polygerrit-ui/app/elements/shared/gr-linked-text/link-text-parser.ts - gerrit - Git at Google

 /**
  * @license
  * Copyright (C) 2015 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 import 'ba-linkify/ba-linkify';
 import {getBaseUrl} from '../../../utils/url-util';
 import {CommentLinkInfo} from '../../../types/common';

 /**
  * Pattern describing URLs with supported protocols.
  */
 const URL_PROTOCOL_PATTERN = /^(.*)(https?:\/\/|mailto:)/;

 export type LinkTextParserCallback = ((text: string, href: string) => void) &
   ((text: null, href: null, fragment: DocumentFragment) => void);

 export interface CommentLinkItem {
   position: number;
   length: number;
   html: HTMLAnchorElement | DocumentFragment;
 }

 export type LinkTextParserConfig = {[name: string]: CommentLinkInfo};

 export class GrLinkTextParser {
   private readonly baseUrl = getBaseUrl();

   /**
    * Construct a parser for linkifying text. Will linkify plain URLs that appear
    * in the text as well as custom links if any are specified in the linkConfig
    * parameter.
    *
    * @constructor
    * @param linkConfig Comment links as specified by the commentlinks field on a
    *     project config.
    * @param callback The callback to be fired when an intermediate parse result
    *     is emitted. The callback is passed text and href strings if a link is to
    *     be created, or a document fragment otherwise.
    * @param removeZeroWidthSpace If true, zero-width spaces will be removed from
    *     R=<email> and CC=<email> expressions.
    */
   constructor(
     private readonly linkConfig: LinkTextParserConfig,
     private readonly callback: LinkTextParserCallback,
     private readonly removeZeroWidthSpace?: boolean
   ) {
     Object.preventExtensions(this);
   }

   /**
    * Emit a callback to create a link element.
    *
    * @param text The text of the link.
    * @param href The URL to use as the href of the link.
    */
   addText(text: string, href: string) {
     if (!text) {
       return;
     }
     this.callback(text, href);
   }

   /**
    * Given the source text and a list of CommentLinkItem objects that were
    * generated by the commentlinks config, emit parsing callbacks.
    *
    * @param text The chuml of source text over which the outputArray items range.
    * @param outputArray The list of items to add resulting from commentlink
    *     matches.
    */
   processLinks(text: string, outputArray: CommentLinkItem[]) {
     this.sortArrayReverse(outputArray);
     const fragment = document.createDocumentFragment();
     let cursor = text.length;

     // Start inserting linkified URLs from the end of the String. That way, the
     // string positions of the items don't change as we iterate through.
     outputArray.forEach(item => {
       // Add any text between the current linkified item and the item added
       // before if it exists.
       if (item.position + item.length !== cursor) {
         fragment.insertBefore(
           document.createTextNode(
             text.slice(item.position + item.length, cursor)
           ),
           fragment.firstChild
         );
       }
       fragment.insertBefore(item.html, fragment.firstChild);
       cursor = item.position;
     });

     // Add the beginning portion at the end.
     if (cursor !== 0) {
       fragment.insertBefore(
         document.createTextNode(text.slice(0, cursor)),
         fragment.firstChild
       );
     }

     this.callback(null, null, fragment);
   }

   /**
    * Sort the given array of CommentLinkItems such that the positions are in
    * reverse order.
    */
   sortArrayReverse(outputArray: CommentLinkItem[]) {
     outputArray.sort((a, b) => b.position - a.position);
   }

   addItem(
     text: string,
     href: string,
     html: null,
     position: number,
     length: number,
     outputArray: CommentLinkItem[]
   ): void;

   addItem(
     text: null,
     href: null,
     html: string,
     position: number,
     length: number,
     outputArray: CommentLinkItem[]
   ): void;

