debugout.js

(debug output) generates a text file from your logs that can be searched, timestamped, downloaded and more. See some examples below.

Debugout's log() accepts any type of object including functions. Debugout is not a monkey patch, but a separate logging class altogether that you use instead of console.

Some highlights of debugout:

• get the entire log, or the tail at run-time or any time
• search and slice the log
• better understand usage patterns with optional timestamps
• toggle live logging (console.log) in one place
• optionally store the output in window.localStorage and continuously add to the same log each session
• optionally cap the log to X most recent lines to limit memory consumption

Try the demo

Installation

Simply include the debugout.js file in your project or install via a package manager:

npm: npm install debugout.js

bower: bower install debugout.js

Usage

Create a new debugout object in the global namespace, at the top of your script, and replace all your console log methods with debugout's log method:

var bugout = new debugout();  // instead of console.log('some object or string') bugout.log('some object or string');

Whatever you log is saved and added to the log file on a new line.

Methods

• log() - like console.log(), but saved!
• getLog() - returns the entire log.
• tail(numLines) - returns the last X lines of the log, where X is the number you pass. Defaults to 100.
• search(string) - returns numbered lines where there were matches for your search. Pass a string.
• getSlice(start, numLines) - get a 'slice' of the log. Pass the starting line and how many lines after it you want
• downloadLog() - downloads a .txt file of the log. See example below.
• clear() - clears the log.
• determineType() - a more granular version of typeof for your convenience

Options

In the debugout function definition, you can edit options:

// log in real time (forwards to console.log) self.realTimeLoggingOn = true;  // insert a timestamp in front of each log self.useTimestamps = false;  // store the output using window.localStorage() and continuously add to the same log each session self.useLocalStorage = false;  // set to false after you're done debugging to avoid the log eating up memory self.recordLogs = true;  // to avoid the log eating up potentially endless memory self.autoTrim = true;  // if autoTrim is true, this many most recent lines are saved self.maxLines = 2500;  // how many lines tail() will retrieve self.tailNumLines = 100;  // filename of log downloaded with downloadLog() self.logFilename = 'log.txt'; // max recursion depth for logged objects self.maxDepth = 25;

Outputting examples

Here are a couple examples of what you can do with the log. Each example assumes that you have established a debugout object and are logging with it:

var bugout = new debugout(); bugout.log('something'); bugout.log(somethingElse); bugout.log('etc');

Example #1: Button that downloads the log as a .txt file

Simply call debugout's downloadLog() method. You can change the filename by editing self.logFilename.

<input type="button" value="Download log" onClick="bugout.downloadLog()">

Example #2: PhoneGap app that attaches the log to an email

Example shown uses the Email Composer plugin and also requires the File plugin: cordova plugin add org.apache.cordova.file.

function sendLog() { 	var logFile = bugout.getLog();  	// save the file locally, so it can be retrieved from emailComposer 	window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function(fileSystem) { 		// create the file if it doesn't exist 		fileSystem.root.getFile('log.txt', {create: true, exclusive: false}, function(file) { 			// create writer 			file.createWriter(function(writer) { 		        // write 	    		writer.write(logFile); 	    		// when done writing, call up email composer 				writer.onwriteend = function(evt) { 		            // params: subject,body,toRecipients,ccRecipients,bccRecipients,bIsHTML,attachments,filename 		            var subject = 'Log from myApp'; 		            var body = 'Attached is a log from my recent testing session.'; 					window.plugins.emailComposer.showEmailComposer(subject,body,[],[],[],false,['log.txt'], ['myApp log']); 		        } 			}, fileSystemError); 		}, fileSystemError); 	}, fileSystemError); } function fileSystemError(error) {     bugout.log('Error getting file system: '+error.code); }

And more...

• Post the log to your server via an ajax request if an error or some other event occurs.
• Allow the user to download a copy of a submitted form.
• Generate a receipt for the user to download.
• Record survey answers and know how long each question took the user to answer.