When generating class files to represent your data model’s entities, mogenerator writes a few convenience class methods for you:
+ (id)insertInManagedObjectContext:(NSManagedObjectContext*)moc_; + (NSString*)entityName; + (NSEntityDescription*)entityInManagedObjectContext:(NSManagedObjectContext*)moc_;
These handy class methods allow you to write something like this:
to create a new instance. Contrast with:
[NSEntityDescription insertNewObjectForEntityForName:@"MyEntity" inManagedObjectContext:moc];
The mogenerator way is more obvious, less code and not stringly typed.
So that’s the backgrounder.
The good news is Apple likes mogenerator so much that they used it to implement iOS’s PhotoLibraryServices.framework.
The bad news is that PhotoLibraryServices.framework is a private framework.
As a first line of defense against naughty developers submitting apps that use undocumented APIs, Apple sweeps up every selector (method name) defined in all private frameworks and puts them on a special list. The “non-public selectors” list.
Unfortunately this includes the convenience methods mentioned above.
If your App Store submission is found to be use non-public selectors Apple may do nothing, issue a warning or reject your submission altogether.
※ ※ ※
I’m not sure what to do about this.
I could not supply the convenience methods and use Core Data directly like an animal. No! I won’t go back. I can’t go back.
Prefixing the methods (perhaps with an
mo_) would provide relief, but only temporarily. When Apple upgrades PhotoLibraryServices to the newer version of mogenerator the cycle would begin anew.
NS is designed for optional class namespacing, but its concepts could be applied to method names as well. Unfortunately at the method level it uglies up the code and confuses Xcode’s code navigator popup menu. Also it would probably require
NS_NAMESPACE preprocessor symbol be defined at the target or project level.
Apple could explicitly whitelist mogenerator’s convenience methods but I’m not holding my breath.
The next version of mogenerator could be released under an “Anyone But Apple” license. The idea is to allow everyone but Apple to use mogenerator. I could prefix the methods and issue the mogenerator upgrade knowing Apple couldn’t upgrade and claim the new methods as their own again.
Sadly, this seems like the most promising option.
(Thanks to Tony Arnold for the wording for the title of this post.)
Update Apr 18: First off, a clarification: it appears Apple has never rejected an application using mogenerator’s methods — they’ve only issued warnings.
Now for the good news: a little birdie has told me Apple has whitelisted mogenerator’s methods.
[NEW] You can now pass .xcdatamodeld paths to mogenerator. mogenerator will look inside the directory, read its hidden
.xccurrentversion file and use the “current” .xcdatamodel file. (Alexander Zats)
[NEW] Replaced mogenerator’s previous testing system (the test mule) with a new Rakefile-based system that eases building & testing from the current source tree and tests both MRC and ARC. (rentzsch)
[NEW] Property declarations generated from attributes can now be qualified as readonly by adding a
mogenerator.readonly to an attribute’s userinfo. (crispinb)
--configuration option that limits generation to the specified configuration. (Sixten Otto)
--base-class-import option for fine-grained control of base class import statements. (David Aspinall)
keyPathsForValuesAffectingValueForKey: generated code (returns after first match). (Sean M)
[CHANGE] Add default private class extension to human source template. (Jonas Schnelli)
[FIX] Align generated code’s pointer asterisks more consistently. (Tony Arnold)
[FIX] Missing import when using mogenerator.customBaseClass entity userinfo key. (Thomas Guthrie)
[FIX] Handle case in generated fetch request wrapper machine code when predicate variables are repeated. (Sergei Winitzki)
[FIX] Explicitly set mogenerator project’s deployment target to 10.6 to avoid segfaulting on 10.8 for some reason. issue 121 (reported by Sixten Otto, diagnosed by Florian Bürger)
[FIX] Cast to unsigned in machine source to avoid clang format string warning. (rentzsch)
[FIX] Don’t attempt to report errors through -[NSApp reportError:] in generated machine source unless targeting AppKit. (rentzsch)
[WORKAROUND] Recent versions of Xcode use an empty string to mark entities that do not have a custom subclass. (Matthias Bauch)
[CHANGE] make_installer.command: assume PackageMaker now lives in /Applications/Utilities. (rentzsch)
[NEW] mogenerator’s standard templates are now bundled into the mogenerator binary itself. This should solve the problem of templates growing out of sync with the intended version of mogenerator (exacerbated by the now-popular homebrew installer). You can still use your own templates with the
--template-group parameters. issue 79 (Ingvar Nedrebo, rentzsch).
[NEW] Support for per-entity custom base classes, set via
mogenerator.customBaseClass key in the entity’s user info. (Trevor Squires)
[CHANGE] mogenerator installer no longer installs separate template files (but it won’t touch those already installed).
[CHANGE] mogenerator’s .pkg installer no longer includes Xmo’d since 1) Xmo’d doesn’t work with Xcode 4 yet and 2) Xcode.app now lives in /Applications, so the installer needs to get smarter to cope.
