Add FeedReader

chrome/content/zotero/xpcom/feedReader.js

@@ -0,0 +1,530 @@
+/*
+    ***** BEGIN LICENSE BLOCK *****
+    
+    Copyright © 2015 Center for History and New Media
+                     George Mason University, Fairfax, Virginia, USA
+                     http://zotero.org
+    
+    This file is part of Zotero.
+    
+    Zotero is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+    
+    Zotero is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+    
+    You should have received a copy of the GNU Affero General Public License
+    along with Zotero.  If not, see <http://www.gnu.org/licenses/>.
+    
+    ***** END LICENSE BLOCK *****
+*/
+
+
+/**
+ * Sample feeds:
+ * 
+ * http://cyber.law.harvard.edu/rss/examples/rss2sample.xml
+ * http://feeds.feedburner.com/acs/acbcct
+ * http://www.cell.com/molecular-cell/current.rss
+ * http://ieeexplore.ieee.org/search/searchresult.jsp?searchField%3DSearch_All%26queryText%3Dwater&searchOrigin=saved_searches&rssFeed=true&rssFeedName=water
+ * http://www.sciencemag.org/rss/current.xml
+ * http://rss.sciencedirect.com/publication/science/20925212
+ * http://www.ncbi.nlm.nih.gov/entrez/eutils/erss.cgi?rss_guid=1fmfIeN4X5Q8HemTZD5Rj6iu6-FQVCn7xc7_IPIIQtS1XiD9bf
+ * http://export.arxiv.org/rss/astro-ph
+ */
+
+/**
+ * class Zotero.FeedReader
+ * Asynchronously reads an ATOM/RSS feed
+ *
+ * @param {String} url URL of the feed
+ *
+ * @property {Zotero.Promise<Object>} feedProperties An object
+ *   representing feed properties
+ * @property {Zotero.Promise<FeedItem>*} itemIterator Returns an iterator
+ *   for feed items. The iterator returns FeedItem promises that have to be
+ *   resolved before requesting the next promise. When all items are exhausted.
+ *   the promise resolves to null.
+ * @method {void} terminate Stops retrieving/parsing the feed. Data parsed up
+ *   to this point is still available.
+ */
+Zotero.FeedReader = new function() {
+	let ios = Components.classes["@mozilla.org/network/io-service;1"]
+		.getService(Components.interfaces.nsIIOService);
+	
+	/*****************************
+	 * Item processing functions *
+	 *****************************/
+	 
+	 /**
+	  * Determine item type based on item data
+	  */
+	function guessItemType(item) {
+		// Default to journalArticle
+		item.itemType = 'journalArticle';
+		
+		if (item.ISSN) {
+			return; // journalArticle
+		}
+		
+		if (item.ISBN) {
+			item.itemType = 'bookSection';
+			return;
+		}
+		
+		if (item.publicationType) {
+			let type = item.publicationType.toLowerCase();
+			if (type.indexOf('conference') != -1) {
+				item.itemType = 'conferencePaper';
+				return;
+			}
+			if (type.indexOf('journal') != -1) {
+				item.itemType = 'journalArticle';
+				return;
+			}
+			if (type.indexOf('book') != -1) {
+				item.itemType = 'bookSection';
+				return;
+			}
+		}
+	};
+	
+	/*
+	 * Fetch creators from given field of a feed entry
+	 */
+	function processCreators(feedEntry, field, role) {
+		let names = [],
+			nameStr;
+		try {
+			let personArr = feedEntry[field]; // Seems like this part can throw if there is no author data in the feed
+			for (let i=0; i<personArr.length; i++) {
+				let person = personArr.queryElementAt(i, Components.interfaces.nsIFeedPerson);
+				if (!person || !person.name) continue;
+				
+				let name = Zotero.Utilities.trimInternal(person.name);
+				if (!name) continue;
+				