   /**
    * Create a CommentLinkItem and append it to the given output array. This
    * method can be called in either of two ways:
    * - With `text` and `href` parameters provided, and the `html` parameter
    *   passed as `null`. In this case, the new CommentLinkItem will be a link
    *   element with the given text and href value.
    * - With the `html` paremeter provided, and the `text` and `href` parameters
    *   passed as `null`. In this case, the string of HTML will be parsed and the
    *   first resulting node will be used as the resulting content.
    *
    * @param text The text to use if creating a link.
    * @param href The href to use as the URL if creating a link.
    * @param html The html to parse and use as the result.
    * @param  position The position inside the source text where the item
    *     starts.
    * @param length The number of characters in the source text
    *     represented by the item.
    * @param outputArray The array to which the
    *     new item is to be appended.
    */
   addItem(
     text: string | null,
     href: string | null,
     html: string | null,
     position: number,
     length: number,
     outputArray: CommentLinkItem[]
   ): void {
     if (href) {
       const a = document.createElement('a');
       a.setAttribute('href', href);
       a.textContent = text;
       a.target = '_blank';
       a.rel = 'noopener';
       outputArray.push({
         html: a,
         position,
         length,
       });
     } else if (html) {
       // addItem has 2 overloads. If href is null, then html
       // can't be null.
       // TODO(TS): remove if(html) and keep else block without condition
       const fragment = document.createDocumentFragment();
       // Create temporary div to hold the nodes in.
       const div = document.createElement('div');
       div.innerHTML = html;
       while (div.firstChild) {
         fragment.appendChild(div.firstChild);
       }
       outputArray.push({
         html: fragment,
         position,
         length,
       });
     }
   }

   /**
    * Create a CommentLinkItem for a link and append it to the given output
    * array.
    *
    * @param text The text for the link.
    * @param href The href to use as the URL of the link.
    * @param position The position inside the source text where the link
    *     starts.
    * @param length The number of characters in the source text
    *     represented by the link.
    * @param outputArray The array to which the
    *     new item is to be appended.
    */
   addLink(
     text: string,
     href: string,
     position: number,
     length: number,
     outputArray: CommentLinkItem[]
   ) {
     // TODO(TS): remove !test condition
     if (!text || this.hasOverlap(position, length, outputArray)) {
       return;
     }
     if (
       !!this.baseUrl &&
       href.startsWith('/') &&
       !href.startsWith(this.baseUrl)
     ) {
       href = this.baseUrl + href;
     }
     this.addItem(text, href, null, position, length, outputArray);
   }

   /**
    * Create a CommentLinkItem specified by an HTMl string and append it to the
    * given output array.
    *
    * @param html The html to parse and use as the result.
    * @param position The position inside the source text where the item
    *     starts.
    * @param length The number of characters in the source text
    *     represented by the item.
    * @param outputArray The array to which the
    *     new item is to be appended.
    */
   addHTML(
     html: string,
     position: number,
     length: number,
     outputArray: CommentLinkItem[]
   ) {
     if (this.hasOverlap(position, length, outputArray)) {
       return;
     }
     if (
       !!this.baseUrl &&
       html.match(/<a href="\//g) &&
       !new RegExp(`<a href="${this.baseUrl}`, 'g').test(html)
     ) {
       html = html.replace(/<a href="\//g, `<a href="${this.baseUrl}/`);
     }
     this.addItem(null, null, html, position, length, outputArray);
   }

   /**
    * Does the given range overlap with anything already in the item list.
    */
   hasOverlap(position: number, length: number, outputArray: CommentLinkItem[]) {
     const endPosition = position + length;
     for (let i = 0; i < outputArray.length; i++) {
       const arrayItemStart = outputArray[i].position;
       const arrayItemEnd = outputArray[i].position + outputArray[i].length;
       if (
         (position >= arrayItemStart && position < arrayItemEnd) ||
         (endPosition > arrayItemStart && endPosition <= arrayItemEnd) ||
         (position === arrayItemStart && position === arrayItemEnd)
       ) {
         return true;
       }
     }
     return false;
   }

   /**
    * Parse the given source text and emit callbacks for the items that are
    * parsed.
    */
   parse(text?: string | null) {
     if (text) {
       window.linkify(text, {
         callback: (text: string, href?: string) => this.parseChunk(text, href),
       });
     }
   }

