+function isArrayOf (value: any, validator: (value: any) => boolean) {
+ return isArray(value) && value.every(v => validator(v))
+}
+
+function isDateValid (value: string) {
+ return exists(value) && validator.isISO8601(value)
+}
+
+function isIdValid (value: string) {
+ return exists(value) && validator.isInt('' + value)
+}
+
+function isUUIDValid (value: string) {
+ return exists(value) && validator.isUUID('' + value, 4)
+}
+
+function isIdOrUUIDValid (value: string) {
+ return isIdValid(value) || isUUIDValid(value)
+}
+
+function isBooleanValid (value: any) {
+ return typeof value === 'boolean' || (typeof value === 'string' && validator.isBoolean(value))
+}
+
+function toIntOrNull (value: string) {
+ const v = toValueOrNull(value)
+
+ if (v === null || v === undefined) return v
+ if (typeof v === 'number') return v
+
+ return validator.toInt('' + v)
+}
+
+function toBooleanOrNull (value: any) {
+ const v = toValueOrNull(value)
+
+ if (v === null || v === undefined) return v
+ if (typeof v === 'boolean') return v
+
+ return validator.toBoolean('' + v)
+}
+
+function toValueOrNull (value: string) {
+ if (value === 'null') return null
+
+ return value
+}
+
+function toArray (value: any) {
+ if (value && isArray(value) === false) return [ value ]
+
+ return value
+}
+
+function toIntArray (value: any) {
+ if (!value) return []
+ if (isArray(value) === false) return [ validator.toInt(value) ]
+
+ return value.map(v => validator.toInt(v))