polygerrit-ui/app/elements/shared/gr-formatted-text/gr-formatted-text.ts - gerrit - Git at Google

 /**
  * @license
  * Copyright (C) 2016 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 '../gr-linked-text/gr-linked-text';
 import '../../../styles/shared-styles';
 import {PolymerElement} from '@polymer/polymer/polymer-element';
 import {customElement, property} from '@polymer/decorators';
 import {htmlTemplate} from './gr-formatted-text_html';
 import {CommentLinks} from '../../../types/common';

 const CODE_MARKER_PATTERN = /^(`{1,3})([^`]+?)\1$/;

 interface Block {
   type: string;
   text?: string;
   blocks?: Block[];
   items?: string[];
 }

 declare global {
   interface HTMLElementTagNameMap {
     'gr-formatted-text': GrFormattedText;
   }
 }

 export interface GrFormattedText {
   $: {
     container: HTMLElement;
   };
 }

 @customElement('gr-formatted-text')
 export class GrFormattedText extends PolymerElement {
   static get template() {
     return htmlTemplate;
   }

   @property({type: String, observer: '_contentChanged'})
   content?: string;

   @property({type: Object})
   config?: CommentLinks;

   @property({type: Boolean})
   noTrailingMargin = false;

   static get observers() {
     return ['_contentOrConfigChanged(content, config)'];
   }

   /** @override */
   ready() {
     super.ready();
     if (this.noTrailingMargin) {
       this.classList.add('noTrailingMargin');
     }
   }

   _contentChanged(content: string) {
     // In the case where the config may not be set (perhaps due to the
     // request for it still being in flight), set the content anyway to
     // prevent waiting on the config to display the text.
     if (this.config) return;
     this._contentOrConfigChanged(content);
   }

   /**
    * Given a source string, update the DOM inside #container.
    */
   _contentOrConfigChanged(content?: string) {
     const container = this.$.container;

     // Remove existing content.
     while (container.firstChild) {
       container.removeChild(container.firstChild);
     }

     // Add new content.
     for (const node of this._computeNodes(this._computeBlocks(content))) {
       if (node) container.appendChild(node);
     }
   }

   /**
    * Given a source string, parse into an array of block objects. Each block
    * has a `type` property which takes any of the following values.
    * * 'paragraph'
    * * 'quote' (Block quote.)
    * * 'pre' (Pre-formatted text.)
    * * 'list' (Unordered list.)
    * * 'code' (code blocks.)
    *
    * For blocks of type 'paragraph', 'pre' and 'code' there is a `text`
    * property that maps to a string of the block's content.
    *
    * For blocks of type 'list', there is an `items` property that maps to a
    * list of strings representing the list items.
    *
    * For blocks of type 'quote', there is a `blocks` property that maps to a
    * list of blocks contained in the quote.
    *
    * NOTE: Strings appearing in all block objects are NOT escaped.
    */
   _computeBlocks(content?: string): Block[] {
     if (!content) return [];

     const result = [];
     const lines = content.replace(/[\s\n\r\t]+$/g, '').split('\n');

     for (let i = 0; i < lines.length; i++) {
       if (!lines[i].length) {
         continue;
       }

       if (this._isCodeMarkLine(lines[i])) {
         // handle multi-line code
         let nextI = i + 1;
         while (!this._isCodeMarkLine(lines[nextI]) && nextI < lines.length) {
           nextI++;
         }

         if (this._isCodeMarkLine(lines[nextI])) {
           result.push({
             type: 'code',
             text: lines.slice(i + 1, nextI).join('\n'),
           });
           i = nextI;
           continue;
         }