   /**
    * Callback that is pased into the linkify function. ba-linkify will call this
    * method in either of two ways:
    * - With both a `text` and `href` parameter provided: this indicates that
    *   ba-linkify has found a plain URL and wants it linkified.
    * - With only a `text` parameter provided: this represents the non-link
    *   content that lies between the links the library has found.
    *
    */
   parseChunk(text: string, href?: string) {
     // TODO(wyatta) switch linkify sequence, see issue 5526.
     if (this.removeZeroWidthSpace) {
       // Remove the zero-width space added in gr-change-view.
       text = text.replace(/^(CC|R)=\u200B/gm, '$1=');
     }

     // If the href is provided then ba-linkify has recognized it as a URL. If
     // the source text does not include a protocol, the protocol will be added
     // by ba-linkify. Create the link if the href is provided and its protocol
     // matches the expected pattern.
     if (href) {
       const result = URL_PROTOCOL_PATTERN.exec(href);
       if (result) {
         const prefixText = result[1];
         if (prefixText.length > 0) {
           // Fix for simple cases from
           // https://bugs.chromium.org/p/gerrit/issues/detail?id=11697
           // When leading whitespace is missed before link,
           // linkify add this text before link as a schema name to href.
           // We suppose, that prefixText just a single word
           // before link and add this word as is, without processing
           // any patterns in it.
           this.parseLinks(prefixText, {});
           text = text.substring(prefixText.length);
           href = href.substring(prefixText.length);
         }
         this.addText(text, href);
         return;
       }
     }
     // For the sections of text that lie between the links found by
     // ba-linkify, we search for the project-config-specified link patterns.
     this.parseLinks(text, this.linkConfig);
   }

   /**
    * Walk over the given source text to find matches for comemntlink patterns
    * and emit parse result callbacks.
    *
    * @param text The raw source text.
    * @param config A comment links specification object.
    */
   parseLinks(text: string, config: LinkTextParserConfig) {
     // The outputArray is used to store all of the matches found for all
     // patterns.
     const outputArray: CommentLinkItem[] = [];
     for (const [configName, linkInfo] of Object.entries(config)) {
       // TODO(TS): it seems, the following line can be rewritten as:
       // if(enabled === false || enabled === 0 || enabled === '')
       // Should be double-checked before update
       // eslint-disable-next-line eqeqeq
       if (linkInfo.enabled != null && linkInfo.enabled == false) {
         continue;
       }
       // PolyGerrit doesn't use hash-based navigation like the GWT UI.
       // Account for this.
       const html = linkInfo.html;
       const link = linkInfo.link;
       if (html) {
         linkInfo.html = html.replace(/<a href="#\//g, '<a href="/');
       } else if (link) {
         if (link[0] === '#') {
           linkInfo.link = link.substr(1);
         }
       }

       const pattern = new RegExp(linkInfo.match, 'g');

       let match;
       let textToCheck = text;
       let susbtrIndex = 0;

       while ((match = pattern.exec(textToCheck))) {
         textToCheck = textToCheck.substr(match.index + match[0].length);
         let result = match[0].replace(
           pattern,
           // Either html or link has a value. Otherwise an exception is thrown
           // in the code below.
           (linkInfo.html || linkInfo.link)!
         );

         if (linkInfo.html) {
           let i;
           // Skip portion of replacement string that is equal to original to
           // allow overlapping patterns.
           for (i = 0; i < result.length; i++) {
             if (result[i] !== match[0][i]) {
               break;
             }
           }
           result = result.slice(i);

           this.addHTML(
             result,
             susbtrIndex + match.index + i,
             match[0].length - i,
             outputArray
           );
         } else if (linkInfo.link) {
           this.addLink(
             match[0],
             result,
             susbtrIndex + match.index,
             match[0].length,
             outputArray
           );
         } else {
           throw Error(
             'linkconfig entry ' +
               configName +
               ' doesn’t contain a link or html attribute.'
           );
         }

