecting the Projects tab. Select the desired project and click the Delete button next to the Derived Data path. This is more of a &quot;surgical strike&quot; for problem projects.


The content of &#39;Derived Data&#39; is generated during Build-time. You can delete it safely. Follow below steps for deleting &#39;Derived Data&#39; :

1. Select **Xcode -&gt; Preferences..**

![Step 1][1]

2. This will open pop-up window. Select &#39;**Locations**&#39; tab.
   In Locations sub-tab you can see &#39;**Derived Data**&#39;
   Click on arrow icon next to path.

![Step 2][2]

3. This will open-up folder containing &#39;Derived Data&#39;
   Right click and Delete folder.

![Step 3][3]


  [1]: http://i.stack.imgur.com/YlPIf.png
  [2]: http://i.stack.imgur.com/qdvZQ.png
  [3]: http://i.stack.imgur.com/C0NUC.png

Yes those data are generated during the build time and you can delete them if you want, its not a issue. 

It will be recreated when you build again.

I have a select element wrapped by a span element. I am not allowed to use the select id but I am allowed to use the span id.
I am trying to write a javascript/jquery function in which the input is a number i, which is one of the values of the select&#39;s options. The function will turn the relevant option to selected.

    &lt;span id=&quot;span_id&quot;&gt;
    	&lt;select id=&quot;h273yrjdfhgsfyiruwyiywer&quot; multiple=&quot;multiple&quot;&gt;
    		&lt;option value=&quot;1&quot;&gt;cleaning&lt;/option&gt;
    		&lt;option value=&quot;2&quot;&gt;food-2&lt;/option&gt;
    		&lt;option value=&quot;3&quot;&gt;toilet&lt;/option&gt;
    		&lt;option value=&quot;4&quot;&gt;baby&lt;/option&gt;
    		&lt;option value=&quot;6&quot;&gt;knick-knacks&lt;/option&gt;
    		&lt;option value=&quot;9&quot;&gt;junk-2&lt;/option&gt;
    		&lt;option value=&quot;10&quot;&gt;cosmetics&lt;/option&gt;
    	&lt;/select&gt;
    &lt;/span&gt;

I wrote something as follows (this does not completely work, which is why I am posting this question):

    function select_option(i) {
    
    	options = $(&#39;#span_id&#39;).children(&#39;select&#39;).children(&#39;option&#39;);
    	//alert(options.length); //7
    	//alert(options[0]); //[object HTMLOptionElement]
    	//alert(options[0].val()); //not a jquery element
    	//alert(options[0].value); //1
    
    	//the following does not seem to work since the elements of options are DOM ones not jquery&#39;s
    	option = options.find(&quot;[value=&#39;&quot; + i + &quot;&#39;]&quot;);
    	//alert(option.attr(&quot;value&quot;)); //undefined
    	option.attr(&#39;selected&#39;, &#39;selected&#39;);
    	
    }

Thanks!

jQuery select option elements by value

I am looking to take an icon that is colored (and will be a link) and turn it greyscale until the user places their mouse over the icon (where it would then color the image).

Is this possible to do, and in a way that is IE &amp; Firefox supported?

Image Greyscale with CSS &amp; re-color on mouse-over?

I&#39;d like to remove old (replaceable?) data and *DerivedData* contents seem a likely candidate. Since it&#39;s name *DerivedData*, I assume that it&#39;s info that, if missing, would be generated during a build phase and if present, is used during that same phase. It seems logical then that I could delete any old project data without fear and if I should ever build that old project, the first time through would take longer than normal sine it has to recreate all this derived data.

Am I mistaken here?

How can I safely delete in my ~/Library/Developer/Xcode/DerivedData directory?

I'd like to remove old (replaceable?) data and DerivedData contents seem a likely candidate. Since it's name DerivedData, I assume that it's info that, if missing, would be generated during a build phase and if present, is used during that same phase. It seems logical then that I could delete any old project data without fear and if I should ever build that old project, the first time through would take longer than normal sine it has to recreate all this derived data.
Am I mistaken here?

In my little iPad app I have a &quot;switch language&quot; function that uses an observer. Every view controller registers itself with my observer during its `viewDidLoad:`.

