AFNetworkReachabilityManager.h

// AFNetworkReachabilityManager.h
// 
// Copyright (c) 2013 AFNetworking (http://afnetworking.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#import <Foundation/Foundation.h>
#import <SystemConfiguration/SystemConfiguration.h>

#import <netinet/in.h>
#import <netinet6/in6.h>
#import <arpa/inet.h>
#import <ifaddrs.h>
#import <netdb.h>

typedef NS_ENUM(NSInteger, AFNetworkReachabilityStatus) {
    AFNetworkReachabilityStatusUnknown          = -1,
    AFNetworkReachabilityStatusNotReachable     = 0,
    AFNetworkReachabilityStatusReachableViaWWAN = 1,
    AFNetworkReachabilityStatusReachableViaWiFi = 2,
};

/**
 `AFNetworkReachabilityManager` monitors the reachability of domains, and addresses for both WWAN and WiFi network interfaces.
 
 See Apple's Reachability Sample Code (https://developer.apple.com/library/ios/samplecode/reachability/)
 */
@interface AFNetworkReachabilityManager : NSObject

/**
 The current network reachability status.
 */
@property (readonly, nonatomic, assign) AFNetworkReachabilityStatus networkReachabilityStatus;

/**
 Whether or not the network is currently reachable.
 */
@property (readonly, nonatomic, assign, getter = isReachable) BOOL reachable;

/**
 Whether or not the network is currently reachable via WWAN.
 */
@property (readonly, nonatomic, assign, getter = isReachableViaWWAN) BOOL reachableViaWWAN;

/**
 Whether or not the network is currently reachable via WiFi.
 */
@property (readonly, nonatomic, assign, getter = isReachableViaWiFi) BOOL reachableViaWiFi;

///---------------------
/// @name Initialization
///---------------------

/**
 Returns the shared network reachability manager.
 */
+ (instancetype)sharedManager;

/**
 Creates and returns a network reachability manager for the specified domain.
 
 @param domain The domain used to evaluate network reachability.
 
 @return An initialized network reachability manager, actively monitoring the specified domain.
 */
+ (instancetype)managerForDomain:(NSString *)domain;

/**
 Creates and returns a network reachability manager for the socket address.

 @param address The socket address used to evaluate network reachability.

 @return An initialized network reachability manager, actively monitoring the specified socket address.
 */
+ (instancetype)managerForAddress:(const struct sockaddr_in *)address;

/**
 Initializes an instance of a network reachability manager from the specified reachability object.
 
 @param reachability The reachability object to monitor.
 
 @return An initialized network reachability manager, actively monitoring the specified reachability.
 */
- (instancetype)initWithReachability:(SCNetworkReachabilityRef)reachability;

///--------------------------------------------------
/// @name Starting & Stopping Reachability Monitoring
///--------------------------------------------------

/**
 Starts monitoring for changes in network reachability status.
 */
- (void)startMonitoring;

/**
 Stops monitoring for changes in network reachability status.
 */
- (void)stopMonitoring;

///-------------------------------------------------
/// @name Getting Localized Reachability Description
///-------------------------------------------------

/**
 Returns a localized string representation of the current network reachability status.
 */
- (NSString *)localizedNetworkReachabilityStatusString;

///---------------------------------------------------
/// @name Setting Network Reachability Change Callback
///---------------------------------------------------

/**
 Sets a callback to be executed when the network availability of the `baseURL` host changes.

 @param block A block object to be executed when the network availability of the `baseURL` host changes.. This block has no return value and takes a single argument which represents the various reachability states from the device to the `baseURL`.
 */
- (void)setReachabilityStatusChangeBlock:(void (^)(AFNetworkReachabilityStatus status))block;

@end

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

/**
 ## Network Reachability

 The following constants are provided by `AFNetworkReachabilityManager` as possible network reachability statuses.

 enum {
 AFNetworkReachabilityStatusUnknown,
 AFNetworkReachabilityStatusNotReachable,
 AFNetworkReachabilityStatusReachableViaWWAN,
 AFNetworkReachabilityStatusReachableViaWiFi,
 }

 `AFNetworkReachabilityStatusUnknown`
 The `baseURL` host reachability is not known.

 `AFNetworkReachabilityStatusNotReachable`
 The `baseURL` host cannot be reached.

 `AFNetworkReachabilityStatusReachableViaWWAN`
 The `baseURL` host can be reached via a cellular connection, such as EDGE or GPRS.

 `AFNetworkReachabilityStatusReachableViaWiFi`
 The `baseURL` host can be reached via a Wi-Fi connection.

 ### Keys for Notification UserInfo Dictionary

 Strings that are used as keys in a `userInfo` dictionary in a network reachability status change notification.

 `AFNetworkingReachabilityNotificationStatusItem`
 A key in the userInfo dictionary in a `AFNetworkingReachabilityDidChangeNotification` notification.
 The corresponding value is an `NSNumber` object representing the `AFNetworkReachabilityStatus` value for the current reachability status.
 */

///--------------------
/// @name Notifications
///--------------------

/**
 Posted when network reachability changes.
 This notification assigns no notification object. The `userInfo` dictionary contains an `NSNumber` object under the `AFNetworkingReachabilityNotificationStatusItem` key, representing the `AFNetworkReachabilityStatus` value for the current network reachability.

 @warning In order for network reachability to be monitored, include the `SystemConfiguration` framework in the active target's "Link Binary With Library" build phase, and add `#import <SystemConfiguration/SystemConfiguration.h>` to the header prefix of the project (`Prefix.pch`).
 */
extern NSString * const AFNetworkingReachabilityDidChangeNotification;
extern NSString * const AFNetworkingReachabilityNotificationStatusItem;

///--------------------
/// @name Functions
///--------------------

/**
 Returns a localized string representation of an `AFNetworkReachabilityStatus` value.
 */
extern NSString * AFStringFromNetworkReachabilityStatus(AFNetworkReachabilityStatus status);