Move get_documenter over from Sphinx

because it was removed upstream in sphinx-doc/sphinx#13985

Author: pllim

sphinx_automodapi/automodsumm.py

@@ -479,13 +479,14 @@ def generate_automodsumm_docs(lines, srcfn, app=None, suffix='.rst',
     """
 
     from sphinx.jinja2glue import BuiltinTemplateLoader
-    from sphinx.ext.autosummary import import_by_name, get_documenter
+    from sphinx.ext.autosummary import import_by_name
     from sphinx.util.osutil import ensuredir
     from sphinx.util.inspect import safe_getattr
     from jinja2 import FileSystemLoader, TemplateNotFound
     from jinja2.sandbox import SandboxedEnvironment
 
     from .utils import find_autosummary_in_lines_for_automodsumm as find_autosummary_in_lines
+    from .utils import get_documenter
 
     # Create our own templating environment - here we use Astropy's
     # templates rather than the default autosummary templates, in order to

sphinx_automodapi/utils.py

@@ -7,7 +7,8 @@
 from sphinx.ext.autosummary.generate import find_autosummary_in_docstring
 
 __all__ = ['cleanup_whitespace',
-           'find_mod_objs', 'find_autosummary_in_lines_for_automodsumm']
+           'find_mod_objs', 'find_autosummary_in_lines_for_automodsumm',
+           'get_documenter']
 
 # We use \n instead of os.linesep because even on Windows, the generated files
 # use \n as the newline character.
@@ -227,3 +228,19 @@ def find_autosummary_in_lines_for_automodsumm(lines, module=None, filename=None)
             continue
 
     return documented
+
+
+# This used to be in Sphinx proper but removed in
+# https://github.com/sphinx-doc/sphinx/pull/13985
+def get_documenter(app, obj, parent):
+    """Get an autodoc.Documenter class suitable for documenting the given
+    object.
+
+    *obj* is the Python object to be documented, and *parent* is an
+    another Python object (e.g. a module or a class) to which *obj*
+    belongs to.
+    """
+    from sphinx.ext.autosummary import _get_documenter
+
+    obj_type = _get_documenter(obj, parent)
+    return app.registry.documenters[obj_type]