Module: Supercast::Util

Defined in:
lib/supercast/util.rb

Constant Summary collapse

OPTS_USER_SPECIFIED =

Options that a user is allowed to specify.

Set[
  :api_key,
].freeze
OPTS_COPYABLE =

Options that should be copyable from one DataObject to another including options that may be internal.

(
  OPTS_USER_SPECIFIED + Set[:api_base]
).freeze
OPTS_PERSISTABLE =

Options that should be persisted between API requests. This includes client, which is an object containing an HTTP client to reuse.

(
  OPTS_USER_SPECIFIED + Set[:client]
).freeze

Class Method Summary collapse

Class Method Details

.check_api_key!(key) ⇒ Object

Raises:

  • (TypeError) 


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# File 'lib/supercast/util.rb', line 185

def self.check_api_key!(key)
  raise TypeError, 'api_key must be a string' unless key.is_a?(String)

  key
end

.check_string_argument!(key) ⇒ Object

Raises:

  • (TypeError) 


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# File 'lib/supercast/util.rb', line 179

def self.check_string_argument!(key)
  raise TypeError, 'argument must be a string' unless key.is_a?(String)

  key
end

.convert_to_supercast_object(data, opts = {}) ⇒ Object

Converts a hash of fields or an array of hashes into a DataObject or array of DataObjects. These new objects will be created as a concrete type as dictated by their ‘object` field (e.g. an `object` value of `creator` would create an instance of Creator), but if `object` is not present or of an unknown type, the newly created instance will fall back to being a DataObject.

Attributes

  • data - Hash of fields and values to be converted into a DataObject.

  • opts - Options for DataObject like an API key that will be reused on subsequent API calls.



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# File 'lib/supercast/util.rb', line 55

def self.convert_to_supercast_object(data, opts = {})
  opts = normalize_opts(opts)

  case data
  when Array
    data.map { |i| convert_to_supercast_object(i, opts) }
  when Hash
    # Try converting to a known object class. If none available, fall back
    # to generic DataObject
    object_classes.fetch(data[:object], DataObject).construct_from(data, opts)
  else
    data
  end
end

.encode_parameters(params) ⇒ Object

Encodes a hash of parameters in a way that’s suitable for use as query parameters in a URI or as form parameters in a request body. This mainly involves escaping special characters from parameter keys and values (e.g. ‘&`).



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# File 'lib/supercast/util.rb', line 106

def self.encode_parameters(params)
  Util.flatten_params(params)
      .map { |k, v| "#{url_encode(k)}=#{url_encode(v)}" }.join('&')
end

.flatten_params(params, parent_key = nil) ⇒ Object 



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# File 'lib/supercast/util.rb', line 122

def self.flatten_params(params, parent_key = nil)
  result = []

  # do not sort the final output because arrays (and arrays of hashes
  # especially) can be order sensitive, but do sort incoming parameters
  params.each do |key, value|
    calculated_key = parent_key ? "#{parent_key}[#{key}]" : key.to_s
    if value.is_a?(Hash)
      result += flatten_params(value, calculated_key)
    elsif value.is_a?(Array)
      result += flatten_params_array(value, calculated_key)
    else
      result << [calculated_key, value]
    end
  end

  result
end

.flatten_params_array(value, calculated_key) ⇒ Object 



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# File 'lib/supercast/util.rb', line 141

def self.flatten_params_array(value, calculated_key)
  result = []
  value.each_with_index do |elem, i|
    if elem.is_a?(Hash)
      result += flatten_params(elem, "#{calculated_key}[#{i}]")
    elsif elem.is_a?(Array)
      result += flatten_params_array(elem, calculated_key)
    else
      result << ["#{calculated_key}[#{i}]", elem]
    end
  end
  result
end

.log_debug(message, data = {}) ⇒ Object 



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# File 'lib/supercast/util.rb', line 78

def self.log_debug(message, data = {})
  log_at_level(Supercast::LEVEL_DEBUG, message, data, color: :blue)
end

