revision

README.md

@@ -88,6 +88,7 @@ add_tracer :method_name, 'custom_span_name', { attributes: { 'any' => 'attribute
 
 For example, if you want to instrument class or instance method `create_session` inside an application controller:
 
+To instrument instance method
 ```ruby
 class SessionsController < ApplicationController
   include SolarWindsAPM::API::Tracer
@@ -100,11 +101,21 @@ class SessionsController < ApplicationController
   def create_session(user)
   end
 
-  def self.create_session(user)
-  end
-
   # instrument instance method create_session
   add_tracer :create_session, 'custom_name', { attributes: { 'foo' => 'bar' }, kind: :consumer }
+end
+```
+
+To instrument class method
+```ruby
+class SessionsController < ApplicationController
+  def create
+    user = User.find_by(email: params[:session][:email].downcase)
+    create_session(user)
+  end
+
+  def self.create_session(user)
+  end
 
   # instrument class method create_session
   class << self

lib/solarwinds_apm/api/custom_instrumentation.rb

@@ -14,31 +14,49 @@ def self.included(base)
       end
 
       module ClassMethods
-        # Helper function to instrument custom function
+        # Helper method to instrument custom method
         #
         # `add_tracer` can add a custom span to the specified instance or class method that is already defined.
         # It requires the custom span name and optionally takes the span kind and additional attributes
         # in hash format.
         #
         # === Argument:
         #
-        # * +method_name+ - (String) A non-empty string that match the function name that need to be instrumented
+        # * +method_name+ - (String) A non-empty string that match the method name that need to be instrumented
         # * +span_name+ - (String, optional, default = method_name) A non-empty string that define the span name (default to method_name)
-        # * +options+ - (Hash, optional, default = {}) A hash with desired attributes
+        # * +options+ - (Hash, optional, default = {}) A hash with desired options include attributes and span kind e.g. {attributes: {}, kind: :consumer}
         #
         # === Example:
         #
         #   class DogfoodsController < ApplicationController
+        #     include SolarWindsAPM::API::Tracer
         #
         #     def create
         #       @dogfood = Dogfood.new(params.permit(:brand, :name))
         #       @dogfood.save
-        #       custom_function
+        #       custom_method
         #     end
         #
-        #     def custom_function
+        #     def custom_method
+        #     end
+        #     add_tracer :custom_method, 'custom_name', { attributes: { 'foo' => 'bar' }, kind: :consumer }
+        #
+        #   end
+        # 
+        #   class DogfoodsController < ApplicationController
+        #     def create
+        #       @dogfood = Dogfood.new(params.permit(:brand, :name))
+        #       @dogfood.save
+        #       custom_method
+        #     end
+        #
+        #     def self.custom_method
+        #     end
+        #
+        #     class << self
+        #       include SolarWindsAPM::API::Tracer
+        #       add_tracer :custom_method, 'custom_name', { attributes: { 'foo' => 'bar' }, kind: :consumer }
         #     end
-        #     add_tracer :custom_function, 'custom_name', { attributes: { 'foo' => 'bar' }, kind: :consumer }
         #
         #   end
         #