See Also functionality for items and notes

Item.addSeeAlso(itemID)
Item.removeSeeAlso(itemID)
Item.getSeeAlso() -- array of linked items

Relationships are mutual

Closes #82, Notes: see also table

chrome/chromeFiles/content/scholar/xpcom/data_access.js

@@ -981,6 +981,60 @@ Scholar.Item.prototype.removeTag = function(tagID){
 }
 
 
+//
+// Methods dealing with See Also links
+//
+// save() is not required for See Also functions
+//
+Scholar.Item.prototype.addSeeAlso = function(itemID){
+	if (itemID==this.getID()){
+		Scholar.debug('Cannot add item as See Also of itself', 2);
+		return false;
+	}
+	
+	Scholar.DB.beginTransaction();
+	
+	if (!Scholar.Items.get(itemID)){
+		Scholar.DB.commitTransaction();
+		throw ("Cannot add invalid item " + itemID + " as See Also");
+		return false;
+	}
+	
+	// Check both ways, using a UNION to take advantage of indexes
+	var sql = "SELECT (SELECT COUNT(*) FROM itemSeeAlso WHERE itemID=?1 AND "
+		+ "linkedItemID=?2) + (SELECT COUNT(*) FROM itemSeeAlso WHERE "
+		+ "linkedItemID=?1 AND itemID=?2)";
+	if (Scholar.DB.valueQuery(sql, [this.getID(), itemID])){
+		Scholar.DB.commitTransaction();
+		Scholar.debug("Item " + itemID + " already linked", 2);
+		return false;
+	}
+	
+	var sql = "INSERT INTO itemSeeAlso VALUES (?,?)";
+	Scholar.DB.query(sql, [this.getID(), {int:itemID}]);
+	Scholar.DB.commitTransaction();
+	Scholar.Notifier.trigger('modify', 'item', [this.getID(), itemID]);
+	return true;
+}
+
+Scholar.Item.prototype.removeSeeAlso = function(itemID){
+	Scholar.DB.beginTransaction();
+	var sql = "DELETE FROM itemSeeAlso WHERE itemID=? AND linkedItemID=?";
+	Scholar.DB.query(sql, [this.getID(), itemID]);
+	var sql = "DELETE FROM itemSeeAlso WHERE itemID=? AND linkedItemID=?";
+	Scholar.DB.query(sql, [itemID, this.getID()]);
+	Scholar.DB.commitTransaction();
+	Scholar.Notifier.trigger('modify', 'item', [this.getID(), itemID]);
+}
+
+Scholar.Item.prototype.getSeeAlso = function(){
+	// Check both ways, using a UNION to take advantage of indexes
+	var sql ="SELECT linkedItemID FROM itemSeeAlso WHERE itemID=?1 UNION "
+		+ "SELECT itemID FROM itemSeeAlso WHERE linkedItemID=?1";
+	return Scholar.DB.columnQuery(sql, this.getID());
+}
+
+
 /**
 * Delete item from database and clear from Scholar.Items internal array
 **/
@@ -990,7 +1044,9 @@ Scholar.Item.prototype.erase = function(){
 	}
 	
 	Scholar.debug('Deleting item ' + this.getID());
-		
+	
+	var changedItems = [];
+	
 	Scholar.DB.beginTransaction();
 	
 	// Remove item from parent collections
@@ -1006,7 +1062,7 @@ Scholar.Item.prototype.erase = function(){
 		if (sourceItemID){
 			var sourceItem = Scholar.Items.get(sourceItemID);
 			sourceItem.decrementNoteCount();
-			Scholar.Notifier.trigger('modify', 'item', sourceItemID);
+			changedItems.push(sourceItemID);
 		}
 	}
 	// If not note, unassociate any notes for which this is a source
@@ -1015,16 +1071,25 @@ Scholar.Item.prototype.erase = function(){
 		
 		var sql = "SELECT itemID FROM itemNotes WHERE sourceItemID=" + this.getID();
 		var childNotes = Scholar.DB.columnQuery(sql);
+		if (childNotes){
+			changedItems.push(childNotes);
+		}
 		
 		var sql = "UPDATE itemNotes SET sourceItemID=NULL WHERE sourceItemID="
 			+ this.getID();
 		Scholar.DB.query(sql);
 	}
 	