         // Update the substring location so we know where we are in relation to
         // the initial full text string.
         susbtrIndex = susbtrIndex + match.index + match[0].length;
       }
     }
     this.processLinks(text, outputArray);
   }
 }
	/**
	* @license
	* Copyright (C) 2015 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	import 'ba-linkify/ba-linkify';
	import {getBaseUrl} from '../../../utils/url-util';
	import {CommentLinkInfo} from '../../../types/common';

	/**
	* Pattern describing URLs with supported protocols.
	*/
	const URL_PROTOCOL_PATTERN = /^(.*)(https?:\/\/\|mailto:)/;

	export type LinkTextParserCallback = ((text: string, href: string) => void) &
	((text: null, href: null, fragment: DocumentFragment) => void);

	export interface CommentLinkItem {
	position: number;
	length: number;
	html: HTMLAnchorElement \| DocumentFragment;
	}

	export type LinkTextParserConfig = {[name: string]: CommentLinkInfo};

	export class GrLinkTextParser {
	private readonly baseUrl = getBaseUrl();

	/**
	* Construct a parser for linkifying text. Will linkify plain URLs that appear
	* in the text as well as custom links if any are specified in the linkConfig
	* parameter.
	*
	* @constructor
	* @param linkConfig Comment links as specified by the commentlinks field on a
	* project config.
	* @param callback The callback to be fired when an intermediate parse result
	* is emitted. The callback is passed text and href strings if a link is to
	* be created, or a document fragment otherwise.
	* @param removeZeroWidthSpace If true, zero-width spaces will be removed from
	* R=<email> and CC=<email> expressions.
	*/
	constructor(
	private readonly linkConfig: LinkTextParserConfig,
	private readonly callback: LinkTextParserCallback,
	private readonly removeZeroWidthSpace?: boolean
	) {
	Object.preventExtensions(this);
	}

	/**
	* Emit a callback to create a link element.
	*
	* @param text The text of the link.
	* @param href The URL to use as the href of the link.
	*/
	addText(text: string, href: string) {
	if (!text) {
	return;
	}
	this.callback(text, href);
	}

	/**
	* Given the source text and a list of CommentLinkItem objects that were
	* generated by the commentlinks config, emit parsing callbacks.
	*
	* @param text The chuml of source text over which the outputArray items range.
	* @param outputArray The list of items to add resulting from commentlink
	* matches.
	*/
	processLinks(text: string, outputArray: CommentLinkItem[]) {
	this.sortArrayReverse(outputArray);
	const fragment = document.createDocumentFragment();
	let cursor = text.length;

	// Start inserting linkified URLs from the end of the String. That way, the
	// string positions of the items don't change as we iterate through.
	outputArray.forEach(item => {
	// Add any text between the current linkified item and the item added
	// before if it exists.
	if (item.position + item.length !== cursor) {
	fragment.insertBefore(
	document.createTextNode(
	text.slice(item.position + item.length, cursor)
	),
	fragment.firstChild
	);
	}
	fragment.insertBefore(item.html, fragment.firstChild);
	cursor = item.position;
	});

	// Add the beginning portion at the end.
	if (cursor !== 0) {
	fragment.insertBefore(
	document.createTextNode(text.slice(0, cursor)),
	fragment.firstChild
	);
	}

	this.callback(null, null, fragment);
	}

	/**
	* Sort the given array of CommentLinkItems such that the positions are in
	* reverse order.
	*/
	sortArrayReverse(outputArray: CommentLinkItem[]) {
	outputArray.sort((a, b) => b.position - a.position);
	}

	addItem(
	text: string,
	href: string,
	html: null,
	position: number,
	length: number,
	outputArray: CommentLinkItem[]
	): void;

	addItem(
	text: null,
	href: null,
	html: string,
	position: number,
	length: number,
	outputArray: CommentLinkItem[]
	): void;