+				let commas = name.split(',').length - 1,
+						other = name.split(/\s(?:and|&)\s|;/).length - 1,
+						separators = commas + other;
+				if (personArr.length == 1 &&
+					// Has typical name separators
+					(other || commas > 1
+					// If only one comma and first part has more than one space,
+					// it's probably not lastName, firstName
+						|| (commas == 1 && name.split(/\s*,/)[0].indexOf(' ') != -1)
+					)
+				) {
+					// Probably multiple authors listed in a single field
+					nameStr = name;
+					break; // For clarity. personArr.length == 1 anyway
+				} else {
+					names.push(name);
+				}
+			}
+		} catch(e) {
+			if (e.result != Components.results.NS_ERROR_FAILURE) throw e
+			
+			if (field != 'authors') return [];
+			
+			// ieeexplore places these in "authors"... sigh
+			nameStr = getFeedField(feedEntry, null, 'authors');
+			if (nameStr) nameStr = Zotero.Utilities.trimInternal(nameStr);
+			if (!nameStr) return [];
+		}
+		
+		if (nameStr) {
+			names = nameStr.split(/\s(?:and|&)\s|\s*[,;]\s*/);
+		}
+		
+		let creators = [];
+		for (let i=0; i<names.length; i++) {
+			let creator = Zotero.Utilities.cleanAuthor(
+				names[i],
+				role,
+				names[i].split(',').length == 2
+			);
+			if (!creator.firstName) {
+				creator.fieldMode = 1;
+			}
+			
+			creators.push(creator);
+		}
+		return creators;
+	}
+	
+	/*********************
+	 * Utility functions *
+	 *********************/
+	/*
+	 * Convert HTML-formatted text to Zotero-compatible formatting
+	 */
+	let domDiv = Zotero.Utilities.Internal.getDOMDocument().createElement("div");
+	function getRichText(feedText, field) {
+		let domFragment = feedText.createDocumentFragment(domDiv);
+		return Zotero.Utilities.dom2text(domFragment, field);
+	}
+	
+	/*
+	 * Format JS date as SQL date + time zone offset
+	 */
+	function formatDate(date) {
+		let offset = (date.getTimezoneOffset() / 60) * -1;
+		let absOffset = Math.abs(offset);
+		offset = offset
+			? ' ' + (offset < 0 ? '-' : '+')
+				+ Zotero.Utilities.lpad(Math.floor(absOffset), '0', 2)
+				+ ('' + ( (absOffset - Math.floor(absOffset)) || '' )).substr(1) // Get ".5" fraction or "" otherwise
+			: '';
+		return Zotero.Date.dateToSQL(date, false) + offset;
+	}
+	
+	/*
+	 * Get field value from feed entry by namespace:fieldName
+	 */
+	// Properties are stored internally as ns+name, but only some namespaces are
+	// supported. Others are just "null"
+	let ns = {
+		'prism': 'null',
+		'dc': 'dc:'
+	}
+	function getFeedField(feedEntry, namespace, field) {
+		let prefix = namespace ? ns[namespace] || 'null' : '';
+		try {
+			return feedEntry.fields.getPropertyAsAUTF8String(prefix+field);
+		} catch(e) {}
+		
+		try {
+			if (namespace && !ns[namespace]) {
+				prefix = namespace + ':';
+				return feedEntry.fields.getPropertyAsAUTF8String(prefix+field);
+			}
+		} catch(e) {}
+		
+		return;
+	}
+	
+	/*
+	 * Parse feed entry into a Zotero item
+	 */
+	function getFeedItem(feedEntry, feedInfo) {
+		// ID is not required, but most feeds have these and we have to rely on them
+		// to handle updating properly
+		if (!feedEntry.id) {
+			Zotero.debug("FeedReader: Feed item missing an ID");
+			return;
+		}
+		
+		let item = {
+			guid: feedEntry.id
+		};
+				
+		if (feedEntry.title) item.title = getRichText(feedEntry.title, 'title');
+		
+		if (feedEntry.summary) {
+			item.abstractNote = getRichText(feedEntry.summary, 'abstractNote');
