hdr: add _Header._has_header_part

Author: ondrej-111

docx/enum/section.py

@@ -9,6 +9,33 @@
 from .base import alias, XmlEnumeration, XmlMappedEnumMember
 
 
+@alias('WD_HEADER_FOOTER')
+class WD_HEADER_FOOTER_INDEX(XmlEnumeration):
+    """
+    alias: **WD_HEADER_FOOTER**
+
+    Specifies one of the three possible header/footer definitions for a section.
+
+    For internal use only; not part of the python-docx API.
+    """
+
+    __ms_name__ = "WdHeaderFooterIndex"
+
+    __url__ = "https://docs.microsoft.com/en-us/office/vba/api/word.wdheaderfooterindex"
+
+    __members__ = (
+        XmlMappedEnumMember(
+            "PRIMARY", 1, "default", "Header for odd pages or all if no even header."
+        ),
+        XmlMappedEnumMember(
+            "FIRST_PAGE", 2, "first", "Header for first page of section."
+        ),
+        XmlMappedEnumMember(
+            "EVEN_PAGE", 3, "even", "Header for even pages of recto/verso section."
+        ),
+    )
+
+
 @alias('WD_ORIENT')
 class WD_ORIENTATION(XmlEnumeration):
     """

docx/oxml/section.py

@@ -6,9 +6,13 @@
 
 from copy import deepcopy
 
-from docx.enum.section import WD_ORIENTATION, WD_SECTION_START
+from docx.enum.section import WD_HEADER_FOOTER, WD_ORIENTATION, WD_SECTION_START
 from docx.oxml.simpletypes import ST_SignedTwipsMeasure, ST_TwipsMeasure
-from docx.oxml.xmlchemy import BaseOxmlElement, OptionalAttribute, ZeroOrOne
+from docx.oxml.xmlchemy import (
+    BaseOxmlElement,
+    OptionalAttribute,
+    ZeroOrOne,
+)
 
 
 class CT_PageMar(BaseOxmlElement):
@@ -93,6 +97,15 @@ def footer(self, value):
         pgMar = self.get_or_add_pgMar()
         pgMar.footer = value
 
+    def get_headerReference(self, type_):
+        """Return headerReference element of *type_* or None if not present."""
+        matching_headerReferences = self.xpath(
+            "./w:headerReference[@w:type='%s']" % WD_HEADER_FOOTER.to_xml(type_)
+        )
+        if len(matching_headerReferences) == 0:
+            return None
+        return matching_headerReferences[0]
+
     @property
     def gutter(self):
         """

docx/section.py

@@ -7,6 +7,7 @@
 from collections import Sequence
 
 from docx.blkcntnr import BlockItemContainer
+from docx.enum.section import WD_HEADER_FOOTER
 from docx.shared import lazyproperty
 
 
@@ -242,4 +243,5 @@ def is_linked_to_previous(self):
     @property
     def _has_header_part(self):
         """True if a header is explicitly defined for this section."""
-        raise NotImplementedError
+        headerReference = self._sectPr.get_headerReference(WD_HEADER_FOOTER.PRIMARY)
+        return False if headerReference is None else True

features/hdr-header-footer.feature

@@ -4,7 +4,6 @@ Feature: Header and footer behaviors
   I need properties and methods on _Header and _Footer objects
 
 
-  @wip
   Scenario Outline: _Header.is_linked_to_previous getter
     Given a _Header object <with-or-no> header definition as header
      Then header.is_linked_to_previous is <value>

tests/test_section.py

@@ -370,8 +370,26 @@ def it_knows_when_its_linked_to_the_previous_header(
 
         assert is_linked is expected_value
 
+    def it_knows_when_it_has_a_header_part_to_help(self, has_header_part_fixture):
+        sectPr, expected_value = has_header_part_fixture
+        header = _Header(sectPr, None)
+
+        has_header_part = header._has_header_part
+
+        assert has_header_part is expected_value
+
     # fixtures -------------------------------------------------------
 
+    @pytest.fixture(
+        params=[
+            ("w:sectPr", False), ("w:sectPr/w:headerReference{w:type=default}", True)
+        ]
+    )
+    def has_header_part_fixture(self, request):
+        sectPr_cxml, expected_value = request.param
+        sectPr = element(sectPr_cxml)
+        return sectPr, expected_value
+
     @pytest.fixture(params=[(False, True), (True, False)])
     def is_linked_fixture(self, request):
         has_header_part, expected_value = request.param