Merge pull request #223 from jelovirt/feature/generate-empty-title

Support Markdown files without top level header

src/main/java/com/elovirta/dita/markdown/MarkdownParserImpl.java

@@ -1,5 +1,6 @@
 package com.elovirta.dita.markdown;
 
+import com.elovirta.dita.markdown.renderer.HeaderIdGenerator;
 import com.vladsch.flexmark.ast.Heading;
 import com.vladsch.flexmark.ast.Text;
 import com.vladsch.flexmark.ext.anchorlink.AnchorLink;
@@ -11,6 +12,7 @@
 import com.vladsch.flexmark.util.data.DataSet;
 import com.vladsch.flexmark.util.sequence.BasedSequence;
 import java.net.URI;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.ResourceBundle;
@@ -130,49 +132,89 @@ protected void validate(Document root) {
    * If document doesn't start with H1, generate H1 from YAML metadata or file name.
    */
   protected Document preprocess(Document root, URI input) throws SAXException {
-    if (DitaRenderer.WIKI.get(options) && isWiki(root)) {
-      generateRootHeading(root, input);
-    }
-    if (DitaRenderer.FIX_ROOT_HEADING.get(options) && isWiki(root)) {
-      if (errorHandler != null) {
-        errorHandler.warning(
-          new SAXParseException(MESSAGES.getString("error.missing_title"), null, input.toString(), 1, 1)
-        );
+    if (isWiki(root) && !DitaRenderer.MAP.get(options)) {
+      final Map<String, String> header = parseYamlHeader(root);
+      if (DitaRenderer.WIKI.get(options)) {
+        generateRootHeading(root, header.get("id"), header.getOrDefault("title", getTextFromFile(input)));
+      } else if (DitaRenderer.FIX_ROOT_HEADING.get(options)) {
+        if (errorHandler != null) {
+          errorHandler.warning(
+            new SAXParseException(MESSAGES.getString("error.missing_title"), null, input.toString(), 1, 1)
+          );
+        }
+        generateRootHeading(root, header.get("id"), header.getOrDefault("title", getTextFromFile(input)));
+      } else if (MarkdownReader.PROCESSING_MODE.get(options)) {
+        if (errorHandler != null) {
+          errorHandler.error(
+            new SAXParseException(MESSAGES.getString("error.missing_title"), null, input.toString(), 1, 1)
+          );
+        }
+      } else {
+        if (errorHandler != null) {
+          errorHandler.warning(
+            new SAXParseException(MESSAGES.getString("error.missing_title"), null, input.toString(), 1, 1)
+          );
+        }
+        String id = header.get("id");
+        if (id == null) {
+          id =
+            HeaderIdGenerator.generateId(
+              getTextFromFile(input),
+              DitaRenderer.HEADER_ID_GENERATOR_TO_DASH_CHARS.get(root),
+              DitaRenderer.HEADER_ID_GENERATOR_NO_DUPED_DASHES.get(root)
+            );
+        }
+        generateRootHeading(root, id, header.get("title"));
       }
-      generateRootHeading(root, input);
     }
     return root;
   }
 
-  private void generateRootHeading(Document root, URI input) {
+  private static String getId(final String contents) {
+    return contents.toLowerCase().replaceAll("[^\\w\\s]", "").trim().replaceAll("\\s+", "-");
+  }
+
+  private Map<String, String> parseYamlHeader(Document root) {
+    Map<String, String> res = new HashMap<>();
     final YamlFrontMatterBlock yaml = root.getFirstChild() instanceof YamlFrontMatterBlock
       ? (YamlFrontMatterBlock) root.getFirstChild()
       : null;
-    String title = getTextFromFile(input);
-    final Heading heading = new Heading();
     if (yaml != null) {
       final AbstractYamlFrontMatterVisitor v = new AbstractYamlFrontMatterVisitor();
       v.visit(root);
       final Map<String, List<String>> metadata = v.getData();
       final List<String> ids = metadata.get("id");
       if (ids != null && !ids.isEmpty()) {
-        heading.setAnchorRefId(ids.get(0));
+        res.put("id", ids.get(0));
       }
       final List<String> titles = metadata.get("title");
       if (titles != null && !titles.isEmpty()) {
-        title = titles.get(0);
+        String title = titles.get(0);
         if (
           (title.charAt(0) == '\'' && title.charAt(title.length() - 1) == '\'') ||
           (title.charAt(0) == '"' && title.charAt(title.length() - 1) == '"')
         ) {
           title = title.substring(1, title.length() - 1);
         }
+        res.put("title", title);
       }
     }
+    return res;
+  }
+
+  private void generateRootHeading(Document root, String id, String title) {
+    final Heading heading = new Heading();
+    if (id != null) {
+      heading.setAnchorRefId(id);
+    }
     heading.setLevel(1);
-    final AnchorLink anchorLink = new AnchorLink();
-    anchorLink.appendChild(new Text(title));
-    heading.appendChild(anchorLink);
+    if (id == null) {
+      final AnchorLink anchorLink = new AnchorLink();
+      anchorLink.appendChild(new Text(title != null ? title : ""));
+      heading.appendChild(anchorLink);
+    } else {
+      heading.appendChild(new Text(title != null ? title : ""));
+    }
     root.prependChild(heading);
   }
 

src/main/java/com/elovirta/dita/markdown/MarkdownReader.java

@@ -45,6 +45,7 @@ public class MarkdownReader implements XMLReader {
   private static final ServiceLoader<SchemaProvider> schemaLoader = ServiceLoader.load(SchemaProvider.class);
 
   public static final DataKey<Collection<String>> FORMATS = new DataKey<>("FORMATS", List.of("markdown", "md"));
+  /** Strict processing mode. */
   public static final DataKey<Boolean> PROCESSING_MODE = new DataKey<>("PROCESSING_MODE", false);
 
