nifi-manifest/nifi-extension-manifest-model/src/main/java/org/apache/nifi/extension/manifest/InputRequirement.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.nifi.extension.manifest;

import io.swagger.annotations.ApiModel;

@ApiModel
public enum InputRequirement {

    /**
     * This value is used to indicate that the Processor requires input from other Processors
     * in order to run. As a result, the Processor will not be valid if it does not have any
     * incoming connections.
     */
    INPUT_REQUIRED,

    /**
     * This value is used to indicate that the Processor will consume data from an incoming
     * connection but does not require an incoming connection in order to perform its task.
     * If the {@link InputRequirement} annotation is not present, this is the default value
     * that is used.
     */
    INPUT_ALLOWED,

    /**
     * This value is used to indicate that the Processor is a "Source Processor" and does
     * not accept incoming connections. Because the Processor does not pull FlowFiles from
     * an incoming connection, it can be very confusing for users who create incoming connections
     * to the Processor. As a result, this value can be used in order to clarify that incoming
     * connections will not be used. This prevents the user from even creating such a connection.
     */
    INPUT_FORBIDDEN;

}