/*
 * #%L
 * fujion
 * %%
 * Copyright (C) 2021 Fujion Framework
 * %%
 * 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.
 *
 * #L%
 */
package org.fujion.annotation;

import java.lang.annotation.*;

/**
 * Annotation to mark a field to be serialized as part of an option map.
 */
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Option {

    /**
     * The value of the map key to be used when serializing the field. Will default to the field
     * name. May contain an EL expression (use variable name "value" to access the field value).
     *
     * @return Value of the map key.
     */
    String value() default "";
    
    /**
     * Optional destination type for the conversion.
     *
     * @return The destination type for the conversion. Default is no conversion.
     */
    Class<?> convertTo() default Object.class;

    /**
     * Optional EL expression to convert value to a new type. Use variable name "value" to access
     * current value. EL prefix ("${") and suffix ("}") are optional.
     *
     * @return The EL expression to convert the value. Default is none.
     */
    String convertUsing() default "";
    
    /**
     * Ignore the annotation. Useful to explicitly show that the field is not to be serialized.
     *
     * @return If true, ignore the annotation. Default is false.
     */
    boolean ignore() default false;

    /**
     * If true, a value is required.
     *
     * @return If true, an exception is thrown if the field's value is null.
     */
    boolean required() default false;
}
