src/Linkifier.ts

   1 /**
   2  * @license MIT
   3  */
   4
   5 import { LinkMatcherOptions } from './Interfaces';
   6 import { LinkMatcher, LinkMatcherHandler, LinkMatcherValidationCallback } from './Types';
   7
   8 const INVALID_LINK_CLASS = 'xterm-invalid-link';
   9
  10 const protocolClause = '(https?:\\/\\/)';
  11 const domainCharacterSet = '[\\da-z\\.-]+';
  12 const negatedDomainCharacterSet = '[^\\da-z\\.-]+';
  13 const domainBodyClause = '(' + domainCharacterSet + ')';
  14 const tldClause = '([a-z\\.]{2,6})';
  15 const ipClause = '((\\d{1,3}\\.){3}\\d{1,3})';
  16 const localHostClause = '(localhost)';
  17 const portClause = '(:\\d{1,5})';
  18 const hostClause = '((' + domainBodyClause + '\\.' + tldClause + ')|' + ipClause + '|' + localHostClause + ')' + portClause + '?';
  19 const pathClause = '(\\/[\\/\\w\\.\\-%]*)*';
  20 const queryStringHashFragmentCharacterSet = '[0-9\\w\\[\\]\\(\\)\\/\\?\\!#@$%&\'*+,:;\\=\\.\\-]*';
  21 const queryStringClause = '(\\?' + queryStringHashFragmentCharacterSet + ')?';
  22 const hashFragmentClause = '(#' + queryStringHashFragmentCharacterSet + ')?';
  23 const negatedPathCharacterSet = '[^\\/\\w\\.\\-%]+';
  24 const bodyClause = hostClause + pathClause + queryStringClause + hashFragmentClause;
  25 const start = '(?:^|' + negatedDomainCharacterSet + ')(';
  26 const end = ')($|' + negatedPathCharacterSet + ')';
  27 const strictUrlRegex = new RegExp(start + protocolClause + bodyClause + end);
  28
  29 /**
  30  * The ID of the built in http(s) link matcher.
  31  */
  32 const HYPERTEXT_LINK_MATCHER_ID = 0;
  33
  34 /**
  35  * The Linkifier applies links to rows shortly after they have been refreshed.
  36  */
  37 export class Linkifier {
  38   /**
  39    * The time to wait after a row is changed before it is linkified. This prevents
  40    * the costly operation of searching every row multiple times, pntentially a
  41    * huge aount of times.
  42    */
  43   protected static TIME_BEFORE_LINKIFY = 200;
  44
  45   protected _linkMatchers: LinkMatcher[];
  46
  47   private _document: Document;
  48   private _rows: HTMLElement[];
  49   private _rowTimeoutIds: number[];
  50   private _nextLinkMatcherId = HYPERTEXT_LINK_MATCHER_ID;
  51
  52   constructor(document: Document, rows: HTMLElement[]) {
  53     this._document = document;
  54     this._rows = rows;
  55     this._rowTimeoutIds = [];
  56     this._linkMatchers = [];
  57     this.registerLinkMatcher(strictUrlRegex, null, { matchIndex: 1 });
  58   }
  59
  60   /**
  61    * Queues a row for linkification.
  62    * @param {number} rowIndex The index of the row to linkify.
  63    */
  64   public linkifyRow(rowIndex: number): void {
  65     const timeoutId = this._rowTimeoutIds[rowIndex];
  66     if (timeoutId) {
  67       clearTimeout(timeoutId);
  68     }
  69     this._rowTimeoutIds[rowIndex] = setTimeout(this._linkifyRow.bind(this, rowIndex), Linkifier.TIME_BEFORE_LINKIFY);
  70   }
  71
  72   /**
  73    * Attaches a handler for hypertext links, overriding default <a> behavior
  74    * for standard http(s) links.
  75    * @param {LinkHandler} handler The handler to use, this can be cleared with
  76    * null.
  77    */
  78   public attachHypertextLinkHandler(handler: LinkMatcherHandler): void {
  79     this._linkMatchers[HYPERTEXT_LINK_MATCHER_ID].handler = handler;
  80   }
  81
  82   /**
  83    * Registers a link matcher, allowing custom link patterns to be matched and
  84    * handled.
  85    * @param {RegExp} regex The regular expression to search for, specifically
  86    * this searches the textContent of the rows. You will want to use \s to match
  87    * a space ' ' character for example.
  88    * @param {LinkHandler} handler The callback when the link is called.
