Merge branch 'pr-173'

This closes #173

Author: kinow

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - [179](https://github.com/Smashing/smashing/pull/179) Replace Travis CI by GH actions
 - [178](https://github.com/Smashing/smashing/pull/178) Relax dependencies; pinned minor, free patch version (thanks @dylanratcliffe)
+- [173](https://github.com/Smashing/smashing/pull/173) Send only data that is needed on the dashboard (thanks @toy)
 
 ## 2021-01-30 - 1.3.1
 

javascripts/dashing.coffee

@@ -53,8 +53,9 @@ class Dashing.Widget extends Batman.View
     super
 
     @mixin($(@node).data())
-    Dashing.widgets[@id] ||= []
-    Dashing.widgets[@id].push(@)
+    if @id # skip widgets without id
+      Dashing.widgets[@id] ||= []
+      Dashing.widgets[@id].push(@)
 
     type = Batman.Filters.dashize(@view)
     $(@node).addClass("widget widget-#{type} #{@id}")
@@ -121,34 +122,38 @@ Dashing.widgets = widgets = {}
 Dashing.lastEvents = lastEvents = {}
 Dashing.debugMode = false
 
-source = new EventSource('events')
-source.addEventListener 'open', (e) ->
-  console.log("Connection opened", e)
-
-source.addEventListener 'error', (e)->
-  console.log("Connection error", e)
-  if (e.currentTarget.readyState == EventSource.CLOSED)
-    console.log("Connection closed")
-    setTimeout (->
-      window.location.reload()
-    ), 5*60*1000
-
-source.addEventListener 'message', (e) ->
-  data = JSON.parse(e.data)
-  if lastEvents[data.id]?.updatedAt != data.updatedAt
-    if Dashing.debugMode
-      console.log("Received data for #{data.id}", data)
-    lastEvents[data.id] = data
-    if widgets[data.id]?.length > 0
-      for widget in widgets[data.id]
-        widget.receiveData(data)
-
-source.addEventListener 'dashboards', (e) ->
-  data = JSON.parse(e.data)
-  if Dashing.debugMode
-    console.log("Received data for dashboards", data)
-  if data.dashboard is '*' or window.location.pathname is "/#{data.dashboard}"
-    Dashing.fire data.event, data
+Dashing.on 'run', ->
+  setTimeout -> # run only when all widgets are created
+    ids = Object.keys(Dashing.widgets)
+    source = new EventSource('events?ids=' + encodeURIComponent(ids.join(',')))
+    source.addEventListener 'open', (e) ->
+      console.log("Connection opened", e)
+
+    source.addEventListener 'error', (e)->
+      console.log("Connection error", e)
+      if (e.currentTarget.readyState == EventSource.CLOSED)
+        console.log("Connection closed")
+        setTimeout (->
+          window.location.reload()
+        ), 5*60*1000
+
+    source.addEventListener 'message', (e) ->
+      data = JSON.parse(e.data)
+      if lastEvents[data.id]?.updatedAt != data.updatedAt
+        if Dashing.debugMode
+          console.log("Received data for #{data.id}", data)
+        lastEvents[data.id] = data
+        if widgets[data.id]?.length > 0
+          for widget in widgets[data.id]
+            widget.receiveData(data)
+
+    source.addEventListener 'dashboards', (e) ->
+      data = JSON.parse(e.data)
+      if Dashing.debugMode
+        console.log("Received data for dashboards", data)
+      if data.dashboard is '*' or window.location.pathname is "/#{data.dashboard}"
+        Dashing.fire data.event, data
+  , 0
 
 $(document).ready ->
   Dashing.run()

lib/dashing/app.rb

@@ -36,7 +36,7 @@ def authenticated?(token)
 set :assets_prefix, '/assets'
 set :digest_assets, false
 set :server, 'thin'
-set :connections, []
+set :connections, {}
 set :history_file, 'history.yml'
 set :public_folder, File.join(settings.root, 'public')
 set :views, File.join(settings.root, 'dashboards')
@@ -54,7 +54,7 @@ def authenticated?(token)
   settings.sprockets.append_path("assets/#{path}")
 end
 
