Broadcom Objective-C Style Guide

This document describes the Objective-C coding style of the iOS Mobile SDK team. This guideline is recommended to comply with all Objective-C implementations of our products.

Review Apple Official Coding Guideline

Beyond the guidelines defined in this document, we also recommend reviewing the Apple official coding guidelines.

Programming with Objective-C
Cocoa Fundamentals Guide
Coding Guidelines for Cocoa
App Programming Guide for iOS

iOS Mobile SDK

The iOS Mobile SDK Mobile consists of these frameworks:

MASFoundation
MASUI
MASConnecta
MASIdentityManagement
MASStorage

All of frameworks are recommended to comply with the coding guideline. For more information about the iOS Mobile SDK, see developer website.

Documentation

All code should be properly documented in .h and .m files. Code documentation should adhere to Apple Doc's format.

Our team uses a tool that automatically generates document format in Xcode called VVDocumenter available through Alcatraz.

Recommendation: Install Alcatraz and VVDocumenter. This tool automatically generates the proper documentation format for methods, properties, classes, and any other form of section required for documentation.

Pragma Mark

# pragma mark - categorizes methods or properties in the header and implementation files in Xcode. It makes the code easier to organize and navigate by other developers.

Commonly Used Pragma Mark

There are few a commonly used # pragma mark in MASFoundation. Follow these guidelines for categories.

# pragma mark - Properties
# pragma mark - Lifecycle
# pragma mark - Public
# pragma mark - Private

These are commonly used # pragma mark - in MASFoundation. Any other functional group of methods are fine, as long as it makes sense to everyone.

For example:

In MASDevice.h, methods that are related to BLE functionalities could be grouped in # pragma mark - Bluetooth Central/Peripheral.

Pragma Mark syntax

Follow the standard format of pragma mark that is also compatible with Apple Doc.

For example:

///--------------------------------------
/// @name Properties
///--------------------------------------

# pragma mark - Properties

Not:

#pragma mark - 
#pragma mark - Properties

Note: Allow one space between # and the pragma mark.

Organization of Pragma Mark

Order of the # pragma mark matters. Place all of the commonly used # pragma mark at the top, followed by the others.
Order of the # pragma mark should be identical in both header and implementation files.
All of the methods under # pragma mark should be in alphabetical order.

Imports

Imports may or may not be in alphabetical order
Always make use of foward declaration in the interface (.h) file. I.e. @class MASObject instead of #import "MASObject.h"

For example:

//
// All imported classes should be in alphabetical order
//
#import <MASFoundation/MASApplication.h>
#import <MASFoundation/MASAuthenticationProvider.h>
#import <MASFoundation/MASAuthenticationProviders.h>
#import <MASFoundation/MASConfiguration.h>
#import <MASFoundation/MASDevice.h>
#import <MASFoundation/MASFile.h>
#import <MASFoundation/MASGroup.h>
#import <MASFoundation/MASObject.h>
#import <MASFoundation/MASUser.h>
#import <MASFoundation/MASSessionSharingQRCode.h>
#import <MASFoundation/MASMessage.h>

Not:

#import <MASFoundation/MASObject.h>
#import <MASFoundation/MASAuthenticationProviders.h>
#import <MASFoundation/MASAuthenticationProvider.h>
#import <MASFoundation/MASConfiguration.h>
#import <MASFoundation/MASMessage.h>
#import <MASFoundation/MASDevice.h>
#import <MASFoundation/MASFile.h>
#import <MASFoundation/MASApplication.h>
#import <MASFoundation/MASGroup.h>
#import <MASFoundation/MASUser.h>
#import <MASFoundation/MASSessionSharingQRCode.h>

Constants

Constants are meant to be used 1) for easy reproduction of commonly used values in multiple places in same or multiple classes and 2) to avoid insertion of hard coded values in the implementation file. For contant values that will be publicly available, place constants in MASConstant.h file; otherwise, place constants in MASConstantsPrivate.h files.

For constants syntax, always declare the variable as a static constant and avoid using #define unless it is meant to be used as a macro.

For example:

static NSString *const MASPublicConstantValue = @"MASPublicConstantValue";

Not:

#define MASAvoidUsingThisConstant @"MASAvoidUsingThisConstant"

Spacing / Newline

Use consistent spacing format across all places in the code.
For indentation, use 4 spaces. In Xcode's preference > Text Editing > Indentation, Tab and indent 4 spaces (default value).

Documentation / In-line Comment

Documentation

For methods, properties, and class documentation, use VVDocumenter to ensure consistency for documentation styles.

For example:

Method

/**
 *  Sets the MASDeviceRegistrationType property.  The default is MASDeviceRegistrationTypeClientCredentials.
 *
 *  @param registrationType The MASDeviceRegistrationType.
 */
+ (void)setDeviceRegistrationType:(MASDeviceRegistrationType)registrationType;

Property

/**
 *  The class name of the object.
 */
@property (nonatomic, readonly, copy) NSString *className;

In-line Comment

Add an in-line comment above the line of code
Add in-line comments to ensure understanding for other developers
Use leading and trailing empty in-line comment, //
Add 1 space between the comments and in-line comment section

For example:

//
// Place an in-line comment like this
//

Not:

//Don't do in-line comment like this

Property / Enum

Spacing

Spaces should be added for each word and * and property name should not have a space.

