From 73ae6d9c2e6ebf5e80706c287cf34ecdf3db4f16 Mon Sep 17 00:00:00 2001
From: Francis Charette Migneault <francis.charette.migneault@gmail.com>
Date: Fri, 27 Oct 2023 23:36:00 -0400
Subject: [PATCH] properly handle optional reference in UOM

---
 pywps/inout/basic.py   |  2 +-
 tests/test_describe.py | 14 +++++++++++---
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/pywps/inout/basic.py b/pywps/inout/basic.py
index d1a7f9ed2..1cfb6ac75 100644
--- a/pywps/inout/basic.py
+++ b/pywps/inout/basic.py
@@ -77,7 +77,7 @@ def __init__(self, uom='', reference=None):
         self.reference = reference
 
         if self.reference is None:
-            self.reference = OGCUNIT[self.uom]
+            self.reference = OGCUNIT.get(self.uom, '')
 
     @property
     def json(self):
diff --git a/tests/test_describe.py b/tests/test_describe.py
index 229bb0da1..72a7b1322 100644
--- a/tests/test_describe.py
+++ b/tests/test_describe.py
@@ -10,6 +10,7 @@
 from pywps import LiteralOutput, ComplexOutput, BoundingBoxOutput
 from pywps import get_ElementMakerForVersion, OGCTYPE, Format, NAMESPACES, OGCUNIT
 from pywps.inout.literaltypes import LITERAL_DATA_TYPES
+from pywps.inout.basic import UOM
 from pywps.app.basic import get_xpath_ns
 from pywps.app.Common import Metadata
 from pywps.inout.literaltypes import AllowedValue
@@ -41,7 +42,7 @@ def get_default_value(el):
 def get_single_uom(el):
     ows = el.nsmap["ows"]
     unit = el.text
-    href = el.attrib[f"{{{ows}}}reference"]
+    href = el.attrib.get(f"{{{ows}}}reference")
     return {"uom": unit, "reference": href}
 
 
@@ -286,13 +287,20 @@ def hello(request):
                                 inputs=[LiteralInput('the_number',
                                                      'Input number',
                                                      data_type='float',
-                                                     uoms=['metre', 'feet'])])
+                                                     uoms=[
+                                                         'metre',
+                                                         'feet',
+                                                         'undef',
+                                                         UOM('pixel', 'http://schema.com/#pixel'),
+                                                     ])])
         result = self.describe_process(hello_process)
         uoms = {
             'default': {'uom': 'metre', 'reference': OGCUNIT['metre']},
             'supported': [
                 {'uom': 'metre', 'reference': OGCUNIT['metre']},
-                {'uom': 'feet', 'reference': OGCUNIT['feet']}
+                {'uom': 'feet', 'reference': OGCUNIT['feet']},
+                {'uom': 'undef', 'reference': None},  # no mapping to known OGC URN
+                {'uom': 'pixel', 'reference': 'http://schema.com/#pixel'},
             ]
         }
         assert result.inputs == [('the_number', 'literal', 'float', None, uoms)]