JSON Schema Validator

This class validates JSON payloads by using predefined schema based on basic necessary data types. Data types validation can be extended by creating new classes and new constraints can be added by writing new functions in Constraints class.

This schema validator works on following types:

• text
• numeric
• date
• array
• boolean
• choices

Constraints:

• max_length (string length)
• required (for mandatory fiels)
• value_range min_value max_value (for numeric field)
• choices choices array
• min_item_count
• max_item_count (for array data type, to restrict number of items)
• sub_nodes (for nested objects)

Example Schema:

$_payLoadSchema = [
    [
        'node' => [
            'name' => 'title',
            'type' => 'text',
            'required' => true,
            'max_length' => 20
        ]
    ],
    [
        'node' => [
            'name' => 'action',
            'type' => 'text',
            'required' => true,
            'max_length' => 20,
            'choices' => [
                "CUSTOMER_DATA",
                "CUSTOMER_CREATE"
            ]
        ]
    ],
    [
        'node' => [
            'name' => 'transaction_amount',
            'type' => 'numeric',
            'required' => true,
            'value_range' => [
                'min_value' => 10,
                'max_value' => 100
            ]
        ]
    ],
    [
        'node' => [
            'name' => 'transaction_date',
            'type' => 'choices',
            'required' => true,
            'choices' => [
                "2018-01-01",
                "2018-01-02"
            ]
        ]
    ],
    [
        'node' => [
            'name' => 'customer_ids',
            'type' => 'array',
            'required' => true,
            'max_item_count' => 2
        ]
    ],
    [
        'node' => [
            'name' => 'is_active',
            'type' => 'boolean',
            'required' => false
        ]
    ],
    [
        'node' => [
            'name' => 'additional_data',
            'type' => 'object',
            'sub_nodes' => [
                ['node' => [
                        'name' => 'additional_field_1',
                        'type' => 'text',
                        'max_length' => "100"
                    ]],
                ['node' => [
                        'name' => 'additional_field_2',
                        'type' => 'numeric'
                    ]]
            ]
        ]
    ]
];

Sample JSON Payload to Validate

$json_raw = '
{
  "title": "This is titlle",
  "action": "CUSTOMER_CREATE",
  "transaction_amount": "44",
  "transaction_date": "2018-01-01",
  "customer_ids": [
    1001,
    1002,
    1003
  ],
  "is_active": true,
  "additional_data": {
    "additional_field_2": 10
  }
}    
';

Usage:

<?php

	$jsonschemavalidator = new JsonSchemaValidator();
	$jsonschemavalidator->validateSchema($_payLoadSchema, $json_raw);
	
	if($validated){
		echo "JSON Validated";
	} else {
		echo "JSON not validated";
		print_r($jsonschemavalidator->getErrors());
	}