Class: LetterGroup::Presenter

Inherits:
Object
  • Object
show all
Defined in:
lib/letter_group/presenter.rb

Constant Summary collapse

LETTER_MATCHER =

true makes it case insensitive

-> to_match, letter { to_match =~ Regexp.new("^#{letter}", true) }
ALPHABET = 
("a".."z").to_a.freeze
ALPHABET_AND_OTHER = 
(ALPHABET + ["other"]).freeze
DEFAULT_SELECTED = 
("a".."c").to_a.freeze
IN_GROUPS = 
ALPHABET_AND_OTHER.each_slice(3)

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(array_of_hashes = [], alpha_key:, unique_key:, selected: nil, field_groups: {}) ⇒ Presenter

Returns a new instance of Presenter.

Raises:

  • (ArgumentError) 


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# File 'lib/letter_group/presenter.rb', line 17

def initialize(array_of_hashes = [], alpha_key:, unique_key:, selected: nil, field_groups: {})
  # With this sort of data triage many of the result rows must be combined to represent a single data issue.
  #   (the nature of SQL JOINS)
  # Thus we can only get a count by tallying up the total for each group.
  # since they each will know how to find their own unique problems
  @array_of_hashes = array_of_hashes # responds to each with PGresult-like tuples
  @fields = array_of_hashes.first ? array_of_hashes.first.keys : []
  @alpha_key = alpha_key.to_s     # like "leads_last_name" or "leads_email"
  @unique_key = unique_key.to_s   # like "leads_id" or "leads_email"
  raise ArgumentError, "#{self.class} Looks like alpha_key (#{@alpha_key} was not part of the select on fields: #{@fields.inspect}" unless @fields.empty? || @fields.include?(@alpha_key)
  raise ArgumentError, "#{self.class} Looks like unique_key (#{@unique_key} was not part of the select on fields: #{@fields.inspect}" unless @fields.empty? || @fields.include?(@unique_key)
  @field_groups = field_groups || {}
  @groups = {}
  divide_into_letters
  set_selected(selected)
  @total_selected = each.inject(0) {|memo, group| memo += group.total; memo }
  raise ArgumentError, "Unable to allocate all data into groups" unless @array_of_hashes.empty?
end

Instance Attribute Details

#array_of_hashes ⇒ Object (readonly)

Returns the value of attribute array_of_hashes.



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# File 'lib/letter_group/presenter.rb', line 15

def array_of_hashes
  @array_of_hashes
end

#groups ⇒ Object (readonly)

Returns the value of attribute groups.



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# File 'lib/letter_group/presenter.rb', line 15

def groups
  @groups
end

#selected ⇒ Object (readonly)

Returns the value of attribute selected.



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# File 'lib/letter_group/presenter.rb', line 15

def selected
  @selected
end

#total_selected ⇒ Object (readonly)

Returns the value of attribute total_selected.



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# File 'lib/letter_group/presenter.rb', line 15

def total_selected
  @total_selected
end

Instance Method Details

#count_for(letters) ⇒ Object 



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# File 'lib/letter_group/presenter.rb', line 45

def count_for(letters)
  groups.values_at(*letters).flatten.inject(0) {|memo, group| memo += group.total; memo }
end

#each ⇒ Object 



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# File 'lib/letter_group/presenter.rb', line 36

def each
  return enum_for(:each) unless block_given? # Sparkling magic!
  selected.each do |letter|
    for_letter = groups[letter]
    next unless for_letter
    yield for_letter
  end
end