Adds pagination; after a lot of 'vada poche' moments

Signed-off-by: Akash Manohar J <akash@akash.im>

Gemfile

@@ -11,6 +11,7 @@ gem 'devise_bushido_authenticatable'
 gem 'bushido'
 gem 'thin'
 gem 'faye'
+gem 'kaminari'
 
 # Gems used only for assets and not required
 # in production environments by default.

Gemfile.lock

@@ -116,6 +116,10 @@ GEM
       railties (>= 3.2.0, < 5.0)
       thor (~> 0.14)
     json (1.6.5)
+    kaminari (0.13.0)
+      actionpack (>= 3.0.0)
+      activesupport (>= 3.0.0)
+      railties (>= 3.0.0)
     libv8 (3.3.10.4)
     mail (2.4.3)
       i18n (>= 0.4.0)
@@ -221,6 +225,7 @@ DEPENDENCIES
   faye
   jasmine!
   jquery-rails
+  kaminari
   rails (= 3.2.2)
   rspec-rails
   sass-rails (~> 3.2.3)

app/assets/javascripts/backbone/collections/activities.js.coffee

@@ -1,7 +1,11 @@
 class Kandan.Collections.Activities extends Backbone.Collection
 
-  urlRoot: ()->
+  url: ()->
     "channels/#{@channel_id}/activities"
 
-  initialize: (options)->
-    @channel_id = @get('channel_id')
+  initialize: (models, options)->
+    @channel_id = options.channel_id
+
+  parse: (response)->
+    @more_activities = response.more_activities
+    response.activities

app/assets/javascripts/backbone/helpers/channels.js.coffee

@@ -1,32 +1,58 @@
 class Kandan.Helpers.Channels
 
-  @channel_el: (channel_id)->
-    $("#channels-#{channel_id}")
+  @channel_activities_el: (channel_id)->
+    $("#channel-activities-#{channel_id}")
+
+  @channel_pagination_el: (channel_id)->
+    $("#channels-#{channel_id} .pagination")
 
   @selected_tab: ()->
     $('#channels').tabs('option', 'selected')
 
+
   @get_active_channel_id: ()->
     $("#channels .ui-tabs-panel")
       .eq(@selected_tab())
       .data('channel_id')
 
+
   @new_activity_view: (activity_attributes)->
     activity = new Kandan.Models.Activity(activity_attributes)
     activity_view  = new Kandan.Views.ShowActivity({activity: activity})
     return activity_view
 
+
   @add_activity: (activity_attributes, state)->
     if activity_attributes.channel_id
       @add_message(activity_attributes, state)
     else
       @add_notification(activity_attributes)
 
+
   @add_message: (activity_attributes, state)->
-    @channel_el(activity_attributes.channel_id)
+    @channel_activities_el(activity_attributes.channel_id)
       .append(@new_activity_view(activity_attributes).render().el)
+    @set_pagination_data(activity_attributes.channel_id)
+
 
   @add_notification: (activity_attributes)->
-    $channel_elements = $("#channels .ui-tabs-panel")
+    $channel_elements = $(".channel-activities")
     for el in $channel_elements
-      $(el).append(@new_activity_view(activity_attributes).render().el)
+      $(el).append(@new_activity_view(activity_attributes).render().el)
+
+
+  @set_pagination_state: (channel_id, more_activities, oldest)->
+    @channel_pagination_el(channel_id).data('oldest', oldest)
+    if more_activities == true
+      console.log "show pagination"
+      @channel_pagination_el(channel_id).show()
+    else
+      console.log "hide pagination"
+      @channel_pagination_el(channel_id).hide()
+
+
+  @set_pagination_data: (channel_id)->
+    $oldest_activity = @channel_activities_el(channel_id).find(".activity").first()
+    if $oldest_activity.length != 0
+      console.log "oldest activity id", $oldest_activity.data('activity_id')
+      @channel_pagination_el(channel_id).data('oldest', $oldest_activity.data('activity_id'))

app/assets/javascripts/backbone/models/activity.js.coffee

@@ -1,5 +1,5 @@
 class Kandan.Models.Activity extends Backbone.Model
-  urlRoot: ()->
+  url: ()->
     "channels/#{@get('channel_id')}/activities"
 
   initialize: (options)->

app/assets/javascripts/backbone/models/channel.js.coffee

@@ -5,7 +5,9 @@ class Kandan.Models.Channel extends Backbone.Model
     # console.log @activities
 
   parse: (response)->
-    activities = new Kandan.Collections.Activities()
+    activities = new Kandan.Collections.Activities([], {channel_id: response.id})
     activities.add(response.activities)
     @activities = activities
+    @more_activities = response.more_activities
+
     response

app/assets/javascripts/backbone/plugins/embeds.js.coffee

@@ -22,7 +22,6 @@ class Kandan.Plugins.Embeds
   @register_image_modifier: ()->
     Kandan.Modifiers.register @image_regex, (message, state)=>
       message.content = @image_template({ image_url: message.content })
-      console.log message.content
       return Kandan.Helpers.Activities.build_from_message_template(message)
 
 

app/assets/javascripts/backbone/views/list_activities.js.coffee

@@ -2,10 +2,41 @@ class Kandan.Views.ListActivities extends Backbone.View
   tagName: 'div'
   # className: 'activities'
 
