Objective-C Coding Style

Transcript

1. Objective-C Coding Style
2. General rules For methods that represent actions an object • takes, start the name with a verb. E.g.: • - (void)invokeWithTarget:(id)target; • - (void)selectTabViewItem:(NSTabViewItem *)tabViewItem •
3. General rules If the method returns an attribute of the • receiver, name the method after the attribute. E.g.: • - (NSSize)cellSize; Right. - (NSSize)calcCellSize; Wrong. - (NSSize)getCellSize; Wrong.
4. General rules Make the word before the argument describe • the argument. E.g.: • - (id)viewWithTag:(NSInteger)aTag; Right. - (id)taggedView:(int)aTag; Wrong.
5. General rules Don’t use “and” to link keywords that are • attributes of the receiver. E.g.: • - (int)runModalForDirectory:(NSString *)path file:(NSString *) name types:(NSArray *)fileTypes; Right. - (int)runModalForDirectory:(NSString *)path andFile:(NSString *)name andTypes:(NSArray *)fileTypes; Wrong.
6. Accessor Methods Accessor methods are those methods that set and return • the value of a property of an object. If the property is expressed as a noun, the format is: • - (NSString *)title; • - (void)setTitle:(NSString *)aTitle; • If the property is expressed as an adjective, the format is: • - (BOOL)isEditable; • - (void)setEditable:(BOOL)flag; •
7. Accessor Methods If the property is expressed as a verb, the format is: • - (BOOL)showsAlpha; • - (void)setShowsAlpha:(BOOL)flag; • The verb should be in the simple present tense. • - (void)setAcceptsGlyphInfo:(BOOL)flag; Right. - (BOOL)acceptsGlyphInfo; Right. - (void)setGlyphInfoAccepted:(BOOL)flag; Wrong. - (BOOL)glyphInfoAccepted; Wrong.
8. Accessor Methods You may use modal verbs (verbs preceded by “can”, “should”, • “will”, and so on) to clarify meaning, but don’t use “do” or “does”. - (BOOL)canHide; • - (BOOL)doesAcceptGlyphInfo; •
9. Accessor Methods Use “get” only for methods that return objects and values • indirectly. You should use this form for methods only when multiple items need to be returned. E.g.: • - (void)getLineDash:(float *)pattern count:(int *)count phase:(float • *)phase;
10. Delegate Methods Start the name by identifying the class of the object • that’s sending the message. E.g.: • - (BOOL)tableView:(NSTableView *)tableView shouldSelectRow:(int)row; • - (BOOL)application:(NSApplication *)sender openFile:(NSString • *)filename;
11. Delegate Methods Use “did” or “will” for methods that are invoked to • notify the delegate that something has happened or is about to happen. E.g.: • - (void)browserDidScroll:(NSBrowser *)sender; • - (NSUndoManager *)windowWillReturnUndoManager:(NSWindow • *)window;
12. Naming notifications [Name of associated class] • + [Did | Will] • + [UniquePartOfName] • + Notification • E.g.: • NSApplicationDidBecomeActiveNotification NSWindowDidMiniaturizeNotification NSTextViewDidChangeSelectionNotification NSColorPanelColorDidChangeNotification
13. Coding Style Position of “*”: • NSString *varName; • Method declaration • - (void)doSomethingWithString:(NSString *)theString{ • } A space after -/+ space No space for first argument
14. Coding Style Method with arguments: (void)doSomgthingWith:(GTMFoo *)theFoo - rect:(CGRect)theRect interval:(float)theInterval{ } Align with “:”
15. Coding Style Method name shorter than arguments: - (void)short:(GTMFoo *)theFoo longKeyword:(NSRect)theRect evenLongerKeyword:(float)theInterval{ } At least 4 space indentation • Align vertically •
16. Coding Style For constent like (#define, enums, const), use ‘k’ as prefix: • E.g.: kInvalidHandle • #Import/#Include • Import objectiveC; • Include c/c++ • Import whole framework even when only need a few files • #import <Foundation/NSArray.h> • #import <Foundation/Foundation.h> •
17. Coding Style BOOL trap: • BOOL defined as unsigned char • DO NOT compare BOOL with YES/NO • BOOL great = [foo isGreat]; • If(great == YES) • If(great) •
18. Reference Coding guidelines for Cocoa • https://developer.apple.com/library/ios/#documentation/Cocoa /Conceptual/CodingGuidelines/CodingGuidelines.html#//apple_ ref/doc/uid/10000146-SW1 Daniel’s Objective-C Coding Style http://www.slideshare.net/AVking/daniels-objective-c-coding- style-guidelines?from=embed