JSON Array

Example Path: examples/JSON/JsonLexer/JsonArray

JSON Array Application

Overview

This application demonstrates how to use the JSON Lexer library classes ParsedJsonDataSet and JsonRef to create and access JSON array information. The program builds a JSON array with numeric data and then reads back the stored values.

Application Details

Application Name:** JsonArray

The application showcases the fundamental operations of:

• Building JSON data structures programmatically
• Storing arrays within JSON datasets
• Accessing and iterating through JSON array elements
• Converting JSON data to native data types

Code Structure

Main Components

BuildJsonArray()

This function demonstrates the JSON array creation process:

• Initializes the JSON data set building process
• Creates an array named "FirstArray"
• Populates the array with integers 0-9
• Finalizes the array and dataset construction

ReadJsonArray()

This function shows how to access and iterate through JSON array data:

• Retrieves a reference to the "FirstArray"
• Iterates through array elements using index-based access
• Converts JSON values to native double format
• Prints each array element with its index

UserMain()

The main application entry point that:

• Initializes the system
• Enables system diagnostics
• Waits for network connectivity (5 seconds)
• Orchestrates the build and read operations
• Displays the complete JSON object structure
• Enters an infinite loop with 1-second delays

Expected Output

When executed, the application will:

1. Display "Application started" message
2. Show "Build JSON Object:" followed by the complete JSON structure
3. Display each array element in the format: " [index]: [value]"
4. Show "End of Array Reached" when iteration completes

Example output format:

Application started
 
Build JSON Object: 
[JSON structure display]
 
     0: 0
     1: 1
     2: 2
     ...
     9: 9
End of Array Reached

Dependencies

The application requires:

• init.h - System initialization functions
• json_lexer.h - JSON parsing and manipulation library
• Network stack (uses DHCP and network timing functions)
• RTOS functionality (uses OSTimeDly and TICKS_PER_SECOND)

Key Features

• Dynamic JSON Construction: Build JSON arrays programmatically at runtime
• Type Safety: Automatic conversion between JSON and native data types
• Iterator Support: Easy traversal of array elements using index notation
• Validation: Built-in validity checking for array elements
• Debug Output: Complete JSON object structure printing capability

Usage Notes

• The application waits for network initialization before proceeding
• System diagnostics are enabled for development/debugging purposes
• The main loop runs indefinitely with 1-second intervals
• Array elements are accessed using standard bracket notation
• The Valid() method is used to detect the end of array iteration

Technical Implementation

The application leverages the JSON Lexer library's object-oriented approach to JSON manipulation, using:

• ParsedJsonDataSet for the main JSON container
• JsonRef for element references and access
• Method chaining for efficient array construction
• Implicit type conversion for data access