	/**
	* Create a CommentLinkItem and append it to the given output array. This
	* method can be called in either of two ways:
	* - With `text` and `href` parameters provided, and the `html` parameter
	* passed as `null`. In this case, the new CommentLinkItem will be a link
	* element with the given text and href value.
	* - With the `html` paremeter provided, and the `text` and `href` parameters
	* passed as `null`. In this case, the string of HTML will be parsed and the
	* first resulting node will be used as the resulting content.
	*
	* @param text The text to use if creating a link.
	* @param href The href to use as the URL if creating a link.
	* @param html The html to parse and use as the result.
	* @param position The position inside the source text where the item
	* starts.
	* @param length The number of characters in the source text
	* represented by the item.
	* @param outputArray The array to which the
	* new item is to be appended.
	*/
	addItem(
	text: string \| null,
	href: string \| null,
	html: string \| null,
	position: number,
	length: number,
	outputArray: CommentLinkItem[]
	): void {
	if (href) {
	const a = document.createElement('a');
	a.setAttribute('href', href);
	a.textContent = text;
	a.target = '_blank';
	a.rel = 'noopener';
	outputArray.push({
	html: a,
	position,
	length,
	});
	} else if (html) {
	// addItem has 2 overloads. If href is null, then html
	// can't be null.
	// TODO(TS): remove if(html) and keep else block without condition
	const fragment = document.createDocumentFragment();
	// Create temporary div to hold the nodes in.
	const div = document.createElement('div');
	div.innerHTML = html;
	while (div.firstChild) {
	fragment.appendChild(div.firstChild);
	}
	outputArray.push({
	html: fragment,
	position,
	length,
	});
	}
	}

	/**
	* Create a CommentLinkItem for a link and append it to the given output
	* array.
	*
	* @param text The text for the link.
	* @param href The href to use as the URL of the link.
	* @param position The position inside the source text where the link
	* starts.
	* @param length The number of characters in the source text
	* represented by the link.
	* @param outputArray The array to which the
	* new item is to be appended.
	*/
	addLink(
	text: string,
	href: string,
	position: number,
	length: number,
	outputArray: CommentLinkItem[]
	) {
	// TODO(TS): remove !test condition
	if (!text \|\| this.hasOverlap(position, length, outputArray)) {
	return;
	}
	if (
	!!this.baseUrl &&
	href.startsWith('/') &&
	!href.startsWith(this.baseUrl)
	) {
	href = this.baseUrl + href;
	}
	this.addItem(text, href, null, position, length, outputArray);
	}

	/**
	* Create a CommentLinkItem specified by an HTMl string and append it to the
	* given output array.
	*
	* @param html The html to parse and use as the result.
	* @param position The position inside the source text where the item
	* starts.
	* @param length The number of characters in the source text
	* represented by the item.
	* @param outputArray The array to which the
	* new item is to be appended.
	*/
	addHTML(
	html: string,
	position: number,
	length: number,
	outputArray: CommentLinkItem[]
	) {
	if (this.hasOverlap(position, length, outputArray)) {
	return;
	}
	if (
	!!this.baseUrl &&
	html.match(/<a href="\//g) &&
	!new RegExp(`<a href="${this.baseUrl}`, 'g').test(html)
	) {
	html = html.replace(/<a href="\//g, `<a href="${this.baseUrl}/`);
	}
	this.addItem(null, null, html, position, length, outputArray);
	}

	/**
	* Does the given range overlap with anything already in the item list.
	*/
	hasOverlap(position: number, length: number, outputArray: CommentLinkItem[]) {
	const endPosition = position + length;
	for (let i = 0; i < outputArray.length; i++) {
	const arrayItemStart = outputArray[i].position;
	const arrayItemEnd = outputArray[i].position + outputArray[i].length;
	if (
	(position >= arrayItemStart && position < arrayItemEnd) \|\|
	(endPosition > arrayItemStart && endPosition <= arrayItemEnd) \|\|
	(position === arrayItemStart && position === arrayItemEnd)
	) {
	return true;
	}
	}
	return false;
	}

	/**
	* Parse the given source text and emit callbacks for the items that are
	* parsed.
	*/
	parse(text?: string \| null) {
	if (text) {
	window.linkify(text, {
	callback: (text: string, href?: string) => this.parseChunk(text, href),
	});
	}
	}

