@Override
protected String doInBackground(String... strings) {
    Parser parser = Parser.builder(OPTIONS)
            .extensions(EXTENSIONS)
            .build();

    HtmlRenderer renderer = HtmlRenderer.builder(OPTIONS)
            .escapeHtml(true)
            .attributeProviderFactory(new IndependentAttributeProviderFactory() {
                @Override
                public AttributeProvider create(NodeRendererContext context) {
                    return new CustomAttributeProvider();
                }
            })
            .nodeRendererFactory(new NodeRendererFactoryImpl())
            .extensions(EXTENSIONS)
            .build();

    return renderer.render(parser.parse(strings[0]));
}
 

private String parseBuildAndRender(String text) {
    Parser parser = Parser.builder(OPTIONS)
            .extensions(EXTENSIONS)
            .build();

    HtmlRenderer renderer = HtmlRenderer.builder(OPTIONS)
            .escapeHtml(mEscapeHtml)
            .attributeProviderFactory(new IndependentAttributeProviderFactory() {
                @Override
                public AttributeProvider create(NodeRendererContext context) {
                    return new CustomAttributeProvider();
                }
            })
            .nodeRendererFactory(new NodeRendererFactoryImpl())
            .extensions(EXTENSIONS)
            .build();

    return renderer.render(parser.parse(text));
}
 

@Override
public void extend(Builder rendererBuilder, String rendererType) {
	rendererBuilder.attributeProviderFactory(new IndependentAttributeProviderFactory() {
		
		@Override
		public AttributeProvider create(NodeRendererContext context) {
			return new AttributeProvider() {

				@Override
				public void setAttributes(Node node, AttributablePart part, Attributes attributes) {
					if (node instanceof Block) {
						int startOffset = node.getStartOffset();
						int endOffset = node.getEndOffset();
						Node document = node.getDocument();
						if (document != null) {
							int leadingWhitespaces = 0;
							for (int i=startOffset; i<endOffset; i++) {
								if (Character.isWhitespace(document.getChars().charAt(i))) {
									leadingWhitespaces++;
								} else {
									break;
								}
							}
							int trailingWhitespaces = 0;
							for (int i=endOffset-1; i>=startOffset; i--) {
								if (Character.isWhitespace(document.getChars().charAt(i))) {
									trailingWhitespaces++;
								} else {
									break;
								}
							}
							attributes.addValue("data-" + DATA_START_ATTRIBUTE, String.valueOf(startOffset+leadingWhitespaces));
							attributes.addValue("data-" + DATA_END_ATTRIBUTE, String.valueOf(endOffset-trailingWhitespaces));
						}
					}
				}
				
			};
		}
	});
}