MarkupLine.java

/*
 * Portions of this software was developed by employees of the National Institute
 * of Standards and Technology (NIST), an agency of the Federal Government and is
 * being made available as a public service. Pursuant to title 17 United States
 * Code Section 105, works of NIST employees are not subject to copyright
 * protection in the United States. This software may be subject to foreign
 * copyright. Permission in the United States and in foreign countries, to the
 * extent that NIST may hold copyright, to use, copy, modify, create derivative
 * works, and distribute this software and its documentation without fee is hereby
 * granted on a non-exclusive basis, provided that this notice and disclaimer
 * of warranty appears in all copies.
 *
 * THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND, EITHER
 * EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY WARRANTY
 * THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS, ANY IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND FREEDOM FROM
 * INFRINGEMENT, AND ANY WARRANTY THAT THE DOCUMENTATION WILL CONFORM TO THE
 * SOFTWARE, OR ANY WARRANTY THAT THE SOFTWARE WILL BE ERROR FREE.  IN NO EVENT
 * SHALL NIST BE LIABLE FOR ANY DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT,
 * INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM,
 * OR IN ANY WAY CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
 * CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY PERSONS OR
 * PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS SUSTAINED FROM, OR AROSE OUT
 * OF THE RESULTS OF, OR USE OF, THE SOFTWARE OR SERVICES PROVIDED HEREUNDER.
 */

package gov.nist.secauto.metaschema.core.datatype.markup;

import com.vladsch.flexmark.html.HtmlRenderer;
import com.vladsch.flexmark.parser.Parser;
import com.vladsch.flexmark.util.ast.Block;
import com.vladsch.flexmark.util.ast.Document;
import com.vladsch.flexmark.util.ast.Node;
import com.vladsch.flexmark.util.data.DataSet;
import com.vladsch.flexmark.util.data.MutableDataSet;
import com.vladsch.flexmark.util.misc.Extension;

import gov.nist.secauto.metaschema.core.datatype.markup.flexmark.FlexmarkConfiguration;
import gov.nist.secauto.metaschema.core.datatype.markup.flexmark.FlexmarkFactory;
import gov.nist.secauto.metaschema.core.datatype.markup.flexmark.SuppressPTagExtension;

import java.util.Collection;
import java.util.LinkedList;
import java.util.List;

import edu.umd.cs.findbugs.annotations.NonNull;

public class MarkupLine
    extends AbstractMarkupString<MarkupLine> {

  @NonNull
  private static final DataSet FLEXMARK_CONFIG = newParserOptions();

  @NonNull
  private static final FlexmarkFactory FLEXMARK_FACTORY = new FlexmarkFactory(FLEXMARK_CONFIG);

  @SuppressWarnings("null")
  @NonNull
  protected static DataSet newParserOptions() {
    MutableDataSet options = new MutableDataSet();
    // disable inline HTML
    options.set(Parser.HTML_BLOCK_PARSER, false);
    // disable list processing
    options.set(Parser.LIST_BLOCK_PARSER, false);
    options.set(HtmlRenderer.SUPPRESS_HTML_BLOCKS, true);

    Collection<Extension> currentExtensions = Parser.EXTENSIONS.get(FlexmarkConfiguration.FLEXMARK_CONFIG);
    List<Extension> extensions = new LinkedList<>(currentExtensions);
    extensions.add(SuppressPTagExtension.create());
    Parser.EXTENSIONS.set(options, extensions);

    return FlexmarkConfiguration.newFlexmarkConfig(options);
  }

  @NonNull
  public static MarkupLine fromHtml(@NonNull String html) {
    return new MarkupLine(
        parseHtml(html, FLEXMARK_FACTORY.getFlexmarkHtmlConverter(), FLEXMARK_FACTORY.getMarkdownParser()));
  }

  @NonNull
  public static MarkupLine fromMarkdown(@NonNull String markdown) {
    return new MarkupLine(parseMarkdown(markdown, FLEXMARK_FACTORY.getMarkdownParser()));
  }

  @Override
  public FlexmarkFactory getFlexmarkFactory() {
    return FLEXMARK_FACTORY;
  }

  protected MarkupLine(@NonNull Document astNode) {
    super(astNode);
    Node child = astNode.getFirstChild();
    if (child instanceof Block && child.getNext() != null) {
      throw new IllegalStateException("multiple blocks not allowed");
    } // else empty markdown
  }

  @Override
  public MarkupLine copy() {
    // TODO: find a way to do a deep copy
    // this is a shallow copy that uses the same underlying Document object
    return new MarkupLine(getDocument());
  }

  @Override
  public boolean isBlock() {
    return false;
  }
}