DefaultBlogViewController.java
/*
* #%L
* *********************************************************************************************************************
*
* NorthernWind - lightweight CMS
* http://northernwind.tidalwave.it - git clone https://bitbucket.org/tidalwave/northernwind-src.git
* %%
* Copyright (C) 2011 - 2021 Tidalwave s.a.s. (http://tidalwave.it)
* %%
* *********************************************************************************************************************
*
* 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.
*
* *********************************************************************************************************************
*
*
* *********************************************************************************************************************
* #L%
*/
package it.tidalwave.northernwind.frontend.ui.component.blog;
import javax.annotation.Nonnull;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Optional;
import java.util.function.Function;
import java.time.Instant;
import java.time.ZonedDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.format.FormatStyle;
import it.tidalwave.util.Finder;
import it.tidalwave.util.Key;
import it.tidalwave.util.spi.SimpleFinderSupport;
import it.tidalwave.northernwind.core.model.Content;
import it.tidalwave.northernwind.core.model.HttpStatusException;
import it.tidalwave.northernwind.core.model.RequestLocaleManager;
import it.tidalwave.northernwind.core.model.ResourcePath;
import it.tidalwave.northernwind.core.model.ResourceProperties;
import it.tidalwave.northernwind.core.model.SiteNode;
import it.tidalwave.northernwind.frontend.ui.RenderContext;
import it.tidalwave.northernwind.frontend.ui.spi.VirtualSiteNode;
import lombok.AllArgsConstructor;
import lombok.EqualsAndHashCode;
import lombok.Getter;
import lombok.RequiredArgsConstructor;
import lombok.With;
import lombok.extern.slf4j.Slf4j;
import static java.util.Collections.*;
import static java.util.Comparator.comparing;
import static java.util.stream.Collectors.*;
import static javax.servlet.http.HttpServletResponse.*;
import static it.tidalwave.util.LocalizedDateTimeFormatters.getDateTimeFormatterFor;
import static it.tidalwave.northernwind.util.CollectionFunctions.*;
import static it.tidalwave.northernwind.util.UrlEncoding.*;
import static it.tidalwave.northernwind.core.model.Content.*;
import static it.tidalwave.northernwind.frontend.ui.component.Properties.*;
import static it.tidalwave.northernwind.frontend.ui.component.nodecontainer.NodeContainerViewController.*;
import static lombok.AccessLevel.PUBLIC;
/***********************************************************************************************************************
*
* <p>A default implementation of the {@link BlogViewController} that is independent of the presentation technology.
* This class is capable to render:</p>
*
* <ul>
* <li>blog posts (in various ways)</li>
* <li>an index of the blog</li>
* <li>a tag cloud</li>
* </ul>
*
* <p>It accepts path parameters as follows:</p>
*
* <ul>
* <li>{@code <uri>}: selects a single post with the given uri;</li>
* <li>{@code <category>}: selects posts with the given category;</li>
* <li>{@code tags/<tag>}: selects posts with the given tag;</li>
* <li>{@code index}: renders a post index, with links to single posts;</li>
* <li>{@code index/<category>}: renders an index of posts with the given category;</li>
* <li>{@code index/tag/<tag>}: renders an index of posts with the given tag.</li>
* </ul>
*
* <p>Supported properties of the {@link SiteNode}:</p>
*
* <ul>
* <li>{@code P_CONTENT_PATHS}: one or more {@code Content} that contains the posts to render; they are folders and can have
* sub-folders, which will be searched for in a recursive fashion;</li>
* <li>{@code P_MAX_FULL_ITEMS}: the max. number of posts to be rendered in full;</li>
* <li>{@code P_MAX_LEADIN_ITEMS}: the max. number of posts to be rendered with lead-in text;</li>
* <li>{@code P_MAX_ITEMS}: the max. number of posts to be rendered as links;</li>
* <li>{@code P_DATE_FORMAT}: the pattern for formatting date and times;</li>
* <li>{@code P_TIME_ZONE}: the time zone for rendering dates (defaults to CET);</li>