[NEW] Support for Xcode 4.3 and it’s relocation of
momc into its bundle. Only supports /Applications/Xcode.app for now. (Matt McGlincy)
[NEW] Can now generate
NSFetchedResultsController creation code for to-many relationships (use
--template-var frc=true). (Daniel Tull)
[DOC] Link to John Blanco’s Getting Started with Mogenerator.
[NEW] Now generates Mike Ash-style constant structures for attributes, relationships and fetched properties. This allows you to write code like
[obj valueForKey:PersonMOAttributes.age]. Tip: you’ll need to enable ARC generation (
--template-var arc=true) if you’re using ARC. (Daniel Tull)
--base-class-force option, for specifying a base class even if the model file’s entities don’t specify one. (Joe Carroll)
[NEW] PONSO: NSSet-based templates, improved inverse relationship logic and plug memory leak. (Tyrone Trevorrow)
[FIX] PONSO: Added import for super entity in machine headers. (Tyrone Trevorrow)
[FIX] Migrate from deprecated
-[NSString initWithContentsOfFile:] and fix a MiscMerge warning where an immutable object was assigned to a mutable ivar. (Joshua Smith)
[NEW] New template that dumps a binary .xcdatamodel into a pseudo-ASCII-plist format perfect for diffing. A great way to compare two versions of a data model. (Brian Webster)
[NEW] Attributes and relationships are now sorted for generation. This should eliminate spurious changes to source files when unrelated model entities are changed. After upgrading to 1.23 you probably want to regenerate all your source files without a model change, just to let things settle in before your next real model change. (Nikita Zhuk)
[NEW] Support for generation of PONSOs: Plain Old NSObjects. These are in-memory, typesafe non-CoreData classes generated from your Xcode data models. Generate reams of ObjC classes from a single data model. Supports relationships and basic serialization. See
contributed templates/Nikita Zhuk/ponso/README.txt for details. (Nikita Zhuk)
[NEW] Support for
momc error-reporting options:
MOMC_SUPPRESS_INVERSE_TRANSIENT_ERROR. (Nikita Zhuk)
[NEW] Now generates output directories if they don’t already exist or presents an error message if they cannot be created. (Scott Little)
include.m. (Zac Bowling)
[NEW] You can now use
--template-var to pass arbitrary command-line options through to templates. (Adam Cox)
[NEW] Update MiscMerge to NS(U)Integer for 64-bit compatibility. (Nikita Zhuk)
[FIX] Memory leaks in MiscMerge. (Nikita Zhuk)
mogenerate.command upgraded to use double-dash option names. (rentzsch)
[FIX] Set mogeneratorTestMule’s
mogenerate.command executable bit. (rentzsch)
-keyPathsForValuesAffectingValueForKey: is now generated in machine.m files, populated by your entity’s scalar attributes. The idea is code like
myObject.myIntAttributeValue++ tells Core Data that
myIntAttribute has changed (handy when you’re KVO-observing
myIntAttribute). (Tony Arnold)
[NEW] When a model file has multiple versions (
.xcdatamodeld files) Xmo’d now uses the “current” version of the model (set the “xmod” command on the xcdatamodeld group). (Vincent Guerci)
[NEW] mogenerator and Xmo’d now supports model-relative paths for the
--template-path argument. (tonklon)
[NEW] Machine templates now include fetched properties by default. (Jonathan del Strother)
[NEW] Xmo’d: better support for
--(machine|human|output)-dir model option path: now they can be full or relative to the model file. Xcode group and file references are no longer deleted/re-added with every save. (John Turnipseed)
--log-command model option. When enabled, Xmo’d will log (to Console.app) the generated+executed
mogenerator invocation. Good for automation debugging and also can provide training wheels for using mogenerator directly. (rentzsch)
nil substitution dictionary in generated fetch request wrapper code, which resulted in an
NSInvalidArgumentException reason “Cannot substitute a nil substitution dictionary.” (Anthony Mittaz)
[NEW] Xmo’d: model comments that start with
-- are passed as args to mogenerator. This allows accessing command-line options such as
--base-class. (David LeBer)
[CHANGE] LLVM 2/Xcode 4 doesn’t like
[NSDictionary dictionaryWithObjectsAndKeys:nil], issuing a “missing sentinel in method dispatch” warning. Add
prettyFetchRequests so we can just generate
NSDictionary *substitutionVariables = nil in that case. (Anthony Mittaz)
[FIX] Variable shadowing bug which would cause v1.19’s
xcode-select functionality to always fail. (Nikita Zhuk)
Forgot to mention v1.19 here:
xcode-selectto dynamically discover our way to
momcinstead of only hard-coding
/Developer. (Josh Abernathy)
[NEW] Xmo’d works with versioned data models. (rentzsch)
[NEW] Support for fetched properties (Nikita Zhuk)
NSParameterAssert(moc) in fetch request wrappers. (rentzsch)
Interestingly, as of this writing mogenerator 1.16 was downloaded ~60 times (a record) while 1.17 was downloaded 526 times (another record). Is word finally getting out?
Meh, probably just the influx of iPhone Core Data coders.