Crate jsonschema

jsonschema

A crate for performing fast JSON Schema validation. It is fast due to schema compilation into a validation tree, which reduces runtime costs for working with schema parameters.

Supports:

• JSON Schema drafts 4, 6, 7 (except some optional test cases);
• Loading remote documents via HTTP(S);

Partially supported drafts (some keywords are not implemented):

• Draft 2019-09 (requires the draft201909 feature enabled)
• Draft 2020-12 (requires the draft202012 feature enabled)

This library is functional and ready for use, but its API is still evolving to the 1.0 API.

Usage Examples:

A schema can be compiled with two main flavours:

• using default configurations

let compiled_schema = JSONSchema::compile(&schema).expect("A valid schema");

• using custom configurations (such as define a Draft version)

let compiled_schema = JSONSchema::options()
    .with_draft(Draft::Draft7)
    .compile(&schema)
    .expect("A valid schema");

Example (CLI tool to highlight print errors)

use jsonschema::{Draft, JSONSchema};
use serde_json::json;

let schema = json!({"maxLength": 5});
let instance = json!("foo");
let compiled = JSONSchema::options()
    .with_draft(Draft::Draft7)
    .compile(&schema)
    .expect("A valid schema");
let result = compiled.validate(&instance);
if let Err(errors) = result {
    for error in errors {
        println!("Validation error: {}", error);
        println!("Instance path: {}", error.instance_path);
    }
}

Each error has an instance_path attribute that indicates the path to the erroneous part within the validated instance. It could be transformed to JSON Pointer via .to_string() or to Vec<String> via .into_vec().

Re-exports

• pub use error::ErrorIterator;
• pub use error::ValidationError;

Modules

• error
  Error types
• output
  Implementation of json schema output formats specified in https://json-schema.org/draft/2020-12/json-schema-core.html#rfc.section.12.2
• paths
  Facilities for working with paths within schemas or validated instances.
• primitive_type
  Primitive types for property type validators

Structs

• CompilationOptions
  Full configuration to guide the JSONSchema compilation.
• JSONSchema
  The structure that holds a JSON Schema compiled into a validation tree

Enums

• Draft
  JSON Schema Draft version

Traits

• Keyword
  Trait that allows implementing custom validation for keywords.
• SchemaResolver
  A resolver that resolves external schema references. Internal references such as #/definitions and JSON pointers are handled internally.

Functions

• is_valid
  A shortcut for validating instance against schema. Draft version is detected automatically.

Type Aliases

• SchemaResolverError
  An opaque error type that is returned by resolvers on resolution failures.