Notifiers

.rspec

@@ -0,0 +1 @@
+--require spec_helper

.travis.yml

@@ -8,7 +8,6 @@ rvm:
   - 2.1
   - 2.2
   - 2.3.0
-  - rbx-2
   - ruby-head
 matrix:
   allow_failures:

Gemfile

@@ -7,3 +7,5 @@ gem 'rspec'
 gem 'guard'
 gem 'guard-rspec'
 gem 'coveralls', :require => false
+gem 'pry-byebug'
+gem 'rubocop'

README.md

@@ -7,8 +7,8 @@ ErrbitPlugins are Ruby gems that extend the functionality of Errbit. To get
 started, create a Ruby gem and add 'errbit_plugin' as a dependency in your
 gem's gemspec.
 
-Now you can start adding plugins. At the moment, there is only one kind of
-plugin you can create, and that is the issue tracker.
+Now you can start adding plugins. Keep reading to learn about what you can do
+with Errbit plugins.
 
 ### Issue Trackers
 An issue tracker plugin is a Ruby class that enables you to link errors within
@@ -122,7 +122,86 @@ class MyIssueTracker < ErrbitPlugin::IssueTracker
 end
 ```
 
+### Notifiers
+A Notifier is a Ruby class that can notify an external system when Errbit
+receives notices. When configuring an app within the Errbit UI, you can choose
+to enable a notifier which will delegate the business of sending notifications
+to the selected notifier.
 
+Your notifier plugin is responsible for implementing the interface defined by
+ErrbitPlugin::Notifier. All of the required methods must be implemented and the
+class must extend ErrbitPlugin::Notifier. Here's an example:
+```ruby
+class MyNotifier < ErrbitPlugin::Notifier
+
+  # A unique label for your notifier plugin used internally by errbit
+  def self.label
+    'my-notifier'
+  end
+
+  def self.note
+    'a note about this notifier that users will see in the UI'
+  end
+
+  # Form fields that will be presented to the administrator when setting up
+  # or editing the errbit app. The values we collect will be availble for use
+  # later when its time to notify.
+  def self.fields
+    {
+      username: {
+        placeholder: "Some placeholder text"
+      },
+      password: {
+        placeholder: "Some more placeholder text"
+      }
+    }
+  end
+
+  # Icons to display during user interactions with this notifier. This method
+  # should return a hash of two-tuples, the key names being 'create', 'goto',
+  # and 'inactive'. The two-tuples should contain the icon media type and the
+  # binary icon data.
+  def self.icons
+    @icons ||= {
+      create: [ 'image/png', File.read('./path/to/create.png') ],
+      goto: [ 'image/png', File.read('./path/to/goto.png') ],
+      inactive: [ 'image/png', File.read('./path/to/inactive.png') ],
+    }
+  end
+
+  # If this notifier can be in a configured or non-configured state, you can let
+  # errbit know by returning a Boolean here
+  def configured?
+    # In this case, we'll say this notifier is configured when username
+    # is set
+    !!params['username']
+  end
+
+  # Called to validate user input. Just return a hash of errors if there are
+  # any
+  def errors
+    if @params['field_one']
+      {}
+    else
+      { :field_one, 'Field One must be present' }
+    end
+  end
+
+  # notify is called when Errbit decides its time to notify external systems
+  # about a new error notice. notify receives an instance of the notice's problem
+  # which you can interrogate for any information you'd like to include in the
+  # notification message.
+  def notify(problem)
+    # Send a notification! Use HTTP, SMTP, FTP, RabbitMQ or whatever you want
+    # to notify your external system.
+  end
+
+  # The URL for your remote issue tracker
+  def url
+    'http://some-remote-tracker.com'
+  end
+end
+```
 
 ## Contributing
 

lib/errbit_plugin.rb

@@ -1,5 +1,7 @@
-require "errbit_plugin/version"
-require "errbit_plugin/registry"
-require "errbit_plugin/issue_tracker"
-require "errbit_plugin/validate_issue_tracker"
-require "errbit_plugin/issue_trackers/none"
+require 'errbit_plugin/version'
+require 'errbit_plugin/registry'
+require 'errbit_plugin/issue_tracker'
+require 'errbit_plugin/validate_issue_tracker'
+require 'errbit_plugin/notifier'
+require 'errbit_plugin/validate_notifier'
+require 'errbit_plugin/issue_trackers/none'

lib/errbit_plugin/notifier.rb

@@ -0,0 +1,10 @@
+module ErrbitPlugin
+  # abstract class for issue trackers
