org.xlcloud.service.heat.template.fields.IntrinsicFunctionField Maven / Gradle / Ivy

/*
 * Copyright 2012 AMG.lab, a Bull Group Company
 * 
 * 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 org.xlcloud.service.heat.template.fields;

import org.apache.commons.lang.StringUtils;
import org.json.JSONException;


/**
 * Intrinsic Function for AWS CloudFormation templates
 * 
 * @see AWS CloudFormation Intrinsic Function Reference
 * 
 * @author Piotr Kulasek-Szwed, AMG.net
 */
public enum IntrinsicFunctionField implements JsonKey {

    REF("Ref"),
    BASE64("Fn::Base64"),
    JOIN("Fn::Join"),
    GET_ATT("Fn::GetAtt"),
    GET_AZS("Fn::GetAZs"),
    FIND_IN_MAP("Fn::FindInMap");

    private String jsonKey;

    private IntrinsicFunctionField( String key ) {
        this.jsonKey = key;
    }

    /** {@inheritDoc} */
    @Override
    public String jsonKey() {
        return jsonKey;
    }

    /**
     * @param key
     *            key to check, cannot be null or blank
     * @return false if specified key doesn't correspond to any (supported)
     *         intrinsic function
     */
    public static boolean isFunction(String key) {
        try {
            return getFunctionField(key) != null;
        } catch (JSONException e) {
            return false;
        }
    }

    /**
     * @param key
     *            key to check, cannot be null or blank
     * @return {@link IntrinsicFunctionField} corresponding to specified key or
     *         null - if non of (supported) intrinsic functions correspond to
     *         one
     * @throws JSONException 
     */
    public static IntrinsicFunctionField getFunctionField(String key) throws JSONException {
        if (StringUtils.isBlank(key)) {
            throw new JSONException("Intrinsic function name cannot be empty");
        }
        for (IntrinsicFunctionField field : values()) {
            if (field.jsonKey.equals(key)) {
                return field;
            }
        }
        return null;
    }
}