         // otherwise treat it as regular line and continue
         // check for other cases
       }

       if (this._isSingleLineCode(lines[i])) {
         // no guard check as _isSingleLineCode tested on the pattern
         const codeContent = lines[i].match(CODE_MARKER_PATTERN)![2];
         result.push({type: 'code', text: codeContent});
       } else if (this._isList(lines[i])) {
         let nextI = i + 1;
         while (this._isList(lines[nextI])) {
           nextI++;
         }
         result.push(this._makeList(lines.slice(i, nextI)));
         i = nextI - 1;
       } else if (this._isQuote(lines[i])) {
         let nextI = i + 1;
         while (this._isQuote(lines[nextI])) {
           nextI++;
         }
         const blockLines = lines
           .slice(i, nextI)
           .map(l => l.replace(/^[ ]?>[ ]?/, ''));
         result.push({
           type: 'quote',
           blocks: this._computeBlocks(blockLines.join('\n')),
         });
         i = nextI - 1;
       } else if (this._isPreFormat(lines[i])) {
         let nextI = i + 1;
         // include pre or all regular lines but stop at next new line
         while (
           this._isPreFormat(lines[nextI]) ||
           (this._isRegularLine(lines[nextI]) && lines[nextI].length)
         ) {
           nextI++;
         }
         result.push({
           type: 'pre',
           text: lines.slice(i, nextI).join('\n'),
         });
         i = nextI - 1;
       } else {
         let nextI = i + 1;
         while (this._isRegularLine(lines[nextI])) {
           nextI++;
         }
         result.push({
           type: 'paragraph',
           text: lines.slice(i, nextI).join('\n'),
         });
         i = nextI - 1;
       }
     }

     return result;
   }

   /**
    * Take a block of comment text that contains a list, generate appropriate
    * block objects and append them to the output list.
    *
    * * Item one.
    * * Item two.
    * * item three.
    *
    * TODO(taoalpha): maybe we should also support nested list
    *
    * @param lines The block containing the list.
    */
   _makeList(lines: string[]) {
     const items = [];
     for (let i = 0; i < lines.length; i++) {
       let line = lines[i];
       line = line.substring(1).trim();
       items.push(line);
     }
     return {type: 'list', items};
   }

   _isRegularLine(line: string) {
     // line can not be recognized by existing patterns
     if (line === undefined) return false;
     return (
       !this._isQuote(line) &&
       !this._isCodeMarkLine(line) &&
       !this._isSingleLineCode(line) &&
       !this._isList(line) &&
       !this._isPreFormat(line)
     );
   }

   _isQuote(line: string) {
     return line && (line.startsWith('> ') || line.startsWith(' > '));
   }

   _isCodeMarkLine(line: string) {
     return line && line.trim() === '```';
   }

   _isSingleLineCode(line: string) {
     return line && CODE_MARKER_PATTERN.test(line);
   }

   _isPreFormat(line: string) {
     return line && /^[ \t]/.test(line);
   }

   _isList(line: string) {
     return line && /^[-*] /.test(line);
   }

   _makeLinkedText(content = '', isPre?: boolean) {
     const text = document.createElement('gr-linked-text');
     text.config = this.config;
     text.content = content;
     text.pre = true;
     if (isPre) {
       text.classList.add('pre');
     }
     return text;
   }

   /**
    * Map an array of block objects to an array of DOM nodes.
    */
   _computeNodes(blocks: Block[]): HTMLElement[] {
     return blocks.map(block => {
       if (block.type === 'paragraph') {
         const p = document.createElement('p');
         p.appendChild(this._makeLinkedText(block.text));
         return p;
       }

       if (block.type === 'quote') {
         const bq = document.createElement('blockquote');
         for (const node of this._computeNodes(block.blocks || [])) {
           if (node) bq.appendChild(node);
         }
         return bq;
       }

       if (block.type === 'code') {
         const code = document.createElement('code');
         code.textContent = block.text || '';
         return code;
       }

       if (block.type === 'pre') {
         return this._makeLinkedText(block.text, true);
       }

       if (block.type === 'list') {
         const ul = document.createElement('ul');
         const items = block.items || [];
         for (const item of items) {
           const li = document.createElement('li');
           li.appendChild(this._makeLinkedText(item));
           ul.appendChild(li);
         }
         return ul;
       }