+  class Notifier
+    attr_reader :options
+
+    def initialize(options)
+      @options = options
+    end
+  end
+end

lib/errbit_plugin/notifiers/none.rb

@@ -0,0 +1,27 @@
+module ErrbitPlugin
+  class NoneNotifier < Notifier
+    LABEL = 'none'.freeze
+    NOTE = 'No notifications'.freeze
+
+    def self.label; LABEL; end
+    def self.note; NOTE; end
+    def self.fields; {}; end
+    def self.icons
+      @icons ||= {
+        create: ['image/png', read_static_file('none_create.png')],
+        goto: ['image/png', read_static_file('none_create.png')],
+        inactive: ['image/png', read_static_file('none_inactive.png')],
+      }
+    end
+    def self.read_static_file(file)
+      File.read(File.expand_path(File.join(
+        File.dirname(__FILE__), '..', '..', '..', 'static', file)))
+    end
+    def configured?; false; end
+    def errors; {}; end
+    def url; ''; end
+    def notify(*); true; end
+  end
+end
+
+ErrbitPlugin::Registry.add_notifier(ErrbitPlugin::NoneNotifier)

lib/errbit_plugin/registry.rb

@@ -4,30 +4,56 @@ class AlreadyRegisteredError < StandardError; end
 
   module Registry
     @issue_trackers = {}
+    @notifiers = {}
 
     def self.add_issue_tracker(klass)
+      validate = ValidateIssueTracker.new(klass)
+
+      unless validate.valid?
+        raise IncompatibilityError.new(validate.errors.join('; '))
+      end
+
       key = klass.label
 
       if issue_trackers.has_key?(key)
         raise AlreadyRegisteredError,
           "issue_tracker '#{key}' already registered"
       end
 
-      validate = ValidateIssueTracker.new(klass)
-
-      if validate.valid?
-        @issue_trackers[key] = klass
-      else
-        raise IncompatibilityError.new(validate.errors.join('; '))
-      end
+      @issue_trackers[key] = klass
     end
 
     def self.clear_issue_trackers
-      @issue_trackers = {}
+      @issue_trackers.clear
     end
 
     def self.issue_trackers
       @issue_trackers
     end
+
+    def self.add_notifier(klass)
+      validate = ValidateNotifier.new(klass)
+
+      unless validate.valid?
+        raise IncompatibilityError.new(validate.errors.join('; '))
+      end
+
+      key = klass.label
+
+      if notifiers.has_key?(key)
+        raise AlreadyRegisteredError,
+          "notifier '#{key}' already registered"
+      end
+
+      @notifiers[key] = klass
+    end
+
+    def self.clear_notifiers
+      @notifiers.clear
+    end
+
+    def self.notifiers
+      @notifiers
+    end
   end
 end

lib/errbit_plugin/validate_notifier.rb

@@ -0,0 +1,62 @@
+module ErrbitPlugin
+  class ValidateNotifier
+    def initialize(klass)
+      @klass = klass
+      @errors = []
+    end
+    attr_reader :errors
+
+    def valid?
+      valid_inherit = good_inherit?
+      valid_instance_methods = implements_instance_methods?
+      valid_class_methods = implements_class_methods?
+
+      valid_inherit && valid_instance_methods && valid_class_methods
+    end
+
+    private
+
+    def good_inherit?
+      unless @klass.ancestors.include?(ErrbitPlugin::Notifier)
+        add_errors(:not_inherited)
+        false
+      else
+        true
+      end
+    end
+
+    def implements_instance_methods?
+      impl = [:configured?, :errors, :notify, :url].map do |method|
+        if instance.respond_to?(method)
+          true
+        else
+          add_errors(:instance_method_missing, method)
+          false
+        end
+      end
+
+      impl.all? { |value| value == true }
+    end
+
+    def implements_class_methods?
+      impl = [:label, :fields, :note, :icons].map do |method|
+        if @klass.respond_to?(method)
+          true
+        else
+          add_errors(:class_method_missing, method)
+          false
+        end
+      end
+
+      impl.all? { |value| value == true }
+    end
+
+    def instance
+      @instance ||= @klass.new({})
+    end
+
+    def add_errors(key, value=nil)
+      @errors << [key, value].compact
+    end
+  end
+end

spec/errbit_plugin/notifier_spec.rb

@@ -0,0 +1,9 @@
+describe ErrbitPlugin::Notifier do
+  describe '#initialize' do
+    it 'stores options' do
+      opts = { one: 'two' }
+      obj = described_class.new(opts)
+      expect(obj.options).to eq(opts)
+    end
+  end
+end