mediawiki-extensions-Discus.../modules/ThreadItem.js
Bartosz Dziewoński 3137d76f40 Connect sub-threads to their parent threads
Our threads now also contain all replies to their sub-threads.
This is similar to how sections work in MediaWiki, where the parent
section also contains the content of all the lower-level sections.
We're going to need this for notifications about replies in a thread.

Bug: T264478
Change-Id: I241fc58e2088a7555942824b0f184ed21e3a8b6f
2020-10-22 02:05:02 +02:00

199 lines
5.9 KiB
JavaScript

/* global moment */
/**
* @external CommentItem
*/
var utils = require( './utils.js' );
/**
* A thread item, either a heading or a comment
*
* @class ThreadItem
* @constructor
* @param {string} type `heading` or `comment`
* @param {number} level Indentation level
* @param {Object} range Object describing the extent of the comment, including the
* signature and timestamp. It has the same properties as a Range object: `startContainer`,
* `startOffset`, `endContainer`, `endOffset` (we don't use a real Range because they change
* magically when the DOM structure changes).
*/
function ThreadItem( type, level, range ) {
this.type = type;
this.level = level;
this.range = range;
/**
* @member {string} Unique ID (within the page) for this comment, intended to be used to
* find this comment in other revisions of the same page
*/
this.id = null;
/**
* @member {CommentItem[]} Replies to this thread item
*/
this.replies = [];
this.rootNode = null;
}
OO.initClass( ThreadItem );
/**
* Create a new ThreadItem from a JSON serialization
*
* @param {string|Object} json JSON serialization or hash object
* @param {Object} commentsById Collection of comments by ID for building replies/parent pointers
* @param {Node} placeholderNode Placeholder node in the DOM which contained this JSON
* @return {ThreadItem}
* @throws {Error} Unknown ThreadItem type
*/
ThreadItem.static.newFromJSON = function ( json, commentsById, placeholderNode ) {
// The page can be served from the HTTP cache (Varnish), and the JSON may be generated
// by an older version of our PHP code. Code below must be able to handle that.
// See ThreadItem::jsonSerialize() in PHP.
var CommentItem, HeadingItem, item, idEscaped,
hash = typeof json === 'string' ? JSON.parse( json ) : json;
switch ( hash.type ) {
case 'comment':
// Late require to avoid circular dependency
CommentItem = require( './CommentItem.js' );
item = new CommentItem(
hash.level,
hash.range,
hash.signatureRanges,
moment( hash.timestamp ),
hash.author
);
break;
case 'heading':
HeadingItem = require( './HeadingItem.js' );
item = new HeadingItem(
hash.range,
hash.headingLevel,
hash.placeholderHeading
);
break;
default:
throw new Error( 'Unknown ThreadItem type ' + hash.name );
}
item.id = hash.id;
if ( hash.type === 'comment' ) {
idEscaped = $.escapeSelector( item.id );
item.range = {
startContainer: document.querySelector( '[data-mw-comment-start="' + idEscaped + '"]' ),
startOffset: 0,
endContainer: document.querySelector( '[data-mw-comment-end="' + idEscaped + '"]' ),
endOffset: 0
};
} else {
item.range = {
startContainer: placeholderNode,
startOffset: 0,
endContainer: placeholderNode,
endOffset: 0
};
}
// Setup replies/parent pointers
item.replies = hash.replies.map( function ( id ) {
commentsById[ id ].parent = item;
return commentsById[ id ];
} );
return item;
};
/**
* Get the list of authors in the comment tree below this thread item.
*
* Usually called on a HeadingItem to find all authors in a thread.
*
* @return {string[]} Author usernames
*/
ThreadItem.prototype.getAuthorsBelow = function () {
var authors = {};
function getAuthorSet( comment ) {
authors[ comment.author ] = true;
// Get the set of authors in the same format from each reply
comment.replies.map( getAuthorSet );
}
this.replies.map( getAuthorSet );
return Object.keys( authors ).sort();
};
/**
* Get the name of the page from which this thread item is transcluded (if any).
*
* @return {string|boolean} `false` if this item is not transcluded. A string if it's transcluded
* from a single page (the page title, in text form with spaces). `true` if it's transcluded, but
* we can't determine the source.
*/
ThreadItem.prototype.getTranscludedFrom = function () {
var coveredNodes, i, node, dataMw;
// If some template is used within the comment (e.g. {{ping|…}} or {{tl|…}}, or a
// non-substituted signature template), that *does not* mean the comment is transcluded.
// We only want to consider comments to be transcluded if all wrapper elements (usually
// <li> or <p>) are marked as part of a single transclusion.
// If we can't find "exact" wrappers, using only the end container works out well
// (because the main purpose of this method is to decide on which page we should post
// replies to the given comment, and they'll go after the comment).
coveredNodes = utils.getFullyCoveredSiblings( this ) ||
[ this.range.endContainer ];
node = utils.getTranscludedFromElement( coveredNodes[ 0 ] );
for ( i = 1; i < coveredNodes.length; i++ ) {
if ( node !== utils.getTranscludedFromElement( coveredNodes[ i ] ) ) {
// Comment is only partially transcluded, that should be fine
return false;
}
}
if ( !node ) {
// No mw:Transclusion node found, this item is not transcluded
return false;
}
dataMw = JSON.parse( node.getAttribute( 'data-mw' ) );
// Only return a page name if this is a simple single-template transclusion.
if (
dataMw &&
dataMw.parts &&
dataMw.parts.length === 1 &&
dataMw.parts[ 0 ].template &&
dataMw.parts[ 0 ].template.target.href
) {
// Slice off the './' prefix and convert to text form (underscores to spaces, URL-decoded)
return mw.libs.ve.normalizeParsoidResourceName( dataMw.parts[ 0 ].template.target.href );
}
// Multi-template transclusion, or a parser function call, or template-affected wikitext outside
// of a template call, or a mix of the above
return true;
};
/**
* Return a native Range object corresponding to the item's range.
*
* @return {Range}
*/
ThreadItem.prototype.getNativeRange = function () {
var
doc = this.range.startContainer.ownerDocument,
nativeRange = doc.createRange();
nativeRange.setStart( this.range.startContainer, this.range.startOffset );
nativeRange.setEnd( this.range.endContainer, this.range.endOffset );
return nativeRange;
};
// TODO: Implement getHTML/getText if required
module.exports = ThreadItem;