Enable markdown descriptions.

Author: mkalus

src/main/java/org/segrada/rendering/markdown/MarkdownRenderer.java

@@ -0,0 +1,164 @@
+package org.segrada.rendering.markdown;
+
+import com.google.inject.Injector;
+import com.vladsch.flexmark.ext.emoji.EmojiExtension;
+import com.vladsch.flexmark.ext.tables.TablesExtension;
+import com.vladsch.flexmark.ext.typographic.TypographicExtension;
+import com.vladsch.flexmark.ext.wikilink.WikiLink;
+import com.vladsch.flexmark.ext.wikilink.internal.WikiLinkLinkRefProcessor;
+import com.vladsch.flexmark.html.HtmlRenderer;
+import com.vladsch.flexmark.html.HtmlRenderer.Builder;
+import com.vladsch.flexmark.html.HtmlWriter;
+import com.vladsch.flexmark.html.renderer.*;
+import com.vladsch.flexmark.parser.Parser;
+import com.vladsch.flexmark.util.ast.Node;
+import com.vladsch.flexmark.util.ast.TextCollectingVisitor;
+import com.vladsch.flexmark.util.data.DataHolder;
+import com.vladsch.flexmark.util.data.MutableDataHolder;
+import com.vladsch.flexmark.util.data.MutableDataSet;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.segrada.model.prototype.ISource;
+import org.segrada.service.SourceService;
+import org.unbescape.html.HtmlEscape;
+
+import java.util.*;
+
+public class MarkdownRenderer {
+    /**
+     * reference to injector
+     */
+    public static Injector injector;
+
+    /**
+     * cache for source reference links
+     * TODO: use different cache, because otherwise this might fill up memory eventually, rather unlikely, but there is no deletion of old keys here
+     */
+    private static final Map<String, String> sourceReferenceCache = new HashMap<>();
+
+    public static void setInjector(Injector injector) {
+        MarkdownRenderer.injector = injector;
+    }
+
+    /**
+     * get current source service instance from injector
+     * @return SourceService instance
+     */
+    public static SourceService getSourceService() {
+        return injector.getInstance(SourceService.class);
+    }
+
+    // markdown data holder with custom extension + more extensions defined below
+    final private static DataHolder OPTIONS = new MutableDataSet()
+            .set(TablesExtension.CLASS_NAME, "table table-condensed")
+            .set(Parser.EXTENSIONS, Arrays.asList(
+                    CustomExtension.create(), // will use wiki link renderer to work links
+                    EmojiExtension.create(),
+                    TablesExtension.create(),
+                    TypographicExtension.create()
+            )).toImmutable();
+
+    // markdown parser and renderer
+    static final Parser PARSER = Parser.builder(OPTIONS).build();
+    static final HtmlRenderer RENDERER = HtmlRenderer.builder(OPTIONS).build();
+
+    /**
+     * Render or remove links
+     */
+    public static class BibliographicEntryLinkNodeRenderer implements NodeRenderer {
+        @Override
+        public @Nullable Set<NodeRenderingHandler<?>> getNodeRenderingHandlers() {
+            HashSet<NodeRenderingHandler<?>> set = new HashSet();
+            set.add(new NodeRenderingHandler(WikiLink.class, this::render));
+            return set;
+        }
+
+        private void render(Node node, @NotNull NodeRendererContext context, @NotNull HtmlWriter html) {
+            if (node instanceof WikiLink) {
+                WikiLink link = (WikiLink)node;
+
+                String possibleKey = link.getLink().toString();
+
+                SourceService sourceService = getSourceService();
+
+                // fallback in case of errors
+                if (sourceService == null) {
+                    html.text(node.getChars().unescape());
+                    return;
+                }
+
+                // find corresponding source
+                ISource source = sourceService.findByRef(possibleKey);
+                if (source == null) {
+                    // not found: just print text
+                    html.text(node.getChars().unescape());
+                } else {
+                    // otherwise: create nice link
+                    String url = "source/show/" + source.getUid();
+
+                    ResolvedLink resolvedLink = context.resolveLink(LinkType.LINK, url, (Boolean)null);
+                    html.attr("href", url);
+                    html.attr("class", "sg-data-add");
+                    html.attr("title", source.getShortRef());
+                    html.srcPos(node.getChars()).withAttr(resolvedLink).tag("a");
+                    html.text(source.getShortTitle());
+                    html.tag("/a");
+                }
+            }
+        }
+
+        public static class Factory implements NodeRendererFactory {
+            public Factory() {
+            }
+
+            @NotNull
+            public NodeRenderer apply(@NotNull DataHolder options) {
+                return new BibliographicEntryLinkNodeRenderer();
+            }
+        }
+    }
+
+    static class CustomExtension implements Parser.ParserExtension, HtmlRenderer.HtmlRendererExtension {
+        @Override
+        public void rendererOptions(@NotNull MutableDataHolder options) {
+
+        }
+
+        @Override
+        public void parserOptions(MutableDataHolder mutableDataHolder) {
+        }
+
+        @Override
+        public void extend(Parser.Builder parserBuilder) {
+            parserBuilder.linkRefProcessorFactory(new WikiLinkLinkRefProcessor.Factory()); // we will use wiki link extension to help us build links
+        }
+
+        @Override
+        public void extend(@NotNull Builder htmlRendererBuilder, @NotNull String rendererType) {
+            htmlRendererBuilder.nodeRendererFactory(new BibliographicEntryLinkNodeRenderer.Factory());
+        }
+
+        static CustomExtension create() {
+            return new CustomExtension();
+        }
+    }
+
+    /**
+     * renders markdown to HTML
+     * @param markdown source
+     * @return html
+     */
+    public static String render(String markdown) {
+        return RENDERER.render(PARSER.parse(markdown));
+    }
+
+    /**
+     * converts markdown to plain text
+     * @param markdown source
+     * @return text
+     */
+    public static String toPlainText(String markdown) {
+        TextCollectingVisitor textCollectingVisitor = new TextCollectingVisitor();
+        return  textCollectingVisitor.collectAndGetText(PARSER.parse(markdown));
+    }
+}