  89    * @param {LinkMatcherOptions} [options] Options for the link matcher.
  90    * @return {number} The ID of the new matcher, this can be used to deregister.
  91    */
  92   public registerLinkMatcher(regex: RegExp, handler: LinkMatcherHandler, options: LinkMatcherOptions = {}): number {
  93     if (this._nextLinkMatcherId !== HYPERTEXT_LINK_MATCHER_ID && !handler) {
  94       throw new Error('handler must be defined');
  95     }
  96     const matcher: LinkMatcher = {
  97       id: this._nextLinkMatcherId++,
  98       regex,
  99       handler,
 100       matchIndex: options.matchIndex,
 101       validationCallback: options.validationCallback,
 102       priority: options.priority || 0
 103     };
 104     this._addLinkMatcherToList(matcher);
 105     return matcher.id;
 106   }
 107
 108   /**
 109    * Inserts a link matcher to the list in the correct position based on the
 110    * priority of each link matcher. New link matchers of equal priority are
 111    * considered after older link matchers.
 112    * @param matcher The link matcher to be added.
 113    */
 114   private _addLinkMatcherToList(matcher: LinkMatcher): void {
 115     if (this._linkMatchers.length === 0) {
 116       this._linkMatchers.push(matcher);
 117       return;
 118     }
 119
 120     for (let i = this._linkMatchers.length - 1; i >= 0; i--) {
 121       if (matcher.priority <= this._linkMatchers[i].priority) {
 122         this._linkMatchers.splice(i + 1, 0, matcher);
 123         return;
 124       }
 125     }
 126
 127     this._linkMatchers.splice(0, 0, matcher);
 128   }
 129
 130   /**
 131    * Deregisters a link matcher if it has been registered.
 132    * @param {number} matcherId The link matcher's ID (returned after register)
 133    * @return {boolean} Whether a link matcher was found and deregistered.
 134    */
 135   public deregisterLinkMatcher(matcherId: number): boolean {
 136     // ID 0 is the hypertext link matcher which cannot be deregistered
 137     for (let i = 1; i < this._linkMatchers.length; i++) {
 138       if (this._linkMatchers[i].id === matcherId) {
 139         this._linkMatchers.splice(i, 1);
 140         return true;
 141       }
 142     }
 143     return false;
 144   }
 145
 146   /**
 147    * Linkifies a row.
 148    * @param {number} rowIndex The index of the row to linkify.
 149    */
 150   private _linkifyRow(rowIndex: number): void {
 151     const row = this._rows[rowIndex];
 152     if (!row) {
 153       return;
 154     }
 155     const text = row.textContent;
 156     for (let i = 0; i < this._linkMatchers.length; i++) {
 157       const matcher = this._linkMatchers[i];
 158       const uri = this._findLinkMatch(text, matcher.regex, matcher.matchIndex);
 159       if (uri) {
 160         const linkElement = this._doLinkifyRow(rowIndex, uri, matcher.handler);
 161         // Fire validation callback
 162         if (linkElement && matcher.validationCallback) {
 163           matcher.validationCallback(uri, isValid => {
 164             if (!isValid) {
 165               linkElement.classList.add(INVALID_LINK_CLASS);
 166             }
 167           });
 168         }
 169         // Only allow a single LinkMatcher to trigger on any given row.
 170         return;
 171       }
 172     }
 173   }
 174
 175   /**
 176    * Linkifies a row given a specific handler.
 177    * @param {number} rowIndex The index of the row to linkify.
 178    * @param {string} uri The uri that has been found.
 179    * @param {handler} handler The handler to trigger when the link is triggered.
 180    * @return The link element if it was added, otherwise undefined.
 181    */
 182   private _doLinkifyRow(rowIndex: number, uri: string, handler?: LinkMatcherHandler): HTMLElement {
 183     // Iterate over nodes as we want to consider text nodes
 184     const nodes = this._rows[rowIndex].childNodes;
 185     for (let i = 0; i < nodes.length; i++) {
 186       const node = nodes[i];
 187       const searchIndex = node.textContent.indexOf(uri);
 188       if (searchIndex >= 0) {
 189         const linkElement = this._createAnchorElement(uri, handler);
 190         if (node.textContent.length === uri.length) {
 191           // Matches entire string
 192
 193           if (node.nodeType === 3 /*Node.TEXT_NODE*/) {
 194             this._replaceNode(node, linkElement);
 195           } else {
 196             const element = (<HTMLElement>node);
 197             if (element.nodeName === 'A') {
 198               // This row has already been linkified
 199               return;
 200             }
 201             element.innerHTML = '';
 202             element.appendChild(linkElement);
 203           }
 204         } else {
 205           // Matches part of string
 206           this._replaceNodeSubstringWithNode(node, linkElement, uri, searchIndex);
 207         }
 208         return linkElement;
 209       }
 210     }
 211   }
 212
 213   /**
 214    * Finds a link match in a piece of text.
