# Check if a field match a regular expression
#
# ~~~
# var validator = new ObjectValidator
# validator.add new RegexField("title", "[A-Z][a-z]+".to_re)
# assert not validator.validate("""{ "title": "foo" }""")
# assert validator.validate("""{ "title": "Foo" }""")
# ~~~
class RegexField
	super RequiredField

	autoinit field, re, required

	# Regular expression to match
	var re: Regex

	redef fun validate_field(v, obj) do
		if not super then return false
		var val = obj.get_or_null(field)
		if val == null then
			if required == null or required == true then
				v.validation.add_error(field, "Expected String got `null`")
				return false
			else
				return true
			end
		end
		if not val isa String then
			v.validation.add_error(field, "Expected String got `{val.class_name}`")
			return false
		end
		if not val.has(re) then
			v.validation.add_error(field, "Does not match `{re.string}`")
			return false
		end
		return true
	end
end