org.apache.nifi.expression.ExpressionLanguageScope Maven / Gradle / Ivy
/*
* 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.expression;
/**
* Indicates the scope of expression language on a property descriptor.
*
* Scope of the expression language is hierarchical.
* NONE -> VARIABLE_REGISTRY -> FLOWFILE_ATTRIBUTES
*
* When scope is set to FlowFiles attributes, variables are evaluated
* against attributes of each incoming flow file. If no matching attribute
* is found, variable registry will be checked.
*
* NONE - expression language is not supported
*
* VARIABLE_REGISTRY is hierarchically constructed as below:
* |---- Variables defined at process group level and then, recursively, up
* | to the higher process group until the root process group.
* |--- Variables defined in custom properties files through the
* | nifi.variable.registry.properties property in nifi.properties file.
* |-- Environment variables defined at JVM level and system properties.
*
* FLOWFILE_ATTRIBUTES - will check attributes of each individual flow file
*
*/
public enum ExpressionLanguageScope {
/**
* Expression language is disabled
*/
NONE("Not Supported"),
/**
* Expression language is evaluated against variables in registry
*/
VARIABLE_REGISTRY("Variable Registry Only"),
/**
* Expression language is evaluated per flow file using attributes
*/
FLOWFILE_ATTRIBUTES("Variable Registry and FlowFile Attributes");
private String description;
private ExpressionLanguageScope(String description) {
this.description = description;
}
public String getDescription() {
return this.description;
}
}