For examples:

Property

@property (nonatomic, copy, readwrite) NSString *userName;

Enum

typedef NS_ENUM(NSInteger, MASDeviceRegistrationType)

Not:

@property(nonatomic, copy,readwrite) NSString*userName;

Newline

Use 2 new lines between each property declaration and 1 new line for the first property in pragma mark section in .h file. And use proper documentation for the description of the property.

For examples:

///--------------------------------------
/// @name Managing Object Properties
///--------------------------------------

# pragma mark - Managing Object Properties

/**
 *  The class name of the object.
 */
@property (nonatomic, readonly, copy) NSString *className;


/**
 *  The id of the object.
 */
@property (nonatomic, readonly, copy) NSString *objectId;

///--------------------------------------
/// @name MAS Constants
///--------------------------------------

# pragma mark - MAS Constants

/**
 * The enumerated MASRegistrationTypes.
 */
typedef NS_ENUM(NSInteger, MASDeviceRegistrationType)
{
    /**
     * Unknown encoding type.
     */
    MASDeviceRegistrationTypeUnknown = -1,
    
    /**
     * The client credentials registration type.
     */
    MASDeviceRegistrationTypeClientCredentials,
...
...
};


/**
 * The enumerated MASRequestResponseTypes that can indicate what data format is expected
 * in a request or a response.
 */
typedef NS_ENUM(NSInteger, MASRequestResponseType)
{
...
...

Not:

///--------------------------------------
/// @name Managing Object Properties
///--------------------------------------
# pragma mark - Managing Object Properties
/**
 *  The class name of the object.
 */
@property (nonatomic, readonly, copy) NSString *className;
/**
 *  The id of the object.
 */
@property (nonatomic, readonly, copy) NSString *objectId;

Method

Spacing

Use 1 space after the method scope and between the method segments.
Use 1 space between object type and * for every parameter and return type of the method if needed.

For example:

+ (void)start:(MASCompletionErrorBlock)completion;

+ (MASObject *)currentObject;

- (void)setObject:(id)object forKeyedSubscript:(id <NSCopying>)key;

Not:

+ (void)start: (MASCompletionErrorBlock)completion;

+(MASObject*)currentObject;

-(void)setObject:(id)object forKeyedSubscript:(id<NSCopying>)key;

Newline

Use 3 new lines between each method declarations and 1 new line for the first property in pragma mark section in .h file.
Use 2 new lines between each method declarations and 1 new line for the first property in pragma mark section in .m file.
Opening and closing braces for method implementation should always be in newline.
All private methods that are not present in .h file should also be documented in .m file with same documentation format.

For example: (.h file)

///--------------------------------------
/// @name Accessors
///--------------------------------------

# pragma mark - Accessors

/**
 *  Returns the value associated with a given key.
 *
 *  @param key The given identifying key for which to return the corresponding value.
 *
 *  @return The value associated with a given key.
 */
- (id)objectForKey:(id)key;



/**
 *  Sets the object associated with a given key.
 *
 *  @param object The object for `key`. A strong reference to the object is maintaned by MASObject.
 *                Raises an `NSInvalidArgumentException` if `object` is `nil`.
 *                If you need to represent a `nil` value - use `NSNull`.
 *
 *  @param key    The key for `object`. Raises an `NSInvalidArgumentException` if `key` is `nil`.
 */
- (void)setObject:(id)object forKey:(id <NSCopying>)key;

For example: (.m file)

#pragma mark - pragma section

- (id)objectForKey:(id)key
{
...
    return object;
}


- (void)setObject:(id)object forKey:(id <NSCopying>)key
{
...
}

If/Switch/For and other statements

Spacing / Newline

Use 1 space in between control statement and bracket as well as properties and operator.
Opening brace should always be in new line for first if statement, other else or else if's opening brace should be placed in the same line.
Closing brace should always be in new line.
Opening and closing brace should always be included even for one line of code in the statement.

For example:

if (isBoolean) 
{
...
}
else {

}

if (isBoolean && isNotBoolean && [[MASObject currentObject] isBoolean]) 
{
...
}
else if (otherBoolean) {
...
}

if (isBoolean)
{
  counter++;
}

switch (type) {
    //
    // Configuration
    //
    case MASSwitchValue:
        value = @"value";
        break;
            
    //
    // Default
    //
    default: 
      value = @"default";
      break;
}

for (NSString *stringObj in objects)
{
...
}

Not:

if(isBoolean){
...
}else{

}

if (isBoolean && isNotBoolean&& [[MASObject currentObject]isBoolean]){
...
} else if(otherBoolean) 
{
...
}

if (isBoolean) counter++;

switch(type){
    case MASSwitchValue:
        value = @"value";
        break;
            
    default: 
      value = @"default";
      break;
}

for(NSString *stringObj in objects){
...
}

Nullability for Swift

Because we want to support Swift with bridge header, please be aware of Nullability while writing codes in Objective-C. In Objective-C, Nullability does not make any difference, but it will make a difference when developers are using our framework in Swift.

