style: if ! changed by unless

- if ! changed by unless as it is more readable
- !object.blank? is equivalent to object.present?, also more readable

app/controllers/admin/events_controller.rb

@@ -103,7 +103,7 @@ module Admin
       comment.commentable = @event
       comment.user_id = current_user.id
       comment.save!
-      if !params[:parent].nil?
+      unless params[:parent].nil?
         comment.move_to_child_of(params[:parent])
       end
 
@@ -202,7 +202,7 @@ module Admin
 
     def get_event
       @event = @conference.program.events.find(params[:id])
-      if !@event
+      unless @event
         redirect_to admin_conference_program_events_path(conference_id: @conference.short_title),
                     error: 'Error! Could not find event!'
         return

app/controllers/admin/questions_controller.rb

@@ -67,7 +67,7 @@ module Admin
     def destroy
       if can? :destroy, @question
         # Do not delete global questions
-        if !@question.global
+        unless @question.global
 
           # Delete question and its answers
           begin

app/controllers/application_controller.rb

@@ -47,7 +47,7 @@ class ApplicationController < ActionController::Base
   rescue_from CanCan::AccessDenied do |exception|
     Rails.logger.debug "Access denied on #{exception.action} #{exception.subject.inspect}"
     message = exception.message
-    message << ' Maybe you need to sign in?' if !current_user
+    message << ' Maybe you need to sign in?' unless current_user
     redirect_to root_path, alert: message
   end
 

app/controllers/conference_registrations_controller.rb

@@ -52,7 +52,7 @@ class ConferenceRegistrationsController < ApplicationController
       ahoy.track 'Registered', title: 'New registration'
 
       # Sign in the new user
-      if !current_user
+      unless current_user
         sign_in(@registration.user)
       end
 
@@ -96,7 +96,7 @@ class ConferenceRegistrationsController < ApplicationController
 
   def set_registration
     @registration = Registration.find_by(conference: @conference, user: current_user)
-    if !@registration
+    unless @registration
       redirect_to new_conference_conference_registration_path(@conference.short_title),
                   error: "Can't find a registration for #{@conference.title} for you. Please register."
     end

app/models/conference.rb

@@ -551,7 +551,7 @@ class Conference < ActiveRecord::Base
         result[state.name] = count
       end
 
-      if !conference.events_per_week
+      unless conference.events_per_week
         conference.events_per_week = {}
       end
 
@@ -692,7 +692,7 @@ class Conference < ActiveRecord::Base
     events_per_week.each do |week, values|
       values.each do |state, value|
         if [:confirmed, :unconfirmed].include?(state)
-          if !result[state.to_s.capitalize]
+          unless result[state.to_s.capitalize]
             result[state.to_s.capitalize] = {}
           end
           result[state.to_s.capitalize][week.strftime('%W').to_i] = value
@@ -768,7 +768,7 @@ class Conference < ActiveRecord::Base
   def assert_keys_are_continuously(hash)
     keys = hash.keys
     (keys.min..keys.max).each do |key|
-      if !hash[key]
+      unless hash[key]
         hash[key] = 0
       end
     end
@@ -1004,7 +1004,7 @@ class Conference < ActiveRecord::Base
   # Adds a random color to the conference
   #
   def add_color
-    if !color
+    unless color
       self.color = get_color
     end
   end

app/models/contact.rb

@@ -7,7 +7,7 @@ class Contact < ActiveRecord::Base
             format: URI::regexp(%w(http https)), allow_blank: true
 
   def has_social_media?
-    return true if !facebook.blank? || !twitter.blank? || !googleplus.blank? || !instagram.blank? || !email.blank?
+    return true if facebook.present? || twitter.present? || googleplus.present? || instagram.present? || email.present?
     false
   end
 end

app/models/event.rb

@@ -115,9 +115,7 @@ class Event < ActiveRecord::Base
 
   def submitter
     result = event_users.where(event_role: 'submitter').first
-    if !result.nil?
+    if result.nil?
-      result.user
-    else
       user = nil
       # Perhaps the event_users haven't been saved, if this is a new proposal
       event_users.each do |u|
@@ -126,6 +124,8 @@ class Event < ActiveRecord::Base
         end
       end
       user
+    else
+      result.user
     end
   end
 
