Class: Miscellany::SlicedResponse::Slice

Inherits:
Object
  • Object
show all
Defined in:
lib/miscellany/controller/sliced_response.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(items, options = {}) ⇒ Slice

Returns a new instance of Slice.



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# File 'lib/miscellany/controller/sliced_response.rb', line 76

def initialize(items, options={})
  @items = items
  @options = options
end

Instance Attribute Details

#items ⇒ Object (readonly)

Returns the value of attribute items.



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# File 'lib/miscellany/controller/sliced_response.rb', line 73

def items
  @items
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/miscellany/controller/sliced_response.rb', line 74

def options
  @options
end

#page_number ⇒ Object

Returns the value of attribute page_number.



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# File 'lib/miscellany/controller/sliced_response.rb', line 70

def page_number
  @page_number
end

#page_size ⇒ Object

Returns the value of attribute page_size.



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# File 'lib/miscellany/controller/sliced_response.rb', line 70

def page_size
  @page_size
end

#slice_end ⇒ Object

Returns the value of attribute slice_end.



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# File 'lib/miscellany/controller/sliced_response.rb', line 69

def slice_end
  @slice_end
end

#slice_start ⇒ Object

Returns the value of attribute slice_start.



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# File 'lib/miscellany/controller/sliced_response.rb', line 69

def slice_start
  @slice_start
end

#sort ⇒ Object

Returns the value of attribute sort.



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# File 'lib/miscellany/controller/sliced_response.rb', line 71

def sort
  @sort
end

Class Method Details

.build(queryset, arg, options = {}) ⇒ Object 



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# File 'lib/miscellany/controller/sliced_response.rb', line 81

def self.build(queryset, arg, options={})
  new(queryset, options).tap do |slice|
    if arg.is_a?(Array)
      slice_bounds = arg
    elsif arg.is_a?(String)
      slice_bounds = arg.split(':').map(&:to_i)
    elsif arg.is_a?(Range)
      slice_bounds = arg.minmax
    elsif arg.respond_to? :[]
      if arg[:slice] == 'all' || arg[:page] == 'all'
        slice_bounds = [0, -1]
      elsif arg[:slice].present?
        slice_bounds = arg[:slice].split(':').map(&:to_i)
      else
        # :default_page_size and :default_size are two names callers use for the
        # same thing; honor either so a caller passing only one isn't left with 0.
        default_page_size = options[:default_page_size] || options[:default_size]
        page_size = slice[:page_size] = (arg[:page_size] || default_page_size).to_i
        if page_size < 1
          raise HttpErrorHandling::HttpError.new(message: "page_size must be at least 1")
        end

        # Clamped rather than rejected, so that a page past either end of the
        # collection stays a valid (if empty) request. Matches ComplexQuery#page.
        page_number = slice[:page_number] = [(arg[:page] || 1).to_i, 1].max
        slice_bounds = [(page_number - 1) * page_size, page_number * page_size]
      end

      begin
        slice[:sort] = options[:sort_parser]&.parse(arg[:sort], ignore_errors: true, default: true)
      rescue Miscellany::SortLang::Parser::SortParsingError => e
        raise HttpErrorHandling::HttpError.new(message: e.message)
      end
    end

    if slice_bounds.present?
      slice[:slice_start] = slice_bounds[0]
      slice[:slice_end] = slice_bounds[1]
    end

    if slice[:slice_end] == -1
      raise HttpErrorHandling::HttpError.new(message: "cannot request whole collection") unless options[:allow_all]
    else
      if options[:max_size] && (slice[:slice_end] - slice[:slice_start]) > [options[:max_size], options[:default_size]].max
        raise HttpErrorHandling::HttpError.new(message: "cannot request more than #{options[:max_size]} objects")
      end
    end
  end
end

Instance Method Details

#[](key) ⇒ Object 



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# File 'lib/miscellany/controller/sliced_response.rb', line 131

def [](key)
  send(key)
end

#[]=(key, val) ⇒ Object 



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# File 'lib/miscellany/controller/sliced_response.rb', line 135

def []=(key, val)
  send(:"#{key}=", val)
end

#render_json ⇒ Object 



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# File 'lib/miscellany/controller/sliced_response.rb', line 139

def render_json
  return @rendered_json if defined?(@rendered_json)

  json = @rendered_json = {
    slice_start: slice_start,
    slice_end: slice_end,
  }

  rendered_items

  if page_size.present?
    json[:page] ||= page_number
    json[:page_size] ||= page_size
  end

  if total_item_count.present?
    json[:total_count] ||= total_item_count
    json[:page_count] ||= (total_item_count.to_f / page_size).ceil if page_size.present?
  end

  if sort.present?
    json[:sort] ||= sort.map do |s|
      "#{s[:key] || s[:column]} #{s[:order] || 'ASC'}"
    end.join(', ')
  end

  json[:slice_start] ||= 0
  json[:slice_end] ||= total_item_count

  json[:items] = rendered_items

  json
end

#rendered_json ⇒ Object 



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# File 'lib/miscellany/controller/sliced_response.rb', line 172

def rendered_json; render_json; end