    - (void)viewDidLoad
    {
        [super viewDidLoad];
        [observer registerObject:self];
    }

When the user hits the &quot;change language&quot; button, the new language is stored in my model and the observer is notified and calls an `updateUi:` selector on its registered objects.

This works very well, except for when I have view controllers in a TabBarController.  This is because when the tab bar loads, it fetches the tab icons from its child controllers without initializing the views, so `viewDidLoad:` isn&#39;t called, so those view controllers don&#39;t receive language change notifications. Because of this, I moved my `registerObject:` calls into the `init` method.

Back when I used `viewDidLoad:` to register with my observer, I used `viewDidUnload:` to unregister. Since I&#39;m now registering in `init`, it makes a lot of sense to unregister in `dealloc`.

But here is my problem. When I write:

    - (void) dealloc
    {
        [observer unregisterObject:self];
        [super dealloc];
    }

I get this error:

&gt; ARC forbids explicit message send of &#39;dealloc&#39;

Since I need to call `[super dealloc]` to ensure superclasses clean up properly, but ARC forbids that, I&#39;m now stuck. Is there another way to get informed when my object is dying?

Custom dealloc and ARC (Objective-C)

Is it possible to programmatically change the keyboard type of a uitextfield so that something like this would be possible:

    if(user is prompted for numeric input only)
        [textField setKeyboardType: @&quot;Number Pad&quot;];

    if(user is prompted for alphanumeric input)
        [textField setKeyboardType: @&quot;Default&quot;];

Programmatically change UITextField Keyboard type

I know that the presence of the more view controller (navigation bar) pushes down the UIView by its height.  I also know that this height = 44px.  I have also discovered that this push down maintains the `[self.view].frame.origin.y = 0`.

So how do I determine the height of this navigation bar, other than just setting it to a constant?

Or, shorter version, how do I determine that my UIView is showing with the navigation bar on top?

---------
The light bulb started to come on. Unfortunately, I have not discovered a uniform way to correct the problem, as described below.

I believe that my whole problem centers on my autoresizingMasks. And the reason I have concluded that is the same symptoms exist, with or without a UIWebView. And that symptom is that everything is peachy for Portrait. For Landscape, the bottom-most UIButton pops down behind the TabBar.

For example, on one UIView, I have, from top to bottom:

UIView – both springs set (default case) and no struts

UIScrollView - If I set the two springs, and clear everything else (like the UIView), then the UIButton intrudes on the object immediately above it. If I clear everything, then UIButton is OK, but the stuff at the very top hides behind the StatusBar Setting only the top strut, the UIButton pops down behind the Tab Bar.

UILabel and UIImage next vertically – top strut set, flexible everywhere else

Just to complete the picture for the few that have a UIWebView:

UIWebView - Struts: top, left, right Springs: both

UIButton – nothing set, i.e., flexible everywhere

Although my light bulb is dim, there appears to be hope.


---------------

Please bear with me because I needed more room than that provided for a short reply comment.

Thanks for trying to understand what I am really fishing for ... so here goes.

1) Each UIViewController (a TabBar app) has a UIImage, some text and whatever on top. Another common denominator is a UIButton on the bottom. On some of the UIViewControllers I have a UIWebView above the UIButton.

So, UIImage, text etc. UIWebView (on SOME) UIButton

Surrounding all the above is a UIScrollView.

2) For those that have a UIWebView, its autoresizingMask looks like:

       —
       |
       —

       ^
       |
       |
|—| ←----→ |—|
       |
       | 
       V
The UIButton&#39;s mask has nothing set, i.e., flexible everywhere

Within my -viewDidLoad, I call my -repositionSubViews within which I do the following:

If there is no UIWebView, I do nothing except center the UIButton that I placed with IB.

If I do have a UIWebView, then I determine its *content*Height and set its frame to enclose the entire content.

    UIScrollView *scrollViewInsideWebView = [[webView_ subviews] lastObject];
    webViewContentHeight = scrollViewInsideWebView.contentSize.height;
    [webView_ setFrame:CGRectMake(webViewOriginX, webViewOriginY,
                              sameWholeViewScrollerWidth, webViewContentHeight)]
Once I do that, then I programmatically push the UIButton down so that it ends up placed below the UIWebView.

Everything works, until I rotate it from Portrait to Landscape.

I call my -repositionSubViews within my -didRotateFromInterfaceOrientation.