src/main/java/org/segrada/rendering/markup/DefaultMarkupFilter.java

@@ -64,7 +64,7 @@ public class DefaultMarkupFilter extends MarkupFilter {
 			"->", "→",
 	};
 
-	private static final Pattern bibRefPattern = Pattern.compile("\\[\\[([^:\\[\\]]+:[^\\[\\]]+)\\]\\]");
+	private static final Pattern bibRefPattern = Pattern.compile("\\[\\[([^]]+)\\]\\]");
 
 	/**
 	 * @return pattern to find bibliographic references

src/main/java/org/segrada/rendering/markup/MarkdownMarkupFilter.java

@@ -0,0 +1,42 @@
+package org.segrada.rendering.markup;
+
+import org.jsoup.Jsoup;
+import org.jsoup.parser.Parser;
+import org.jsoup.safety.Whitelist;
+import org.segrada.rendering.markdown.MarkdownRenderer;
+
+/**
+ * Copyright 2015-2021 Maximilian Kalus [[email protected]]
+ *
+ * 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.
+ *
+ * Markdown markup filter
+ */
+public class MarkdownMarkupFilter extends MarkupFilter {
+    @Override
+    public String toHTML(String markupText) {
+        return MarkdownRenderer.render(markupText);
+    }
+
+    @Override
+    public String toPlain(String markupText) {
+        // sane default
+        if (markupText == null || markupText.equals("")) return "";
+
+        // remove bibliographic entries
+        String plainText = markupText.replaceAll("\\[\\[[\\w:]+\\]\\]", "").replaceAll("\\[[0-9f]+:\\]", "");
+
+        // clean
+        return MarkdownRenderer.toPlainText(plainText);
+    }
+}

src/main/java/org/segrada/servlet/SegradaGuiceServletContextListener.java

@@ -10,7 +10,9 @@
 import org.segrada.config.ServiceModule;
 import org.segrada.config.TemplateModule;
 import org.segrada.controller.*;
+import org.segrada.rendering.markdown.MarkdownRenderer;
 import org.segrada.rendering.markup.DefaultMarkupFilter;
+import org.segrada.rendering.markup.MarkdownMarkupFilter;
 
 import javax.servlet.annotation.WebListener;
 import java.util.Map;
@@ -94,6 +96,7 @@ protected void configureServlets() {
 		OrientDBFilter.setInjector(injector);
 		SegradaSimplePageCachingFilter.setInjector(injector);
 		DefaultMarkupFilter.setInjector(injector);
+		MarkdownRenderer.setInjector(injector);
 		CheckAuthentication.setInjector(injector);
 
 		return injector;

src/main/resources/less/single/segrada.less

@@ -145,6 +145,10 @@ td .sg-data-taglist span {
 
 .sg-description {
   margin-top: 20px;
+
+  hr {
+    border-color: #000;
+  }
 }
 
 .sg-map {

src/main/webapp/WEB-INF/templates/partials/form.html

@@ -69,6 +69,12 @@ <h2>Text area with markup</h2>
 					HTML
 				</label>
 			</div>
+			<div class="radio-inline">
+				<label>
+					<input class="sg-plain-editor" th:attr="data-editor=${'#' + name + '-' + id}" type="radio" th:id="${markupName + '-' + id + '_markdown'}" th:name="${markupName}" value="markdown" th:checked="${#strings.equals('markdown', markupField)}">
+					Markdown
+				</label>
+			</div>
 		</div>
 	</div>
 </div>