* <li>{@code P_INDEX}: if {@code true}, forces an index rendering (useful e.g. when used in sidebars);</li>
* <li>{@code P_TAG_CLOUD}: if {@code true}, forces a tag cloud rendering (useful e.g. when used in sidebars).</li>
* </ul>
*
* <p>The {@code P_DATE_FORMAT} property accepts any valid pattern in Java 8, plus the values {@code S-}, {@code M-},
* {@code L-}, {@code F-}, which stand for small/medium/large and full patterns for a given locale.</p>
*
* <p>Supported properties of the {@link Content}:</p>
*
* <ul>
* <li>{@code P_TITLE}: the title;</li>
* <li>{@code P_FULL_TEXT}: the full text;</li>
* <li>{@code P_LEADIN_TEXT}: the lead-in text;</li>
* <li>{@code P_ID}: the unique id;</li>
* <li>{@code P_IMAGE_ID}: the id of an image representative of the post;</li>
* <li>{@code P_PUBLISHING_DATE}: the publishing date;</li>
* <li>{@code P_CREATION_DATE}: the creation date;</li>
* <li>{@code P_TAGS}: the tags;</li>
* <li>{@code P_CATEGORY}: the category.</li>
* </ul>
*
* <p>When preparing for rendering, the following dynamic properties will be set, only if a single post is rendered:</p>
*
* <ul>
* <li>{@code PD_URL}: the canonical URL of the post;</li>
* <li>{@code PD_ID}: the unique id of the post;</li>
* <li>{@code PD_IMAGE_ID}: the id of the representative image.</li>
* </ul>
*
* <p>Concrete implementations must provide two methods for rendering the blog posts and the tag cloud:</p>
*
* <ul>
* <li>{@link #renderPosts(java.util.List, java.util.List, java.util.List) }</li>
* <li>{@link #renderTagCloud(java.util.Collection) }</li>
* </ul>
*
* @author Fabrizio Giudici
*
**********************************************************************************************************************/
@RequiredArgsConstructor @Slf4j
public abstract class DefaultBlogViewController implements BlogViewController
{
/*******************************************************************************************************************
*
*
******************************************************************************************************************/
@AllArgsConstructor(access = PUBLIC) @Getter @EqualsAndHashCode
public static class TagAndCount
{
public final String tag;
public final int count;
@With
public final String rank;
public TagAndCount (@Nonnull final String tag)
{
this(tag, 1, "");
}
@Nonnull
public TagAndCount reduced (@Nonnull final TagAndCount other)
{
if (!this.tag.equals(other.tag))
{
throw new IllegalArgumentException("Mismatching " + this + " vs " + other);
}
return new TagAndCount(tag, this.count + other.count, "");
}
@Override @Nonnull
public String toString()
{
return String.format("TagAndCount(%s, %d, %s)", tag, count, rank);
}
}
/*******************************************************************************************************************
*
* A {@link Finder} which returns virtual {@link SiteNode}s representing the multiple contents served by the
* {@link SiteNode} associated to this controller. This is typically used to create site maps.
*
******************************************************************************************************************/
// TODO: add eventual localized versions
@RequiredArgsConstructor
private static class VirtualSiteNodeFinder extends SimpleFinderSupport<SiteNode>
{
private static final long serialVersionUID = 1L;
@Nonnull
private final transient DefaultBlogViewController controller;
public VirtualSiteNodeFinder (@Nonnull final VirtualSiteNodeFinder other, @Nonnull final Object override)
{
super(other, override);
final VirtualSiteNodeFinder source = getSource(VirtualSiteNodeFinder.class, other, override);
this.controller = source.controller;
}
@Override @Nonnull
protected List<? extends SiteNode> computeResults()
{
return controller.findAllPosts(controller.getViewProperties())
.stream()
.peek(p -> log.trace(">>>> virtual node for: {}", p.getExposedUri()))
.flatMap(post -> createVirtualNode(post).stream())
.collect(toList());
}
@Nonnull
private Optional<VirtualSiteNode> createVirtualNode (@Nonnull final Content post)
{
final SiteNode siteNode = controller.siteNode;
return post.getExposedUri().map(uri -> new VirtualSiteNode(siteNode,
siteNode.getRelativeUri().appendedWith(uri),
post.getProperties()));
}
}
