class Fog::Schema::DataValidator
This validates a data object against a Ruby based schema to see if they match.
-
An object matches the schema if +==+ or +===+ returns
true
-
Hashes match if all the key's values match the classes given in the schema as well. This can be configured in the options
-
Arrays match when every element in the data matches the case given in the schema.
The schema and validation are very simple and probably not suitable for some cases.
The following classes can be used to check for special behaviour
-
Fog::Boolean
- value may betrue
orfalse
-
Fog::Nullable::Boolean
- value may betrue
,false
ornil
-
Fog::Nullable::Integer
- value may be an Integer ornil
All the “nullable” objects will pass if the value is of the class or if it is nil
. This allows you to match APIs that may include keys when the value is not available in some cases but will always be a String. Such as an password that is only displayed on the reset action.
The keys for “nullable” resources should always be present but original matcher had a bug that allowed these to also appear to work as optional keys/values.
If you need the original behaviour, data with a missing key is still valid, then you may pass the :allow_optional_rules
option to the validate
method.
That is not recommended because you are describing a schema with optional keys in a format that does not support it.
Setting :allow_extra_keys
as true
allows the data to contain keys not declared by the schema and still pass. This is useful if new attributes appear in the API in a backwards compatible manner and can be ignored.
This is the behaviour you would have seen with strict
being false
in the original test helper.
@example Schema
example
{ "id" => String, "ram" => Integer, "disks" => [ "size" => Float ], "dns_name" => Fog::Nullable::String, "active" => Fog::Boolean, "created" => DateTime }
Attributes
This returns the last message set by the validator
@return [String]
Public Class Methods
# File lib/fog/schema/data_validator.rb, line 69 def initialize @message = nil end
Public Instance Methods
Checks if the data structure matches the schema passed in and returns true
if it fits.
@param [Object] data Hash or Array to check @param [Object] schema Schema
pattern to check against @param [Boolean] options @option options [Boolean] :allow_extra_keys
If +true+ does not fail if extra keys are in the data that are not in the schema.
@option options [Boolean] :allow_optional_rules
If +true+ does not fail if extra keys are in the schema that do not match the data. Not recommended!
@return [Boolean] Did the data fit the schema?
# File lib/fog/schema/data_validator.rb, line 87 def validate(data, schema, options = {}) valid = validate_value(schema, data, options) unless valid @message = "#{data.inspect} does not match #{schema.inspect}" end valid end
Private Instance Methods
This contains a slightly modified version of the Hashidator gem but unfortunately the gem does not cope with Array schemas.
@see github.com/vangberg/hashidator/blob/master/lib/hashidator.rb
# File lib/fog/schema/data_validator.rb, line 103 def validate_value(validator, value, options) Fog::Logger.write :debug, "[yellow][DEBUG] #{value.inspect} against #{validator.inspect}[/]\n" case validator when Array return false if value.is_a?(Hash) value.respond_to?(:all?) && value.all? { |x| validate_value(validator[0], x, options) } when Symbol value.respond_to? validator when Hash return false if value.is_a?(Array) # When being strict values not specified in the schema are fails # Validator is empty but values are not return false if !options[:allow_extra_keys] && value.respond_to?(:empty?) && !value.empty? && validator.empty? # Validator has rules left but no more values return false if !options[:allow_optional_rules] && value.respond_to?(:empty?) && value.empty? && !validator.empty? validator.all? do |key, sub_validator| Fog::Logger.write :debug, "[blue][DEBUG] #{key.inspect} against #{sub_validator.inspect}[/]\n" validate_value(sub_validator, value[key], options) end else result = validator == value result = validator === value unless result # Repeat unless we have a Boolean already unless result.is_a?(TrueClass) || result.is_a?(FalseClass) result = validate_value(result, value, options) end if result Fog::Logger.write :debug, "[green][DEBUG] Validation passed: #{value.inspect} against #{validator.inspect}[/]\n" else Fog::Logger.write :debug, "[red][DEBUG] Validation failed: #{value.inspect} against #{validator.inspect}[/]\n" end result end end