Functions for validating a string against a JSON Schema. More...

#include "my_rapidjson_size_t.h"
#include <rapidjson/schema.h>
#include <cstddef>
#include <string>
#include "my_alloc.h"

Classes
class	Json_schema_validation_report
	Json_schema_validation_report contains a more detailed report about a failed JSON Schema validation. More...

class	Json_schema_validator
	Json_schema_validator is an object that contains a JSON Schema that can be re-used multiple times. More...

class	Json_schema_validator::My_remote_schema_document_provider
	This object acts as a handler/callback for the JSON schema validator and is called whenever a schema reference is encountered in the JSON document. More...

Functions
bool	is_valid_json_schema (const char document_str, size_t document_length, const char json_schema_str, size_t json_schema_length, const char function_name, bool is_valid, Json_schema_validation_report *report)
	This function will validate a JSON document against a JSON Schema using the validation provided by rapidjson. More...

unique_ptr_destroy_only< const Json_schema_validator >	create_json_schema_validator (MEM_ROOT mem_root, const char json_schema_str, size_t json_schema_length, const char *function_name)
	Create a Json_schema_validator, allocated on a given MEM_ROOT. More...

Detailed Description

Functions for validating a string against a JSON Schema.

A JSON Schema is a way to describe the structure of a JSON document. The JSON Schema is a JSON document in itself, and allows you to define required names/attributes, data types etc. As an example, here is a minimal example of a JSON Schema describing that the JSON document MUST be an object:

{ "type": "object" }

If the JSON document to be validated is anything else than an object (array, scalar), the validation will fail.

This file contains one class for validation JSON documents against a cached JSON Schema, and free functions for validation any string input against a (unparsed) JSON Schema. We use the rapidjson library to do the actual validation with the following notable behaviors:

1) Remote references are not supported. If the user provides a JSON Schema with a remote reference, an error will be raised. 2) JSON Schema supports regex patterns, and we use std::regex as the regex engine. If an invalid regex pattern is provided in the JSON Schema, the regex pattern will be silently ignored. 3) rapidjson currently supports JSON Schema draft-v4, while there are newer versions available (as of writing, draft-v7 is the latest version).

Function Documentation

◆ create_json_schema_validator()

unique_ptr_destroy_only< const Json_schema_validator > create_json_schema_validator	(	MEM_ROOT *	mem_root,
		const char *	json_schema_str,
		size_t	json_schema_length,
		const char *	function_name
	)

Create a Json_schema_validator, allocated on a given MEM_ROOT.

Parameters

mem_root	The MEM_ROOT to allocate the validator on
json_schema_str	A pointer to the JSON Schema
json_schema_length	The length of the JSON Schema input
function_name	The function name of the caller (to be used in error reporting)

Return values

nullptr on error (my_error has been called)

◆ is_valid_json_schema()

bool is_valid_json_schema	(	const char *	document_str,
		size_t	document_length,
		const char *	json_schema_str,
		size_t	json_schema_length,
		const char *	function_name,
		bool *	is_valid,
		Json_schema_validation_report *	report
	)

This function will validate a JSON document against a JSON Schema using the validation provided by rapidjson.