Optional codegen args

schema_salad/codegen.py

@@ -1,7 +1,7 @@
 """Generate langauge specific loaders for a particular SALAD schema."""
 import sys
 from io import open
-from typing import Any, Dict, List, MutableMapping, Optional
+from typing import Any, Dict, List, MutableMapping, MutableSequence, Optional
 
 from . import schema
 from .codegen_base import CodeGenBase
@@ -63,8 +63,16 @@ def codegen(
                 document_roots.append(rec["name"])
 
             field_names = []
+            optional_fields = set()
             for field in rec.get("fields", []):
-                field_names.append(shortname(field["name"]))
+                field_name = shortname(field["name"])
+                field_names.append(field_name)
+                tp = field["type"]
+                if (
+                    isinstance(tp, MutableSequence)
+                    and tp[0] == "https://w3id.org/cwl/salad#null"
+                ):
+                    optional_fields.add(field_name)
 
             idfield = ""
             for field in rec.get("fields", []):
@@ -78,6 +86,7 @@ def codegen(
                 rec.get("abstract", False),
                 field_names,
                 idfield,
+                optional_fields,
             )
             gen.add_vocab(shortname(rec["name"]), rec["name"])
 

schema_salad/codegen_base.py

@@ -1,6 +1,6 @@
 """Base class for the generation of loaders from schema-salad definitions."""
 import collections
-from typing import Any, Dict, List, MutableSequence, Optional, Union
+from typing import Any, Dict, List, MutableSequence, Optional, Union, Set
 
 from . import schema
 
@@ -76,6 +76,7 @@ def begin_class(
         abstract: bool,
         field_names: MutableSequence[str],
         idfield: str,
+        optional_fields: Set[str],
     ) -> None:
         """Produce the header for the given class."""
         raise NotImplementedError()

schema_salad/java_codegen.py

@@ -4,7 +4,16 @@
 import string
 from io import StringIO
 from io import open as io_open
-from typing import Any, Dict, List, MutableMapping, MutableSequence, Optional, Union
+from typing import (
+    Any,
+    Dict,
+    List,
+    MutableMapping,
+    MutableSequence,
+    Optional,
+    Union,
+    Set,
+)
 from urllib.parse import urlsplit
 
 import pkg_resources
@@ -154,6 +163,7 @@ def begin_class(
         abstract: bool,
         field_names: MutableSequence[str],
         idfield: str,
+        optional_fields: Set[str],
     ) -> None:
         cls = self.interface_name(classname)
         self.current_class = cls

schema_salad/python_codegen.py

@@ -1,6 +1,16 @@
 """Python code generator for a given schema salad definition."""
 from io import StringIO
-from typing import IO, Any, Dict, List, MutableMapping, MutableSequence, Optional, Union
+from typing import (
+    IO,
+    Any,
+    Dict,
+    List,
+    MutableMapping,
+    MutableSequence,
+    Optional,
+    Union,
+    Set,
+)
 
 from pkg_resources import resource_stream
 
@@ -74,12 +84,13 @@ def prologue(self):
 
     def begin_class(
         self,  # pylint: disable=too-many-arguments
-        classname,  # type: str
-        extends,  # type: MutableSequence[str]
-        doc,  # type: str
-        abstract,  # type: bool
-        field_names,  # type: MutableSequence[str]
-        idfield,  # type: str
+        classname: str,
+        extends: MutableSequence[str],
+        doc: str,
+        abstract: bool,
+        field_names: MutableSequence[str],
+        idfield: str,
+        optional_fields: Set[str],
     ):  # type: (...) -> None
         classname = self.safe_name(classname)
 
@@ -102,11 +113,21 @@ def begin_class(
             self.out.write("    pass\n\n\n")
             return
 
+        required_field_names = [f for f in field_names if f not in optional_fields]
+        optional_field_names = [f for f in field_names if f in optional_fields]
+
         safe_inits = ["        self,"]  # type: List[str]
         safe_inits.extend(
             [
                 "        {},  # type: Any".format(self.safe_name(f))
-                for f in field_names
+                for f in required_field_names
+                if f != "class"
+            ]
+        )
+        safe_inits.extend(
+            [
+                "        {}=None,  # type: Any".format(self.safe_name(f))
+                for f in optional_field_names
                 if f != "class"
             ]
         )
@@ -237,10 +258,12 @@ def end_class(self, classname, field_names):
             "    attrs = frozenset({attrs})\n".format(attrs=field_names)
         )
 
-        safe_inits = [
+        safe_init_fields = [
             self.safe_name(f) for f in field_names if f != "class"
         ]  # type: List[str]
 
+        safe_inits = [f + "=" + f for f in safe_init_fields]
+
         safe_inits.extend(
             ["extension_fields=extension_fields", "loadingOptions=loadingOptions"]
         )