Merge from trunk

[plcapi.git] / trunk / PLC / Parameter.py

diff --git a/trunk/PLC/Parameter.py b/trunk/PLC/Parameter.py
new file mode 100644 (file)
index 0000000..fc25b93
--- /dev/null
+++ b/trunk/PLC/Parameter.py
@@ -0,0 +1,105 @@
+#
+# Shared type definitions
+#
+# Mark Huang <mlhuang@cs.princeton.edu>
+# Copyright (C) 2006 The Trustees of Princeton University
+#
+# $Id$
+#
+
+from types import *
+from PLC.Faults import *
+
+class Parameter:
+    """
+    Typed value wrapper. Use in accepts and returns to document method
+    parameters. Set the optional and default attributes for
+    sub-parameters (i.e., dict fields).
+    """
+
+    def __init__(self, type, doc = "",
+                 min = None, max = None,
+                 optional = None,
+                 ro = False,
+                 nullok = False):
+        # Basic type of the parameter. Must be a builtin type
+        # that can be marshalled by XML-RPC.
+        self.type = type
+
+        # Documentation string for the parameter
+        self.doc = doc
+
+        # Basic value checking. For numeric types, the minimum and
+        # maximum possible values, inclusive. For string types, the
+        # minimum and maximum possible UTF-8 encoded byte lengths.
+        self.min = min
+        self.max = max
+
+        # Whether the sub-parameter is optional or not. If None,
+        # unknown whether it is optional.
+        self.optional = optional
+
+        # Whether the DB field is read-only.
+        self.ro = ro
+
+        # Whether the DB field can be NULL.
+        self.nullok = nullok
+
+    def type(self):
+        return self.type
+
+    def __repr__(self):
+        return repr(self.type)
+
+class Mixed(tuple):
+    """
+    A list (technically, a tuple) of types. Use in accepts and returns
+    to document method parameters that may return mixed types.
+    """
+
+    def __new__(cls, *types):
+        return tuple.__new__(cls, types)
+
+
+def python_type(arg):
+    """
+    Returns the Python type of the specified argument, which may be a
+    Python type, a typed value, or a Parameter.
+    """
+
+    if isinstance(arg, Parameter):
+        arg = arg.type
+
+    if isinstance(arg, type):
+        return arg
+    else:
+        return type(arg)
+
+def xmlrpc_type(arg):
+    """
+    Returns the XML-RPC type of the specified argument, which may be a
+    Python type, a typed value, or a Parameter.
+    """
+
+    arg_type = python_type(arg)
+
+    if arg_type == NoneType:
+        return "nil"
+    elif arg_type == IntType or arg_type == LongType:
+        return "int"
+    elif arg_type == bool:
+        return "boolean"
+    elif arg_type == FloatType:
+        return "double"
+    elif arg_type in StringTypes:
+        return "string"
+    elif arg_type == ListType or arg_type == TupleType:
+        return "array"
+    elif arg_type == DictType:
+        return "struct"
+    elif arg_type == Mixed:
+        # Not really an XML-RPC type but return "mixed" for
+        # documentation purposes.
+        return "mixed"
+    else:
+        raise PLCAPIError, "XML-RPC cannot marshal %s objects" % arg_type