AWS IoT Embedded C Device SDK
Data Structures | Typedefs | Enumerations | Functions
aws_iot_shadow_json_data.h File Reference

This file is the interface for all the Shadow related JSON functions. More...

#include <stddef.h>

Go to the source code of this file.

Data Structures

struct  jsonStruct
 This is the struct form of a JSON Key value pair. More...
 

Typedefs

typedef struct jsonStruct jsonStruct_t
 This is a static JSON object that could be used in code.
 
typedef void(* jsonStructCallback_t) (const char *pJsonValueBuffer, uint32_t valueLength, jsonStruct_t *pJsonStruct_t)
 Every JSON name value can have a callback. The callback should follow this signature.
 

Enumerations

enum  JsonPrimitiveType {
  SHADOW_JSON_INT32, SHADOW_JSON_INT16, SHADOW_JSON_INT8, SHADOW_JSON_UINT32,
  SHADOW_JSON_UINT16, SHADOW_JSON_UINT8, SHADOW_JSON_FLOAT, SHADOW_JSON_DOUBLE,
  SHADOW_JSON_BOOL, SHADOW_JSON_STRING, SHADOW_JSON_OBJECT
}
 All the JSON object types enum. More...
 

Functions

IoT_Error_t aws_iot_shadow_init_json_document (char *pJsonDocument, size_t maxSizeOfJsonDocument)
 Initialize the JSON document with Shadow expected name/value. More...
 
IoT_Error_t aws_iot_shadow_add_reported (char *pJsonDocument, size_t maxSizeOfJsonDocument, uint8_t count,...)
 Add the reported section of the JSON document of jsonStruct_t. More...
 
IoT_Error_t aws_iot_shadow_add_desired (char *pJsonDocument, size_t maxSizeOfJsonDocument, uint8_t count,...)
 Add the desired section of the JSON document of jsonStruct_t. More...
 
IoT_Error_t aws_iot_finalize_json_document (char *pJsonDocument, size_t maxSizeOfJsonDocument)
 Finalize the JSON document with Shadow expected client Token. More...
 
IoT_Error_t aws_iot_fill_with_client_token (char *pBufferToBeUpdatedWithClientToken, size_t maxSizeOfJsonDocument)
 Fill the given buffer with client token for tracking the Repsonse. More...
 

Enumeration Type Documentation

JSON number types need to be split into proper integer / floating point data types and sizes on embedded platforms.

Function Documentation

IoT_Error_t aws_iot_fill_with_client_token ( char *  pBufferToBeUpdatedWithClientToken,
size_t  maxSizeOfJsonDocument 
)

This function will add the AWS_IOT_MQTT_CLIENT_ID with a sequence number. Every time this function is used the sequence number gets incremented

Parameters
pBufferToBeUpdatedWithClientTokenbuffer to be updated with the client token string
maxSizeOfJsonDocumentmaximum size of the pBufferToBeUpdatedWithClientToken that can be used
Returns
An IoT Error Type defining if the buffer was null or the entire string was not filled up
IoT_Error_t aws_iot_finalize_json_document ( char *  pJsonDocument,
size_t  maxSizeOfJsonDocument 
)

This function will automatically increment the client token every time this function is called.

Note
Ensure the size of the Buffer is enough to hold the entire JSON Document. If the finalized section is not invoked then the JSON doucment will not be valid
Parameters
pJsonDocumentThe JSON Document filled in this char buffer
maxSizeOfJsonDocumentmaximum size of the pJsonDocument that can be used to fill the JSON document
Returns
An IoT Error Type defining if the buffer was null or the entire string was not filled up
IoT_Error_t aws_iot_shadow_add_desired ( char *  pJsonDocument,
size_t  maxSizeOfJsonDocument,
uint8_t  count,
  ... 
)

This is a variadic function and please be careful with the usage. count is the number of jsonStruct_t types that you would like to add in the reported section This function will add "desired":{<all the="" values="" that="" needs="" to="" be="" added>="">}

Note
Ensure the size of the Buffer is enough to hold the reported section + the init section. Always use the same JSON document buffer used in the iot_shadow_init_json_document function. This function will accommodate the size of previous null terminated string, so pass the max size of the buffer
Parameters
pJsonDocumentThe JSON Document filled in this char buffer
maxSizeOfJsonDocumentmaximum size of the pJsonDocument that can be used to fill the JSON document
counttotal number of arguments(jsonStruct_t object) passed in the arguments
Returns
An IoT Error Type defining if the buffer was null or the entire string was not filled up
IoT_Error_t aws_iot_shadow_add_reported ( char *  pJsonDocument,
size_t  maxSizeOfJsonDocument,
uint8_t  count,
  ... 
)

This is a variadic function and please be careful with the usage. count is the number of jsonStruct_t types that you would like to add in the reported section This function will add "reported":{<all the="" values="" that="" needs="" to="" be="" added>="">}

Note
Ensure the size of the Buffer is enough to hold the reported section + the init section. Always use the same JSON document buffer used in the iot_shadow_init_json_document function. This function will accommodate the size of previous null terminated string, so pass teh max size of the buffer
Parameters
pJsonDocumentThe JSON Document filled in this char buffer
maxSizeOfJsonDocumentmaximum size of the pJsonDocument that can be used to fill the JSON document
counttotal number of arguments(jsonStruct_t object) passed in the arguments
Returns
An IoT Error Type defining if the buffer was null or the entire string was not filled up
IoT_Error_t aws_iot_shadow_init_json_document ( char *  pJsonDocument,
size_t  maxSizeOfJsonDocument 
)

This Function will fill the JSON Buffer with a null terminated string. Internally it uses snprintf This function should always be used First, followed by iot_shadow_add_reported and/or iot_shadow_add_desired. Always finish the call sequence with iot_finalize_json_document

Note
Ensure the size of the Buffer is enough to hold the entire JSON Document.
Parameters
pJsonDocumentThe JSON Document filled in this char buffer
maxSizeOfJsonDocumentmaximum size of the pJsonDocument that can be used to fill the JSON document
Returns
An IoT Error Type defining if the buffer was null or the entire string was not filled up