package io.vertx.ext.web.api.validation;

import io.vertx.codegen.annotations.VertxGen;
import io.vertx.ext.web.api.RequestParameter;

import java.util.List;

This function is an inner wrapper for ParameterTypeValidator inside ValidationHandler parameter maps. Don't
instantiate this class, if you want to add custom ParameterTypeValidator to a parameter use functions in HTTPRequestValidationHandler 
Author:
Francesco Guardiani @slinkydeveloper/**
 * This function is an inner wrapper for ParameterTypeValidator inside ValidationHandler parameter maps. <b>Don't
 * instantiate this class</b>, if you want to add custom ParameterTypeValidator to a parameter use functions in
 * {@link HTTPRequestValidationHandler}
 *
 * @author Francesco Guardiani @slinkydeveloper
 */
@VertxGen
public interface ParameterValidationRule {

  
This function return the name of the parameter expected into parameter lists
Returns:
name of the parameter/**
   * This function return the name of the parameter expected into parameter lists
   *
   * @return name of the parameter
   */
  String getName();

  
This function will be called when there is only a string as parameter. It will throw a ValidationError in an
error during validation occurs
Params:
value – list of values that will be validated
Throws:
ValidationException – /**
   * This function will be called when there is only a string as parameter. It will throw a ValidationError in an
   * error during validation occurs
   *
   * @param value list of values that will be validated
   * @throws ValidationException
   */
  RequestParameter validateSingleParam(String value) throws ValidationException;

  
This function will be called when there is a List that need to be validated. It must check if array is
expected or not. It will throw a ValidationError in an error during validation occurs
Params:
value – list of values that will be validated
Throws:
ValidationException – /**
   * This function will be called when there is a List<String> that need to be validated. It must check if array is
   * expected or not. It will throw a ValidationError in an error during validation occurs
   *
   * @param value list of values that will be validated
   * @throws ValidationException
   */
  RequestParameter validateArrayParam(List<String> value) throws ValidationException;

  
Return true if parameter is optional
Returns:
true if is optional, false otherwise/**
   * Return true if parameter is optional
   *
   * @return true if is optional, false otherwise
   */
  boolean isOptional();

  
Return ParameterTypeValidator instance used inside this parameter validation rule
Returns:
/**
   * Return ParameterTypeValidator instance used inside this parameter validation rule
   *
   * @return
   */
  ParameterTypeValidator parameterTypeValidator();

  
allowEmptyValue is used in query, header, cookie and form parameters. This is its behaviour:

During validation, the ValidationHandler check if there's a parameter with combination of location and name
as defined in this rule 
If it not exists, It will check allowEmptyValue and if there's a default value set inside
ParameterTypeValidator:

If this condition it's true, It marks as validated the parameter and returns the default value (inside
RequestParameter)
If this condition it's false, It throws ValidationException

If the parameter exists, It checks if parameter is null or empty string:

If allowEmptyValue it's true, It marks as validated the parameter and returns the default value if it exists
(inside RequestParameter)
If allowEmptyValue it's false, It throws ValidationException


Returns:
value of allowEmptyValue/**
   * allowEmptyValue is used in query, header, cookie and form parameters. This is its behaviour:
   * <ol>
   * <li>During validation, the ValidationHandler check if there's a parameter with combination of location and name
   * as defined in this rule </li>
   * <li>If it not exists, It will check allowEmptyValue and if there's a default value set inside
   * ParameterTypeValidator:</li>
   * <ul>
   * <li>If this condition it's true, It marks as validated the parameter and returns the default value (inside
   * RequestParameter)</li>
   * <li>If this condition it's false, It throws ValidationException</li>
   * </ul>
   * <li>If the parameter exists, It checks if parameter is null or empty string:</li>
   * <ul>
   * <li>If allowEmptyValue it's true, It marks as validated the parameter and returns the default value if it exists
   * (inside RequestParameter)</li>
   * <li>If allowEmptyValue it's false, It throws ValidationException</li>
   * </ul>
   * </ol>
   *
   * @return value of allowEmptyValue
   */
  boolean allowEmptyValue();

}