Constants

Defined constants of the Shadow library.

Libraries may #define constants in their headers with special meanings. This page describes the meanings and uses of any constants defined by the Shadow library. Related constants are shown in a single section on this page.

Shadow Initializers

Provides default values for the data types of the Shadow library.

#define AWS_IOT_SHADOW_CALLBACK_INFO_INITIALIZER    { 0 }        
#define AWS_IOT_SHADOW_DOCUMENT_INFO_INITIALIZER    { 0 }        
#define AWS_IOT_SHADOW_OPERATION_INITIALIZER        NULL         

All user-facing data types of the Shadow library should be initialized using one of the following.

Warning

Failing to initialize a Shadow data type with the appropriate initializer may result in undefined behavior!

Note

The initializers may change at any time in future versions, but their names will remain the same.

Example

AwsIotShadowCallbackInfo_t callbackInfo = AWS_IOT_SHADOW_CALLBACK_INFO_INITIALIZER;
AwsIotShadowDocumentInfo_t documentInfo = AWS_IOT_SHADOW_DOCUMENT_INFO_INITIALIZER;
AwsIotShadowOperation_t operation = AWS_IOT_SHADOW_OPERATION_INITIALIZER;

Shadow Function Flags

Flags that modify the behavior of Shadow library functions.

Flags should be bitwise-ORed with each other to change the behavior of Shadow library functions.

The following flags are valid for the Shadow operation functions: AwsIotShadow_DeleteAsync, AwsIotShadow_GetAsync, AwsIotShadow_UpdateAsync, and their blocking versions.

• AWS_IOT_SHADOW_FLAG_WAITABLE
  Allows the use of AwsIotShadow_Wait for blocking until completion.
• AWS_IOT_SHADOW_FLAG_KEEP_SUBSCRIPTIONS
  Maintain the subscriptions for the Shadow operation topics, even after this function returns.

The following flags are valid for AwsIotShadow_RemovePersistentSubscriptions. These flags are not valid for the Shadow operation functions.

• AWS_IOT_SHADOW_FLAG_REMOVE_DELETE_SUBSCRIPTIONS
  Remove the persistent subscriptions from a Shadow delete operation.
• AWS_IOT_SHADOW_FLAG_REMOVE_GET_SUBSCRIPTIONS
  Remove the persistent subscriptions from a Shadow get operation.
• AWS_IOT_SHADOW_FLAG_REMOVE_UPDATE_SUBSCRIPTIONS
  Remove the persistent subscriptions from a Shadow update operation.

Note

The values of the flags may change at any time in future versions, but their names will remain the same. Additionally, flags which may be used at the same time will be bitwise-exclusive of each other.