       console.warn('Unrecognized type.');
       return document.createElement('span');
     });
   }
 }
	/**
	* @license
	* Copyright (C) 2016 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 '../gr-linked-text/gr-linked-text';
	import '../../../styles/shared-styles';
	import {PolymerElement} from '@polymer/polymer/polymer-element';
	import {customElement, property} from '@polymer/decorators';
	import {htmlTemplate} from './gr-formatted-text_html';
	import {CommentLinks} from '../../../types/common';

	const CODE_MARKER_PATTERN = /^(`{1,3})([^`]+?)\1$/;

	interface Block {
	type: string;
	text?: string;
	blocks?: Block[];
	items?: string[];
	}

	declare global {
	interface HTMLElementTagNameMap {
	'gr-formatted-text': GrFormattedText;
	}
	}

	export interface GrFormattedText {
	$: {
	container: HTMLElement;
	};
	}

	@customElement('gr-formatted-text')
	export class GrFormattedText extends PolymerElement {
	static get template() {
	return htmlTemplate;
	}

	@property({type: String, observer: '_contentChanged'})
	content?: string;

	@property({type: Object})
	config?: CommentLinks;

	@property({type: Boolean})
	noTrailingMargin = false;

	static get observers() {
	return ['_contentOrConfigChanged(content, config)'];
	}

	/** @override */
	ready() {
	super.ready();
	if (this.noTrailingMargin) {
	this.classList.add('noTrailingMargin');
	}
	}

	_contentChanged(content: string) {
	// In the case where the config may not be set (perhaps due to the
	// request for it still being in flight), set the content anyway to
	// prevent waiting on the config to display the text.
	if (this.config) return;
	this._contentOrConfigChanged(content);
	}

	/**
	* Given a source string, update the DOM inside #container.
	*/
	_contentOrConfigChanged(content?: string) {
	const container = this.$.container;

	// Remove existing content.
	while (container.firstChild) {
	container.removeChild(container.firstChild);
	}

	// Add new content.
	for (const node of this._computeNodes(this._computeBlocks(content))) {
	if (node) container.appendChild(node);
	}
	}

	/**
	* Given a source string, parse into an array of block objects. Each block
	* has a `type` property which takes any of the following values.
	* * 'paragraph'
	* * 'quote' (Block quote.)
	* * 'pre' (Pre-formatted text.)
	* * 'list' (Unordered list.)
	* * 'code' (code blocks.)
	*
	* For blocks of type 'paragraph', 'pre' and 'code' there is a `text`
	* property that maps to a string of the block's content.
	*
	* For blocks of type 'list', there is an `items` property that maps to a
	* list of strings representing the list items.
	*
	* For blocks of type 'quote', there is a `blocks` property that maps to a
	* list of blocks contained in the quote.
	*
	* NOTE: Strings appearing in all block objects are NOT escaped.
	*/
	_computeBlocks(content?: string): Block[] {
	if (!content) return [];

	const result = [];
	const lines = content.replace(/[\s\n\r\t]+$/g, '').split('\n');

	for (let i = 0; i < lines.length; i++) {
	if (!lines[i].length) {
	continue;
	}

	if (this._isCodeMarkLine(lines[i])) {
	// handle multi-line code
	let nextI = i + 1;
	while (!this._isCodeMarkLine(lines[nextI]) && nextI < lines.length) {
	nextI++;
	}

	if (this._isCodeMarkLine(lines[nextI])) {
	result.push({
	type: 'code',
	text: lines.slice(i + 1, nextI).join('\n'),
	});
	i = nextI;
	continue;
	}