Use _Nullable and _Nonnull type annotation in properties and methods.

For example:

@property (copy, nullable) NSString *name;
@property (copy, readonly, nonnull) NSDictionary *thisDictionary;

For more detail, see this blog post

Project Configuration Guideline

Because we are maintaining multiple frameworks, ensure that all frameworks use the same style, format, and file structure.

File Structure

For any new files or folder (groups in xCode), use the following folder structure.

- Framework name folder (i.e. MASFoundation, MASUI, MASConnecta)
-- Framework public header file
-- Class (Folder)
--- categories
--- models
--- _private_
---- categories
---- services
---- models
-- Vender

All public files should be located under Classes, categories (under Classes) and models (under Classes).
All private files should be located under categories, services, models, or any other folders under _private folder.
When making a new group in Xcode, create an actual directory in file system, and add the directory into the project as group.
If third-party libraries are being used, include them in the Vendor folder.
It is recommended to rename the prefix of third-party libraries to avoid any conflict with other developers' project which may use the same library.
Verify that you have a valid third-party library license, and that you are allowed to use it.

Class Naming

All classes should start with the prefix, MAS, except for the category class from iOS SDK or other vendors.

All frameworks

For a newly created model class, the class should be inherited from MASObject.h.
For a newly created service class, the class should be inherited from MASService.h.
For a class used in two or more frameworks, a model of the class must be created in MASFoundation and a category of the class in the specific framework.

MASService

When you create a new service class, make sure to implement a service class that is inherited from MASService.

Define a constant in MASConstantsPrivate.h class with a uniquely generated UUID.
When you are creating a service class in an external framework outside of MASFoundation, include the UUID in MASConstantsPrivate.h and use the same UUID value in the external service class' + (NSString *)serviceUUID property.

For example:

+ (NSString *)serviceUUID
{
    // DO NOT change this without a corresponding change in MASFoundation
    return @"8b66aaa4-efbf-11e5-9ce9-5e5517507c66";
}

MASUI

For a newly created viewController class, the class should be inherited from MASViewController.h.

Category Class

For public category classes, specify the name using the framework name. If the category is not public, use the framework name and the word Private in the end. Privates categories must be created under the _private_ folder.

For example:

// For public category class
@interface NSData (MASFoundation)

// For private category class. Must reside inside the _private_ folder
@interface MASUser (MASFoundationPrivate)

Framework Error Handling

All frameworks handle errors with proper framework error domains.

In MASConstants, or any framework constant file, properly define the error domain constants. The error domain format should be com.ca.FRAMEWORKNAME:SUB_DOMAIN.

For example:

// The NSString error domain used by all MAS server related Foundation level NSErrors.
static NSString *const MASFoundationErrorDomain = @"com.ca.MASFoundation:ErrorDomain";

// The NSString error domain used by all MAS local level NSErrors.
static NSString *const MASFoundationErrorDomainLocal = @"com.ca.MASFoundation.localError:ErrorDomain";

// The NSString error domain used by all target API level NSErrors.
static NSString *const MASFoundationErrorDomainTargetAPI = @"com.ca.MASFoundation.targetAPI:ErrorDomain";

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GUIDELINES.md

GUIDELINES.md

Broadcom Objective-C Style Guide

Review Apple Official Coding Guideline

iOS Mobile SDK

Table of Contents

Documentation

Pragma Mark

Commonly Used Pragma Mark

Pragma Mark syntax

Organization of Pragma Mark

Imports

Constants

Spacing / Newline

Documentation / In-line Comment

Documentation

In-line Comment

Property / Enum

Spacing

Newline

Method

Spacing

Newline

If/Switch/For and other statements

Spacing / Newline

Nullability for Swift

Project Configuration Guideline

File Structure

Class Naming

All frameworks

MASService

MASUI

Category Class

Framework Error Handling

Files

GUIDELINES.md

Latest commit

History

GUIDELINES.md

File metadata and controls

Broadcom Objective-C Style Guide

Review Apple Official Coding Guideline

iOS Mobile SDK

Table of Contents

Documentation

Pragma Mark

Commonly Used Pragma Mark

Pragma Mark syntax

Organization of Pragma Mark

Imports

Constants

Spacing / Newline

Documentation / In-line Comment

Documentation

In-line Comment

Property / Enum

Spacing

Newline

Method

Spacing

Newline

If/Switch/For and other statements

Spacing / Newline

Nullability for Swift

Project Configuration Guideline

File Structure

Class Naming

All frameworks

MASService

MASUI

Category Class

Framework Error Handling