+			
+			if (!item.title) {
+				// We will probably have to trim this, so let's use plain text to
+				// avoid splitting inside some markup
+				let title = Zotero.Utilities.trimInternal(feedEntry.summary.plainText());
+				let splitAt = title.lastIndexOf(' ', 50);
+				if (splitAt == -1) splitAt = 50;
+				
+				item.title = title.substr(0, splitAt);
+				if (splitAt <= title.length) item.title += '...';
+			}
+		}
+		
+		if (feedEntry.link) item.url = feedEntry.link.spec;
+		
+		if (feedEntry.updated) item.dateModified = new Date(feedEntry.updated);
+		
+		if (feedEntry.published) {
+			let date = new Date(feedEntry.published);
+			
+			if (!date.getUTCSeconds() && !(date.getUTCHours() && date.getUTCMinutes())) {
+				// There was probably no time, but there may have been a a date range,
+				// so something could have ended up in the hour _or_ minute field
+				item.date = getFeedField(feedEntry, null, 'pubDate')
+					/* In case it was magically pulled from some other field */
+					|| ( date.getUTCFullYear() + '-'
+						+ (date.getUTCMonth() + 1) + '-'
+						+  date.getUTCDate() );
+			} else {
+				item.date = formatDate(date);
+				// Add time zone
+			}
+			
+			if (!item.dateModified) {
+				items.dateModified = date;
+			}
+		}
+		
+		if (!item.dateModified) {
+			// When there's no reliable modification date, we can assume that item doesn't get updated
+			Zotero.debug("FeedReader: Feed item missing a modification date (" + item.guid + ")");
+			item.dateModified = null;
+		}
+		
+		if (!item.date && item.dateModified) {
+			// Use lastModified date
+			item.date = formatDate(item.dateModified);
+		}
+		
+		// Convert date modified to string, since those are directly comparable
+		if (item.dateModified) item.dateModified = Zotero.Date.dateToSQL(item.dateModified, true);
+		
+		if (feedEntry.rights) item.rights = getRichText(feedEntry.rights, 'rights');
+		
+		item.creators = processCreators(feedEntry, 'authors', 'author');
+		if (!item.creators.length) {
+			// Use feed authors as item author. Maybe not the best idea.
+			for (let i=0; i<feedInfo.creators.length; i++) {
+				if (feedInfo.creators[i].creatorType != 'author') continue;
+				item.creators.push(feedInfo.creators[i]);
+			}
+		}
+		
+		let contributors = processCreators(feedEntry, 'contributors', 'contributor');
+		if (contributors.length) item.creators = item.creators.concat(contributors);
+		
+		/** Done with basic metadata, now look for better data **/
+		
+		let date = getFeedField(feedEntry, 'prism', 'publicationDate')
+			|| getFeedField(feedEntry, 'dc', 'date');
+		if (date) item.date = date;
+		
+		let publicationTitle = getFeedField(feedEntry, 'prism', 'publicationName')
+			|| getFeedField(feedEntry, 'dc', 'source')
+			|| getFeedField(feedEntry, null, 'pubTitle');
+		if (publicationTitle) item.publicationTitle = publicationTitle;
+		
+		let publicationType = getFeedField(feedEntry, null, 'pubType');
+		if (publicationType) item.publicationType = publicationType;
+		
+		let startPage = getFeedField(feedEntry, null, 'startPage');
+		let endPage = getFeedField(feedEntry, null, 'endPage');
+		if (startPage || endPage) {
+			item.pages = ( startPage || '' )
+				+ ( endPage && startPage ? '–' : '' )
+				+ ( endPage || '' );
+		}
+		
+		let issn = getFeedField(feedEntry, 'prism', 'issn');
+		if (issn) item.ISSN = issn;
+		
