Add XhtmlToMarkdown library

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/xhtml/XhtmlToMarkdownConverter.java

@@ -0,0 +1,334 @@
+package org.hl7.fhir.utilities.xhtml;
+
+import org.hl7.fhir.utilities.DebugUtilities;
+import org.hl7.fhir.utilities.Utilities;
+
+public class XhtmlToMarkdownConverter {
+
+  public String convert(XhtmlNode x) {
+    StringBuilder b = new StringBuilder();
+    convert(b, x);
+    return b.toString();
+  }
+
+  private void convert(StringBuilder b, XhtmlNode x) {
+    for (XhtmlNode c : x.getChildNodes()) {
+      if (c.getNodeType() == NodeType.Text) {
+        paragraph(b, c, true, false);
+      } else if (c.getName() != null) {
+        convertNode(b, c);
+      }
+    }
+
+  }
+
+  public void convertNode(StringBuilder b, XhtmlNode c) throws Error {
+    switch (c.getName()) {
+    case "p":
+      paragraph(b, c, true, false);
+      break;
+    case "hr":
+      b.append("-------\r\n");
+      break;
+    case "a":
+      paragraph(b, c, true, false);
+      break;
+    case "h1":
+      b.append("# "+c.allText());
+      break;
+    case "h2":
+      b.append("## "+c.allText());
+      break;
+    case "h3":
+      b.append("### "+c.allText());
+      break;
+    case "h4":
+      b.append("#### "+c.allText());
+      break;
+    case "h5":
+      b.append("##### "+c.allText());
+      break;
+    case "h6":
+      b.append("###### "+c.allText());
+      break;
+    case "strong":
+    case "em":
+    case "i":
+    case "span":
+    case "img":
+    case "br":
+    case "wbr":
+    case "code":
+    case "del":
+    case "sup":
+    case "sub":
+    case "u":
+    case "b":
+      paragraph(b, c, true, false);
+      break;
+    case "div":
+      convert(b, c);
+      break;
+    case "ul":
+      convertUL(b, c);
+      break;
+    case "li":
+      convertLI(b, c);
+      break;
+    case "ol":
+      convertOL(b, c);
+      break;
+    case "table":
+    case "tbody":
+      convertTable(b, c);
+      break;
+    case "iframe":
+      convertIFrame(b, c);
+      break;
+    case "form":
+    case "select":
+    case "input":
+    case "textarea":
+    case "option":
+      convertForm(b, c);
+      break;
+    case "label":
+    case "cite":
+      convertLabel(b, c);
+      break;
+    case "figure":
+    case "figcaption":
+      convert(b, c);
+      break;
+    case "dl":
+    case "tt":
+      convertDL(b, c);
+      break;
+    case "blockquote":
+      b.append("\r\n");
+      b.append("> ");
+      paragraph(b, c, false, true);
+      b.append("\r\n");
+      break;
+    case "pre":
+      b.append("````\r\n");
+      convert(b, c);
+      b.append("\r\n````\r\n");
+      break;
+    default:
+      throw new Error("not done yet: "+c.getName());
+    }
+  }
+
+  private void convertDL(StringBuilder b, XhtmlNode c) {
+    DebugUtilities.breakpoint();   
+  }
+
+  private void convertIFrame(StringBuilder b, XhtmlNode c) {
+   b.append(c.toString());
+  }
+
+  private void convertForm(StringBuilder b, XhtmlNode c) {
+    b.append(c.toString());
+  }
+
+  private void convertLabel(StringBuilder b, XhtmlNode c) {
+    convert(b, c);
+  }
+
+  private void convertTable(StringBuilder b, XhtmlNode x) {
+    boolean first = true;
+    for (XhtmlNode c : x.getChildNodes()) {
+      if ("tbody".equals(c.getName())) {
+        convertTable(b, c);
+      } else if ("tr".equals(c.getName())) {
+        if (first) {
+          first = false;
+          b.append("\r\n");
+        }
+        boolean header = false;
+        for (XhtmlNode g : c.getChildNodes()) {
+          if (Utilities.existsInList(g.getName(), "td", "th")) {
+            if ("th".equals(g.getName())) {
+              header = true;
+            }
+            b.append("|");
+            paragraph(b, g, false, true);
+          }
+        }
+        b.append("\r\n");
+        if (header) {
+          for (XhtmlNode g : c.getChildNodes()) {
