FetchFromUrlMode.java

/*
 * Made with all the love in the world
 * by scireum in Remshalden, Germany
 *
 * Copyright by scireum GmbH
 * http://www.scireum.de - info@scireum.de
 */

package sirius.biz.storage.layer3;

import sirius.biz.jobs.params.EnumParameter;
import sirius.biz.jobs.params.Parameter;
import sirius.kernel.nls.NLS;

import java.net.URI;
import java.util.function.Predicate;

/**
 * Determines the behavior of {@link VirtualFile#loadFromUrl(URI, FetchFromUrlMode)} or
 * {@link VirtualFile#resolveOrLoadChildFromURL(URI, FetchFromUrlMode, Predicate)}.
 */
public enum FetchFromUrlMode {
    /**
     * Fetches the data from the URL if either the local file does not exist or if the contents on the remote server
     * have been modified since the last fetch.
     */
    NON_EXISTENT_OR_MODIFIED,

    /**
     * Only fetches the data from the server if the local file does not exist.
     */
    NON_EXISTENT,

    /**
     * Always fetches the data from the server.
     */
    ALWAYS_FETCH,

    /**
     * Never fetches any data from the server. Note that this will not perform any network request and thus for URLs
     * which do not reveal the effective file name, <tt>VirtualFile.resolveOrLoadChildFromURL</tt> will fail with an
     * appropriate error message.
     */
    NEVER_FETCH;

    /**
     * Provides a parameter to be used to select the mode to use during an import job.
     */
    public static final Parameter<FetchFromUrlMode> PARAMETER = createParameter();

    private static Parameter<FetchFromUrlMode> createParameter() {
        return new EnumParameter<>("fetchFromUrlMode",
                                   "$FetchFromUrlMode.parameter.name",
                                   FetchFromUrlMode.class).withDefault(FetchFromUrlMode.NON_EXISTENT_OR_MODIFIED)
                                                          .withDescription("$FetchFromUrlMode.parameter.description")
                                                          .markRequired()
                                                          .build();
    }

    @Override
    public String toString() {
        return NLS.get(getClass().getSimpleName() + "." + name());
    }
}