Tag: PHP

YANG – A Data Modeling Language for the Network Configuration Protocol (NETCONF)

In the spirit of validating everything against a schema (validating JSON, validating CSV), here is another option – YANG:

YANG is a data modeling language for the definition of data sent over the NETCONF network configuration protocol. The name is an acronym for “Yet Another Next Generation”. The YANG data modeling language was developed by the NETMOD working group in the Internet Engineering Task Force (IETF) and was published as RFC 6020 in October 2010. The data modeling language can be used to model both configuration data as well as state data of network elements. Furthermore, YANG can be used to define the format of event notifications emitted by network elements and it allows data modelers to define the signature of remote procedure calls that can be invoked on network elements via the NETCONF protocol. The language, being protocol independent, can then be converted into any encoding format, e.g. XML or JSON, that the network configuration protocol supports.

YANG is a modular language representing data structures in an XML tree format. The data modeling language comes with a number of built-in data types. Additional application specific data types can be derived from the built-in data types. More complex reusable data structures can be represented as groupings. YANG data models can use XPATH expressions to define constraints on the elements of a YANG data model.

Like many other standards, formats, and tools developed by very smart people, YANG can be used for much more than just networking configuration.  If you data and states fit into its model, give it a try.

Here are a few resources that you might find useful in the process:

WordPress Plugin : Image Processing Queue

As described in “Introducing WP Image Processing Queue – On‑the‑Fly Image Processing Done Right“, Image Processing Queue plugin tries to solve several issues with On-The-Fly Image Processing (OTFIP) in WordPress.  Some of the things that it improves are:

  • Response times for pages with non-yet generated thumbnails.
  • Server CPU spikes for pages which use a lot of images on sites with a lot of configured thumbnail sizes (49? really? WOW! I don’t think I’ve seen more than 10 in the wild, which is still a lot).
  • Server disk space issues caused by removed images and leftover thumbnails.

This is a very useful direction and I hope all the necessary bits will make it into the WordPress core.  But even for those who don’t use WordPress, the whole discussion and implementation are a handy reference.

PHPUnit Snapshot Assertions – a way to test without writing actual test cases

phpunit-snapshot-assertions – is an interesting addition to the PHPUnit assertions which allows testing against previously created snapshots.  This is particularly useful for testing the outputs of API end-points, format conversion functions, and the like.  Instead of testing the actual functionality, these assertions allow to compare the output of the current test run with the known good output of a previously created snapshot.

This works well for generic text, but even better for widely used formats like JSON and XML, where, in case of a failed assertion, a meaningful difference can be provided.

Here is a blog post providing some more details on philosophy and methodology.

Charles – web debugging proxy application

Charles is a web debugging proxy application for Windows, Mac OS, and Linux.  Here’s a quick description from the project’s website:

Charles is an HTTP proxy / HTTP monitor / Reverse Proxy that enables a developer to view all of the HTTP and SSL / HTTPS traffic between their machine and the Internet. This includes requests, responses and the HTTP headers (which contain the cookies and caching information).

And here are some key features:

  • SSL Proxying – view SSL requests and responses in plain text
  • Bandwidth Throttling to simulate slower Internet connections including latency
  • AJAX debugging – view XML and JSON requests and responses as a tree or as text
  • AMF – view the contents of Flash Remoting / Flex Remoting messages as a tree
  • Repeat requests to test back-end changes
  • Edit requests to test different inputs
  • Breakpoints to intercept and edit requests or responses
  • Validate recorded HTML, CSS and RSS/atom responses using the W3C validator

Pretty much every browser these days comes with developer tools (like Google Chrome, for example).

But these are mostly useful for requests made by the browser itself.  Often, like depicted in “PHP and cURL: How WordPress makes HTTP requests” blog post from which I learned about Charles, one needs to examine requests made by the application itself – like WordPress in this particular case.

The developer tools of the browser won’t be very useful, but a proxy application like Charles would.  Setting up a proxy will send all requests through it, allowing for easy inspection and debugging.

How to Synchronize WordPress Live and Development Databases

SitePoint runs through a few options that one can use to synchronize WordPress live and development databases.  I’ve linked to  some of these options before, but it’s nice to have them all conveniently together.  The solutions discussed include WordPress-specific tools:

as well as generic tools, such mysqldump, mysqlpump, rsync, and git.

Overall, it’s a pretty complete list of tools.  The one I’d like to add though is WP CLI, which allows a great deal of automation when it comes to WordPress, including things like database imports and exports, post and option management, and more.