private static final Map<String, Function<Locale, DateTimeFormatter>> DATETIME_FORMATTER_MAP_BY_STYLE = new HashMap<>();
static
{
DATETIME_FORMATTER_MAP_BY_STYLE.put("S-", locale -> getDateTimeFormatterFor(FormatStyle.SHORT, locale));
DATETIME_FORMATTER_MAP_BY_STYLE.put("M-", locale -> getDateTimeFormatterFor(FormatStyle.MEDIUM, locale));
DATETIME_FORMATTER_MAP_BY_STYLE.put("L-", locale -> getDateTimeFormatterFor(FormatStyle.LONG, locale));
DATETIME_FORMATTER_MAP_BY_STYLE.put("F-", locale -> getDateTimeFormatterFor(FormatStyle.FULL, locale));
}
protected static final List<Key<ZonedDateTime>> DATE_KEYS = List.of(P_PUBLISHING_DATE, P_CREATION_DATE);
public static final ZonedDateTime TIME0 = Instant.ofEpochMilli(0).atZone(ZoneId.of("GMT"));
public static final String DEFAULT_TIMEZONE = "CET";
private static final int NO_LIMIT = 9999;
private static final String INDEX_PREFIX = "index";
private static final String TAG_PREFIX = "tag";
private static final ResourcePath TAG_CLOUD = ResourcePath.of("tags");
private static final Comparator<Content> REVERSE_DATE_COMPARATOR = (p1, p2) ->
p2.getProperty(DATE_KEYS).orElse(TIME0).compareTo(p1.getProperty(DATE_KEYS).orElse(TIME0));
@Nonnull
private final SiteNode siteNode;
@Nonnull
private final BlogView view;
@Nonnull
private final RequestLocaleManager requestLocaleManager;
private Optional<String> tag = Optional.empty();
private Optional<String> uriOrCategory = Optional.empty();
private boolean indexMode;
private boolean tagCloudMode;
protected Optional<String> title = Optional.empty();
/* VisibleForTesting */ final List<Content> fullPosts = new ArrayList<>();
/* VisibleForTesting */ final List<Content> leadInPosts = new ArrayList<>();
/* VisibleForTesting */ final List<Content> linkedPosts = new ArrayList<>();
/*******************************************************************************************************************
*
* {@inheritDoc}
*
******************************************************************************************************************/
@Override
public void prepareRendering (@Nonnull final RenderContext context)
throws HttpStatusException
{
log.info("prepareRendering(RenderContext) for {}", siteNode);
final ResourceProperties viewProperties = getViewProperties();
indexMode = viewProperties.getProperty(P_INDEX).orElse(false);
ResourcePath pathParams = context.getPathParams(siteNode);
tagCloudMode = viewProperties.getProperty(P_TAG_CLOUD).orElse(false);
if (pathParams.equals(TAG_CLOUD))
{
tagCloudMode = true;
}
else if (pathParams.startsWith(INDEX_PREFIX))
{
indexMode = true;
pathParams = pathParams.withoutLeading();
}
if (pathParams.startsWith(TAG_PREFIX) && (pathParams.getSegmentCount() == 2)) // matches(TAG_PREFIX, ".*")
{
tag = Optional.of(pathParams.getTrailing());
}
else if (pathParams.getSegmentCount() == 1)
{
uriOrCategory = Optional.of(pathParams.getLeading());
}
else if (!pathParams.isEmpty())
{
throw new HttpStatusException(SC_BAD_REQUEST);
}
if (tagCloudMode)
{
setTitle(context);
}
else
{
prepareBlogPosts(context, viewProperties);
if ((fullPosts.size() == 1) && leadInPosts.isEmpty() && linkedPosts.isEmpty())
{
setDynamicProperties(context, fullPosts.get(0));
}
else
{
setTitle(context);
}
}
}
/*******************************************************************************************************************
*
* {@inheritDoc}
*
******************************************************************************************************************/
@Override
public void renderView (@Nonnull final RenderContext context)
throws Exception
{
log.info("renderView() for {}", siteNode);
if (tagCloudMode)
{
renderTagCloud();
}
else
{
renderPosts(fullPosts, leadInPosts, linkedPosts);
}
}
/*******************************************************************************************************************
*
* {@inheritDoc}
*
******************************************************************************************************************/
@Override @Nonnull
public Finder<SiteNode> findVirtualSiteNodes()
{
return new VirtualSiteNodeFinder(this);
}
/*******************************************************************************************************************
*
* Renders the blog posts. Must be implemented by concrete subclasses.
