Parse Test

JSON Parser Test Application

Overview

This application demonstrates the usage of a JSON lexer and parser library, specifically showcasing how to use the ParsedJsonDataSet and JsonRef classes to create and access JSON information. The program is designed as a test application that parses a complex JSON structure and demonstrates various access methods and type checking capabilities.

Application Details

• Application Name: JsonParseTest
• Main File: main.cpp
• Purpose: Parse Test demonstration for JSON Lexer classes

Features

The application demonstrates the following JSON parsing capabilities:

1. JSON Data Structure

The program works with a complex nested JSON structure that includes:

• Boolean values (SUCCESS, b3, aftaav)
• Null values (ACTION, b4)
• Numeric values (integers and floats)
• String values
• Nested objects (JDATA, bar, b2, s4, wa)
• Arrays (av, a, z)
• Mixed-type arrays containing numbers, strings, objects, and nested arrays

2. Access Methods

The application demonstrates two primary methods for accessing JSON data:

Explicit Type Enforcement

int32_t j = pjd.object("wa").name("a")[5].name("z")[1];
const char *str = pjd.object("wa").name("a")[4];
NBString nbs = pjd.object("JDATA").object("bar").object("b2").object("s4").name("Sub4a");

Simplified Access (Without Type Enforcement)

j = pjd("wa")("a")[5]("z")[1];
str = pjd("wa")("a")[4];
nbs = (const char*)(pjd("JDATA")("bar")("b2")("s4")("Sub4a"));

3. Type Checking

The application includes comprehensive type checking capabilities:

• IsNumber() - Check if value is numeric
• IsObject() - Check if value is a JSON object
• IsNull() - Check if value is null
• IsArray() - Check if value is an array
• IsBool() - Check if value is boolean
• IsString() - Check if value is a string

4. Error Handling

The application demonstrates proper error handling for:

• Non-existent objects and properties
• Invalid parse attempts
• Validation using JsonRef.Valid() method

JSON Structure Example

The embedded JSON data structure includes:

{
    "SUCCESS": true,
    "ACTION": null,
    "JDATA": {
        "foo": 7,
        "bar": {
            "b1": "Sb1",
            "b2": {
                "s1": "Sub1",
                "s2": "Sub2",
                "s3": "Sub3",
                "s4": {
                    "Sub4a": "Test4a",
                    "Sub4b": "Test4b"
                },
                "s5": "Sub5",
                "s6": "Sub6"
            },
            "b3": true,
            "b4": null
        },
        "bogus": "Bstring",
        "nubog": 1234.57,
        "av": [1, 2, 3, 4, 5, 6, 7, 8, 9, 10],
        "aftaav": true
    },
    "wa": {
        "a": [1, 2, 3, 4, "bob", 
              {"b": "c", "z": [1, 2, 3]}, 
              [12, 10, 9, "zoro"], 
              93]
    }
}

Key Classes

ParsedJsonDataSet

• Main class for parsing and storing JSON data
• Supports initialization from character array data
• Provides PrintObject() method for debugging
• Supports both explicit and simplified access methods

JsonRef

• Reference class for accessing JSON elements
• Provides type checking methods
• Includes validation through Valid() method
• Supports automatic type conversion

Usage Pattern

1. Initialize: Create a ParsedJsonDataSet object with JSON data
2. Access: Use either explicit or simplified syntax to navigate the JSON structure
3. Validate: Check if the parse was successful using Valid()
4. Type Check: Verify data types before processing
5. Extract: Convert to appropriate C++ types (int32_t, const char*, NBString, etc.)

System Requirements

• Embedded system environment (references to DHCP, network waiting)
• NetBurner platform (references to NBString, system diagnostics)
• Real-time operating system (OSTimeDly, TICKS_PER_SECOND)

Build Dependencies

• init.h - System initialization
• json_lexer.h - JSON parsing library

Example Output

The application provides detailed console output showing:

• Parsed integer values from nested structures
• String extraction from various JSON locations
• Error handling for non-existent properties
• Type validation results
• Success/failure status of parse operations