Ticket #258: README

Introduction

* The js/ folder contains:

  - index.php - a servlet described below
  - piwik.js - the uncompressed piwik.js source for you to study or reference
  - README - this documentation file

Why Use "js/index.php"?

* js/index.php (or implicitly as "js/") can be used to serve up the minified
  piwik.js

  - it supports conditional-GET and Last-Modified, so piwik.js can be cached
    by the browser
  - it supports deflate/gzip compression if your web server (e.g., Apache
    without mod_deflate or mod_gzip), shrinking the data transfer to 8K

* js/index.php (or implicitly as "js/") can also act as a proxy to piwik.php

* If you are concerned about the impact of browser-based privacy filters which
  attempt to block tracking, you can change your tracking code to use "js/"
  instead of "piwik.js" and "piwik.php", respectively.

Deployment

* piwik.js is minified using YUICompressor 2.4.2.
  To install YUICompressor run:
    $ cd /path/to/piwik/js/
    $ wget http://www.julienlecomte.net/yuicompressor/yuicompressor-2.4.2.zip
    $ unzip yuicompressor-2.4.2.zip
    
  To compress the code containing the evil "eval", either apply the patch from
  http://yuilibrary.com/projects/yuicompressor/ticket/2343811,
  or run:
    $ cd /path/to/piwik/js/
    $ sed '/<DEBUG>/,/<\/DEBUG>/d' < piwik.js | sed 's/eval/replacedEvilString/' | java -jar yuicompressor-2.4.2/build/yuicompressor-2.4.2.jar --type js --line-break 1000 | sed 's/replacedEvilString/eval/' > piwik-min.js && cp piwik-min.js ../piwik.js
    
  This will generate the minify /path/to/piwik/js/piwik-min.js and copy it to
  /path/to/piwik/piwik.js

* In a production environment, the tests/javascript folder is not used and can
  be removed (if present).

  Note: if the file "js/tests/enable_sqlite" exists, additional unit tests
        (requires the sqlite extension) are enabled.