	// otherwise treat it as regular line and continue
	// check for other cases
	}

	if (this._isSingleLineCode(lines[i])) {
	// no guard check as _isSingleLineCode tested on the pattern
	const codeContent = lines[i].match(CODE_MARKER_PATTERN)![2];
	result.push({type: 'code', text: codeContent});
	} else if (this._isList(lines[i])) {
	let nextI = i + 1;
	while (this._isList(lines[nextI])) {
	nextI++;
	}
	result.push(this._makeList(lines.slice(i, nextI)));
	i = nextI - 1;
	} else if (this._isQuote(lines[i])) {
	let nextI = i + 1;
	while (this._isQuote(lines[nextI])) {
	nextI++;
	}
	const blockLines = lines
	.slice(i, nextI)
	.map(l => l.replace(/^[ ]?>[ ]?/, ''));
	result.push({
	type: 'quote',
	blocks: this._computeBlocks(blockLines.join('\n')),
	});
	i = nextI - 1;
	} else if (this._isPreFormat(lines[i])) {
	let nextI = i + 1;
	// include pre or all regular lines but stop at next new line
	while (
	this._isPreFormat(lines[nextI]) \|\|
	(this._isRegularLine(lines[nextI]) && lines[nextI].length)
	) {
	nextI++;
	}
	result.push({
	type: 'pre',
	text: lines.slice(i, nextI).join('\n'),
	});
	i = nextI - 1;
	} else {
	let nextI = i + 1;
	while (this._isRegularLine(lines[nextI])) {
	nextI++;
	}
	result.push({
	type: 'paragraph',
	text: lines.slice(i, nextI).join('\n'),
	});
	i = nextI - 1;
	}
	}

	return result;
	}

	/**
	* Take a block of comment text that contains a list, generate appropriate
	* block objects and append them to the output list.
	*
	* * Item one.
	* * Item two.
	* * item three.
	*
	* TODO(taoalpha): maybe we should also support nested list
	*
	* @param lines The block containing the list.
	*/
	_makeList(lines: string[]) {
	const items = [];
	for (let i = 0; i < lines.length; i++) {
	let line = lines[i];
	line = line.substring(1).trim();
	items.push(line);
	}
	return {type: 'list', items};
	}

	_isRegularLine(line: string) {
	// line can not be recognized by existing patterns
	if (line === undefined) return false;
	return (
	!this._isQuote(line) &&
	!this._isCodeMarkLine(line) &&
	!this._isSingleLineCode(line) &&
	!this._isList(line) &&
	!this._isPreFormat(line)
	);
	}

	_isQuote(line: string) {
	return line && (line.startsWith('> ') \|\| line.startsWith(' > '));
	}

	_isCodeMarkLine(line: string) {
	return line && line.trim() === '```';
	}

	_isSingleLineCode(line: string) {
	return line && CODE_MARKER_PATTERN.test(line);
	}

	_isPreFormat(line: string) {
	return line && /^[ \t]/.test(line);
	}

	_isList(line: string) {
	return line && /^[-*] /.test(line);
	}

	_makeLinkedText(content = '', isPre?: boolean) {
	const text = document.createElement('gr-linked-text');
	text.config = this.config;
	text.content = content;
	text.pre = true;
	if (isPre) {
	text.classList.add('pre');
	}
	return text;
	}

	/**
	* Map an array of block objects to an array of DOM nodes.
	*/
	_computeNodes(blocks: Block[]): HTMLElement[] {
	return blocks.map(block => {
	if (block.type === 'paragraph') {
	const p = document.createElement('p');
	p.appendChild(this._makeLinkedText(block.text));
	return p;
	}

	if (block.type === 'quote') {
	const bq = document.createElement('blockquote');
	for (const node of this._computeNodes(block.blocks \|\| [])) {
	if (node) bq.appendChild(node);
	}
	return bq;
	}

	if (block.type === 'code') {
	const code = document.createElement('code');
	code.textContent = block.text \|\| '';
	return code;
	}

	if (block.type === 'pre') {
	return this._makeLinkedText(block.text, true);
	}

	if (block.type === 'list') {
	const ul = document.createElement('ul');
	const items = block.items \|\| [];
	for (const item of items) {
	const li = document.createElement('li');
	li.appendChild(this._makeLinkedText(item));
	ul.appendChild(li);
	}
	return ul;
	}

	console.warn('Unrecognized type.');
	return document.createElement('span');
	});
	}
	}