Why does the content height of my UIWebView not change with rotation?.

From Portrait to Landscape, the content width should expand and the content height should shrink. It does visually as it should, but not according to my NSLog.

Anyway, with or without a UIWebView, the button I&#39;ve talked about moves below the TabBar when in Landscape mode but it will not scroll up to be seen. I see it behind the TabBar when I scroll &quot;vigorously&quot;, but then it &quot;falls back&quot; behind the TabBar.

Bottom line, this last is the reason I&#39;ve asked about the height of the TabBar and the NavigationBar because the TabBar plants itself at the bottom of the UIView and the NavigationBar pushes the UIView down.

Now, I&#39;m going to add a comment or two here because they wouldn&#39;t have made sense earlier.

With no UIWebView, I leave everything as is as seen by IB.

With a UIWebView, I increase the UIWebView&#39;s frame.height to its contentHeight and also adjust upward the height of the surrounding UIScrollView that surrounds all the sub-views.

Well there you have it.


Programmatically get height of navigation bar

The `UIKeyboardAnimationCurveUserInfoKey` has a `UIViewAnimationCurve` value. How do I convert it to the corresponding `UIViewAnimationOptions` value for use with the `options` argument of `+[UIView animateWithDuration:delay:options:animations:completion:]`?

    // UIView.h

    typedef enum {
        UIViewAnimationCurveEaseInOut,         // slow at beginning and end
        UIViewAnimationCurveEaseIn,            // slow at beginning
        UIViewAnimationCurveEaseOut,           // slow at end
        UIViewAnimationCurveLinear
    } UIViewAnimationCurve;

    // ...
    
    enum {
        // ...
        UIViewAnimationOptionCurveEaseInOut            = 0 &lt;&lt; 16, // default
        UIViewAnimationOptionCurveEaseIn               = 1 &lt;&lt; 16,
        UIViewAnimationOptionCurveEaseOut              = 2 &lt;&lt; 16,
        UIViewAnimationOptionCurveLinear               = 3 &lt;&lt; 16,
        // ...
    };
    typedef NSUInteger UIViewAnimationOptions;

Obviously, I could create a simple category method with a `switch` statement, like so:

    // UIView+AnimationOptionsWithCurve.h

    @interface UIView (AnimationOptionsWithCurve)
    @end
    
    // UIView+AnimationOptionsWithCurve.m

    @implementation UIView (AnimationOptionsWithCurve)
    
    + (UIViewAnimationOptions)animationOptionsWithCurve:(UIViewAnimationCurve)curve {
        switch (curve) {
            case UIViewAnimationCurveEaseInOut:
                return UIViewAnimationOptionCurveEaseInOut;
            case UIViewAnimationCurveEaseIn:
                return UIViewAnimationOptionCurveEaseIn;
            case UIViewAnimationCurveEaseOut:
                return UIViewAnimationOptionCurveEaseOut;
            case UIViewAnimationCurveLinear:
                return UIViewAnimationOptionCurveLinear;
        }
    }

    @end

But, is there an even easier/better way?

iOS: How to convert UIViewAnimationCurve to UIViewAnimationOptions?

Been having my first crack at Core Data and I&#39;m getting the following error when running my code on my device, but it works fine on the simulator..

&gt; 
*** Terminating app due to uncaught exception &#39;NSInvalidArgumentException&#39;, reason: &#39;Cannot create an NSPersistentStoreCoordinator with a nil model&#39;

Some of my methods that might be causing the problem:

        - (NSManagedObjectContext *)managedObjectContext
    {
        if (__managedObjectContext != nil)
        {
            return __managedObjectContext;
        }
        
        NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
        if (coordinator != nil)
        {
            __managedObjectContext = [[NSManagedObjectContext alloc] init];
            [__managedObjectContext setPersistentStoreCoordinator:coordinator];
        }
        return __managedObjectContext;
    }
    
    /**
     Returns the managed object model for the application.
     If the model doesn&#39;t already exist, it is created from the application&#39;s model.
     */
    - (NSManagedObjectModel *)managedObjectModel
    {
        if (__managedObjectModel != nil)
        {
            return __managedObjectModel;
        }
        NSURL *modelURL = [[NSBundle mainBundle] URLForResource:@&quot;RugbyOnTv&quot; withExtension:@&quot;momd&quot;];
        __managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];    
        return __managedObjectModel;
    }
    