+		let isbn = getFeedField(feedEntry, 'prism', 'isbn')
+			|| getFeedField(feedEntry, null, 'isbn')
+		if (isbn) item.ISBN = isbn;
+		
+		let identifier = getFeedField(feedEntry, 'dc', 'identifier');
+		if (identifier) {
+			let cleanId = Zotero.Utilities.cleanDOI(identifier);
+			if (cleanId) {
+				if (!item.DOI) item.DOI = cleanId;
+			} else if (cleanId = Zotero.Utilities.cleanISBN(identifier)) {
+				if (!item.ISBN) item.ISBN = cleanId;
+			} else if (cleanId = Zotero.Utilities.cleanISSN(identifier)) {
+				if (!item.ISSN) item.ISSN = cleanId;
+			}
+		}
+		
+		let publisher = getFeedField(feedEntry, 'dc', 'publisher');
+		if (publisher) item.publisher = publisher;
+		
+		let rights = getFeedField(feedEntry, 'prism', 'copyright')
+			|| getFeedField(feedEntry, 'dc', 'rights')
+			|| getFeedField(feedEntry, null, 'copyright');
+		if (rights) item.rights = rights;
+		
+		let language = getFeedField(feedEntry, 'dc', 'language')
+			|| getFeedField(feedEntry, null, 'language');
+		if (language) item.language = language;
+		
+		/** Incorporate missing values from feed metadata **/
+		
+		let supplementFields = ['publicationTitle', 'ISSN', 'publisher', 'rights', 'language'];
+		for (let i=0; i<supplementFields.length; i++) {
+			let field = supplementFields[i];
+			if (!item[field] && feedInfo[field]) {
+				item[field] = feedInfo[field];
+			}
+		}
+		
+		guessItemType(item);
+		
+		return item;
+	}
+	
+	/*********************
+	 * FeedReader object *
+	 *********************/
+	let FeedReader = function(url) {
+		if (!url) throw new Error("Feed URL must be supplied");
+		
+		this._feed = Zotero.Promise.defer(); // Fetched asynchronously
+		
+		this._feedProperties = this._feed.promise
+		.then(function(feed) {
+			let info = {};
+			
+			info.title = feed.title ? feed.title.plainText() : '';
+			info.subtitle = feed.subtitle ? feed.subtitle.plainText() : '';
+			
+			if (feed.updated) info.updated = new Date(feed.updated);
+			
+			// categories: MDN says "not yet implemented"
+			
+			info.creators = processCreators(feed, 'authors', 'author');
+			
+			// TODO: image as icon
+			
+			let publicationTitle = getFeedField(feed, 'prism', 'publicationName')
+				|| getFeedField(feed, null, 'pubTitle');
+			if (publicationTitle) info.publicationTitle = publicationTitle;
+			
+			let publisher = getFeedField(feed, 'dc', 'publisher');
+			if (publisher) info.publisher = publisher;
+			
+			let rights = (feed.rights && feed.rights.plainText())
+				|| getFeedField(feed, 'prism', 'copyright')
+				|| getFeedField(feed, 'dc', 'rights')
+				|| getFeedField(feed, null, 'copyright');
+			if (rights) info.rights = rights;
+			
+			let issn = getFeedField(feed, 'prism', 'issn');
+			if (issn) info.ISSN = issn;
+			
+			let isbn = getFeedField(feed, 'prism', 'isbn')
+				|| getFeedField(feed, null, 'isbn')
+			if (isbn) info.ISBN = isbn;
+			
+			let language = getFeedField(feed, 'dc', 'language')
+				|| getFeedField(feed, null, 'language');
+			if (language) info.language = language;
+			
+			let ttl = getFeedField(feed, null, 'ttl');
+			if (ttl) info.ttl = ttl;
+			
+			return info;
+		});
+		
+		// Array of deferred item promises
+		this._feedItems = [Zotero.Promise.defer()];
+		
+		// Process items once they're available and push them into the array
+		Zotero.Promise.join(
+			this._feed.promise,
+			this._feedProperties,
+			(feed, feedInfo) => {
+				let items = feed.items;