+  events: {
+    "click .pagination": "load_more_activities"
+  }
+
   render: ()->
-    for activity in @options.channel.activities.models
+    @channel = @options.channel
+    $activities_list = $("<div class='channel-activities'></div>").attr('id', "channel-activities-#{@channel.get('id')}")
+    for activity in @channel.activities.models
       activity_view = new Kandan.Views.ShowActivity({activity: activity, state: Kandan.Helpers.Activities.HISTORY_STATE})
-      $(@el).append(activity_view.render().el)
-    $(@el).attr('id', "channels-#{@options.channel.get('id')}")
-    $(@el).data('channel_id', @options.channel.get('id'))
-    @
+      $activities_list.append(activity_view.render().el)
+
+    $pagination = $("<div class='pagination'>previous messages</div>")
+    oldest = 0
+    oldest = @channel.activities.toJSON()[0].id if @channel.activities.toJSON()[0]
+
+    $pagination.data('oldest', oldest)
+    $(@el).append($pagination)
+    $(@el).find(".pagination").hide() if @channel.more_activities == false
+    $(@el).append($activities_list)
+    $(@el).attr('id', "channels-#{@channel.get('id')}")
+    $(@el).data('channel_id', @channel.get('id'))
+    @
+
+  load_more_activities: ()->
+    oldest = $(@el).find(".pagination").data('oldest')
+    activities = new Kandan.Collections.Activities([], {channel_id: @channel.get('id')})
+    activities.fetch({
+      data: { oldest: oldest },
+      success: (collection)=>
+        _.each collection.models.reverse(), (activity)=>
+          activity_view = new Kandan.Views.ShowActivity({activity: activity})
+          $(@el).find(".channel-activities").prepend(activity_view.render().el)
+        Kandan.Helpers.Channels.set_pagination_state(
+          collection.channel_id,
+          collection.more_activities,
+          _.last(collection.models).get('id')
+        )
+    })

app/assets/javascripts/backbone/views/list_channel_activity_areas.js.coffee

@@ -1,6 +1,7 @@
 class Kandan.Views.ListChannelActivityAreas extends Backbone.View
   # template: JST['list_channel_activity_areas']
 
+
   render: ()->
     for channel in @options.channels.models
       view = new Kandan.Views.ListActivities({activities: channel.activities})

app/assets/javascripts/backbone/views/show_activity.js.coffee

@@ -15,6 +15,7 @@ class Kandan.Views.ShowActivity extends Backbone.View
       else
         @compiled_template = Kandan.Helpers.Activities.build_from_message_template $.extend(activity, {content: _.escape(activity.content)})
 
-
+    $(@el).data('activity_id', activity.id)
+    $(@el).attr('id', "activity-#{activity.id}")
     $(@el).html(@compiled_template)
     @

app/assets/javascripts/backbone/widgets.js.coffee

@@ -14,7 +14,6 @@ class Kandan.Widgets
     widget_names
 
   @init_all: ()->
-    console.log "widget_names", @widget_names()
     @init(widget_name) for widget_name in @widget_names()
 
   @init: (widget_name)->

app/assets/templates/list_channel_activity_areas.jst.eco

@@ -0,0 +1,3 @@
+<div class="pagination"><%= pagination_text %></div>
+<div class="channel-activities">
+</div>

app/controllers/activities_controller.rb

@@ -2,9 +2,25 @@ class ActivitiesController < ApplicationController
   before_filter :authenticate_user!
 
   def index
-    @activities = Channel.find(params[:channel_id]).activities.includes(:user).all
+    oldest = params[:oldest] || 1
+    first_activity_id = 1
+    activities = Channel.find(params[:channel_id]).
+      activities.
+      includes(:user).
+      order('id DESC').
+      where("id < ?", oldest).
+      limit(Kandan::Config.options[:per_page])
+
+
+    first_activity = Activity.order('id').where(:channel_id => params[:channel_id]).first
+    first_activity_id = first_activity.id if not first_activity.nil?
+
+    # NOTE if the action is accessed then there's definitely activities, so skip check for #first to be nil
+    puts "#{first_activity_id} < #{activities.last.id}"
+    more_activities = first_activity_id < activities.last.id
+
     respond_to do |format|
-      format.json { render :json => @activities, :include => :user }
+      format.json { render :text => {:activities => activities.reverse, :more_activities => more_activities }.to_json(:include => :user) }
     end
   end
 

app/controllers/channels_controller.rb

@@ -2,10 +2,24 @@ class ChannelsController < ApplicationController
   before_filter :authenticate_user!
 
   def index
-    @channels = Channel.includes(:activities => :user).all
+    # NOTE Eager loading doesn't respect limit
+    @channels = Channel.find(:all)
+    nested_channel_data = []
+
+    # TODO this can be shortened
+    @channels.each do |channel|
+      activities = []
+      more_activities = (channel.activities.count > Kandan::Config.options[:per_page])
+      channel.activities.order('id DESC').includes(:user).page.each do |activity|
+        activities.push activity.attributes.merge({:user => activity.user.attributes})
+      end
+
+      nested_channel_data.push channel.attributes.merge({:activities => activities.reverse, :more_activities => more_activities})
+    end
+
     respond_to do |format|
       format.json do
-        render :json => @channels, :include => {:activities => {:include=>:user}}
+        render :text => nested_channel_data.to_json
       end
     end
   end

app/models/activity.rb

@@ -1,4 +1,6 @@
 class Activity < ActiveRecord::Base
   belongs_to :user
   belongs_to :channel
+
+  paginates_per Kandan::Config.options[:per_page]
 end

config/kandan_settings.yml

@@ -7,3 +7,5 @@
 # valid options: Faye
 :broadcaster:
   :name: "Faye"
+
+:per_page: 5

lib/faye_extensions/devise_auth.rb

@@ -10,7 +10,7 @@ def incoming(message, callback)
         message['error'] = "Invalid auth token"
       end
     end
-    puts "Message: #{message.inspect}"
+    # puts "Message: #{message.inspect}"
     callback.call(message)
   end