Refactor interfaces and use property builtin to define metadata prope…

…rties

owslib/interfaces.py

@@ -1,16 +1,18 @@
 # Do not import zope.interfaces
 
-class IWebMapService:
-    """Abstraction for an OGC Web Map Service (WMS).
 
-    Properties
-    ----------
-    url : string
-        Online resource URL.
-    version : string
-        WMS protocol version.
-    capabilities : object
-        Describes the capabilities metadata of the WMS.
+class IService:
+    """The OGC Web Service interface.
+    """
+
+    url = property("""Online resource URL (string)""")
+    # XXX: here or in capabilities?
+    version = property("""Protocol version (string)""")
+    capabilities = property("""Implementation of IServiceMetadata (object)""")
+
+
+class IWebMapService(IService):
+    """Abstraction for an OGC Web Map Service (WMS).
     """
 
     def getcapabilities():
@@ -25,17 +27,8 @@ def getfeatureinfo(**kw):
         """Make a request to the WMS, returns data."""
 
 
-class IWebFeatureService:
+class IWebFeatureService(IService):
     """Abstraction for an OGC Web Feature Service (WFS).
-
-    Properties
-    ----------
-    url : string
-        Online resource URL.
-    version : string
-        WFS protocol version.
-    capabilities : object
-        Describes the capabilities metadata of the WFS.
     """
 
     def getcapabilities():
@@ -50,62 +43,93 @@ def describefeaturetype(**kw):
         """Make a request to the WFS, returns data."""
 
 
-class IServiceIdentificationMetadata:
-    """OO-interface to WMS metadata.
+class IWebCoverageService(IService):
+    # TODO
+    pass
 
-    Properties
-    ----------
-    service : string
-        "WMS", "WFS".
-    version : string
-        Version of service protocol.
-    title : string
-        Human-targeted title of service.
-    abstract : string
-        Text describing the service.
-    keywords : list
-        List of strings.
-    rights : list
-        Explanation of rights associated with service.
+
+# Follows the 4 aspects of service metadata
+
+class IServiceIdentificationMetadata:
+    """OO-interface to service identification metadata.
     """
+
+    service = property("""Service name (string): "WMS", "WFS", or "WCS".""")
+    # XXX: here or in service root?
+    version = property("""Version of service protocol (string).""")
+    title = property("""Human-targeted title of service (string).""")
+    abstract = property("""Text describing the service (string).""")
+    keywords = property("""Keyword list (list).""")
+    rights = property("""Explanation of rights associated with service (string).""")
 
-class IServiceProviderMetadata:
-    """OO-interface to WMS metadata.
 
-    Properties
-    ----------
-    provider : string
-        Organization name.
-    url : string
-        URL for provider web site.
-    contact : string
-        How to contact the service provider.
+class IServiceProviderMetadata:
+    """OO-interface to service provider metadata.
     """
 
+    provider = property("""Provider's name (string).""")
+    url = property("""URL for provider's web site (string).""")
+    contact = property("""How to contact the service provider (string).""")
+
+
 class IServiceOperationsMetadata:
-    """OO-interface to WMS metadata.
+    """OO-interface to service operations metadata.
+    """
 
-    Properties
-    ----------
-    operations : list
-        List of operation descriptors.
-    exceptions : list
-        List of exception formats.
+    operations = property("""List of operation descriptors (list). These must implement IOperationMetadata (below).""")
+    exceptions = property("""List of exception formats (list).""")
+
+
+class IServiceContentsMetadata:
+    """OO-interface to service contents metadata.
     """
-
+
+    contents = property("""List of content descriptors (list). These must implement IServiceContent (below).""")
+
+
+# IServiceMetadata aggregates the 4 aspects above
+
+class IServiceMetadata(
+    IServiceIdentificationMetadata, IServiceProviderMetadata,
+    IServiceOperationsMetadata, IServiceContentsMetadata
+    ):
+    """OWS Metadata.
+    """
+
+
+# Second level metadata interfaces
+
 class IOperationMetadata:
-    """OO-interface to WMS metadata.
+    """OO-interface to operation metadata.
+    """
 
-    Properties
-    ----------
-    name : string
-        "GetCapabilities", for example.
-    formatOptions : list
-        List of content types.
-    methods : dict
-        Array of method descriptors, keyed to HTTP verbs.
+    name = property("""Operation name (string): GetCapabilities", for example.""")
+    formatOptions = property("""List of content types (list).""")
+    methods = property("""Mapping of method descriptors, keyed to HTTP verbs. Items must implement IMethodMetadata (below).""")
+
+
+class IMethodMetadata:
+    """OO-interface to method metadata.
     """
 
+    url = property("""Method endpoint URL (string).""")
+    # TODO: constraint
+
+
+class IContentMetadata:
+    """OO-interface to content metadata.
+    """
+
+    id = property("""Unique identifier (string).""")
+    title = property("""Human-targeted title (string).""")
+    boundingBox = property("""Four bounding values and a coordinate reference system identifier (tuple).""")
+    boundingBoxWGS84 = property("""Four bounding values in WGS coordinates.""")
+    crsOptions = property("""List of available coordinate/spatial reference systems (list).""")
+    styles = property("""List of style dicts (list).""")
+
+
+# XXX: needed?
+
 class IContactMetadata:
     """OO-interface to OWS metadata.
 
@@ -121,48 +145,5 @@ class IContactMetadata:
     email : string
     """
 
-class IMethodMetadata:
-    """OO-interface to WMS metadata.
-
-    Properties
-    ----------
-    url : string
-        Method URL.
-    
-    TODO: constraint
-    """
-
-class IServiceContentsMetadata:
-    """OO-interface to WMS metadata.
-
-    Properties
-    ----------
-    contents : list
-        List of content descriptors.
-    """
-
-class IContentMetadata:
-    """OO-interface to WMS metadata.
-
-    Properties
-    ----------
-    id : string
-        Unique identifier.
-    title : string
-        Human-targeted title.
-    boundingBox : 5-tuple
-        Four bounding values and a coordinate reference system identifier.
-    boundingBoxWGS84 : 4-tuple
-        Four bounding values in WGS coordinates.
-    crsOptions : list
-        List of available coordinate/spatial reference systems.
-    styles : list
-        List of style dicts.
-    """
-
-class IServiceMetadata(IServiceIdentificationMetadata, IServiceProvideMetadata,
-                       IServiceOperationsMetadata, IServiceContentsMetadata):
-    """OWS Metadata.
-    """