Refactor JsonParser

.pre-commit-config.yaml

@@ -2,7 +2,7 @@ exclude: tests/fixtures|docs/examples
 
 repos:
   - repo: https://github.com/asottile/pyupgrade
-    rev: v2.15.0
+    rev: v2.18.1
     hooks:
       - id: pyupgrade
         args: [--py37-plus]
@@ -11,7 +11,7 @@ repos:
     hooks:
       - id: reorder-python-imports
   - repo: https://github.com/ambv/black
-    rev: 21.5b0
+    rev: 21.5b1
     hooks:
       - id: black
   - repo: https://gitlab.com/pycqa/flake8
@@ -26,7 +26,7 @@ repos:
         args: ["--suppress-none-returning"]
 
   - repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v3.4.0
+    rev: v4.0.1
     hooks:
       - id: trailing-whitespace
       - id: end-of-file-fixer

docs/json.rst

@@ -2,8 +2,22 @@
 JSON Binding
 ============
 
-Binding JSON lacks a bit in features and for edge cases with wildcards and derived
-types doing roundtrip conversions is not always possible.
+All binding modules rely on a :class:`~xsdata.formats.dataclass.context.XmlContext`
+instance to cache marshalling information.
+
+It's recommended to either reuse the same parser/serializer instance or reuse the
+context instance.
+
+.. code-block::
+
+    from xsdata.formats.dataclass.context import XmlContext
+    from xsdata.formats.dataclass.parsers import JsonParser
+    from xsdata.formats.dataclass.serializers import JsonSerializer
+
+    context = XmlContext()
+    parser = JsonParser(context=context)
+    serializer = JsonSerializer(context=context)
+
 
 .. testsetup:: *
 
@@ -91,6 +105,28 @@ From json path
     BookForm(author='Hightower, Kim', title='The First Book', genre='Fiction', price=44.95, pub_date=XmlDate(2000, 10, 1), review='An amazing story of nothing.', id='bk001', lang='en')
 
 
+Ignore unknown properties
+-------------------------
+
+.. doctest::
+
+    >>> from tests.fixtures.books import *  # Import all classes
+    >>> from xsdata.formats.dataclass.parsers.config import ParserConfig
+    ...
+    >>> config = ParserConfig(
+    ...     fail_on_unknown_properties=False,
+    ... )
+    >>> json_string = """{
+    ...   "author": "Hightower, Kim",
+    ...   "unknown_property": "I will fail"
+    ... }"""
+    >>> parser = JsonParser(config=config)
+    >>> parser.from_string(json_string, BookForm)
+    BookForm(author='Hightower, Kim', title=None, genre=None, price=None, pub_date=None, review=None, id=None, lang='en')
+
+API :ref:`Reference <ParserConfig>`.
+
+
 Unknown json target type
 ------------------------
 
@@ -113,6 +149,12 @@ all the imported modules to find a matching dataclass.
     >>> parser.from_string(json_string)
     BookForm(author='Hightower, Kim', title='The First Book', genre='Fiction', price=44.95, pub_date=XmlDate(2000, 10, 1), review='An amazing story of nothing.', id='bk001', lang='en')
 
+.. warning::
+
+    The class locator searches for a dataclass that includes all the input object
+    properties. This process doesn't work for documents with unknown properties even
+    if the configuration option is disabled!
+
 
 List of Objects
 ---------------

tests/fixtures/models.py

@@ -0,0 +1,61 @@
+from dataclasses import dataclass, field
+from typing import List, Dict, Union, Optional
+from xml.etree.ElementTree import QName
+
+
+@dataclass
+class TypeA:
+    x: int
+
+
+@dataclass
+class TypeB:
+    x: int
+    y: str
+
+
+@dataclass
+class TypeC:
+    x: int
+    y: str
+    z: float
+
+
+@dataclass
+class TypeD:
+    x: int
+    y: str
+    z: Optional[bool]
+
+
+@dataclass
+class ExtendedType:
+    a: Optional[TypeA] = field(default=None)
+    any: Optional[object] = field(default=None)
+    wildcard: Optional[object] = field(default=None, metadata={"type": "Wildcard"})
+
+
+@dataclass
+class ChoiceType:
+    choice: List[object] = field(metadata={
+        "type": "Elements",
+        "choices": (
+            {"name": "a", "type": TypeA},
+            {"name": "b", "type": TypeB},
+            {"name": "int", "type": int},
+            {"name": "int2", "type": int},
+            {"name": "float", "type": float},
+            {"name": "qname", "type": QName},
+            {"name": "tokens", "type": List[int], "tokens": True},
+        )
+    })
+
+
+@dataclass
+class UnionType:
+    element: Union[TypeA, TypeB, TypeC, TypeD]
+
+
+@dataclass
+class AttrsType:
+    attrs: Dict[str, str] = field(metadata={"type": "Attributes"})

tests/formats/dataclass/models/test_builders.py

@@ -92,7 +92,7 @@ def test_build_with_no_dataclass_raises_exception(self, *args):
         with self.assertRaises(XmlContextError) as cm:
             XmlMetaBuilder.build(int, None, return_input, return_input)
 
-        self.assertEqual(f"Object {int} is not a dataclass.", str(cm.exception))
+        self.assertEqual(f"Type '{int}' is not a dataclass.", str(cm.exception))
 
     def test_build_vars(self):
         result = XmlMetaBuilder.build_vars(BookForm, None, text.pascal_case, str.upper)