   /**
@@ -90,6 +91,7 @@ public class MarkdownReader implements XMLReader {
     features.put("http://lwdita.org/sax/features/specialization-concept", DitaRenderer.SPECIALIZATION_CONCEPT);
     features.put("http://lwdita.org/sax/features/specialization-task", DitaRenderer.SPECIALIZATION_TASK);
     features.put("http://lwdita.org/sax/features/specialization-reference", DitaRenderer.SPECIALIZATION_REFERENCE);
+    features.put("http://lwdita.org/sax/features/wiki", DitaRenderer.WIKI);
     features.put("http://lwdita.org/sax/features/fix-root-heading", DitaRenderer.FIX_ROOT_HEADING);
     features.put("http://lwdita.org/sax/features/map", DitaRenderer.MAP);
     FEATURES = Collections.unmodifiableMap(features);
@@ -131,7 +133,7 @@ public MarkdownReader() {
         .set(TablesExtension.DISCARD_EXTRA_COLUMNS, true)
         .set(TablesExtension.HEADER_SEPARATOR_COLUMN_MATCH, true)
         .set(DitaRenderer.SPECIALIZATION, true)
-        .set(DitaRenderer.WIKI, true)
+        .set(DitaRenderer.ID_FROM_YAML, true)
     );
   }
 

src/main/plugin.xml

@@ -48,6 +48,7 @@
     <parser format="mditamap" class="com.elovirta.dita.markdown.MDitamapReader"/>
     <parser format="wikidocs" class="com.elovirta.dita.markdown.MarkdownReader">
       <feature name="http://lwdita.org/sax/features/shortdesc-paragraph" value="true"/>
+      <feature name="http://lwdita.org/sax/features/wiki" value="true"/>
     </parser>
   </feature>
   <extension-point id="dita.xsl.markdown" name="Markdown overrides XSLT import"/>

src/test/java/com/elovirta/dita/markdown/MarkdownReaderTest.java

@@ -136,10 +136,24 @@ public void test_missingHeader(String file) throws Exception {
         new MutableDataSet()
           .set(Parser.EXTENSIONS, singletonList(YamlFrontMatterExtension.create()))
           .set(DitaRenderer.FIX_ROOT_HEADING, true)
+          .set(DitaRenderer.ID_FROM_YAML, true)
+          .set(DitaRenderer.WIKI, true)
       );
     final TestErrorHandler errorHandler = new TestErrorHandler();
     reader.setErrorHandler(errorHandler);
 
+    run(getSrc() + file, getExp() + "wiki/" + file.replaceAll("\\.md$", ".dita"));
+
+    assertEquals(0, errorHandler.warnings.size());
+  }
+
+  @ParameterizedTest
+  @ValueSource(strings = { "missing_root_header.md", "missing_root_header_with_yaml.md" })
+  public void test_emptyHeader(String file) throws Exception {
+    reader = new MarkdownReader();
+    final TestErrorHandler errorHandler = new TestErrorHandler();
+    reader.setErrorHandler(errorHandler);
+
     run(file);
 
     assertEquals(1, errorHandler.warnings.size());

src/test/java/com/elovirta/dita/utils/AbstractReaderTest.java

@@ -65,7 +65,7 @@ public void run(final String input) throws Exception {
     run(getSrc() + input, getExp() + input.replaceAll("\\.(md|html)$", ".dita"));
   }
 
-  void run(final String input, final String expFile) throws Exception {
+  protected void run(final String input, final String expFile) throws Exception {
     final Document act;
     try (final InputStream in = getClass().getResourceAsStream("/" + input)) {
       act = db.newDocument();

src/test/resources/dita/missing_root_header.dita

@@ -1,7 +1,7 @@
 <topic xmlns:ditaarch="http://dita.oasis-open.org/architecture/2005/" class="- topic/topic "
   specializations="@props/audience @props/deliveryTarget @props/otherprops @props/platform @props/product"
   id="missing-root-header" ditaarch:DITAArchVersion="2.0">
-  <title class="- topic/title ">missing root header</title>
+  <title class="- topic/title "></title>
   <body class="- topic/body ">
     <p class="- topic/p ">Root topic content.</p>
   </body>

