001// Copyright 2013 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007// http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry5.corelib.components;
016
017import org.apache.tapestry5.ComponentResources;
018import org.apache.tapestry5.MarkupWriter;
019import org.apache.tapestry5.annotations.Import;
020import org.apache.tapestry5.annotations.Parameter;
021import org.apache.tapestry5.annotations.SupportsInformalParameters;
022import org.apache.tapestry5.ioc.annotations.Inject;
023import org.apache.tapestry5.services.DateUtilities;
024
025import java.util.Date;
026
027/**
028 * Used to present an interval value using Moment.js's from() or fromNow() functions. The interval
029 * is determined in terms of a start and end date; either (but not both) may be omitted, in which
030 * case the client will dynamically update the element.  In that case, the value will live update, approximately every second.
031 * <p/>
032 * This component will render an empty element. The element will match the template element,
033 * or a "span" if the template did not provide an element. Informal parameters will be rendered
034 * into the element.
035 * <p/>
036 * When the end date is after the start date, the rendered text will be prefixed with "in".
037 * When the end date precedes the start date, the rendered text will be suffixed with "ago".
038 * The plain parameter is used to turn off the prefix or suffix.
039 *
040 * @tapestrydoc
041 * @see LocalDate
042 * @since 5.4
043 */
044@SupportsInformalParameters
045@Import(module = "t5/core/time-interval")
046public class TimeInterval
047{
048    /**
049     * The start date for the interval. If omitted, the start time is considered "now" and will automatically
050     * update in the browser.
051     */
052    @Parameter
053    Date start;
054
055    /**
056     * The end date for the interval. If omitted, the end time is considered "now" and will update automatically
057     * in the browser.
058     */
059    @Parameter()
060    Date end;
061
062    /**
063     * If true, then output is plain: no "in" prefix or "ago" suffix.
064     */
065    @Parameter
066    boolean plain;
067
068    @Inject
069    ComponentResources resources;
070
071    @Inject
072    DateUtilities dateUtilities;
073
074    private String toISO(Date date)
075    {
076        return date == null ? null : dateUtilities.formatISO8601(date);
077    }
078
079    boolean beginRender(MarkupWriter writer)
080    {
081        writer.element(resources.getElementName("span"),
082                // Trigger the client-side logic:
083                "data-timeinterval", "true",
084                "data-timeinterval-start", toISO(start),
085                "data-timeinterval-end", toISO(end));
086
087        if (plain)
088        {
089            writer.attributes("data-timeinterval-plain", true);
090        }
091
092        resources.renderInformalParameters(writer);
093
094        writer.end();
095
096        // Skip the body regardless.
097        return false;
098    }
099
100}