*
* @param fullPosts the posts to be rendered in full
* @param leadinPosts the posts to be rendered with lead in text
* @param linkedPosts the posts to be rendered as references
* @throws Exception if something fails
*
******************************************************************************************************************/
@SuppressWarnings("squid:S00112")
protected abstract void renderPosts (@Nonnull List<Content> fullPosts,
@Nonnull List<Content> leadinPosts,
@Nonnull List<Content> linkedPosts)
throws Exception;
/*******************************************************************************************************************
*
* Renders the tag cloud. Must be implemented by concrete subclasses.
*
* @param tagsAndCount the tags
*
******************************************************************************************************************/
@SuppressWarnings("squid:S00112")
protected abstract void renderTagCloud (@Nonnull Collection<TagAndCount> tagsAndCount);
/*******************************************************************************************************************
*
* Creates a link for a {@link ResourcePath}.
*
* @param path the path
* @return the link
*
******************************************************************************************************************/
@Nonnull
protected final String createLink (@Nonnull final ResourcePath path)
{
return siteNode.getSite().createLink(siteNode.getRelativeUri().appendedWith(path));
}
/*******************************************************************************************************************
*
* Creates a link for a tag.
*
* @param tag the tag
* @return the link
*
******************************************************************************************************************/
@Nonnull
protected final String createTagLink (final String tag)
{
// TODO: shouldn't ResourcePath always encode incoming strings?
String link = siteNode.getSite().createLink(siteNode.getRelativeUri().appendedWith(TAG_PREFIX)
.appendedWith(encodedUtf8(tag)));
// TODO: Workaround because createLink() doesn't append trailing / if the link contains a dot.
// Refactor by passing a parameter to createLink that overrides the default behaviour.
if (!link.endsWith("/") && !link.contains("?"))
{
link += "/";
}
return link;
}
/*******************************************************************************************************************
*
*
******************************************************************************************************************/
@Nonnull
protected final ResourceProperties getViewProperties()
{
return siteNode.getPropertyGroup(view.getId());
}
/*******************************************************************************************************************
*
* Formats a date with the settings taken from the configuration and the request settings.
*
* @param dateTime the date to render
* @return the formatted date
*
******************************************************************************************************************/
@Nonnull
protected final String formatDateTime (@Nonnull final ZonedDateTime dateTime)
{
return dateTime.format(findDateTimeFormatter());
}
/*******************************************************************************************************************
*
* Prepares the blog posts.
*
* @param context the rendering context
* @param properties the view properties
* @throws HttpStatusException status 404 if no post found
*
******************************************************************************************************************/
protected final void prepareBlogPosts (@Nonnull final RenderContext context, @Nonnull final ResourceProperties properties)
throws HttpStatusException
{
final int maxFullItems = indexMode ? 0 : properties.getProperty(P_MAX_FULL_ITEMS).orElse(NO_LIMIT);
final int maxLeadinItems = indexMode ? 0 : properties.getProperty(P_MAX_LEADIN_ITEMS).orElse(NO_LIMIT);
final int maxItems = indexMode ? NO_LIMIT : properties.getProperty(P_MAX_ITEMS).orElse(NO_LIMIT);
log.debug(">>>> preparing blog posts for {}: maxFullItems: {}, maxLeadinItems: {}, maxItems: {} (index: {}, tag: {}, uri: {})",
view.getId(), maxFullItems, maxLeadinItems, maxItems, indexMode, tag.orElse(""), uriOrCategory.orElse(""));
final List<Content> posts = findPosts(context, properties)
.stream()
.filter(post -> post.getProperty(P_TITLE).isPresent())
.sorted(REVERSE_DATE_COMPARATOR)
.collect(toList());
if (posts.isEmpty())
{
throw new HttpStatusException(SC_NOT_FOUND);
}
final List<List<Content>> split = split(posts, 0, maxFullItems, maxFullItems + maxLeadinItems, maxItems);
fullPosts.addAll(split.get(0));
leadInPosts.addAll(split.get(1));
linkedPosts.addAll(split.get(2));
}
/*******************************************************************************************************************
*
* Renders the tag cloud.