+				if (items && items.length) {
+					for (let i=0; i<items.length; i++) {
+						let item = items.queryElementAt(i, Components.interfaces.nsIFeedEntry);
+						if (!item) continue;
+						
+						let feedItem = getFeedItem(item, feedInfo);
+						if (!feedItem) continue;
+						
+						let lastItem = this._feedItems[this._feedItems.length - 1];
+						this._feedItems.push(Zotero.Promise.defer()); // Push a new deferred promise so an iterator has something to return
+						lastItem.resolve(feedItem);
+					}
+				}
+			}
+		)
+		.finally(() => {
+			// Make sure the last promise gets resolved to null
+			let lastItem = this._feedItems[this._feedItems.length - 1];
+			lastItem.resolve(null);
+		});
+		
+		// Set up asynchronous feed processor
+		let feedProcessor = Components.classes["@mozilla.org/feed-processor;1"]
+			.createInstance(Components.interfaces.nsIFeedProcessor);
+		
+		let feedUrl = ios.newURI(url, null, null);
+		feedProcessor.parseAsync(null, feedUrl);
+		
+		feedProcessor.listener = {
+			/*
+			 * MDN suggests that we could use nsIFeedProgressListener to handle the feed
+			 * as it gets loaded, but this is actually not implemented (as of 32.0.3),
+			 * so we have to load the whole feed and handle it in handleResult.
+			 */
+			handleResult: (result) => {
+				if (!result.doc) {
+					this.terminate("No Feed");
+					return;
+				}
+				
+				let newFeed = result.doc.QueryInterface(Components.interfaces.nsIFeed);
+				this._feed.resolve(newFeed);
+			}
+		};
+		
+		Zotero.debug("FeedReader: Fetching feed from " + feedUrl.spec);
+		
+		this._channel = ios.newChannelFromURI(feedUrl);
+		this._channel.asyncOpen(feedProcessor, null); // Sends an HTTP request
+	}
+	
+	Zotero.defineProperty(FeedReader.prototype, 'feedProperties', {
+		get: function() this._feedProperties
+	});
+	
+	/*
+	 * Feed item iterator
+	 * Each iteration returns a _promise_ for an item. The promise _MUST_ be
+	 * resolved before requesting the next item.
+	 * The last item will always be resolved to `null`, unless the feed processing
+	 * is terminated ahead of time, in which case it will be rejected with the reason
+	 * for termination.
+	 */
+	Zotero.defineProperty(FeedReader.prototype, 'itemIterator', {
+		get: function() {
+			let items = this._feedItems;
+			return new function() {
+				let i = 0;
+				this.next = function() {
+					let item = items[i++];
+					return {
+						value: item ? item.promise : null,
+						done: i >= items.length
+					};
+				};
+			}
+		}
+	});
+	
+	/*
+	 * Terminate feed processing at any given time
+	 * @param {String} status Reason for terminating processing
+	 */
+	FeedReader.prototype.terminate = function(status) {
+		Zotero.debug("FeedReader: Terminating feed reader (" + status + ")");
+		
+		// Reject feed promise if not resolved yet
+		if (this._feed.promise.isPending()) {
+			this._feed.reject(status);
+		}
+		
+		// Reject feed item promise if not resolved yet
+		let lastItem = this._feedItems[this._feedItems.length - 1];
+		if (lastItem.promise.isPending()) {
+			lastItem.reject(status);
+		}
+		
+		// Close feed connection
+		if (channel.isPending) {
+			channel.cancel(Components.results.NS_BINDING_ABORTED);
+		}
+	};
+	
+	return FeedReader;
+};

components/zotero-service.js

@@ -85,6 +85,7 @@ const xpcomFilesLocal = [
 	'data/tags',
 	'db',
 	'duplicates',
+	'feedReader',
 	'fulltext',
 	'id',
 	'integration',