module YorkBinCollection

Constants

CALENDARS_ENDPOINT
CollectionDates
EXOR_ENDPOINT
VERSION

Public Class Methods

collection_types() click to toggle source

A hash of collection types, as keys in a CollectionDates object, to their 'friendly' names.

# File lib/york-bin-collection.rb, line 29
def self.collection_types
  {
    recycling: 'Recycling',
    household: 'Household waste',
    garden: 'Garden waste'
  }
end

get_collection_dates(uprn) click to toggle source

Given a valid UPRN in the City of York, returns an CollectionDates struct of dates each bin will be collected. The keys are :recycling, :household and :garden. @param [String] uprn A valid UPRN. @return [CollectionDates] The known waste collection dates.

# File lib/york-bin-collection.rb, line 43
def self.get_collection_dates(uprn)
  raise ArgumentError, 'invalid uprn' unless valid_uprn?(uprn)
  url = CALENDARS_ENDPOINT + "?uprn=#{uprn}"
  document = Nokogiri::HTML(open(url))

  # The format of the document is:
  #   body
  #     div.container-fluid
  #       ~header~
  #       div
  #         div.col-xs-12 col-sm-3
  #           h2: December 2018
  #           div.row
  #             div: Tue 04
  #             div: Household waste
  #           ...
  #           h2: January 2019
  #           ...
  #         div.col-xs-12 col-sm-3
  #           h2: March 2019
  #           ...
  #         ...
  
  # Let's start by getting the div which contains the columns, and flatten out
  # the structure to get rid of them
  collection_date_elements = []
  document.css('body > div.container-fluid > div > div.col-xs-12.col-sm-3').each do |col|
    collection_date_elements.push(*col.children)
  end

  collection_dates = CollectionDates.new([], [], [])
  current_heading = nil

  collection_date_elements.each do |row_or_heading|
    if row_or_heading.name == "h2"
      current_heading = row_or_heading.text
    else
      raise 'format error: didn\'t encounter heading before date' unless current_heading

      day, kind = row_or_heading.children.map(&:text)
      date = Date.parse("#{day} #{current_heading}")
      key = collection_types.rassoc(kind)&.first
      raise "unknown collection kind #{kind}" unless kind

      collection_dates.send(key) << date
    end
  end

  collection_dates
end

get_uprns_for_postcode(postcode) click to toggle source

Given a postcode, returns a hash of UPRNs in that postcode to their house addresses. @param [String] postcode A valid postcode, which is permitted to include

a space.

@param [Hash] A hash of UPRNs to short addresses for the property. If the

postcode is invalid, this may be blank.

# File lib/york-bin-collection.rb, line 101
def self.get_uprns_for_postcode(postcode)
  url = "#{EXOR_ENDPOINT}/getPropertiesForPostCode?postcode=#{CGI.escape(postcode)}"
  JSON.parse(open(url).read).map do |property|
    [property['Uprn'].to_s, property['ShortAddress']]
  end.to_h
end

valid_uprn?(uprn) click to toggle source

Checks if a UPRN is syntatically valid; that is, if is a string is alphanumeric. According to the Ordinance Survey, UPRNs can be alphanumeric, although I have yet to find an example with alphabetic characters in. @param [String] uprn The string to validate as a UPRN number. @return [Boolean] True if the string is a syntatically valid UPRN, false

otherwise.

# File lib/york-bin-collection.rb, line 22
def self.valid_uprn?(uprn)
  /[A-Za-z0-9]+/ === uprn || up
end