-	// TODO: remove item from See Also table
+	// Flag See Also links for notification
+	var seeAlso = this.getSeeAlso();
+	if (seeAlso){
+		changedItems = changedItems.concat(seeAlso);
+	}
 	
 	sql = 'DELETE FROM itemCreators WHERE itemID=' + this.getID() + ";\n";
 	sql += 'DELETE FROM itemNotes WHERE itemID=' + this.getID() + ";\n";
+	sql += 'DELETE FROM itemSeeAlso WHERE itemID=' + this.getID() + ";\n";
+	sql += 'DELETE FROM itemSeeAlso WHERE linkedItemID=' + this.getID() + ";\n";
 	sql += 'DELETE FROM itemTags WHERE itemID=' + this.getID() + ";\n";
 	sql += 'DELETE FROM itemData WHERE itemID=' + this.getID() + ";\n";
 	sql += 'DELETE FROM items WHERE itemID=' + this.getID() + ";\n";
@@ -1045,9 +1110,9 @@ Scholar.Item.prototype.erase = function(){
 	
 	Scholar.Items.unload(this.getID());
 	
-	// Send notification of unlinked notes
-	if (childNotes){
-		Scholar.Notifier.trigger('modify', 'item', childNotes);
+	// Send notification of changed items
+	if (changedItems.length){
+		Scholar.Notifier.trigger('modify', 'item', changedItems);
 	}
 	
 	// If we're not in the middle of a larger commit, trigger the notifier now

chrome/chromeFiles/content/scholar/xpcom/schema.js

@@ -385,7 +385,7 @@ Scholar.Schema = new function(){
 		//
 		// Change this value to match the schema version
 		//
-		var toVersion = 27;
+		var toVersion = 28;
 		
 		if (toVersion != _getSchemaSQLVersion()){
 			throw('Schema version does not match version in _migrateSchema()');
@@ -400,10 +400,9 @@ Scholar.Schema = new function(){
 		// Each block performs the changes necessary to move from the
 		// previous revision to that one.
 		for (var i=parseInt(fromVersion) + 1; i<=toVersion; i++){
-			if (i==26){
+			if (i==28){
 				Scholar.DB.query("DROP TABLE IF EXISTS keywords");
 				Scholar.DB.query("DROP TABLE IF EXISTS itemKeywords");
-			} else if(i==27) {
 				Scholar.DB.query("DROP TABLE IF EXISTS scrapers");
 				_initializeSchema();
 			}

schema.sql

@@ -1,4 +1,4 @@
--- 27
+-- 28
 
     DROP TABLE IF EXISTS version;
     CREATE TABLE version (
@@ -89,6 +89,17 @@
     DROP INDEX IF EXISTS itemTags_tagID;
     CREATE INDEX itemTags_tagID ON itemTags(tagID);
     
+    DROP TABLE IF EXISTS itemSeeAlso;
+    CREATE TABLE itemSeeAlso (
+        itemID INT,
+        linkedItemID INT,
+        PRIMARY KEY (itemID, linkedItemID),
+        FOREIGN KEY (itemID) REFERENCES items(itemID),
+        FOREIGN KEY (linkedItemID) REFERENCES items(itemID)
+    );
+    DROP INDEX IF EXISTS itemSeeAlso_linkedItemID;
+    CREATE INDEX itemSeeAlso_linkedItemID ON itemSeeAlso(linkedItemID);
+    
     DROP TABLE IF EXISTS creators;
     CREATE TABLE creators (
         creatorID INT,