ReplaceOperation.java

/*
 * Copyright (c) 2014, Francis Galiegue (fgaliegue@gmail.com)
 *
 * This software is dual-licensed under:
 *
 * - the Lesser General Public License (LGPL) version 3.0 or, at your option, any
 *   later version;
 * - the Apache Software License (ASL) version 2.0.
 *
 * The text of this file and of both licenses is available at the root of this
 * project or, if you have the jar distribution, in directory META-INF/, under
 * the names LGPL-3.0.txt and ASL-2.0.txt respectively.
 *
 * Direct link to the sources:
 *
 * - LGPL 3.0: https://www.gnu.org/licenses/lgpl-3.0.txt
 * - ASL 2.0: http://www.apache.org/licenses/LICENSE-2.0.txt
 */

package com.github.fge.jsonpatch;

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.fasterxml.jackson.databind.node.ObjectNode;
import com.github.fge.jackson.jsonpointer.JsonPointer;

/**
 * JSON Patch {@code replace} operation
 *
 * <p>For this operation, {@code path} points to the value to replace, and
 * {@code value} is the replacement value.</p>
 *
 * <p>It is an error condition if {@code path} does not point to an actual JSON
 * value.</p>
 */
public final class ReplaceOperation
    extends PathValueOperation
{
    @JsonCreator
    public ReplaceOperation(@JsonProperty("path") final JsonPointer path,
        @JsonProperty("value") final JsonNode value)
    {
        super("replace", path, value);
    }

    @Override
    public JsonNode apply(final JsonNode node)
        throws JsonPatchException
    {
        /*
         * FIXME cannot quite be replaced by a remove + add because of arrays.
         * For instance:
         *
         * { "op": "replace", "path": "/0", "value": 1 }
         *
         * with
         *
         * [ "x" ]
         *
         * If remove is done first, the array is empty and add rightly complains
         * that there is no such index in the array.
         */
        if (path.path(node).isMissingNode()) {
            String msg = BUNDLE.getMessage("jsonPatch.noSuchPath");
            if(node!=null) {
                msg = node.toString() + " " + msg;
            }
            throw new JsonPatchException(msg);
        }
        final JsonNode replacement = value.deepCopy();
        if (path.isEmpty())
            return replacement;
        final JsonNode ret = node.deepCopy();
        final JsonNode parent = path.parent().get(ret);
        final String rawToken = Iterables.getLast(path).getToken().getRaw();
        if (parent.isObject())
            ((ObjectNode) parent).replace(rawToken, replacement);
        else
            ((ArrayNode) parent).set(Integer.parseInt(rawToken), replacement);
        return ret;
    }
}