.log_error(message, data = {}) ⇒ Object 



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# File 'lib/supercast/util.rb', line 70

def self.log_error(message, data = {})
  log_at_level(Supercast::LEVEL_ERROR, message, data, color: :cyan)
end

.log_info(message, data = {}) ⇒ Object 



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# File 'lib/supercast/util.rb', line 74

def self.log_info(message, data = {})
  log_at_level(Supercast::LEVEL_INFO, message, data, color: :cyan)
end

.normalize_headers(headers) ⇒ Object

Normalizes header keys so that they’re all lower case and each hyphen-delimited section starts with a single capitalized letter. For example, ‘request-id` becomes `Request-Id`. This is useful for extracting certain key values when the user could have set them with a variety of diffent naming schemes.



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# File 'lib/supercast/util.rb', line 196

def self.normalize_headers(headers)
  headers.each_with_object({}) do |(k, v), new_headers|
    k = k.to_s.tr('_', '-') if k.is_a?(Symbol)
    k = k.split('-').reject(&:empty?).map(&:capitalize).join('-')

    new_headers[k] = v
  end
end

.normalize_id(id) ⇒ Object 



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# File 'lib/supercast/util.rb', line 155

def self.normalize_id(id)
  if id.is_a?(Hash) # overloaded id
    params_hash = id.dup
    id = params_hash.delete(:id)
  else
    params_hash = {}
  end
  [id, params_hash]
end

.normalize_opts(opts) ⇒ Object

The secondary opts argument can either be a string or hash Turn this value into an api_key and a set of headers



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# File 'lib/supercast/util.rb', line 167

def self.normalize_opts(opts)
  case opts
  when String
    { api_key: opts }
  when Hash
    check_api_key!(opts.fetch(:api_key)) if opts.key?(:api_key)
    opts.clone
  else
    raise TypeError, 'normalize_opts expects a string or a hash'
  end
end

.object_classes ⇒ Object 



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# File 'lib/supercast/util.rb', line 39

def self.object_classes
  @object_classes ||= Supercast::DataTypes.object_names_to_classes
end

.objects_to_ids(obj) ⇒ Object 



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# File 'lib/supercast/util.rb', line 24

def self.objects_to_ids(obj)
  case obj
  when Resource
    obj.id
  when Hash
    res = {}
    obj.each { |k, v| res[k] = objects_to_ids(v) unless v.nil? }
    res
  when Array
    obj.map { |v| objects_to_ids(v) }
  else
    obj
  end
end

.secure_compare(str_a, str_b) ⇒ Object

Constant time string comparison to prevent timing attacks Code borrowed from ActiveSupport



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# File 'lib/supercast/util.rb', line 207

def self.secure_compare(str_a, str_b)
  return false unless str_a.bytesize == str_b.bytesize

  l = str_a.unpack "C#{str_a.bytesize}"

  res = 0
  str_b.each_byte { |byte| res |= byte ^ l.shift }
  res.zero?
end

.symbolize_names(object) ⇒ Object 



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# File 'lib/supercast/util.rb', line 82

def self.symbolize_names(object)
  case object
  when Hash
    new_hash = {}
    object.each do |key, value|
      key = (begin
               key.to_sym
             rescue StandardError
               key
             end) || key
      new_hash[key] = symbolize_names(value)
    end
    new_hash
  when Array
    object.map { |value| symbolize_names(value) }
  else
    object
  end
end

.url_encode(key) ⇒ Object

Encodes a string in a way that makes it suitable for use in a set of query parameters in a URI or in a set of form parameters in a request body.



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# File 'lib/supercast/util.rb', line 114

def self.url_encode(key)
  CGI.escape(key.to_s).
    # Don't use strict form encoding by changing the square bracket control
    # characters back to their literals. This is fine by the server, and
    # makes these parameter strings easier to read.
    gsub('%5B', '[').gsub('%5D', ']')
end