@@ -281,7 +281,7 @@ class Event < ActiveRecord::Base
   def generate_guid
     loop do
       @guid = SecureRandom.urlsafe_base64
-      break if !self.class.where(guid: guid).any?
+      break unless self.class.where(guid: guid).any?
     end
     self.guid = @guid
   end

app/models/venue.rb

@@ -44,7 +44,7 @@ class Venue < ActiveRecord::Base
   def generate_guid
     loop do
       @guid = SecureRandom.urlsafe_base64
-      break if !Venue.where(guid: guid).any?
+      break unless Venue.where(guid: guid).any?
     end
     self.guid = @guid
   end

app/views/admin/events/_proposal.html.haml

@@ -106,13 +106,13 @@
           %td
             = @event.language
 
-      - if !@event.room.nil?
+      - unless @event.room.nil?
         %tr
           %td
             %b Room
           %td
             = @event.room.name
-      - if !@event.start_time.nil?
+      - unless @event.start_time.nil?
         %tr
           %td
             %b Scheduled time

app/views/admin/events/index.html.haml

@@ -62,7 +62,7 @@
               - bgcolor=""
             %td{:style=>"background-color: #{bgcolor}"}
               - if @program.show_voting?
-                - if !event.submitter.nil?
+                - unless event.submitter.nil?
                   =link_to event.submitter.name, admin_user_path(event.submitter)
                   - if event.submitter.registrations.count < 1
                     (Unregistered!)

app/views/admin/events/show.html.haml

@@ -23,7 +23,7 @@
           - @event.versions.each do |version|
             %tr
               %td
-                - if !version.whodunnit.nil?
+                - unless version.whodunnit.nil?
                   = User.find(version.whodunnit).name
                 - else
                   No user (probably via the console)
@@ -35,4 +35,3 @@
                 - version.changeset.each_key do |key|
                   = "#{key}: #{version.changeset[key][0]} -> #{version.changeset[key][1]}"
                   %br
-

app/views/admin/lodgings/index.html.haml

@@ -10,7 +10,7 @@
     - slice.each do |lodging|
       .col-md-4
         .thumbnail
-          - if !lodging.picture?
+          - unless lodging.picture?
             %p.text-center
               %i.fa.fa-home.fa-5x
           - else

app/views/conference/_conference_details.html.haml

@@ -13,7 +13,7 @@
           - if conference.venue
             %p
               = "#{conference.venue.city}/#{conference.venue.country_name}"
-          - if !conference.description.blank?
+          - unless conference.description.blank?
             %p
               = markdown(conference.description)
         .col-md-2

app/views/conference/_lodging.html.haml

@@ -13,7 +13,7 @@
       - slice.each do |lodging|
         .col-md-4.col-sm-4.ticket.col-centered.col-top
           .thumbnail
-            - if !lodging.picture?
+            - unless lodging.picture?
               %p.text-center
                 %i.fa.fa-home.fa-5x
             - else

app/views/conference_registrations/_form.html.haml

@@ -7,7 +7,7 @@
           = @conference.title
   .row
     .col-md-8
-      - if !current_user
+      - unless current_user
         %legend
           %span
             =link_to('#signup', role: 'tab', "aria-controls" => "home", "data-toggle" => "tab") do

app/views/conference_registrations/_ticket.html.haml

@@ -5,7 +5,7 @@
         %h4.media-heading
           = ticket.title
         %h5.media-heading
-        -if !ticket.description.blank?
+        -unless ticket.description.blank?
           = markdown(ticket.description)
   %td.col-sm-1.col-md-1
     = text_field_tag("tickets[][#{ticket.id}]", 0, type: 'number', min: 0,

app/views/proposal/new.html.haml

@@ -8,7 +8,7 @@
       = render partial: 'encouragement_text'
   .row
     .col-md-8
-      - if !current_user
+      - unless current_user
         %legend
           %span
             =link_to('#signup', role: 'tab', 'aria-controls' => 'home', 'data-toggle' => 'tab') do

app/views/tickets/_ticket.html.haml

@@ -5,7 +5,7 @@
         %h4.media-heading
           = ticket.title
         %h5.media-heading
-        -if !ticket.description.blank?
+        - unless ticket.description.blank?
           = markdown(ticket.description)
   %td.col-sm-1.col-md-1
     - if ticket.bought?(current_user)