/**
* @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 engine/dataprocessor/dataprocessor
*/
import { type ViewDocumentFragment } from "../view/documentfragment.js";
import type { MatcherPattern } from "../view/matcher.js";
/**
* The data processor interface. It should be implemented by actual data processors.
*
* Each data processor implements a certain format of the data. For example, {@glink features/markdown Markdown data processor}
* will convert the data (a Markdown string) to a {@link module:engine/view/documentfragment~ViewDocumentFragment document fragment}
* and back.
*
* **Note:** While the CKEditor 5 architecture supports changing the data format, in most scenarios we do recommend sticking to
* the default format which is HTML (supported by the {@link module:engine/dataprocessor/htmldataprocessor~HtmlDataProcessor}).
* HTML remains [the best standard for rich-text data](https://medium.com/content-uneditable/a-standard-for-rich-text-data-4b3a507af552).
*
* And please do remember – using Markdown [does not automatically make your
* application/website secure](https://github.com/ckeditor/ckeditor5-markdown-gfm/issues/16#issuecomment-375752994).
*/
export interface DataProcessor {
	/**
	* Converts a {@link module:engine/view/documentfragment~ViewDocumentFragment document fragment} to data.
	*
	* @param viewFragment The document fragment to be processed.
	*/
	toData(viewFragment: ViewDocumentFragment): string;
	/**
	* Converts the data to a {@link module:engine/view/documentfragment~ViewDocumentFragment document fragment}.
	*
	* @param data The data to be processed.
	*/
	toView(data: string): ViewDocumentFragment;
	/**
	* Registers a {@link module:engine/view/matcher~MatcherPattern} for view elements whose content should be treated as raw data
	* and its content should be converted to a
	* {@link module:engine/view/element~ViewElement#getCustomProperty custom property of a view element} called `"$rawContent"` while
	* converting {@link #toView to view}.
	*
	* @param pattern Pattern matching all view elements whose content should be treated as plain text.
	*/
	registerRawContentMatcher(pattern: MatcherPattern): void;
	/**
	* If the processor is set to use marked fillers, it will insert `&nbsp;` fillers wrapped in `<span>` elements
	* (`<span data-cke-filler="true">&nbsp;</span>`) instead of regular `&nbsp;` characters.
	*
	* This mode allows for more precise handling of block fillers (so they do not leak into the editor content) but bloats the
	* editor data with additional markup.
	*
	* This mode may be required by some features and will be turned on by them automatically.
	*
	* @param type Whether to use the default or marked `&nbsp;` block fillers.
	*/
	useFillerType(type: "default" | "marked"): void;
	/**
	* If `false`, comment nodes will be converted to `$comment`. Otherwise comment nodes are ignored.
	*/
	skipComments?: boolean;
}