First check in of map of science visualization

productMods/js/visualization/mapofscience/DownloadManager.js

@@ -0,0 +1,50 @@
+/* $This file is distributed under the terms of the license in /doc/license.txt$ */
+/**
+ * Manage async download contents and make sure don't have the same 
+ * download request in the same time. Provide ability to abort download.
+ */
+
+var DownloadManager = Class.extend({
+	init: function() {
+		this.downloadList = {};
+	},
+	download: function(url, success) {
+		if (!this.hasKey(url)) {
+			this.downloadList[url] = { success: success, // TODO Try removing this property
+					jqxhr: this.startDownload(url, success, this.downloadList)};
+		}
+	},
+	downloadAndWait: function(url, success) {
+		if (!this.hasKey(url)) {
+			$.ajax({
+				url: url,
+				async: false,
+				dataType: 'json',
+				success: function(countData) { success(countData); }
+			});
+		}
+	},
+	startDownload: function(url, success, downloadList) {
+		 return $.getJSON(url, // TODO Not always "latest" //TODO Test on server with big file that consume 3 seconds download time. Then Keep on and off the checkbox while downloading, to verify if the duplicate happens
+				function(countData) {
+			        if (success) {
+						success(countData);
+		 			}
+			        delete(downloadList[url]);
+				}
+			);
+	},
+	hasKey: function(url) {
+		return (this.downloadList[url]);
+	},
+	abort: function(url) {
+		var options = this.downloadList[url];
+		if (options) {
+			options.jqxhr.abort();
+			delete(this.downloadList[url]);
+		}
+	},
+	isDone: function(url) {
+		return !this.hasKey(url);
+	}
+});