/**
* @license Copyright (c) 2003-2026, CKSource Holding sp. z o.o. All rights reserved.
* For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-licensing-options
*/
/**
* @module markdown-gfm/gfmdataprocessor
*/
import { type DataProcessor, type ViewDocument, type ViewDocumentFragment, type MatcherPattern } from "@ckeditor/ckeditor5-engine";
/**
* This data processor implementation uses GitHub Flavored Markdown as input/output data.
*
* See the {@glink features/markdown Markdown output} guide to learn more on how to enable it.
*/
export declare class MarkdownGfmDataProcessor implements DataProcessor {
	/**
	* HTML data processor used to process HTML produced by the Markdown-to-HTML converter and the other way.
	*/
	private _htmlDP;
	/**
	* Helper for converting Markdown to HTML.
	*/
	private _markdown2html;
	/**
	* Helper for converting HTML to Markdown.
	*/
	private _html2markdown;
	/**
	* Creates a new instance of the Markdown data processor class.
	*/
	constructor(document: ViewDocument);
	/**
	* Keeps the specified element in the output as HTML. This is useful if the editor contains
	* features producing HTML that is not a part of the Markdown standard.
	*
	* By default, all HTML tags are removed.
	*
	* @param element The element name to be kept.
	*/
	keepHtml(element: keyof HTMLElementTagNameMap): void;
	/**
	* Converts the provided Markdown string to a view tree.
	*
	* @param data A Markdown string.
	* @returns The converted view element.
	*/
	toView(data: string): ViewDocumentFragment;
	/**
	* Converts the provided {@link module:engine/view/documentfragment~ViewDocumentFragment} to data format – in this
	* case to a Markdown string.
	*
	* @returns Markdown string.
	*/
	toData(viewFragment: ViewDocumentFragment): string;
	/**
	* Registers a {@link module:engine/view/matcher~MatcherPattern} for view elements whose content should be treated as raw data
	* and not processed during the conversion from Markdown to view elements.
	*
	* The raw data can be later accessed by a
	* {@link module:engine/view/element~ViewElement#getCustomProperty custom property of a view element} called `"$rawContent"`.
	*
	* @param pattern The pattern matching all view elements whose content should
	* be treated as raw data.
	*/
	registerRawContentMatcher(pattern: MatcherPattern): void;
	/**
	* This method does not have any effect on the data processor result. It exists for compatibility with the
	* {@link module:engine/dataprocessor/dataprocessor~DataProcessor `DataProcessor` interface}.
	*/
	useFillerType(): void;
}