Merge pull request #241 from macbre/milestone-events

Emit events via npm module for certain page loading milestones

core/ipc.js

@@ -9,10 +9,10 @@ function ipc(event) {
 	this.event = event;
 }
 
-ipc.prototype.push = function(data) {
+ipc.prototype.push = function() {
 	stderr.writeLine(JSON.stringify({
 		event: this.event,
-		data: data
+		data: Array.prototype.slice.apply(arguments)
 	}));
 };
 

core/modules/requestsMonitor/requestsMonitor.js

@@ -1,7 +1,7 @@
 /**
  * Simple HTTP requests monitor and analyzer
  */
-exports.version = '1.1';
+exports.version = '1.2';
 
 exports.module = function(phantomas) {
 	// imports
@@ -280,8 +280,8 @@ exports.module = function(phantomas) {
 	phantomas.on('recv', function(entry, res) {
 		// check the first response which is not a redirect (issue #74)
 		if (!ttfbMeasured && !entry.isRedirect) {
-			phantomas.setMetric('timeToFirstByte', entry.timeToFirstByte);
-			phantomas.setMetric('timeToLastByte', entry.timeToLastByte);
+			phantomas.setMetric('timeToFirstByte', entry.timeToFirstByte, true);
+			phantomas.setMetric('timeToLastByte', entry.timeToLastByte, true);
 
 			ttfbMeasured = true;
 

core/phantomas.js

@@ -692,7 +692,7 @@ phantomas.prototype = {
 				break;
 
 			case 'setMetric':
-				this.setMetric(data.name, data.value);
+				this.setMetric(data.name, data.value, data.isFinal);
 				break;
 
 			case 'incrMetric':
@@ -718,13 +718,20 @@ phantomas.prototype = {
 	},
 
 	// metrics reporting
-	setMetric: function(name, value) {
+	setMetric: function(name, value, isFinal) {
+		var ipc = new (require('./ipc'))('metric');
+
 		value = typeof value === 'string' ? value : (value || 0); // set to zero if undefined / null is provided
 		this.results.setMetric(name, value);
+
+		// trigger an event when the metric value is said to be final (isse #240)
+		if (isFinal === true) {
+			ipc.push(name, value);
+		}
 	},
 
 	setMetricEvaluate: function(name, fn) {
-		this.setMetric(name, this.page.evaluate(fn));
+		this.setMetric(name, this.page.evaluate(fn), true /* isFinal */);
 	},
 
 	setMarkerMetric: function(name) {
@@ -735,7 +742,7 @@ phantomas.prototype = {
 			throw 'setMarkerMetric() called before responseEnd event!';
 		}
 
-		this.results.setMetric(name, value);
+		this.setMetric(name, value, true /* isFinal */);
 		return value;
 	},
 
@@ -746,7 +753,7 @@ phantomas.prototype = {
 		// @ee https://github.com/ariya/phantomjs/wiki/API-Reference-WebPage#evaluatefunction-arg1-arg2--object
 		this.setMetric(name, this.page.evaluate(function(key) {
 			return window.__phantomas.get(key) || 0;
-		}, key));
+		}, key), true /* isFinal */);
 	},
 
 	// get a value set using window.__phantomas browser scope

core/scope.js

@@ -141,8 +141,8 @@
 			sendMsg('log', msg);
 		}
 
-		function setMetric(name, value) {
-			sendMsg('setMetric', {name: name, value: (typeof value !== 'undefined') ? value : 0});
+		function setMetric(name, value, isFinal) {
+			sendMsg('setMetric', {name: name, value: (typeof value !== 'undefined') ? value : 0, isFinal: isFinal === true});
 		}
 
 		function incrMetric(name, incr /* =1 */) {

examples/npm.js

@@ -0,0 +1,36 @@
+#!/usr/bin/env node
+
+/**
+ * Example script that uses phantomas npm module
+ */
+var phantomas = require('../'),
+	run;
+
+console.log('phantomas v%s loaded from %s', phantomas.version, phantomas.path);
+
+run = phantomas('http://google.is', {
+	'analyze-css': true,
+	'assert-requests': 1
+});
+
+console.log('Running phantomas: pid %d', run.pid);
+
+// errors handling
+run.on('error', function(code) {
+	console.log('Exit code #%d', code);
+});
+
+// handle results
+run.on('results', function(results) {
+	console.log('Number of requests: %d', results.getMetric('requests'));
+	console.log('Failed asserts: %j', results.getFailedAsserts());
+});
+
+// events handling
+run.on('progress', function(progress) {
+	console.log('Loading progress: %d%', progress);
+});
+
+run.on('milestone', function(milestone, timing) {
+	console.log('%s at %d ms', milestone, timing);
+});

lib/index.js

@@ -112,6 +112,21 @@ function phantomas(url, options, callback) {
 		events.emit('progress', progress);
 	});
 
+	// handle page loading milestones (#240)
+	var milestoneDebug = require('debug')('phantomas:milestone');
+
+	ipc.on('metric', function(metric, value) {
+		switch(metric) {
+			case 'timeToFirstByte':
+			case 'timeToLastByte':
+			case 'onDOMReadyTime':
+			case 'windowOnLoadTime':
+				milestoneDebug('%s: %d ms', metric, value);
+				events.emit('milestone', metric, value);
+				break;
+		}
+	});
+
 	// process results
 	proc.on('close', function(code) {
 		var debug = require('debug')('phantomas:results'),

lib/ipc.js

@@ -23,10 +23,14 @@ ipc.prototype.init = function() {
 		messages.forEach(function(msg) {
 			if (msg === '') return;
 
-			debug('%s', msg);
 			msg = JSON.parse(msg);
+			debug('%s: %j', msg.event, msg.data);
 
-			self.events.emit(msg.event, msg.data);
+			// send event name and the rest of the data
+			var args = msg.data;
+			args.unshift(msg.event);
+
+			self.events.emit.apply(self.events, args);
 		});
 	});
 };

test/public-api-test.js

@@ -14,7 +14,10 @@ mockery.registerMock('fs', {
 	list: function() {}
 });
 mockery.registerMock('system', {
-	os: {}
+	os: {},
+	stderr: {
+		writeLine: function() {}
+	}
 });
 mockery.registerMock('webpage', {
 	create: function() {