From 31130b8fe4a0cae1a498b3942f3c997ad3a0d6a5 Mon Sep 17 00:00:00 2001
From: Danny van Kooten <dannyvankooten@gmail.com>
Date: Fri, 25 Nov 2016 16:03:47 +0100
Subject: [PATCH] add async tracking snippet with command queue exampel

---
 LICENSE              |  0
 README.md            | 21 +++++++++++++++
 ROADMAP.md           |  1 -
 ana.go               |  3 ++-
 assets/js/tracker.js | 63 ++++++++++++++++++++++++++++----------------
 gulpfile.js          |  9 +++++--
 6 files changed, 71 insertions(+), 26 deletions(-)
 create mode 100644 LICENSE

diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..e69de29
diff --git a/README.md b/README.md
index 1fd3106..593540a 100644
--- a/README.md
+++ b/README.md
@@ -4,3 +4,24 @@ Ana. Open Source Web Analytics.
 This is nowhere near being usable, let alone stable. Treat as a proof of concept.
 
 ![Screenshot of the Ana dashboard](https://github.com/dannyvankooten/ana/raw/master/assets/img/screenshot.png?2)
+
+## Usage
+
+```html
+<!-- Ana tracker -->
+<script>
+(function(d, w, u, o){
+	w[o]=w[o]||function(){
+		(w[o].q=w[o].q||[]).push(arguments)
+	};
+	a=d.createElement('script'),
+	m=d.getElementsByTagName('script')[0];
+	a.async=1;
+	a.src=u;
+	m.parentNode.insertBefore(a,m)
+})(document, window, '//ana.dev/tracker.js', 'ana');
+ana('setTrackerUrl', '//ana.dev/collect');
+ana('trackPageview');
+</script>
+<!-- / Ana tracker -->
+```
diff --git a/ROADMAP.md b/ROADMAP.md
index af7c578..a95debe 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -5,7 +5,6 @@ This is a general draft document for thoughts and todo's. This has no structure.
 
 ### What's cooking?
 
-- Async tracking snippet.
 - Add license file.
 - Get DB creds from env.
 - JS client for consuming API endpoints.
diff --git a/ana.go b/ana.go
index 07c6147..d5d6489 100644
--- a/ana.go
+++ b/ana.go
@@ -37,8 +37,9 @@ func main() {
   r.Handle("/api/screen-resolutions", api.Authorize(api.GetScreenResolutionsHandler)).Methods("GET")
   r.Handle("/api/countries", api.Authorize(api.GetCountriesHandler)).Methods("GET")
   r.Handle("/api/browsers", api.Authorize(api.GetBrowsersHandler)).Methods("GET")
-  
+
   r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir("./static/"))))
+  r.Path("/tracker.js").Handler(http.FileServer(http.Dir("./static/js/")))
   r.Handle("/", http.FileServer(http.Dir("./views/")))
 
   http.ListenAndServe(":8080", handlers.LoggingHandler(os.Stdout, r))
diff --git a/assets/js/tracker.js b/assets/js/tracker.js
index dad826f..642601b 100644
--- a/assets/js/tracker.js
+++ b/assets/js/tracker.js
@@ -1,27 +1,37 @@
 'use strict';
 
-(function() {
-  function jsonToQueryString(json) {
-    var keys = Object.keys(json);
+var queue = window.ana.q || [];
+var trackerUrl = '//ana.dev/collect';
+var commands = {
+  "trackPageview": trackPageview,
+  "setTrackerUrl": setTrackerUrl,
+};
 
-    // omit empty
-    keys = keys.filter(function(k) {
-      return json[k].length > 0;
-    });
+// convert object to query string
+function stringifyObject(json) {
+  var keys = Object.keys(json);
 
-    return '?' +
-        keys.map(function(k) {
-            return encodeURIComponent(k) + '=' +
-                encodeURIComponent(json[k]);
-        }).join('&');
+  // omit empty
+  keys = keys.filter(function(k) {
+    return json[k].length > 0;
+  });
+
+  return '?' +
+      keys.map(function(k) {
+          return encodeURIComponent(k) + '=' +
+              encodeURIComponent(json[k]);
+      }).join('&');
+}
+
+function setTrackerUrl(v) {
+  trackerUrl = v;
+}
+
+function trackPageview() {
+  if( navigator.DonotTrack == 1 ) {
+    return;
   }
 
-  // abort hit if Do Not Track is enabled.
-  // if( navigator.DonotTrack == 1 ) {
-  //   return;
-  // }
-
-  var i = document.createElement('img');
   var d = {
     l: navigator.language,
     p: location.pathname + location.search,
@@ -30,8 +40,17 @@
     r: document.referrer
   };
 
-
-  i.src = 'http://localhost:8080/collect' + jsonToQueryString(d);
-
+  var i = document.createElement('img');
+  i.src = trackerUrl + stringifyObject(d);
   document.body.appendChild(i);
-})();
+}
+
+// override global ana object
+window.ana = function() {
+  var args = [].slice.call(arguments);
+  var c = args.shift();
+  commands[c].apply(this, args);
+};
+
+// process existing queue
+queue.map((i) => ana.apply(this, i));
diff --git a/gulpfile.js b/gulpfile.js
index 2a0a72a..457be8a 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -11,7 +11,7 @@ const rename = require('gulp-rename');
 const gutil = require('gulp-util');
 const sass = require('gulp-sass');
 
-gulp.task('default', [ 'browserify', 'sass' ] );
+gulp.task('default', [ 'browserify', 'sass', 'tracker' ] );
 
 gulp.task('browserify', function () {
     return browserify({
@@ -29,6 +29,11 @@ gulp.task('browserify', function () {
         .pipe(gulp.dest('./static/js/'))
 });
 
+gulp.task('tracker', function() {
+  return gulp.src('./assets/js/tracker.js')
+    .pipe(gulp.dest('./static/js'))
+});
+
 gulp.task('sass', function () {
 	var files = './assets/sass/[^_]*.scss';
 	return gulp.src(files)
@@ -39,6 +44,6 @@ gulp.task('sass', function () {
 });
 
 gulp.task('watch', ['default'], function() {
-  gulp.watch(['./assets/js/**/*.js'], ['browserify'] );
+  gulp.watch(['./assets/js/**/*.js'], ['browserify', 'tracker'] );
   gulp.watch(['./assets/sass/**/*.scss'], ['sass'] );
 });