Implemented cross-backend keyword validation

holoviews/core/options.py

@@ -35,7 +35,7 @@
 import pickle
 import traceback
 from contextlib import contextmanager
-from collections import OrderedDict
+from collections import OrderedDict, defaultdict
 
 import numpy as np
 
@@ -288,6 +288,8 @@ def __init__(self, key=None, allowed_keywords=None, merge_keywords=True, **kwarg
                 else:
                     raise OptionError(kwarg, allowed_keywords)
 
+        for invalid_kw in invalid_kws:
+            StoreOptions.record_option_error(OptionError(invalid_kw, allowed_keywords))
         if invalid_kws and self.warn_on_skip:
             self.warning("Invalid options %s, valid options are: %s"
                          % (repr(invalid_kws), str(sorted(list(set(allowed_keywords))))))
@@ -1051,7 +1053,7 @@ def register(cls, associations, backend, style_aliases={}):
 class StoreOptions(object):
     """
     A collection of utilities for advanced users for creating and
-    setting customized option tress on the Store. Designed for use by
+    setting customized option trees on the Store. Designed for use by
     either advanced users or the %opts line and cell magics which use
     this machinery.
 
@@ -1060,8 +1062,42 @@ class StoreOptions(object):
     access it is best to minimize the number of methods implemented on
     that class and implement the necessary utilities on StoreOptions
     instead.
+
+    Lastly this class offers a means to record all OptionErrors
+    generated by an option specification. This is used for validation
+    purposes.
     """
 
+    #=======================#
+    # OptionError recording #
+    #=======================#
+
+    _errors_recorded = None
+    _option_class_settings = None
+
+    @classmethod
+    def start_recording_errors(cls):
+        "Start collected errors supplied via record_option_error method"
+        cls._option_class_settings = (Options.skip_invalid, Options.warn_on_skip)
+        (Options.skip_invalid, Options.warn_on_skip) = (True, False)
+        cls._errors_recorded = []
+
+    @classmethod
+    def stop_recording_errors(cls):
+        "Stop recording errors and return recorded errors"
+        if cls._errors_recorded is None:
+            raise Exception('Cannot stop recording before it is started')
+        recorded = cls._errors_recorded[:]
+        (Options.skip_invalid ,Options.warn_on_skip) = cls._option_class_settings
+        cls._errors_recorded = None
+        return recorded
+
+    @classmethod
+    def record_option_error(cls, error):
+        "Record an option error if currently recording"
+        if cls._errors_recorded is not None:
+            cls._errors_recorded.append(error)
+
     #===============#
     # ID management #
     #===============#
@@ -1136,19 +1172,33 @@ def apply_customizations(cls, spec, options):
             options[str(key)] = customization
         return options
 
-
     @classmethod
-    def validate_spec(cls, spec, skip=Options.skip_invalid):
-        """
-        Given a specification, validated it against the default
-        options tree (Store.options). Only tends to be useful when
-        invalid keywords generate exceptions instead of skipping.
-        """
-        if skip: return
-        options = OptionTree(items=Store.options().data.items(),
-                             groups=Store.options().groups)
-        return cls.apply_customizations(spec, options)
-
+    def validate_spec(cls, spec, backends=None):
+        """
+        Given a specification, validated it against the options tree for
+        the specified backends by raising OptionError for invalid
+        options. If backends is None, validates against all the
+        currently loaded backend.
+
+        Only useful when invalid keywords generate exceptions instead of
+        skipping i.e Options.skip_invalid is False.
+        """
+        backends =  Store.loaded_backends()if backends is None else backends
+
+        error_info = defaultdict(set)
+        for backend in backends:
+            cls.start_recording_errors()
+            options = OptionTree(items=Store.options(backend).data.items(),
+                                 groups=Store.options(backend).groups)
+            cls.apply_customizations(spec, options)
+            for error in cls.stop_recording_errors():
+                error_info[(error.invalid_keyword, backend)] |= set(error.allowed_keywords)
+
+        for key in set(k for k,_ in error_info.keys()):
+            if set([(key, b) for b in backends]).issubset(set(error_info.keys())):
+                all_allowed = [ error_info[(key,b)] for b in backends ]
+                allowed_union = set().union(*all_allowed)
+                raise OptionError(key, allowed_keywords=sorted(allowed_union))
 
     @classmethod
     def expand_compositor_keys(cls, spec):

holoviews/ipython/magics.py

@@ -597,8 +597,8 @@ def process_element(cls, obj):
 
     @classmethod
     def _format_options_error(cls, err):
-        info = (err.invalid_keyword, err.group_name, ', '.join(err.allowed_keywords))
-        return "Keyword <b>%r</b> not one of following %s options:<br><br><b>%s</b>" % info
+        info = (err.invalid_keyword, ', '.join(err.allowed_keywords))
+        return "Keyword <b>%r</b> not supported by any of the loaded backends. Valid options are :<br><br><b>%s</b>" % info
 
     @classmethod
     def register_custom_spec(cls, spec):