	/**
	* Callback that is pased into the linkify function. ba-linkify will call this
	* method in either of two ways:
	* - With both a `text` and `href` parameter provided: this indicates that
	* ba-linkify has found a plain URL and wants it linkified.
	* - With only a `text` parameter provided: this represents the non-link
	* content that lies between the links the library has found.
	*
	*/
	parseChunk(text: string, href?: string) {
	// TODO(wyatta) switch linkify sequence, see issue 5526.
	if (this.removeZeroWidthSpace) {
	// Remove the zero-width space added in gr-change-view.
	text = text.replace(/^(CC\|R)=\u200B/gm, '$1=');
	}

	// If the href is provided then ba-linkify has recognized it as a URL. If
	// the source text does not include a protocol, the protocol will be added
	// by ba-linkify. Create the link if the href is provided and its protocol
	// matches the expected pattern.
	if (href) {
	const result = URL_PROTOCOL_PATTERN.exec(href);
	if (result) {
	const prefixText = result[1];
	if (prefixText.length > 0) {
	// Fix for simple cases from
	// https://bugs.chromium.org/p/gerrit/issues/detail?id=11697
	// When leading whitespace is missed before link,
	// linkify add this text before link as a schema name to href.
	// We suppose, that prefixText just a single word
	// before link and add this word as is, without processing
	// any patterns in it.
	this.parseLinks(prefixText, {});
	text = text.substring(prefixText.length);
	href = href.substring(prefixText.length);
	}
	this.addText(text, href);
	return;
	}
	}
	// For the sections of text that lie between the links found by
	// ba-linkify, we search for the project-config-specified link patterns.
	this.parseLinks(text, this.linkConfig);
	}

	/**
	* Walk over the given source text to find matches for comemntlink patterns
	* and emit parse result callbacks.
	*
	* @param text The raw source text.
	* @param config A comment links specification object.
	*/
	parseLinks(text: string, config: LinkTextParserConfig) {
	// The outputArray is used to store all of the matches found for all
	// patterns.
	const outputArray: CommentLinkItem[] = [];
	for (const [configName, linkInfo] of Object.entries(config)) {
	// TODO(TS): it seems, the following line can be rewritten as:
	// if(enabled === false \|\| enabled === 0 \|\| enabled === '')
	// Should be double-checked before update
	// eslint-disable-next-line eqeqeq
	if (linkInfo.enabled != null && linkInfo.enabled == false) {
	continue;
	}
	// PolyGerrit doesn't use hash-based navigation like the GWT UI.
	// Account for this.
	const html = linkInfo.html;
	const link = linkInfo.link;
	if (html) {
	linkInfo.html = html.replace(/<a href="#\//g, '<a href="/');
	} else if (link) {
	if (link[0] === '#') {
	linkInfo.link = link.substr(1);
	}
	}

	const pattern = new RegExp(linkInfo.match, 'g');

	let match;
	let textToCheck = text;
	let susbtrIndex = 0;

	while ((match = pattern.exec(textToCheck))) {
	textToCheck = textToCheck.substr(match.index + match[0].length);
	let result = match[0].replace(
	pattern,
	// Either html or link has a value. Otherwise an exception is thrown
	// in the code below.
	(linkInfo.html \|\| linkInfo.link)!
	);

	if (linkInfo.html) {
	let i;
	// Skip portion of replacement string that is equal to original to
	// allow overlapping patterns.
	for (i = 0; i < result.length; i++) {
	if (result[i] !== match[0][i]) {
	break;
	}
	}
	result = result.slice(i);

	this.addHTML(
	result,
	susbtrIndex + match.index + i,
	match[0].length - i,
	outputArray
	);
	} else if (linkInfo.link) {
	this.addLink(
	match[0],
	result,
	susbtrIndex + match.index,
	match[0].length,
	outputArray
	);
	} else {
	throw Error(
	'linkconfig entry ' +
	configName +
	' doesn’t contain a link or html attribute.'
	);
	}

	// Update the substring location so we know where we are in relation to
	// the initial full text string.
	susbtrIndex = susbtrIndex + match.index + match[0].length;
	}
	}
	this.processLinks(text, outputArray);
	}
	}