StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
primarykey
Id
214710
data
AcceptedAnswerId
0
AnswerCount
0
ClosedDate
CommentCount
0
CommunityOwnedDate
2010-07-13T04:07:35.383
CreationDate
2008-10-18T07:24:28.067
FavoriteCount
0
LastActivityDate
2008-10-18T07:24:28.067
LastEditDate
LastEditorUserId
0
OwnerUserId
21834
ParentId
211616
PostTypeId
2
Score
4
ViewCount
0
LastEditorDisplayName
text
Body
Objective-C Runtime Reference It's easy to forget that the syntactic sugar of Objective-C is converted to normal C function calls that are the Object-C Runtime. It's likely that you will never need to actually delve into and use anything in the runtime. That is why I would consider this a 'hidden feature'. Let me give a way one might use the runtime system. Let's say that someone is designing an external framework API that will be used by third parties. And that someone designs a class in the framework that abstractly represents a packet of data, we'll call it <code>MLAbstractDataPacket</code>. Now it's up to the application who is linking in the framework to subclass <code>MLAbstractDataPacket</code> and define the subclass data packets. Every subclass must override the method <code>+(BOOL)isMyKindOfDataPacket:(NSData *)data</code>. With that information in mind... It would be nice if <code>MLAbstractDataPacket</code> provided a convenience method that returned the correct initialized class for a packet of data that comes in the form <code>+(id)initWithDataPacket:(NSData *)data</code>. There's only one problem here. The superclass doesn't know about any of its subclasses. So here you could use the runtime method <code>objc_getClassList()</code> along with <code>objc_getSuperclass()</code> to find the classes that are subclasses of MLAbstractDataPacket. Once you have a list of subclasses you can then try <code>+isMyKindOfDataPacket:</code> on each until one is found or not found. The reference information about this can be found at <a href="http://developer.apple.com/documentation/Cocoa/Reference/ObjCRuntimeRef/Reference/reference.html" rel="nofollow noreferrer">http://developer.apple.com/documentation/Cocoa/Reference/ObjCRuntimeRef/Reference/reference.html</a>.
Tags
Title
singulars
PostAcceptedAnswerId
1. This table or related slice is empty.
PostParentId
1. POHidden features of Objective-C
 singulars
 PostTypePostTypeId
 PTQuestion
PostTypePostTypeId
1. PTAnswer
UserLastEditorUserId
1. This table or related slice is empty.
UserOwnerUserId
1. USMichael Ledford
plurals
PostLinksPostIdRelatedPostId
1. This table or related slice is empty.
PostLinksRelatedPostIdPostId
1. This table or related slice is empty.
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. This table or related slice is empty.
VotesPostIdCreationDate
1. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
2. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
3. VO
 singulars
 PostPostId
 PO
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
CommentsPostId
1. This table or related slice is empty.

Querying!

Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.