change method to properties (#374)

* change method to properties

* fix nullability

Author: e7mac

Leanplum-SDK/Classes/LPInbox.h

@@ -38,50 +38,50 @@ NS_SWIFT_NAME(LeanplumInbox.Message)
 /**
  * Returns the message identifier of the inbox message.
  */
-- (NSString *)messageId;
+@property (strong, nonatomic, readonly, nonnull) NSString *messageId;
 
 /**
  * Returns the title of the inbox message.
  */
-- (NSString *)title;
+@property (strong, nonatomic, readonly, nonnull) NSString *title;
 
 /**
  * Returns the subtitle of the inbox message.
  */
-- (NSString *)subtitle;
+@property (strong, nonatomic, readonly, nonnull) NSString *subtitle;
 
 /**
  * Returns the image path of the inbox message. Can be nil.
  * Use with [UIImage contentsOfFile:].
  */
-- (nullable NSString *)imageFilePath;
+@property (strong, nonatomic, readonly, nullable) NSString *imageFilePath;
 
 /**
  * Returns the image URL of the inbox message.
  * You can safely use this with prefetching enabled.
  * It will return the file URL path instead if the image is in cache.
  */
-- (nullable NSURL *)imageURL;
+@property (strong, nonatomic, readonly, nullable) NSURL *imageURL;
 
 /**
  * Returns the data of the inbox message. Advanced use only.
  */
-- (nullable NSDictionary *)data;
+@property (strong, nonatomic, readonly, nullable) NSDictionary *data;
 
 /**
  * Returns the delivery timestamp of the inbox message.
  */
-- (nullable NSDate *)deliveryTimestamp;
+@property (strong, nonatomic, readonly, nullable) NSDate *deliveryTimestamp;
 
 /**
  * Return the expiration timestamp of the inbox message.
  */
-- (nullable NSDate *)expirationTimestamp;
+@property (strong, nonatomic, readonly, nullable) NSDate *expirationTimestamp;
 
 /**
  * Returns YES if the inbox message is read.
  */
-- (BOOL)isRead;
+@property (assign, nonatomic, readonly) BOOL isRead;
 
 /**
  * Read the inbox message, marking it as read and invoking its open action.
@@ -113,33 +113,33 @@ NS_SWIFT_NAME(LeanplumInbox)
 /**
  * Returns the number of all inbox messages on the device.
  */
-- (NSUInteger)count;
+@property (assign, nonatomic, readonly) NSUInteger count;
 
 /**
  * Returns the number of the unread inbox messages on the device.
  */
-- (NSUInteger)unreadCount;
+@property (assign, nonatomic, readonly) NSUInteger unreadCount;
 
 /**
  * Returns the identifiers of all inbox messages on the device sorted in ascending
  * chronological order, i.e. the id of the oldest message is the first one, and the most
  * recent one is the last one in the array.
  */
-- (NSArray<NSString *> *)messagesIds;
+@property (strong, nonatomic, readonly, nonnull) NSArray<NSString *> *messagesIds;
 
 /**
  * Returns an array containing all of the inbox messages (as LPInboxMessage objects)
  * on the device, sorted in ascending chronological order, i.e. the oldest message is the 
  * first one, and the most recent one is the last one in the array.
  */
-- (NSArray<LPInboxMessage *> *)allMessages;
+@property (strong, nonatomic, readonly, nonnull) NSArray<LPInboxMessage *> *allMessages;
 
 /**
  * Returns an array containing all of the unread inbox messages on the device, sorted
  * in ascending chronological order, i.e. the oldest message is the first one, and the
  * most recent one is the last one in the array.
  */
-- (NSArray<LPInboxMessage *> *)unreadMessages;
+@property (strong, nonatomic, readonly, nonnull) NSArray<LPInboxMessage *> *unreadMessages;
 
 /**
  * Returns the inbox messages associated with the given messageId identifier.