*
******************************************************************************************************************/
private void renderTagCloud()
{
final Collection<TagAndCount> tagsAndCount = findAllPosts(getViewProperties())
.stream()
.flatMap(post -> post.getProperty(P_TAGS).stream().flatMap(Collection::stream))
.collect(toMap(t -> t, TagAndCount::new, TagAndCount::reduced))
.values()
.stream()
.sorted(comparing(TagAndCount::getTag))
.collect(toList());
renderTagCloud(withRanks(tagsAndCount));
}
/*******************************************************************************************************************
*
* Finds all the relevant posts, applying filtering as needed.
*
******************************************************************************************************************/
// TODO: use some short circuit to prevent from loading unnecessary data
@Nonnull
private List<Content> findPosts (@Nonnull final RenderContext context, @Nonnull final ResourceProperties properties)
{
final ResourcePath pathParams = context.getPathParams(siteNode);
final boolean filtering = tag.isPresent() || uriOrCategory.isPresent();
final List<Content> allPosts = findAllPosts(properties);
final List<Content> posts = new ArrayList<>();
//
// The thing works differently in function of pathParams:
// when no pathParams, return all the posts;
// when it matches a category, return all the posts in that category;
// when it matches an exposed URI of a single specific post:
// if not in 'index' mode, return only that post;
// if in 'index' mode, returns all the posts.
//
if (indexMode && !filtering)
{
posts.addAll(allPosts);
}
else
{
if (tag.isPresent())
{
posts.addAll(filteredByTag(allPosts, tag.get()));
}
else
{
posts.addAll(filteredByExposedUri(allPosts, pathParams)
// pathParams matches an exposedUri; thus it's not a category, so an index wants all
.map(singlePost -> indexMode ? allPosts : singletonList(singlePost))
// pathParams didn't match an exposedUri, so it's interpreted as a category to filter posts
.orElseGet(() -> filteredByCategory(allPosts, uriOrCategory)));
}
}
log.debug(">>>> found {} items", posts.size());
return posts;
}
/*******************************************************************************************************************
*
* Finds all the posts.
*
******************************************************************************************************************/
@Nonnull
private List<Content> findAllPosts (@Nonnull final ResourceProperties properties)
{
return properties.getProperty(P_CONTENT_PATHS).orElse(emptyList()).stream()
.flatMap(path -> siteNode.getSite().find(_Content_).withRelativePath(path).stream()
.flatMap(folder -> folder.findChildren().stream()))
.collect(toList());
}
/*******************************************************************************************************************
*
* Returns the proper {@link DateTimeFormatter}. It is built from an explicit pattern, if defined in the current
* {@link SiteNode}; otherwise the one provided by the {@link RequestLocaleManager} is used. The formatter is
* configured with the time zone defined in the {@code SiteNode}, or a default is used.
*
* @return the {@code DateTimeFormatter}
*
******************************************************************************************************************/
@Nonnull
private DateTimeFormatter findDateTimeFormatter()
{
final Locale locale = requestLocaleManager.getLocales().get(0);
final ResourceProperties viewProperties = getViewProperties();
final DateTimeFormatter dtf = viewProperties.getProperty(P_DATE_FORMAT)
.map(s -> s.replaceAll("EEEEE+", "EEEE"))
.map(s -> s.replaceAll("MMMMM+", "MMMM"))
.map(p -> (((p.length() == 2) ? DATETIME_FORMATTER_MAP_BY_STYLE.get(p).apply(locale)
: DateTimeFormatter.ofPattern(p)).withLocale(locale)))
.orElse(requestLocaleManager.getDateTimeFormatter());
final String zoneId = viewProperties.getProperty(P_TIME_ZONE).orElse(DEFAULT_TIMEZONE);
return dtf.withZone(ZoneId.of(zoneId));
}
/*******************************************************************************************************************
*
*
*
******************************************************************************************************************/
private void setDynamicProperties (@Nonnull final RenderContext context, @Nonnull final Content post)
{
context.setDynamicNodeProperty(PD_TITLE, computeTitle(post));
post.getExposedUri().map(this::createLink).ifPresent(l -> context.setDynamicNodeProperty(PD_URL, l));
post.getProperty(P_ID).ifPresent(id -> context.setDynamicNodeProperty(PD_ID, id));
post.getProperty(P_IMAGE_ID).ifPresent(id -> context.setDynamicNodeProperty(PD_IMAGE_ID, id));
}
/*******************************************************************************************************************
*
*
******************************************************************************************************************/
private void setTitle (@Nonnull final RenderContext context)
{
if (tagCloudMode)
{
title = Optional.of("Tags");
}
else if (indexMode)