 215    * @param {string} text The text to search.
 216    * @param {number} matchIndex The regex match index of the link.
 217    * @return {string} The matching URI or null if not found.
 218    */
 219   private _findLinkMatch(text: string, regex: RegExp, matchIndex?: number): string {
 220     const match = text.match(regex);
 221     if (!match || match.length === 0) {
 222       return null;
 223     }
 224     return match[typeof matchIndex !== 'number' ? 0 : matchIndex];
 225   }
 226
 227   /**
 228    * Creates a link anchor element.
 229    * @param {string} uri The uri of the link.
 230    * @return {HTMLAnchorElement} The link.
 231    */
 232   private _createAnchorElement(uri: string, handler: LinkMatcherHandler): HTMLAnchorElement {
 233     const element = this._document.createElement('a');
 234     element.textContent = uri;
 235     if (handler) {
 236       element.addEventListener('click', (event: MouseEvent) => {
 237         // Don't execute the handler if the link is flagged as invalid
 238         if (element.classList.contains(INVALID_LINK_CLASS)) {
 239           return;
 240         }
 241
 242         return handler(event, uri);
 243       });
 244     } else {
 245       element.href = uri;
 246       // Force link on another tab so work is not lost
 247       element.target = '_blank';
 248       element.addEventListener('click', (event: MouseEvent) => {
 249         if (handler) {
 250           return handler(event, uri);
 251         }
 252       });
 253     }
 254     return element;
 255   }
 256
 257   /**
 258    * Replace a node with 1 or more other nodes.
 259    * @param {Node} oldNode The node to replace.
 260    * @param {Node[]} newNodes The new nodes to insert in order.
 261    */
 262   private _replaceNode(oldNode: Node, ...newNodes: Node[]): void {
 263     const parent = oldNode.parentNode;
 264     for (let i = 0; i < newNodes.length; i++) {
 265       parent.insertBefore(newNodes[i], oldNode);
 266     }
 267     parent.removeChild(oldNode);
 268   }
 269
 270   /**
 271    * Replace a substring within a node with a new node.
 272    * @param {Node} targetNode The target node; either a text node or a <span>
 273    * containing a single text node.
 274    * @param {Node} newNode The new node to insert.
 275    * @param {string} substring The substring to replace.
 276    * @param {number} substringIndex The index of the substring within the string.
 277    */
 278   private _replaceNodeSubstringWithNode(targetNode: Node, newNode: Node, substring: string, substringIndex: number): void {
 279     let node = targetNode;
 280     if (node.nodeType !== 3/*Node.TEXT_NODE*/) {
 281       node = node.childNodes[0];
 282     }
 283
 284     // The targetNode will be either a text node or a <span>. The text node
 285     // (targetNode or its only-child) needs to be replaced with newNode plus new
 286     // text nodes potentially on either side.
 287     if (node.childNodes.length === 0 && node.nodeType !== Node.TEXT_NODE) {
 288       throw new Error('targetNode must be a text node or only contain a single text node');
 289     }
 290
 291     const fullText = node.textContent;
 292
 293     if (substringIndex === 0) {
 294       // Replace with <newNode><textnode>
 295       const rightText = fullText.substring(substring.length);
 296       const rightTextNode = this._document.createTextNode(rightText);
 297       this._replaceNode(node, newNode, rightTextNode);
 298     } else if (substringIndex === targetNode.textContent.length - substring.length) {
 299       // Replace with <textnode><newNode>
 300       const leftText = fullText.substring(0, substringIndex);
 301       const leftTextNode = this._document.createTextNode(leftText);
 302       this._replaceNode(node, leftTextNode, newNode);
 303     } else {
 304       // Replace with <textnode><newNode><textnode>
 305       const leftText = fullText.substring(0, substringIndex);
 306       const leftTextNode = this._document.createTextNode(leftText);
 307       const rightText = fullText.substring(substringIndex + substring.length);
 308       const rightTextNode = this._document.createTextNode(rightText);
 309       this._replaceNode(node, leftTextNode, newNode, rightTextNode);
 310     }
 311   }
 312 }