    /**
     Returns the persistent store coordinator for the application.
     If the coordinator doesn&#39;t already exist, it is created and the application&#39;s store added to it.
     */
    - (NSPersistentStoreCoordinator *)persistentStoreCoordinator
    {
        if (__persistentStoreCoordinator != nil)
        {
            return __persistentStoreCoordinator;
        }
        
    	NSString *storePath = [[self applicationDocumentsDirectory] stringByAppendingPathComponent: @&quot;RugbyOnTV.sqlite&quot;];
        
        NSURL *storeUrl = [NSURL fileURLWithPath:storePath];
    	
    	NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES], NSMigratePersistentStoresAutomaticallyOption, [NSNumber numberWithBool:YES], NSInferMappingModelAutomaticallyOption, nil];	
        __persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: [self managedObjectModel]];
        
        NSError *error = nil;
        __persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel:[self managedObjectModel]];
    
        
    	if (![__persistentStoreCoordinator addPersistentStoreWithType:NSSQLiteStoreType configuration:nil URL:storeUrl options:options error:&amp;error]) {
          
            NSLog(@&quot;Unresolved error %@, %@&quot;, error, [error userInfo]);
            abort();
        }    
        
        return __persistentStoreCoordinator;
    }
    
    
        - (NSString *)applicationDocumentsDirectory {
            
            NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
            NSString *basePath = ([paths count] &gt; 0) ? [paths objectAtIndex:0] : nil;
            return basePath;
        }



**EDIT**

I copied and pasted the managedObjectContext method (below) from Apple&#39;s CoreDataBooks and it now works..Not really sure why though

    - (NSManagedObjectModel *)managedObjectModel {
        if (managedObjectModel != nil) {
            return managedObjectModel;
        }
        managedObjectModel = [[NSManagedObjectModel mergedModelFromBundles:nil] retain];    
        return managedObjectModel;
    }



Cannot create an NSPersistentStoreCoordinator with a nil model

Xcode underlines all occurrences of a symbol that the cursor is on. However, the underline doesn&#39;t exactly &quot;pop out&quot; in the source code. Is it possible to make Xcode highlight the background color of the symbol, like Eclipse does it? I can&#39;t find anything in the Preferences panel.

Xcode:

![Xcode][1]

Eclipse:

![Eclipse][2]


  [1]: http://i.stack.imgur.com/jgxnI.png
  [2]: http://i.stack.imgur.com/VhoOr.png

Make Xcode highlight selected symbol more

I&#39;ve submitted three versions of my app onto the App Store using the Build and Archive commands. But... Where are those archives?  

I&#39;ve just learnt that I just need them to be able to read crashlogs.  My `~/Library/Developer/Xcode/Archives` folder is empty (in fact there is one xarchive file inside it I&#39;ve just generated now to test a crashlog reading).

Spotlight does not find any .xarchive.

I never been asked to delete or clear anything else than my project builds (Product - clean) when coding next version.

Xcode - But... Where are our archives?

I&#39;d like to check the contents of an XML file at a specific point of execution while debugging in Xcode. Is it possible to view the contents of the file, either through the Organizer (I&#39;m debugging using actual hardware devices, not the simulator), or by typing in some sort of command into the output/console?

I am using Xcode 4.

Is it possible to view the contents of files in the iOS Application sandbox while debugging?

I&#39;m building a Cocoa Touch Static Library. How should I decide whether to copy a header file as public, private, or project?

Xcode: Copy Headers: Public vs. Private vs. Project?

On my Lion app, I have this data model:

![enter image description here][1]

The relationship `subitems` inside `Item` **is ordered**.
 
Xcode 4.1 (build 4B110) has created for me the file `Item.h`, `Item.m`, `SubItem.h` and `SubItem.h`.
 
