Code Sample - Festivity Events List

gistfile1.rb

##################
# This code sample contains the logic for a page used by arts festival attendees to filter
# the festival's events and find a show they're interested in seeing.
# You can see the event list in action here: http://pghkids.org/events
##################

##################
# FestivityEventsController, which receives a request with search criteria and returns
# a list of matching events to the view.
##################

class FestivityEventsController < ApplicationController
  include Festivity::Mixins::NotFound
  no_login_required
  trusty_layout 'base'

  # Event search requests are cached; because some requests are for the full page and some are AJAX
  # caching separates requests by format.
  caches_action :index, cache_path: proc { |c| c.params.except(:_).merge(format: request.xhr?)}

  def index
    # Default sort is by event start date
    order_by = params[:sort] ? params[:sort] : "start_date"
    @title = "#{current_site.festivity_festival_name}: Events"
    
    # Pass search criteria to the FestivityEventList model to find relevant events
    @events = FestivityEventList.search(
        {dates: search_dates.join(","),
         categories: params[:categories]},
        order_by).events
    
    # If the request is AJAX, only return the event list itself, not the full page
    if request.xhr?
      render partial: "event_list"
    else
      render 'index'
    end
  end
end

##################
# FestivityEventList model, used to collect all matching events
##################

class FestivityEventList

  attr_reader :events

  def initialize(event_performances)
    @events = event_performances.group_by {|perf| perf.event_id }.
        map { |perfs| FestivityEventList::FestivityEvent.new(perfs[0], perfs[1]) }

  end

  def self.search(criteria, order_by)
    # Build the SQL where clause from the supplied criteria
    where_clause = parse_criteria(criteria)
    
    # Search the FestivityEventPerformance view and build a new FestivityEventList object with the results
    FestivityEventList.new(
        FestivityEventList::FestivityEventPerformance.
            includes(:assets).
            joins(:festivity_categories).
            where(where_clause).
            group("performance_id").
            order("featured_item DESC, #{order_by} ASC").
            preload(:festivity_categories)
    )
  end

  private

  # The order of querying, depending on what is passed:
  # - If dates are passed, we search both start and end date between midnight and 11:59pm of that date.
  #   That query returns any matching event ids.
  # - The event ids returned, if any, are added to the where clause for the next query
  # - Any category ids passed are added to the where clause as well.
  def self.parse_criteria(criteria)
    where_clause = {}
    event_ids = event_ids_for_dates(criteria[:dates]) if criteria[:dates]
    where_clause["site_id"] = Page.current_site.id
    where_clause["event_id"] = event_ids if event_ids
    where_clause["festivity_categories.id"] = criteria[:categories].split(",") if criteria[:categories]
    where_clause
  end

  # Return a list of unique event ids that match the provided dates
  def self.event_ids_for_dates(dates)
    FestivityEventList::FestivityEventPerformance.where(date_criteria(dates)).map {|e| e.event_id}.uniq
  end

  # Create a condition for start and end date between midnight and 11:59pm
  # for each date passed in and return the SQL condition
  def self.date_criteria(dates_string)
    date_queries = dates_string.split(',').map do |date_string|
      start_date = DateTime.parse(date_string)
      end_date = start_date.advance(hours: 23, minutes: 59)
      <<-SQL
        (
          (start_date >= '#{start_date}' AND start_date <= '#{end_date}')
          OR
          (end_date >= '#{start_date}' AND end_date <= '#{end_date}')
        )
      SQL
    end
    date_queries.join(" OR ")
  end
end


##################
# FestivityEventPerformance model, tied to a database view which collects event performance data
##################

class FestivityEventList::FestivityEventPerformance < ActiveRecord::Base
  self.table_name = 'festivity_event_performances'
  after_initialize :readonly!

  has_many :festivity_page_categories, foreign_key: :page_id, primary_key: :event_id
  has_many :festivity_categories, through: :festivity_page_categories
  has_many :page_attachments, primary_key: :event_id, foreign_key: :page_id
  has_many :assets, through: :page_attachments

end

##################
# FestivityEvent model representing events which matched the search criteria and wrapping matching performances
##################

class FestivityEventList::FestivityEvent
  include Festivity::Admin::AssetsHelper

  attr_reader :id, :performances, :locations, :categories, :title, :short_description,
              :assets, :header, :sub_header, :featured_item, :buy_url

  def initialize(event_id, performances)
    @id = event_id
    @performances = performances
    # For event-level information, like title, just use the first event performance
    @title = performances.first.event_title
    @short_description = performances.first.short_description
    @header = performances.first.header
    @sub_header = performances.first.sub_header
    @featured_item = performances.first.featured_item
    @buy_url = performances.first.buy_url

    @locations = self.performances.
        map{ |performance| FestivityEventList::FestivityLocation.new ({
        id: performance.location_id,
        slug: performance.location_slug,
        title: performance.location_title,
        directions_url: performance.festivity_directions_url,
        area_id: performance.area_id,
        area_slug: performance.area_slug,
        area_title: performance.area_title}) }.
        uniq{ |location| location.id }

    @categories = performances.first.festivity_categories

    @assets = performances.first.assets

  end

end

##################
# Event List view, demonstrating how matched events are displayed in the browser
##################

#event-list-items
  - @events.each do |event|
    .row.event-list-item{class: event.id, data:{ genre: event.categories.first.id, date: event.performances.first.start_date, location: event.locations.first.id} }
      %hr
      .event-list-item__photo.col-xs-12.col-sm-4
        .photo
          = link_to event_path(event.id) do
            %img.img-responsive{ src: "#{event.image}"}
          - if event.featured_item
            .event_list-item__photo-featured-item
              Featured Event!
      .event-list-item__info.col-xs-12.col-sm-8
        = link_to event_path(event.id) do
          %h2
            = event.title
        %h3
          %span.strong
            = event.header
          %span.light
            = event.sub_header
        %hr
        %p
          - if event.locations.count == 1
            - event_location = event.locations.first
            =link_to location_path(id: event_location.slug) do
              = event_location.title
            @
            =link_to area_path(id: event_location.area_slug) do
              = event_location.area_title
          - else
            Multiple Locations
        - if event.performances.count > 1
          %p
            Multiple dates and times&nbsp;
            %button.btn.btn-sm.btn-default.btn-popover{type: "button", data: {content: date_time_popover(event.performances), html: "true",  placement:"top", toggle: "popover"}, title:"All Dates and Times"}
              Show all
        - else
          - event.performances.each do |perf|
            %p
              = perf.start_date.strftime("%A, %B %d")
              = ", "
              = perf.start_date.strftime("%I:%M%p").downcase
              = " - "
              = perf.end_date.strftime('%I:%M%p').downcase
        %hr
        %p
        .event-list-item__info_short_description
          %span
            = event.short_description.html_safe
        %p
        .event-list-item__button-group
          = link_to  "Details", event_path(event.id), class: 'btn event-list-item__btn'
          - unless event.buy_url.blank?
            = link_to  "Tickets", "#{event.buy_url}", class: 'btn event-list-item__btn', target: '_blank'
          - unless event.locations.first.directions_url.blank?
            = link_to  "Directions", "#{event.locations.first.directions_url}", class: 'btn event-list-item__btn', target: '_blank'