feat: Use the event writer to build element trees

docs/data_binding/tree_serializing.md

@@ -1,41 +1,26 @@
 # Element Tree Serializer
 
-The element tree serializers will render an object into an element tree, that you can
-use to run XPATH evaluations or XSLT transformations.
+The tree serializer will render an object into an element tree, that you can use to run
+XPATH evaluations or XSLT transformations.
 
-There are two implementations based on lxml
-[LxmlTreeSerializer][xsdata.formats.dataclass.serializers.LxmlTreeSerializer] and native
-python [XmlTreeSerializer][xsdata.formats.dataclass.serializers.XmlTreeSerializer].
+The [TreeSerializer][xsdata.formats.dataclass.serializers.TreeSerializer] depends on
+lxml. There is no native python ElementTree implementation because of limitations with
+namespaces.
 
-## xml.etree.ElementTree.Element
-
-```python
->>> from xml.etree import ElementTree
->>> from tests.fixtures.books.fixtures import books
->>> from xsdata.formats.dataclass.serializers import XmlTreeSerializer
-...
->>> serializer = XmlTreeSerializer()
->>> result = serializer.render(books)
-...
->>> result.find(".//title").text
-'The First Book'
-
-```
-
-## lxml.etree.Element
+## Example
 
 ```python
 >>> from lxml import etree
 >>> from tests.fixtures.books.fixtures import books
->>> from xsdata.formats.dataclass.serializers import LxmlTreeSerializer
+>>> from xsdata.formats.dataclass.serializers import TreeSerializer
 ...
->>> serializer = LxmlTreeSerializer()
->>> result = serializer.render(books)
+>>> serializer = TreeSerializer()
+>>> serializer.config.indent = "  "
+>>> result = serializer.render(books, ns_map={'bk': "urn:books"})
 ...
->>> etree.indent(result)
 >>> actual = etree.tostring(result)
 >>> print(actual.decode())
-<ns0:books xmlns:ns0="urn:books">
+<bk:books xmlns:bk="urn:books">
   <book id="bk001" lang="en">
     <author>Hightower, Kim</author>
     <title>The First Book</title>
@@ -52,6 +37,6 @@ python [XmlTreeSerializer][xsdata.formats.dataclass.serializers.XmlTreeSerialize
     <pub_date>2001-01-10</pub_date>
     <review>A masterpiece of the fine art of gossiping.</review>
   </book>
-</ns0:books>
+</bk:books>
 
 ```

tests/formats/dataclass/serializers/writers/test_lxml.py

@@ -1,11 +1,16 @@
 from dataclasses import make_dataclass
 from unittest import TestCase
 
+import lxml
+
 from tests import fixtures_dir
 from tests.fixtures.books.fixtures import books
 from xsdata.formats.dataclass.serializers import XmlSerializer
 from xsdata.formats.dataclass.serializers.config import SerializerConfig
-from xsdata.formats.dataclass.serializers.writers import LxmlEventWriter
+from xsdata.formats.dataclass.serializers.tree import TreeSerializer
+from xsdata.formats.dataclass.serializers.writers import (
+    LxmlEventWriter,
+)
 
 
 class LxmlEventWriterTests(TestCase):
@@ -58,3 +63,30 @@ def test_no_indent(self):
         _, actual = actual.split("\n", 1)
         _, expected = expected.split("\n", 1)
         self.assertEqual(expected.replace("  ", "").replace("\n", ""), actual)
+
+
+class LxmlTreeBuilderTests(TestCase):
+    def setUp(self):
+        super().setUp()
+        self.serializer = TreeSerializer()
+        self.serializer.config.indent = "  "
+
+    def test_render(self):
+        tree = self.serializer.render(books)
+
+        actual = lxml.etree.tostring(tree).decode()
+
+        expected = fixtures_dir.joinpath("books/books_auto_ns.xml").read_text()
+        expected = "\n".join(expected.splitlines()[1:])
+        self.assertEqual(expected, actual)
+
+    def test_render_with_no_indent(self):
+        self.serializer.config.indent = ""
+        tree = self.serializer.render(books)
+
+        lxml.etree.indent(tree, "  ")
+        actual = lxml.etree.tostring(tree).decode()
+
+        expected = fixtures_dir.joinpath("books/books_auto_ns.xml").read_text()
+        expected = "\n".join(expected.splitlines()[1:])
+        self.assertEqual(expected, actual)

tests/integration/benchmarks/test_handlers.py

@@ -5,15 +5,18 @@
 from tests import xsdata_temp_dir
 from tests.integration.benchmarks.utils import make_books, parse, write
 from xsdata.formats.dataclass.context import XmlContext
-from xsdata.formats.dataclass.parsers import handlers as readers
-from xsdata.formats.dataclass.serializers import writers
+from xsdata.formats.dataclass.parsers.handlers import LxmlEventHandler, XmlEventHandler
+from xsdata.formats.dataclass.serializers.writers import LxmlEventWriter, XmlEventWriter
 
 context = XmlContext()
-readers_list = list(readers.__all__)
-writers_list = list(writers.__all__)
-
-readers_list.remove("default_handler")
-writers_list.remove("default_writer")
+readers_list = [
+    LxmlEventHandler,
+    XmlEventHandler,
+]
+writers_list = [
+    XmlEventWriter,
+    LxmlEventWriter,
+]
 
 random.shuffle(readers_list)
 random.shuffle(writers_list)
@@ -27,12 +30,12 @@
 @pytest.mark.parametrize("number", numbers)
 @pytest.mark.parametrize("writer", writers_list)
 def test_serialize(benchmark, writer, number):
-    benchmark(write, number, fixtures[number], getattr(writers, writer))
+    benchmark(write, number, fixtures[number], writer)
 
 
 @pytest.mark.benchmark(disable_gc=True, group="Parse")
 @pytest.mark.parametrize("number", numbers)
 @pytest.mark.parametrize("handler", readers_list)
 def test_parse(benchmark, handler, number):
     src = xsdata_temp_dir.joinpath(f"benchmark_{number}.xml").read_bytes()
-    benchmark(parse, src, getattr(readers, handler))
+    benchmark(parse, src, handler)

xsdata/formats/dataclass/client.py

@@ -1,5 +1,5 @@
 from dataclasses import dataclass, fields
-from typing import Any, Dict, NamedTuple, Optional, Type, Union
+from typing import Any, Dict, Optional, Type, Union
 
 from xsdata.exceptions import ClientValueError
 from xsdata.formats.dataclass.context import XmlContext

xsdata/formats/dataclass/serializers/__init__.py

@@ -1,7 +1,6 @@
 from xsdata.formats.dataclass.serializers.code import PycodeSerializer
 from xsdata.formats.dataclass.serializers.dict import DictEncoder, DictFactory
 from xsdata.formats.dataclass.serializers.json import JsonSerializer
-from xsdata.formats.dataclass.serializers.tree.native import XmlTreeSerializer
 from xsdata.formats.dataclass.serializers.xml import XmlSerializer
 
 __all__ = [
@@ -13,8 +12,8 @@
 ]
 
 try:
-    from xsdata.formats.dataclass.serializers.tree.lxml import LxmlTreeSerializer
+    from xsdata.formats.dataclass.serializers.tree import TreeSerializer
 
-    __all__.append("LxmlTreeSerializer")
+    __all__.append("TreeSerializer")
 except ImportError:  # pragma: no cover
-    pass  # pragma: no cover
+    pass