SoFlo PHP 2013-09 – September

The monthly SoFlo PHP meetup was moved at the last minute to LiveNinja‘s offices in Miami. Thanks to Ptah for jumping in at the last minute with the space. The topic was debugging in PHP. I had to leave before our keynote speaker could get started, but got some good tips from Adrien and Ptah. I’m moving my usual “to Google” list from Google docs to here. Some of this might get fleshed out later as a separate post.

PHP Debugging tools

Xdebug is installed as a PHP extension and will let you step through code, do breakpoints, and other debugger things. There is a Windows build, with a pretty cool wizard that will analyze the output of phpinfo to provide custom install instructions. There is also Zend PHP Debugger, part of the Zend server stack.

Charles Proxy was mentioned as a traffic inspection tool. Looks like it’s similar to Fiddler. It might be worth seeing if it can inspect the SSL payload without the private key (doubtful), I think probably Firebug on the client and Wireshark on the server are a more powerful combination.

Monolog is a centralized logging class which seems pretty cool. Instead of writing myextension_debugprint() and stuffing file_get_contents into it, this might be a more graceful solution.

PHP has added some new functions, error_handler and exception_handler which take a callable function and let you die a little more gracefully when you have some coding mistake. IMO trying anything which throws an exception is critical, but error_handler is nice since writting if ((array_key_exists()) && (isset()) get’s a bit stale.

Some popular IDEs to check out

  • Zend Studio – I got a license for this with my ZCE and should probably install it.
  • PHPStorm – well known and popular
  • Sublime Text – this is a lightweight editor, more like Notepad++ than a brutal IDE. Has an x64 Windows build. After installing and taking a quick look, Notepad++ and even Crimson Editor seem better.

Other stuff

Pimple is a dependency injection container which will instantiate objects on demand instead of all up front.

Postman is a Google Chrome extension which helps you craft HTTP post messages. This is really helpful if you’re doing REST, but also if you’re writing a site scraper.

Server side browser features with phpcaniuse

The Browser Capabilities Project is an effort to determine browser capabilities based on the User-Agent string. It’s a great project which has kept up to date with UA stings. The data is used to power the PHP function get_browser(), and is used by the phpbrowscap standalone project. The challenge with the project is that their features haven’t kept up with the rapid development of web technology.

The CanIUse.com project catalogs granular data about the capabilities of web browsers. They’ve done an excellent job of tracking emerging features like HTML5 canvas and web audio. They also make all of the data available as a json file on github. Thanks!

So what do you do when you have two different projects, with different goals butĀ  some overlap? You create a mashup! Enter PHPCanIuse, which will let you check browser capabilities from the caniuse.com project, based on the decoded UA string from the browscap project.

JQuery and other javascript frameworks have client side feature detection, but there are a few scenarios where you might want to do it server side:

  • Embed a Flash video player or an HTML 5 video
  • Use native websockets or flash based (or, ew, timer based)
  • Send SVG as native markup, or pre-render it as a PNG

DISCLAIMER: Users can theoretically change their UA string, so it can’t be trusted 100%. It’s an advanced feature, so anyone who does, deserves the broken web experience they get.

Using phpcaniuse

phpcaniuse is a composer project. You’ll need the following require:

"robertlabrie/phpcaniuse": "dev-master"

Then as usual just composer install. The class is a single file, so if you hate composer, you canĀ  just include CanIUse.php. Then just instantiate the object

$can = new phpcaniuse\CanIUse($browser,$data);

The $browser object can come from either get_browser() or phpbrowscap. CanIUse expects the object, not the associative array. $data is a string containing the contents of data.json from the caniuse.com project. Pass it in as a string, do not decode it.

The methods are pretty straight forward:

Function Description
check(list) Checks to see if the browser supports the specified list of features. Takes a string of a single feature, or an array of features. Returns the lowest level of support for the list.
featureList() Returns an associative array of all the features tracked by caniuse. The key is the key used to check a feature, and value is a friendly description.
featureGet(feature) Retuns the set of JSON data for the specified feature.
browserCan() Returns an associative array of all features and the status within the browser. Key is the feature, value is the status.
agentMapAdd(browscapName,caniuseName) Adds a mapping between a browscap name and a caniuse name.
browserSet(browser) Sets the browser object. Must come from get_browser() or phpcaniuse.
dataSet(data) Sets the json data from caniuse. Must be a string, not a json object or array.
dataGet() Returns the caniuse json data as an array.

phpcaniuse maps the browser name returned by browscap with the one used by caniuse. It’s currently done for Firefox, Internet Explorer, Opera, Safari and Chrome. Mobile browsers are not done, but if you can identify a mapping, please tell me.

The package includes a demo.php file which will tell you all about your browser.

Understanding the CanIUse.com data.json

The caniuse.com data.json file is broken up into several sections. I’ve laid it out in a table with my working notes, but the best way to understand it is print_r().

agents ie array of browsers – major ones listed here, many others supported
firefox
browser Firefox Seems to match the ->Browser property from browscap
versions …,”24″,”25″ array of browser versions where the index is used by caniuse
chrome
safari
opera
statuses status codes for features
rec Recommendation
pr Proposed Recommendation
cr Candidate Recommendation
wd Working Draft
other Other
unoff Unofficial / Note
cats categories for capabilities
updated date() the date the data was last updated
data
title A friendly title
description A good description
spec URL to specification
status Relates to the status codes above
stats Associative array of browsers, version feature
firefox Or any agent name
23 Vsersion 23
x Supported or not

The actual status codes are outlined below. They’re based on reverse engineering and might not be 100% accurate:

Stat Description
n Not supported
a Partially Supported
a x Partially Supported with prefix
p Polyfill required
y x Supported with prefix
y Supported
u Unknown