-['widgets', File.expand_path('../../../javascripts', __FILE__)]. each do |path|
+['widgets', File.expand_path('../../../javascripts', __FILE__)].each do |path|
   settings.sprockets.append_path(path)
 end
 
@@ -77,9 +77,12 @@ def authenticated?(token)
 get '/events', :provides => 'text/event-stream' do
   protected!
   response.headers['X-Accel-Buffering'] = 'no' # Disable buffering for nginx
+  ids = params[:ids].to_s.split(',').to_set
   stream :keep_open do |out|
-    settings.connections << out
-    out << latest_events
+    settings.connections[out] = ids
+    settings.history.each do |id, event|
+      out << event if ids.include?(id)
+    end
     out.callback { settings.connections.delete(out) }
   end
 end
@@ -131,7 +134,7 @@ def authenticated?(token)
 
 Thin::Server.class_eval do
   def stop_with_connection_closing
-    Sinatra::Application.settings.connections.dup.each(&:close)
+    Sinatra::Application.settings.connections.dup.each_key(&:close)
     stop_without_connection_closing
   end
 
@@ -141,12 +144,12 @@ def stop_with_connection_closing
 
 def send_event(id, body, target=nil)
   body[:id] = id
-  body[:updatedAt] ||= (Time.now.to_f * 1000.0).to_i 
+  body[:updatedAt] ||= (Time.now.to_f * 1000.0).to_i
   event = format_event(body.to_json, target)
   Sinatra::Application.settings.history[id] = event unless target == 'dashboards'
-  Sinatra::Application.settings.connections.each { |out|
+  Sinatra::Application.settings.connections.each { |out, ids|
     begin
-      out << event
+      out << event if target == 'dashboards' || ids.include?(id)
     rescue IOError => e # if the socket is closed an IOError is thrown
       Sinatra::Application.settings.connections.delete(out)
     end
@@ -159,12 +162,6 @@ def format_event(body, name=nil)
   str << "data: #{body}\n\n"
 end
 
-def latest_events
-  settings.history.inject("") do |str, (_id, body)|
-    str << body
-  end
-end
-
 def first_dashboard
   files = Dir[File.join(settings.views, '*')].collect { |f| File.basename(f, '.*') }
   files -= ['layout']

test/app_test.rb

@@ -4,7 +4,9 @@
 class AppTest < Dashing::Test
   def setup
     @connection = []
-    app.settings.connections = [@connection]
+    # stop sinatra from handling Hash value specially which makes it merge new value into previous one
+    app.settings.connections = nil
+    app.settings.connections = {@connection => ['some_widget']}
     app.settings.auth_token = nil
     app.settings.default_dashboard = nil
     app.settings.history_file = File.join(Dir.tmpdir, 'history.yml')
@@ -77,6 +79,38 @@ def test_get_events
     assert_equal 8, parse_data(@connection[0])['value']
   end
 
+  # rubocop:disable Metrics/AbcSize
+  # rubocop:disable Metrics/MethodLength
+  def test_get_events_by_id
+    with_generated_project do
+      post '/widgets/synergy', JSON.generate({ value: 3 })
+      assert_equal 204, last_response.status
+
+      post '/widgets/valuation', JSON.generate({ value: 'a' })
+      assert_equal 204, last_response.status
+
+      get '/events?ids=synergy%2Cvaluation'
+      assert_equal 200, last_response.status
+
+      events = last_response.body.split(/\n+/) # two events, printed with blank lines separating them
+      synergy_event = parse_data(events[0])
+      valuation_event = parse_data(events[1])
+      assert_equal ['synergy', 3], [synergy_event['id'], synergy_event['value']]
+      assert_equal %w[valuation a], [valuation_event['id'], valuation_event['value']]
+    end
+  end
+
+  def test_get_events_by_unknown_id
+    with_generated_project do
+      post '/widgets/synergy', JSON.generate({ value: 3 })
+      assert_equal 204, last_response.status
+
+      get '/events?ids=unknown'
+      assert_equal 200, last_response.status
+      assert_equal '', last_response.body
+    end
+  end
+
   def test_dashboard_events
     post '/dashboards/my_super_sweet_dashboard', JSON.generate({event: 'reload'})
     assert_equal 204, last_response.status