Schema: make MaxLengh compliant with the spec

The attribute MaxLength MAY be specified and the attribute may hold the
constant 'max'.

TODO - the attribute MAY be specified only for the Binary, String, and
Stream types.

Author: filak-sap

pyodata/v2/model.py

@@ -127,16 +127,24 @@ def from_name(name):
 
         return Typ.Types[name]
 
-
 class VariableDeclaration(Identifier):
 
+    MAXIMUM_LENGTH = -1
+
     def __init__(self, name, typ, nullable, max_length, precision):
         super(VariableDeclaration, self).__init__(name)
 
         self._typ = Typ.from_name(typ)
 
         self._nullable = bool(nullable)
-        self._max_length = int(max_length if max_length is not None else 0)
+
+        if not max_length:
+            self._max_length = None
+        elif max_length.upper() == 'MAX':
+            self._max_length = VariableDeclaration.MAXIMUM_LENGTH
+        else:
+            self._max_length = int(max_length)
+
         self._precision = precision
 
     @property

tests/conftest.py

@@ -12,7 +12,7 @@ def metadata():
             <Key><PropertyRef Name="Key"/></Key>
             <Property Name="Key" Type="Edm.String" Nullable="false" sap:unicode="false" sap:label="Key" sap:creatable="false" sap:updatable="false" sap:sortable="false"/>
             <Property Name="DataType" Type="Edm.String" Nullable="false" sap:unicode="false" sap:label="Key" sap:creatable="false" sap:updatable="false" sap:sortable="false"/>
-            <Property Name="Data" Type="Edm.String" Nullable="false" sap:unicode="false" sap:label="Data" sap:creatable="false" sap:updatable="false" sap:sortable="false" sap:filterable="false" sap:text="DataName"/>
+            <Property Name="Data" Type="Edm.String" MaxLength="Max" Nullable="false" sap:unicode="false" sap:label="Data" sap:creatable="false" sap:updatable="false" sap:sortable="false" sap:filterable="false" sap:text="DataName"/>
             <Property Name="DataName" Type="Edm.String" Nullable="false" sap:unicode="false" sap:label="Data" sap:creatable="false" sap:updatable="false" sap:sortable="false" sap:filterable="false"/>
            </EntityType>
            <EntityType Name="DataEntity" sap:content-version="1" sap:value-list="true" sap:label="Data entities">

tests/test_model_v2.py

@@ -3,7 +3,7 @@
 
 import pytest
 
-from pyodata.v2.model import Edmx, Typ
+from pyodata.v2.model import Edmx, Typ, EntityTypeProperty
 
 
 def test_edmx(metadata):
@@ -34,6 +34,7 @@ def test_edmx(metadata):
     master_prop_data = master_entity.proprty('Data')
     assert master_prop_data.text_proprty.name == 'DataName'
     assert master_prop_data.visible
+    assert master_prop_data.max_length == EntityTypeProperty.MAXIMUM_LENGTH
 
     master_prop_data_vh = master_prop_data.value_helper
     assert str(master_prop_data_vh) == 'ValueHelper(MasterEntity/Data)'
@@ -84,7 +85,7 @@ def test_edmx(metadata):
     assert param.name == 'Param'
     assert param.typ.name == 'Edm.String'
     assert not param.nullable
-    assert param.max_length == 0
+    assert param.max_length is None
     assert param.mode == 'In'
     assert param.typ.traits.to_odata('Foo') == "'Foo'"
     assert param.typ.traits.from_odata("'Foo'") == 'Foo'