+            if (Utilities.existsInList(g.getName(), "td", "th")) {
+              b.append("|---");
+            }
+          }
+          b.append("\r\n");
+        }
+      }
+    }
+
+  }
+
+  private void convertUL(StringBuilder b, XhtmlNode x) {
+
+    for (XhtmlNode c : x.getChildNodes()) {
+      if ("li".equals(c.getName())) {
+        b.append("* ");
+        paragraph(b, c, true, true);
+      }
+    }
+  }
+
+  private void convertLI(StringBuilder b, XhtmlNode x) {
+    b.append("* ");
+    paragraph(b, x, true, true);
+  }
+
+  private void convertOL(StringBuilder b, XhtmlNode x) {
+
+    for (XhtmlNode c : x.getChildNodes()) {
+      if ("li".equals(c.getName())) {
+        b.append("1. ");
+        paragraph(b, c, true, true);
+      }
+    }
+  }
+
+  private void paragraph(StringBuilder b, XhtmlNode x, boolean mark, boolean trim) {
+    if (x.getNodeType() == NodeType.Text) {
+      addText(b, trim, x.getContent());
+    } else if (x.getName() != null && !Utilities.existsInList(x.getName(), "p", "li", "td", "th", "blockquote")) {
+      part(b, x, trim);
+    } else {
+      for (XhtmlNode c : x.getChildNodes()) {
+        if (c.getNodeType() == NodeType.Text) {
+          addText(b, trim, c.getContent());
+        } else {
+          part(b, c, trim);
+        }
+      }
+      if (mark) {
+        b.append("\r\n");
+      }
+    }
+  }
+
+  private void addText(StringBuilder b, boolean trim, String content) {
+    if (trim) {
+      content = content.trim();
+    }
+    if (!Utilities.noString(content)) {
+      b.append(content);
+    }
+
+  }
+
+  public void part(StringBuilder b, XhtmlNode c, boolean trim) throws Error {
+    switch (c.getName()) {
+    case "a":
+      b.append("[");
+      process(b, c, trim);
+      b.append("](");
+      b.append(c.getAttribute("href"));
+      b.append(")");
+      break;
+    case "img":
+      b.append("![");
+      b.append(c.allText());
+      b.append("](");
+      b.append(c.getAttribute("src"));
+      b.append(")");
+      break;
+    case "code":
+    case "pre":
+      b.append("```");
+      process(b, c, trim);
+      b.append("```");
+    case "strong":
+    case "em":
+    case "b":
+      b.append("**");
+      process(b, c, trim);
+      b.append("**");
+      break;
+    case "u":
+      b.append("_");
+      process(b, c, trim);
+      b.append("_");
+      break;
+    case "i":
+      b.append("*");
+      process(b, c, trim);
+      b.append("*");
+      break;
+    case "span":
+    case "sup":
+    case "sub":
+    case "s":
+      process(b, c, trim);
+      break;
+    case "div":
+    case "h1":
+    case "h2":
+    case "h3":
+    case "h4":
+    case "h5":
+    case "h6":
+    case "table":
+    case "cite":
+      b.append("\r\n");
+      convertNode(b, c);
+      break;
+    case "p":
+      if (!trim) {
+        b.append("\r\n\r\n");
+      }
+      process(b, c, trim);
+      break;
+    case "ul":
+      b.append("\r\n");
+      convertUL(b, c);
+      break;
+    case "li":
+      b.append("\r\n");
+      convertLI(b, c);
+      break;
+    case "ol":
+      b.append("\r\n");
+      convertOL(b, c);
+      break;
+    case "blockquote":
+      b.append("\r\n");
+      b.append("> ");
+      paragraph(b, c, false, trim);
+      b.append("\r\n");
+      break;
+    case "del":
+    case "dl":
+    case "dd":
+    case "tt":
+      process(b, c, trim);
+    case "br":
+      b.append("\r\n");
+      process(b, c, trim);
+      break;
+    case "wbr":
+      b.append("\r\n");
+      break;
+    default:
+      throw new Error("part not done yet: "+c.getName());
+    }
+  }
+
+  private void process(StringBuilder b, XhtmlNode x, boolean trim) {
+    for (XhtmlNode c : x.getChildNodes()) {
+      if (c.getNodeType() == NodeType.Text) {
+        b.append(c.getContent());
+      } else if (c.getName() != null) {
+        part(b, c, trim);
+      }
+    }
+  }
+
+}