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Scala library to handle form submission
/*
* Copyright 2022 Greenfossil Pte Ltd
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.greenfossil.data.mapping
/**
* A form constraint.
*
* @tparam T type of values handled by this constraint
* @param name the constraint name, to be displayed to final user
* @param args the message arguments, to format the constraint name
* @param f the validation function
*/
case class Constraint[-T](name: Option[String], args: Seq[Any])(f: T => ValidationResult):
/**
* Run the constraint validation.
*
* @param t the value to validate
* @return the validation result
*/
def apply(t: T): ValidationResult = f(t)
end Constraint
/**
* This object provides helpers for creating `Constraint` values.
*
* For example:
* {{{
* val negative = Constraint[Int] {
* case i if i < 0 => Valid
* case _ => Invalid("Must be a negative number.")
* }
* }}}
*/
object Constraint:
/**
* Creates a new anonymous constraint from a validation function.
*
* @param f the validation function
* @return a constraint
*/
def apply[T](f: (T => ValidationResult)): Constraint[T] = apply(None, Nil)(f)
/**
* Creates a new named constraint from a validation function.
*
* @param name the constraint name
* @param args the constraint arguments, used to format the constraint name
* @param f the validation function
* @return a constraint
*/
def apply[T](name: String, args: Any*)(f: (T => ValidationResult)): Constraint[T] = apply(Some(name), args.toSeq)(f)
end Constraint