src/test/resources/dita/missing_root_header_with_yaml.dita

@@ -1,6 +1,6 @@
 <topic xmlns:ditaarch="http://dita.oasis-open.org/architecture/2005/" class="- topic/topic "
   specializations="@props/audience @props/deliveryTarget @props/otherprops @props/platform @props/product"
-  id="yaml-title" ditaarch:DITAArchVersion="2.0">
+  id="yaml-id" ditaarch:DITAArchVersion="2.0">
   <title class="- topic/title ">YAML Title</title>
   <body class="- topic/body ">
     <p class="- topic/p ">Root topic content.</p>

src/test/resources/dita/wiki/missing_root_header.dita

@@ -0,0 +1,16 @@
+<topic xmlns:ditaarch="http://dita.oasis-open.org/architecture/2005/" class="- topic/topic "
+  specializations="@props/audience @props/deliveryTarget @props/otherprops @props/platform @props/product"
+  id="missing-root-header" ditaarch:DITAArchVersion="2.0">
+  <title class="- topic/title ">missing root header</title>
+  <body class="- topic/body ">
+    <p class="- topic/p ">Root topic content.</p>
+  </body>
+  <topic class="- topic/topic "
+    specializations="@props/audience @props/deliveryTarget @props/otherprops @props/platform @props/product"
+    id="nested-topic" ditaarch:DITAArchVersion="2.0">
+    <title class="- topic/title ">Nested Topic</title>
+    <body class="- topic/body ">
+      <p class="- topic/p ">Nested topic content.</p>
+    </body>
+  </topic>
+</topic>

src/test/resources/dita/wiki/missing_root_header_with_yaml.dita

@@ -0,0 +1,8 @@
+<topic xmlns:ditaarch="http://dita.oasis-open.org/architecture/2005/" class="- topic/topic "
+  specializations="@props/audience @props/deliveryTarget @props/otherprops @props/platform @props/product"
+  id="yaml-id" ditaarch:DITAArchVersion="2.0">
+  <title class="- topic/title ">YAML Title</title>
+  <body class="- topic/body ">
+    <p class="- topic/p ">Root topic content.</p>
+  </body>
+</topic>

src/test/resources/dita/yaml.dita

@@ -1,6 +1,6 @@
 <topic xmlns:ditaarch="http://dita.oasis-open.org/architecture/2005/" class="- topic/topic "
   specializations="@props/audience @props/deliveryTarget @props/otherprops @props/platform @props/product"
-  id="yaml-header" ditaarch:DITAArchVersion="2.0">
+  id="extended-profile" ditaarch:DITAArchVersion="2.0">
   <title class="- topic/title ">YAML Header</title>
   <prolog class="- topic/prolog ">
     <author class="- topic/author ">Author One</author>
@@ -22,7 +22,6 @@
     <data class="- topic/data " name="bar" value="bar"/>
     <data class="- topic/data " name="bar" value="baz"/>
     <data class="- topic/data " name="foo" value="foo"/>
-    <data class="- topic/data " name="id" value="extended-profile"/>
     <data class="- topic/data " name="tags" value="nothing"/>
     <data class="- topic/data " name="tags" value="nothingness"/>
     <data class="- topic/data " name="title" value="'This is the title: it contains a colon'"/>

src/test/resources/output/ast/missing_root_header.xml

@@ -1 +1 @@
-<?xml version="1.0" encoding="UTF-8"?><pandoc><div><header id="missing-root-header" level="1">missing root header</header><div><para>Root topic content.</para></div><div id="nested-topic"><header id="nested-topic" level="2">Nested Topic</header><div><para>Nested topic content.</para></div></div></div></pandoc>
+<?xml version="1.0" encoding="UTF-8"?><pandoc><div><header id="missing-root-header" level="1"/><div><para>Root topic content.</para></div><div id="nested-topic"><header id="nested-topic" level="2">Nested Topic</header><div><para>Nested topic content.</para></div></div></div></pandoc>

src/test/resources/output/ast/missing_root_header_with_yaml.xml

@@ -1 +1 @@
-<?xml version="1.0" encoding="UTF-8"?><pandoc><div><header id="yaml-title" level="1">YAML Title</header><div><para>Root topic content.</para></div></div></pandoc>
+<?xml version="1.0" encoding="UTF-8"?><pandoc><div><header id="yaml-id" level="1">YAML Title</header><div><para>Root topic content.</para></div></div></pandoc>

src/test/resources/output/ast/yaml.xml

@@ -1 +1 @@
-<?xml version="1.0" encoding="UTF-8"?><pandoc><div><header id="yaml-header" level="1">YAML Header</header><div/></div></pandoc>
+<?xml version="1.0" encoding="UTF-8"?><pandoc><div><header id="extended-profile" level="1">YAML Header</header><div/></div></pandoc>

src/test/resources/output/markdown/missing_root_header.md

@@ -1,4 +1,4 @@
-# missing root header {#missing-root-header}
+#  {#missing-root-header}
 
 Root topic content.
 

src/test/resources/output/markdown/missing_root_header_with_yaml.md

@@ -1,4 +1,4 @@
-# YAML Title {#yaml-title}
+# YAML Title {#yaml-id}
 
 Root topic content.
 

src/test/resources/output/markdown/yaml.md

@@ -1,2 +1,2 @@
-# YAML Header {#yaml-header}
+# YAML Header {#extended-profile}