Class MarkdownParser

java.lang.Object

org.apache.maven.doxia.parser.AbstractParser

org.apache.maven.doxia.parser.AbstractTextParser

org.apache.maven.doxia.module.markdown.MarkdownParser

All Implemented Interfaces:

MacroExecutor, Markup, TextMarkup, Parser

@Singleton
@Named("markdown")
public class MarkdownParser
extends AbstractTextParser
implements TextMarkup

Implementation of Parser for Markdown documents.

Defers effective parsing to the flexmark-java library, which generates HTML content then delegates parsing of this content to a slightly modified Doxia Xhtml5 parser. (before 1.8, the PegDown library was used)

Since:

1.3

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MarkdownParser.MarkdownHtmlParser	Internal parser for HTML generated by the Markdown library.

Field Summary

Fields

Modifier and Type	Field	Description
private static final com.vladsch.flexmark.html.HtmlRenderer	FLEXMARK_HTML_RENDERER	Flexmark's HTML renderer (its output will be re-parsed and converted to Sink events)
private static final com.vladsch.flexmark.parser.Parser	FLEXMARK_METADATA_PARSER	Flexmark's Markdown Metadata parser
private static final com.vladsch.flexmark.parser.Parser	FLEXMARK_PARSER	Flexmark's Markdown parser (one static instance fits all)
private static final Pattern	METADATA_ENTRY_PATTERN	Regex that captures the key and value of a multimarkdown-style metadata entry.
private static final Pattern	METADATA_SECTION_PATTERN	Regex that identifies a multimarkdown-style metadata section at the start of the document In order to ensure that we have minimal risk of false positives when slurping metadata sections, the first key in the metadata section must be one of these standard keys or else the entire metadata section is ignored.
private MarkdownParser.MarkdownHtmlParser	parser	The parser of the HTML produced by Flexmark, that we will use to convert this HTML to Sink events
private static final Pattern	SELF_CLOSING_HTML_TAG	Matches a self-closing HTML tag, e.g.

Fields inherited from interface Markup

COLON, EOL, EQUAL, GREATER_THAN, LEFT_CURLY_BRACKET, LEFT_SQUARE_BRACKET, LESS_THAN, MINUS, PLUS, QUOTE, RIGHT_CURLY_BRACKET, RIGHT_SQUARE_BRACKET, SEMICOLON, SLASH, SPACE, STAR

Fields inherited from interface Parser

TXT_TYPE, UNKNOWN_TYPE, XML_TYPE

Fields inherited from interface TextMarkup

PIPE

Constructor Summary

Constructors

Constructor	Description
MarkdownParser()

Method Summary

Modifier and Type	Method	Description
private static String	closeSelfClosingNonVoidHtmlTags(String html)	Raw HTML embedded in a Markdown source (e.g.
(package private) static String	normalizeMultilineValue(String value)
void	parse(Reader source, Sink sink, String reference)	Parses the given source model and emits Doxia events into the given sink.
private boolean	processMetadataForHtml(StringBuilder html, StringBuilder source)
(package private) String	toXhtml(Reader source)	uses flexmark-java library to parse content and generate HTML output.
private String	toXhtml(String html)
private boolean	writeHtmlMetadata(StringBuilder html, String key, List<String> values)
private boolean	writeHtmlMetadata(StringBuilder html, Map<String, List<String>> data)

Methods inherited from class AbstractTextParser

getType

Methods inherited from class AbstractParser

addSinkWrapperFactory, doxiaVersion, executeMacro, getBasedir, getMacroManager, getSinkWrapperFactories, getWrappedSink, init, isEmitAnchorsForIndexableEntries, isEmitComments, isSecondParsing, parse, parse, parse, setEmitAnchorsForIndexableEntries, setEmitComments, setMacroExecutor, setSecondParsing

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

METADATA_SECTION_PATTERN

private static final Pattern METADATA_SECTION_PATTERN

Regex that identifies a multimarkdown-style metadata section at the start of the document In order to ensure that we have minimal risk of false positives when slurping metadata sections, the first key in the metadata section must be one of these standard keys or else the entire metadata section is ignored.

See Also:

• Multimarkdown Metadata

METADATA_ENTRY_PATTERN

private static final Pattern METADATA_ENTRY_PATTERN

Regex that captures the key and value of a multimarkdown-style metadata entry. Group 1 captures the key, group 2 captures the value. Multivalues are not supported in the syntax! Multiline values need to be normalized

See Also:

• Multimarkdown Metadata

SELF_CLOSING_HTML_TAG

private static final Pattern SELF_CLOSING_HTML_TAG

Matches a self-closing HTML tag, e.g. <object type="image/svg+xml" data="x.svg"/>. Group 1 is the tag name, group 2 is the raw attribute string. Quoted attribute values are matched as a whole so a / inside one (e.g. a data="a/b" attribute) is not mistaken for the closing slash.

parser

@Inject
private MarkdownParser.MarkdownHtmlParser parser

The parser of the HTML produced by Flexmark, that we will use to convert this HTML to Sink events

FLEXMARK_PARSER

private static final com.vladsch.flexmark.parser.Parser FLEXMARK_PARSER

Flexmark's Markdown parser (one static instance fits all)

FLEXMARK_METADATA_PARSER

private static final com.vladsch.flexmark.parser.Parser FLEXMARK_METADATA_PARSER

Flexmark's Markdown Metadata parser

FLEXMARK_HTML_RENDERER

private static final com.vladsch.flexmark.html.HtmlRenderer FLEXMARK_HTML_RENDERER

Flexmark's HTML renderer (its output will be re-parsed and converted to Sink events)

Constructor Details

MarkdownParser

public MarkdownParser()

Method Details

parse

public void parse(Reader source,
 Sink sink,
 String reference)
           throws ParseException

Description copied from interface: Parser

Parses the given source model and emits Doxia events into the given sink.

Specified by:

parse in interface Parser

Parameters:

source - not null reader that provides the source document.

sink - A sink that consumes the Doxia events.

reference - a string identifying the source (for file based documents the source file path)

Throws:

ParseException - if the model could not be parsed.

processMetadataForHtml

private boolean processMetadataForHtml(StringBuilder html,
 StringBuilder source)

normalizeMultilineValue

static String normalizeMultilineValue(String value)

writeHtmlMetadata

private boolean writeHtmlMetadata(StringBuilder html,
 Map<String, List<String>> data)

writeHtmlMetadata

private boolean writeHtmlMetadata(StringBuilder html,
 String key,
 List<String> values)

toXhtml

String toXhtml(Reader source)
        throws IOException

uses flexmark-java library to parse content and generate HTML output.

Parameters:

source - the Markdown source

Returns:

HTML content generated by flexmark-java

Throws:

IOException - passed through

toXhtml

private String toXhtml(String html)

closeSelfClosingNonVoidHtmlTags

private static String closeSelfClosingNonVoidHtmlTags(String html)

Raw HTML embedded in a Markdown source (e.g. <object type="image/svg+xml" data="x.svg"/>) is passed through untouched by flexmark. HTML5 has no such thing as a self-closing tag outside the fixed list of void elements (br, img, hr, ...): for every other element the trailing slash is simply ignored, so <object .../> is an open tag with no matching close. Left as-is, Jsoup.parse(String) then nests all following content inside that dangling <object>, and the eventual close tag is emitted only once the surrounding block ends - silently hiding everything in between (browsers treat it as <object> fallback content). Close such tags explicitly before jsoup ever sees them, so the element does not swallow its siblings.

Parameters:

html - the HTML generated by rendering the Markdown document

Returns:

the same HTML with self-closing non-void tags rewritten to an explicit open/close pair