Here is the content (autogenerated) of `Item.h`:

    #import &lt;Foundation/Foundation.h&gt;
    
    #import &lt;CoreData/CoreData.h&gt;
    
    @class SubItem;
    
    @interface Item : NSManagedObject {
    @private
    }
    
    @property (nonatomic, retain) NSString * name;
    @property (nonatomic, retain) NSOrderedSet *subitems;
    @end
    
    @interface Item (CoreDataGeneratedAccessors)
    
    - (void)insertObject:(SubItem *)value inSubitemsAtIndex:(NSUInteger)idx;
    - (void)removeObjectFromSubitemsAtIndex:(NSUInteger)idx;
    - (void)insertSubitems:(NSArray *)value atIndexes:(NSIndexSet *)indexes;
    - (void)removeSubitemsAtIndexes:(NSIndexSet *)indexes;
    - (void)replaceObjectInSubitemsAtIndex:(NSUInteger)idx withObject:(SubItem *)value;
    - (void)replaceSubitemsAtIndexes:(NSIndexSet *)indexes withSubitems:(NSArray *)values;
    - (void)addSubitemsObject:(SubItem *)value;
    - (void)removeSubitemsObject:(SubItem *)value;
    - (void)addSubitems:(NSOrderedSet *)values;
    - (void)removeSubitems:(NSOrderedSet *)values;
    
    @end

And here is the content (autogenerated) of `Item.m`:

    #import &quot;Item.h&quot;
    #import &quot;SubItem.h&quot;
    
    @implementation Item
    
    @dynamic name;
    @dynamic subitems;
    
    @end
 
As you can see, the class `Item` offers a method called `addSubitemsObject:`. Unfortunately, when trying to use it in this way:

    Item *item = [NSEntityDescription insertNewObjectForEntityForName:@&quot;Item&quot; inManagedObjectContext:self.managedObjectContext];
    item.name = @&quot;FirstItem&quot;;
    
    SubItem *subItem = [NSEntityDescription insertNewObjectForEntityForName:@&quot;SubItem&quot; inManagedObjectContext:self.managedObjectContext];
    
    [item addSubitemsObject:subItem];

this error appear:

    2011-09-12 10:28:45.236 Test[2002:707] *** -[NSSet intersectsSet:]: set argument is not an NSSet

Can you help me?

**Update:**

After just 1,787 days from my bug report, today (August 1, 2016) Apple wrote me this: *&quot;Please verify this issue with the latest iOS 10 beta build and update your bug report at bugreport.apple.com with your results.&quot;*. Let&#39;s hope this is the right time :)

  [1]: http://i.stack.imgur.com/CYI00.png

Exception thrown in NSOrderedSet generated accessors

I have an iOS app that I want to convert to using **ARC**. I would just use the migration tool, but it errors out for me consistently during the preview phase.

I know I can use the `-fobjc-arc` compiler directive on a file-by-file basis, but I want to enable **ARC** on the entire project, then turn off individual classes using `-fno-objc-arc`. 

New projects in 4.2 can use ARC by default, so there must be a switch somewhere.

Can anyone help me to convert the project to `ARC`



How do you enable ARC project-wide in Xcode 4.2

I use Apple Reachability class from Apple Sample code
[Reachability][1]

in Xcode 4.2 and new Apple 3.0 compiler I get warning in this class that

    + (Reachability*) reachabilityWithAddress: (const struct sockaddr_in*) hostAddress;

*declaration of &#39;struct sockaddr_in*&#39; will not be visible outside of this function* 

I am not good at classic C %) so I dont understand how I can fix this warning or may be I can ignore it at all. 

Thx


  [1]: http://developer.apple.com/library/ios/#samplecode/Reachability/Listings/ReadMe_txt.html

Xcode 4.2 - declaration of &#39;...&#39; will not be visible outside of this function warning

Is there a way to insert a Table Header View (tableHeaderView) in StoryBoard (like we used to do in Interface Builder)?

Content Type	Original Author	Original Content on Stackoverflow
Question	soob	View Question on Stackoverflow
Solution 1 - Ios	Joshua Nozzi	View Answer on Stackoverflow
Solution 2 - Ios	Jayprakash Dubey	View Answer on Stackoverflow
Solution 3 - Ios	amrit_neo	View Answer on Stackoverflow

How can I safely delete in my ~/Library/Developer/Xcode/DerivedData directory?

Ios Problem Overview

Ios Solutions

Solution 1 - Ios

Solution 2 - Ios

Solution 3 - Ios

Image Greyscale with CSS & re-color on mouse-over?

jQuery select option elements by value

Attributions