Implement toolbar extension mechanism for providers

app/helpers/application_helper/toolbar/base.rb

@@ -0,0 +1,67 @@
+class ApplicationHelper::Toolbar::Base
+  include Singleton
+  extend SingleForwardable
+  delegate %i(api_button button select twostate separator definition button_group custom_content) => :instance
+
+  def custom_content(name, args)
+    @definition[name] = ApplicationHelper::Toolbar::Custom.new(name, args)
+  end
+
+  def button_group(name, buttons)
+    @definition[name] = ApplicationHelper::Toolbar::Group.new(name, buttons)
+  end
+
+  def api_button(id, icon, title, text, keys = {})
+    keys[:data] = {
+      'function'      => 'sendDataWithRx',
+      'function-data' => {
+        'type'       => "generic",
+        'controller' => "toolbarActions",
+        'payload'    => {
+          'entity' => keys[:api][:entity].pluralize,
+          'action' => keys[:api][:action]
+        }
+      }.to_json
+    }
+    generic_button(:button, id, icon, title, text, keys)
+  end
+
+  def button(id, icon, title, text, keys = {})
+    generic_button(:button, id, icon, title, text, keys)
+  end
+
+  def select(id, icon, title, text, keys = {})
+    generic_button(:buttonSelect, id, icon, title, text, keys)
+  end
+
+  def twostate(id, icon, title, text, keys = {})
+    generic_button(:buttonTwoState, id, icon, title, text, keys)
+  end
+
+  def separator
+    {:separator => true}
+  end
+
+  attr_reader :definition
+
+  private
+
+  def initialize
+    @loaded = false
+    @definition = {}
+  end
+
+  def generic_button(type, id, icon, title, text, keys)
+    if text.kind_of?(Hash)
+      keys = text
+      text = title
+    end
+    {
+      :type  => type,
+      :id    => id.to_s,
+      :icon  => icon,
+      :title => title,
+      :text  => text
+    }.merge(keys)
+  end
+end

app/helpers/application_helper/toolbar/basic.rb

@@ -1,66 +1,34 @@
-class ApplicationHelper::Toolbar::Basic
-  include Singleton
-  extend SingleForwardable
-  delegate %i(api_button button select twostate separator definition button_group custom_content) => :instance
-
-  attr_reader :definition
-
-  def custom_content(name, args)
-    @definition[name] = ApplicationHelper::Toolbar::Custom.new(name, args)
-  end
-
-  def button_group(name, buttons)
-    @definition[name] = ApplicationHelper::Toolbar::Group.new(name, buttons)
-  end
-
-  def api_button(id, icon, title, text, keys = {})
-    keys[:data] = {
-      'function'      => 'sendDataWithRx',
-      'function-data' => {
-        'type'       => "generic",
-        'controller' => "toolbarActions",
-        'payload'    => {
-          'entity' => keys[:api][:entity].pluralize,
-          'action' => keys[:api][:action]
-        }
-      }.to_json
-    }
-    generic_button(:button, id, icon, title, text, keys)
+class ApplicationHelper::Toolbar::Basic < ApplicationHelper::Toolbar::Base
+  def definition(record = nil)
+    extension_classes_filtered(record).reduce(@definition) do |acc, ext|
+      acc.merge(ext.definition)
+    end
   end
 
-  def button(id, icon, title, text, keys = {})
-    generic_button(:button, id, icon, title, text, keys)
-  end
+  private
 
-  def select(id, icon, title, text, keys = {})
-    generic_button(:buttonSelect, id, icon, title, text, keys)
+  def extension_classes
+    @extension_classes ||= load_extension_classes
   end
 
-  def twostate(id, icon, title, text, keys = {})
-    generic_button(:buttonTwoState, id, icon, title, text, keys)
-  end
+  def extension_classes_filtered(record)
+    return extension_classes if record.nil?
 
-  def separator
-    {:separator => true}
+    # Example:
+    # "ManageIQ::Providers::Amazon::ToolbarOverrides::EmsCloudCenter" is a match for
+    #   "ManageIQ::Providers::Amazon::CloudManager
+    extension_classes.find_all do |ext|
+      ext.name.split('::')[0..2] == record.class.name.split('::')[0..2]
+    end
   end
 
-  private
+  def load_extension_classes
+    return [] if self.class.name.nil?
 
-  def initialize
-    @definition = {}
-  end
-
-  def generic_button(type, id, icon, title, text, keys)
-    if text.kind_of?(Hash)
-      keys = text
-      text = title
-    end
-    {
-      :type  => type,
-      :id    => id.to_s,
-      :icon  => icon,
-      :title => title,
-      :text  => text
-    }.merge(keys)
+    toolbar_base_name = self.class.name.to_s.split('::').last
+    Vmdb::Plugins.collect do |plugin|
+      instance = [plugin.name.chomp('::Engine'), 'ToolbarOverrides', toolbar_base_name].join('::')
+      instance.safe_constantize
+    end.compact
   end
 end

app/helpers/application_helper/toolbar/override.rb

@@ -0,0 +1,3 @@
+class ApplicationHelper::Toolbar::Override < ApplicationHelper::Toolbar::Base
+  # For now this class is empty. However we want the provider toolbar extentions to inherit from here.
+end

app/helpers/application_helper/toolbar_builder.rb

@@ -16,12 +16,12 @@ def build_toolbar(toolbar_name)
 
     build_toolbar_setup
     toolbar_class = toolbar_class(toolbar_name)
-    build_toolbar_from_class(toolbar_class)
+    build_toolbar_from_class(toolbar_class, @record)
   end
 
   def build_toolbar_by_class(toolbar_class)
     build_toolbar_setup
-    build_toolbar_from_class(toolbar_class)
+    build_toolbar_from_class(toolbar_class, @record)
   end
 
   private
@@ -450,8 +450,8 @@ def build_toolbar_setup
     @sep_added = false
   end
 
-  def build_toolbar_from_class(toolbar_class)
-    toolbar_class.definition.each_with_index do |(name, group), group_index|
+  def build_toolbar_from_class(toolbar_class, record)
+    toolbar_class.definition(record).each_with_index do |(_name, group), group_index|
       @sep_added = false
       @groups_added.push(group_index)
       case group