Module: Philiprehberger::HeaderKit::CacheControl

Defined in:
lib/philiprehberger/header_kit/cache_control.rb

Overview

Parses and builds Cache-Control header values.

Supports common directives: max-age, s-maxage, no-cache, no-store, public, private, must-revalidate, proxy-revalidate, no-transform, immutable.

Constant Summary collapse

VALUE_DIRECTIVES = 
%w[max-age s-maxage max-stale min-fresh stale-while-revalidate stale-if-error].freeze

Class Method Summary collapse

Class Method Details

.build(directives) ⇒ String

Build a Cache-Control header string from a directive hash.

Parameters:

  • directives (Hash{Symbol => true, Integer, String}) —

    directive hash

Returns:

  • (String) —

    formatted Cache-Control header value



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# File 'lib/philiprehberger/header_kit/cache_control.rb', line 47

def self.build(directives)
  return '' if directives.nil? || directives.empty?

  parts = directives.map do |key, value|
    directive = key.to_s.tr('_', '-')
    value == true ? directive : "#{directive}=#{value}"
  end

  parts.join(', ')
end

.parse(header) ⇒ Hash{Symbol => true, Integer, String}

Parse a Cache-Control header string into a directive hash.

Boolean directives become ‘true`. Value directives are converted to integers. Keys are symbolized with hyphens replaced by underscores.

Parameters:

  • header (String) —

    the Cache-Control header value

Returns:

  • (Hash{Symbol => true, Integer, String}) —

    parsed directives



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# File 'lib/philiprehberger/header_kit/cache_control.rb', line 19

def self.parse(header)
  return {} if header.nil? || header.strip.empty?

  directives = {}

  header.split(',').each do |part|
    part = part.strip
    next if part.empty?

    key, value = part.split('=', 2)
    key = key.strip.downcase
    sym = key.tr('-', '_').to_sym

    if value
      value = value.strip.delete('"')
      directives[sym] = VALUE_DIRECTIVES.include?(key) ? value.to_i : value
    else
      directives[sym] = true
    end
  end

  directives
end