More specific error handling

2 files changed, 74 insertions, 16 deletions

diff --git a/lib/wmi-lite/wmi.rb b/lib/wmi-lite/wmi.rb
index cc6492d..b712ba9 100644
--- a/lib/wmi-lite/wmi.rb
+++ b/lib/wmi-lite/wmi.rb
@@ -18,32 +18,25 @@
 
 require 'win32ole' if RUBY_PLATFORM =~ /mswin|mingw32|windows/
 require 'wmi-lite/wmi_instance'
+require 'wmi-lite/wmi_exception'
 
 module WmiLite
   class Wmi
     def initialize(namespace = nil)
-      @namespace = namespace
+      @namespace = namespace.nil? ? 'root/cimv2' : namespace
       @connection = nil
     end
 
     def query(wql_query)
-      results = start_query(wql_query)
-      
-      result_set = []
-
-      results.each do | result | 
-        result_set.push(wmi_result_to_snapshot(result))
-      end
-      
-      result_set
+      query_with_context(wql_query)
     end
 
     def instances_of(wmi_class)
-      query("select * from #{wmi_class}")
+      query_with_context("select * from #{wmi_class}", wmi_class)
     end
 
     def first_of(wmi_class)
-      query_result = start_query("select * from #{wmi_class}")
+      query_result = start_query("select * from #{wmi_class}", wmi_class)
       first_result = nil
       query_result.each do | record |
         first_result = record
@@ -54,10 +47,27 @@ module WmiLite
 
     private
 
-    def start_query(wql_query)
-      connect_to_namespace
-      result = @connection.ExecQuery(wql_query)
-      raise_if_failed(result)
+    def query_with_context(wql_query, diagnostic_class_name = nil)
+      results = start_query(wql_query, diagnostic_class_name)
+
+      result_set = []
+
+      results.each do | result |
+        result_set.push(wmi_result_to_snapshot(result))
+      end
+
+      result_set
+    end
+
+    def start_query(wql_query, diagnostic_class_name = nil)
+      result = nil
+      begin
+        connect_to_namespace
+        result = @connection.ExecQuery(wql_query)
+        raise_if_failed(result)
+      rescue WIN32OLERuntimeError => native_exception
+        raise WmiException.new(native_exception, @namespace, wql_query, diagnostic_class_name)
+      end
       result
     end
 
diff --git a/lib/wmi-lite/wmi_exception.rb b/lib/wmi-lite/wmi_exception.rb
new file mode 100644
index 0000000..85c6387
--- /dev/null
+++ b/lib/wmi-lite/wmi_exception.rb
@@ -0,0 +1,48 @@
+#
+# Author:: Adam Edwards (<adamed@getchef.com>)
+# Copyright:: Copyright 2014 Chef Software, Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+module WmiLite
+  class WmiException < Exception
+    def initialize(exception, namespace, query, class_name)
+      error_message = exception.message
+      error_code = nil
+
+      # Parse the error to get the error status code
+      error_code_match = error_message.match(/[^\:]+\:\s*([0-9A-Fa-f]{1,8}).*/)
+      error_code = error_code_match.captures.first if error_code_match
+      error_code = '' if error_code.nil?
+
+      # Use the status code to generate a more friendly message
+      case error_code
+      when /80041010/i
+        if class_name
+          error_message = "The specified class \'#{class_name}\' is not valid in the namespace \'#{namespace}\'.\n#{exception.message}."
+        else
+          error_message = "The specified query \'#{query}\' referenced a class that is not valid in the namespace \'#{namespace}\'\n#{exception.message}."
+        end
+      when /8004100E/i
+        error_message = "The specified namespace \'#{namespace}\' is not valid.\n#{exception.message}"
+      when /80041017/i
+        error_message = "The specified query \'#{query}\' is not valid.\n#{exception.message}"
+      end
+
+      super(error_message)
+    end
+  end
+end
+