Added correct path to documentation.

Added a test case, which has multiple failures.  This test case
should be copied to linkml to get all the ifabsent functions fixed.

Author: hsolbrig

linkml_model/model/schema/meta.yaml

@@ -1329,7 +1329,7 @@ slots:
     inherited: true
     description:  |-
       function that provides a default value for the slot.  Possible values for this slot are defined in
-      linkml_runtime.utils.ifabsent_functions.default_library:
+      linkml.utils.ifabsent_functions.default_library:
         * [Tt]rue -- boolean True
         * [Ff]alse -- boolean False
         * bnode -- blank node identifier

tests/test_ifabsent.py

@@ -0,0 +1,105 @@
+import unittest
+from contextlib import redirect_stdout
+from io import StringIO
+
+from linkml.generators.pythongen import PythonGenerator
+from linkml_runtime.utils.compile_python import compile_python
+
+model_txt = """
+id: https://example.org/ifabsent
+name: ifabsent_test
+
+prefixes:
+  linkml: https://w3id.org/linkml/
+  ex: https://example.org/ifabsent/
+default_prefix: ex
+default_range: string
+
+imports:
+  - linkml:types
+
+slots:
+    bool_true_slot:
+        range: boolean
+        ifabsent: true
+    bool_false_slot:
+        range: boolean
+        ifabsent: False
+    bnode_slot:
+        ifabsent: bnode
+    class_curie_slot:
+        ifabsent: class_curie
+    class_uri_slot:
+        range: uri
+        ifabsent: class_uri
+    default_ns_slot:
+        ifabsent: default_ns
+    default_range_slot:
+        ifabsent: default_range
+    int_42_slot:
+        range: integer
+        ifabsent: int(42)
+    int_0_slot:
+        range: integer
+        # a zero int doesn't work
+        # ifabsent: int(0)
+    neg_int_slot:
+        range: integer
+        ifabsent: int(-117243)
+    slot_uri_slot:
+        range: uri
+        ifabsent: slot_uri
+    slot_curie_slot:
+        ifabsent: slot_curie
+    string_slot:
+        ifabsent: string(s1)
+    mt_string_slot:
+        ifabsent: string()
+        
+classes:
+    HighClass:
+        slots:
+            - bool_true_slot
+            - bool_false_slot
+            - bnode_slot
+            - class_curie_slot
+            - class_uri_slot
+            - default_ns_slot
+            - default_range_slot
+            - int_42_slot
+            - int_0_slot
+            - neg_int_slot
+            - slot_uri_slot
+            - slot_curie_slot
+            - string_slot
+            - mt_string_slot
+"""
+
+class IfAbsentTestCase(unittest.TestCase):
+    def test_ifabsent(self):
+        m = compile_python(PythonGenerator(model_txt).serialize())
+        sample = m.HighClass()
+        self.assertEqual(sample.bool_true_slot, True)
+        self.assertEqual(sample.bool_false_slot, False)
+        print("class_curie_slot fails")
+        # self.assertEqual(sample.class_curie_slot, m.HighClass.class_class_curie)
+        print("class_uri_slot fails")
+        # self.assertEqual(sample.class_uri_slot, m.HighClass.class_class_uri)
+        print("default_ns fails")
+        # self.assertEqual(sample.default_ns_slot, 'ex')
+        print("default_range fails")
+        # self.assertEqual(sample.default_range_slot, 'string')
+        print("int(0) fails")
+        # self.assertEqual(sample.int_0_slot, 0)
+        self.assertEqual(sample.int_42_slot, 42)
+        self.assertEqual(sample.neg_int_slot, -117243)
+        print("slot_curie fails")
+        # self.assertEqual(sample.slot_curie_slot, m.slots.slot_curie_slot.curie)
+        print("slot_uri fails")
+        # self.assertEqual(sample.slot_uri_slot, m.slots.slot_uri_slot.uri)
+        self.assertEqual(sample.string_slot, "s1")
+        self.assertEqual(sample.mt_string_slot, "")
+
+
+if __name__ == '__main__':
+    unittest.main()