class DataMapper::Validations::GenericValidator
All validators extend this base class. Validators must:
-
Implement the initialize method to capture its parameters, also calling super to have this parent class capture the optional, general :if and :unless parameters.
-
Implement the call method, returning true or false. The call method provides the validation logic.
@author Guy van den Berg @since 0.9
Attributes
Public Class Methods
Construct a validator. Capture the :if and :unless clauses when present.
@param [String, Symbol] field
The property specified for validation.
@option [Symbol, Proc] :if
The name of a method or a Proc to call to determine if the validation should occur.
@option [Symbol, Proc] :unless
The name of a method or a Proc to call to determine if the validation should not occur.
@note
All additional key/value pairs are passed through to the validator that is sub-classing this GenericValidator
# File lib/dm-validations/validators/generic_validator.rb, line 36 def initialize(field_name, options = {}) @field_name = field_name @options = DataMapper::Ext::Hash.except(options, :if, :unless) @if_clause = options[:if] @unless_clause = options[:unless] @humanized_field_name = DataMapper::Inflector.humanize(@field_name) end
Public Instance Methods
Returns true if validators are equal
Note that this intentionally do validate options equality
even though it is hard to imagine a situation when multiple validations will be used on the same field with the same conditions but different options, it happens to be the case every once in a while with inferred validations for strings/text and explicitly given validations with different option (usually as Range vs. max limit for inferred validation)
@api semipublic
# File lib/dm-validations/validators/generic_validator.rb, line 152 def ==(other) self.class == other.class && self.field_name == other.field_name && self.if_clause == other.if_clause && self.unless_clause == other.unless_clause && self.options == other.options end
Add an error message to a target resource. If the error corresponds to a specific field of the resource, add it to that field, otherwise add it as a :general message.
@param [Object] target
The resource that has the error.
@param [String] message
The message to add.
@param [Symbol] field_name
The name of the field that caused the error.
# File lib/dm-validations/validators/generic_validator.rb, line 57 def add_error(target, message, field_name = :general) # TODO: should the field_name for a general message be :default??? target.errors.add(field_name, message) end
Call the validator. “call” is used so the operation is BoundMethod and Block compatible. This must be implemented in all concrete classes.
@param [Object] target
The resource that the validator must be called against.
@return [Boolean]
true if valid, otherwise false.
# File lib/dm-validations/validators/generic_validator.rb, line 72 def call(target) raise NotImplementedError, "#{self.class}#call must be implemented" end
@api private
# File lib/dm-validations/validators/generic_validator.rb, line 98 def evaluate_conditional_clause(target, clause) if clause.kind_of?(Symbol) target.__send__(clause) elsif clause.respond_to?(:call) clause.call(target) end end
Determines if this validator should be run against the target by evaluating the :if and :unless clauses optionally passed while specifying any validator.
@param [Object] target
The resource that we check against.
@return [Boolean]
true if should be run, otherwise false.
@api private
# File lib/dm-validations/validators/generic_validator.rb, line 87 def execute?(target) if unless_clause = self.unless_clause !evaluate_conditional_clause(target, unless_clause) elsif if_clause = self.if_clause evaluate_conditional_clause(target, if_clause) else true end end
# File lib/dm-validations/validators/generic_validator.rb, line 160 def inspect "<##{self.class.name} @field_name='#{@field_name}' @if_clause=#{@if_clause.inspect} @unless_clause=#{@unless_clause.inspect} @options=#{@options.inspect}>" end
Test the value to see if it is blank or nil, and if it is allowed. Note that allowing blank without explicitly denying nil allows nil values, since nil.blank? is true.
@param [Object] value
The value to test.
@return [Boolean]
true if blank/nil is allowed, and the value is blank/nil.
@api private
# File lib/dm-validations/validators/generic_validator.rb, line 128 def optional?(value) if value.nil? @options[:allow_nil] || (@options[:allow_blank] && !@options.has_key?(:allow_nil)) elsif DataMapper::Ext.blank?(value) @options[:allow_blank] end end
Set the default value for allow_nil and allow_blank
@param [Boolean] default value
@api private
# File lib/dm-validations/validators/generic_validator.rb, line 111 def set_optional_by_default(default = true) [ :allow_nil, :allow_blank ].each do |key| @options[key] = true unless options.key?(key) end end
Private Instance Methods
Get the corresponding Resource property, if it exists.
Note: DataMapper
validations can be used on non-DataMapper resources. In such cases, the return value will be nil.
@api private
# File lib/dm-validations/validators/generic_validator.rb, line 174 def get_resource_property(resource, property_name) model = resource.model if resource.respond_to?(:model) repository = resource.repository if model properties = model.properties(repository.name) if model properties[property_name] if properties end