{
title = Optional.of("Post index");
if (tag.isPresent())
{
title = Optional.of(String.format("Posts tagged as '%s'", tag.get()));
}
else uriOrCategory.ifPresent(s -> title = Optional.of(String.format("Posts in category '%s'", s)));
}
else
{
title = getViewProperties().getProperty(P_TITLE).map(String::trim).flatMap(DefaultBlogViewController::filterEmptyString);
}
title.ifPresent(view::setTitle);
title.ifPresent(s -> context.setDynamicNodeProperty(PD_TITLE, s));
}
/*******************************************************************************************************************
*
*
******************************************************************************************************************/
@Nonnull
private String computeTitle (@Nonnull final Content post)
{
final String prefix = siteNode.getProperty(P_TITLE).orElse("");
final String title = post.getProperty(P_TITLE).orElse("");
final String separator = "".equals(prefix) || "".equals(title) ? "" : " - ";
return prefix + separator + title;
}
/*******************************************************************************************************************
*
*
******************************************************************************************************************/
@Nonnull
private static List<TagAndCount> withRanks (@Nonnull final Collection<TagAndCount> tagsAndCount)
{
final List<Integer> counts = tagsAndCount.stream()
.map(TagAndCount::getCount)
.distinct()
.sorted(reverseOrder())
.collect(toList());
return tagsAndCount.stream()
.map(tac -> tac.withRank(rankOf(tac.count, counts)))
.collect(toList());
}
/*******************************************************************************************************************
*
* Filters the given posts that match the selected category; returns all the posts if the category is empty.
*
* @param posts the source posts
* @param category the category
* @return the filtered posts
*
******************************************************************************************************************/
@Nonnull
private static List<Content> filteredByCategory (@Nonnull final List<Content> posts,
@Nonnull final Optional<String> category)
{
return posts.stream().filter(post -> hasCategory(post, category)).collect(toList());
}
/*******************************************************************************************************************
*
* Filters the {@code sourcePosts} that matches the selected{@code tag}; returns all
* posts if the category is empty.
*
* @param posts the source posts
* @param tag the tag
* @return the filtered posts
*
******************************************************************************************************************/
@Nonnull
private static List<Content> filteredByTag (@Nonnull final List<Content> posts, @Nonnull final String tag)
{
return posts.stream().filter(post -> hasTag(post, tag)).collect(toList());
}
/*******************************************************************************************************************
*
*
******************************************************************************************************************/
@Nonnull
private static Optional<Content> filteredByExposedUri (@Nonnull final List<Content> posts,
@Nonnull final ResourcePath exposedUri)
{
return posts.stream().filter(post -> post.getExposedUri().map(exposedUri::equals).orElse(false)).findFirst();
}
/*******************************************************************************************************************
*
*
******************************************************************************************************************/
@Nonnull
private static String rankOf (final int count, final List<Integer> counts)
{
assert counts.contains(count);
final int rank = counts.indexOf(count) + 1;
return (rank <= 10) ? Integer.toString(rank) : "Others";
}
/*******************************************************************************************************************
*
*
******************************************************************************************************************/
private static boolean hasCategory (@Nonnull final Content post, @Nonnull final Optional<String> category)
{
return category.isEmpty() || post.getProperty(P_CATEGORY).equals(category);
}
/*******************************************************************************************************************
*
*
******************************************************************************************************************/
private static boolean hasTag (@Nonnull final Content post, @Nonnull final String tag)
{
return post.getProperty(P_TAGS).orElse(emptyList()).contains(tag);
}
/*******************************************************************************************************************
*
*
*
******************************************************************************************************************/
@Nonnull
private static Optional<String> filterEmptyString (@Nonnull final String s)
{
return "".equals(s) ? Optional.empty() : Optional.of(s);
}
}