***************
JSONSchema Path
***************

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About
#####

Object-oriented JSONSchema

Key features
############

* Traverse schema like paths
* Access schema on demand with separate dereferencing accessor layer

Installation
############

.. code-block:: console

   pip install jsonschema-path

Alternatively you can download the code and install from the repository:

.. code-block:: console

   pip install -e git+https://github.com/p1c2u/jsonschema-path.git#egg=jsonschema_path


Usage
#####

.. code-block:: python

   >>> from jsonschema_path import SchemaPath
   
   >>> d = {
   ...     "properties": {
   ...        "info": {
   ...            "$ref": "#/$defs/Info",
   ...        },
   ...     },
   ...     "$defs": {
   ...         "Info": {
   ...             "properties": {
   ...                 "title": {
   ...                     "$ref": "http://example.com",
   ...                 },
   ...                 "version": {
   ...                     "type": "string",
   ...                     "default": "1.0",
   ...                 },
   ...             },
   ...         },
   ...     },
   ... }
   
   >>> path = SchemaPath.from_dict(d)
   
   >>> # Stat keys
   >>> "properties" in path
   True
   
   >>> # Concatenate paths with /
   >>> info_path = path / "properties" / "info"
   
   >>> # Stat keys with implicit dereferencing
   >>> "properties" in info_path
   True
   
   >>> # Concatenate paths with implicit dereferencing
   >>> version_path = info_path / "properties" / "version"
   
   >>> # Open content with implicit dereferencing
   >>> with version_path.open() as contents:
   ...     print(contents)
   {'type': 'string', 'default': '1.0'}

Identity and equality
#####################

Two ``SchemaPath`` instances are equal if they have the same ``parts``
*and* point to the same ``SchemaAccessor``. ``SchemaAccessor`` identity
is per-resource-handle: same wrapped dict (by reference), same
``base_uri``, and same internal resolver instance. In practice:

* Paths derived from the *same* accessor compare equal as expected:

  .. code-block:: python

     >>> accessor = SchemaAccessor.from_schema(d)
     >>> SchemaPath(accessor) / "properties" == SchemaPath(accessor) / "properties"
     True

* Paths from *separate* ``from_dict`` or ``from_schema`` calls do **not**
  compare equal even with identical arguments, because each call builds
  its own accessor:

  .. code-block:: python

     >>> SchemaPath.from_dict(d) == SchemaPath.from_dict(d)
     False

* ``SchemaAccessor`` is hashable, so accessors and paths can be used as
  set members and dict keys.

This is also why the "build one accessor, reuse it" pattern below
matters: it is both a caching optimisation and the contract you need
for path equality to behave the way you expect.

Resolved cache
##############

The resolved-path cache is intended for repeated path lookups and may significantly improve
``read_value``/membership hot paths. When the underlying ``referencing``
registry grows (e.g. an external ``$ref`` pulls in a new document),
cached entries are *rebound* to the new registry on read instead of
being discarded. This relies on registries growing monotonically —
resources are added, never replaced. Handlers that return drifting
content for the same URI violate that assumption; disable caching with
``resolved_cache_maxsize=0`` if you need to defend against it.

This cache is enabled by default
(``resolved_cache_maxsize=128``). You can disable it when creating paths or
accessors, for example:

.. code-block:: python

   >>> path = SchemaPath.from_dict(d, resolved_cache_maxsize=0)

Build **one** :code:`SchemaAccessor` per schema document and reuse it for
every :code:`SchemaPath` you derive from that document. Treat the accessor
as the long-lived handle to the resource; treat paths as cheap views over
it.

.. code-block:: python

   >>> from jsonschema_path import SchemaAccessor, SchemaPath

   >>> # Construct the accessor once, with caching enabled.
   >>> accessor = SchemaAccessor.from_schema(d, resolved_cache_maxsize=128)

   >>> # Derive as many paths as you like from the same accessor.
   >>> root = SchemaPath(accessor)
   >>> info = root / "properties" / "info"
   >>> version = info / "properties" / "version"

   >>> # Every path over `accessor` shares the same resolved-ref cache.
   >>> with version.open() as contents:
   ...     ...

Benchmarks
##########

Benchmarks mirror the lightweight (dependency-free) JSON output format used in
`pathable`.

Run locally with Poetry:

.. code-block:: console

   poetry run python -m tests.benchmarks.bench_parse --output reports/bench-parse.json
   poetry run python -m tests.benchmarks.bench_lookup --output reports/bench-lookup.json

For a quick smoke run:

.. code-block:: console

   poetry run python -m tests.benchmarks.bench_parse --output reports/bench-parse.quick.json --quick
   poetry run python -m tests.benchmarks.bench_lookup --output reports/bench-lookup.quick.json --quick

You can also control repeats/warmup and resolved cache maxsize via env vars:

.. code-block:: console

   export JSONSCHEMA_PATH_BENCH_REPEATS=5
   export JSONSCHEMA_PATH_BENCH_WARMUP=1
   export JSONSCHEMA_PATH_BENCH_RESOLVED_CACHE_MAXSIZE=64

Compare two results:

.. code-block:: console

    poetry run python -m tests.benchmarks.compare_results \
       --baseline reports/bench-lookup-master.json \
       --candidate reports/bench-lookup.json \
       --tolerance 0.20


Related projects
################

* `openapi-core <https://github.com/p1c2u/openapi-core>`__
   Python library that adds client-side and server-side support for the OpenAPI.
* `openapi-spec-validator <https://github.com/p1c2u/openapi-spec-validator>`__
   Python library that validates OpenAPI Specs against the OpenAPI 2.0 (aka Swagger) and OpenAPI 3.0 specification
* `openapi-schema-validator <https://github.com/p1c2u/openapi-schema-validator>`__
   Python library that validates schema against the OpenAPI Schema Specification v3.0.

License
#######

Copyright (c) 2017-2025, Artur Maciag, All rights reserved. Apache-2.0
