Technical Credit

There’s a well-known concept in programming that refers to the negative effects poorly-made decisions can have on the quality of software over time: Technical Debt. The Wikipedia article gives some examples of the causes and the consequences of technical debt.

This financial analogy is a useful one, as it nicely describes the long-term impact of debt – the longer you have it, the worse the problem becomes. Conversely you can have credit (e.g. savings) in your account for a long time, waiting for the proverbial “rainy day” to take advantage of your good planning. Want to splash out on a new pair of sparkly galoshes? No problem!

At the An Event Apart conference in Orlando in October 2016, Jeremy Keith spoke about "Resilience: Building a Robust Web That Lasts" which was a talk about progressive enhancement cleverly disguised as it didn’t use the phrase ‘progressive enhancement’. In that talk Jeremy dropped a knowledge bomb, calling building sofware using the principles of progressive enhancement like building ‘technical credit’.

This, in my opinion, is genius. It’s a gloriously positive spin on technical debt, which is too often seen as the product of bad developers. It’s saying “you, developer, can make a better future”. I love that.

It appears there is little online which talks about this “technical credit” concept. In fact, the only decent resource I could find is a 2014 paper from the Conference on Systems Engineering Research entitled ‘On Technical Credit’. The author, Brian Berenbach, gives a brief but eloquent introduction to the idea that we should concentrate on what should be done, rather than what shouldn’t be done to make a system better.

From the abstract:

"Technical Debt" … refers to the accruing debt or downstream cost that happens when short term priorities trump long term lifecycle costs… technical debt is discussed mostly in the context of bad practices; the author contends that the focus should be on system principles that preclude the introduction, either anticipated or unanticipated, of negative lifecycle impacts.

Sounds great; let’s stop bad things happening. How? The abstract continues:

A set of heuristics is presented that describes what should be done rather than what should not be done. From these heuristics, some emergent trends will be identified. Such trends may be leveraged to design systems with reduced long term lifecycle costs and, on occasion, unexpected benefits.

Emphasis mine. I’ll wait here while you to read the rest of the document.

At this point hopefully you can see the clear link to the principles of progressive enhancement. Let’s look at a few examples emergent trends – which I’ll call ‘properties’ as the paper uses this term – and the (un)expected benefits that progressive enhancement may give. But first, a quick refresher on what progressive enhancement is.

The principles of progressive enhancement

I can’t put progressive enhancement in a neater nutshell than Jeremy does in his talk ‘Enhance!’:

  1. Identify the core functionality
  2. Implement it using the simplest technology possible
  3. Enhance!

For websites this boils down to practical principles like these:

But there’s no hard-and-fast set of rules for progressive enhancement, because every site has different functionality. That’s why it’s considered a philosophy rather than a checklist. As Christian Heilmann said, progressive enhancement is about asking "if" a lot.

Emergent properties

Someone once said words to the effect of "the only constant is change", meaning that the only thing you can rely on is that things will not stay the same. That’s good! Progress is positive and brings with it new opportunities.

These opportunities can be seen as emergent properties – new or existing attributes of things which emerge as time goes on. For example, the increasing uses of mobile computing devices and fast home connection speeds are emerging properties leading to opportunities for new types of business. Likewise, the prevalent use of social media and its unprecedented bulk collection of data about its users is allowing new models for advertising – and, unfortunately, more nefarious uses – to emerge.

These emerging properties are often very difficult if not impossible to predict. Progress can lead to unexpected outcomes. Technology in particular is often put to unanticipated uses and exhibits unexpected behaviour when used at scale.

Who, for example, could have predicted the explosion of new devices and form factors just a few years ago. Devices once the domain of science fiction are now commonplace, and the range of new input types – notably touch and voice – is revolutionising how people interact with technology.

While fixed line download speeds are increasing many in developing nations, who arguably are the ones who could benefit the most from widespread Internet access, are stuck with very slow speeds, if any at all. Clearly we have a long way to go to achieve parity in global access to the Internet.

(Un)expected benefits

With such a wide array of both expected and unexpected properties of the current technological revolution, building our systems in such a way to both be resilient to potential failures and benefit from unanticipated events surely is a no-brainer. The ‘On Technical Credit’ paper defines this approach as Technical Credit:

Technical Credit is the investment in the engineering, designing and constructing of software or systems over and above the minimum necessary effort, in anticipation of emergent properties paying dividends at a later date.

This is Progressive Enhancement. It’s about putting some thought in up-front to ask those tricky "what if" questions. Questions such as:

Thinking about these, and many other, potential problems leads you to follow the recipe given by Jeremy which I quoted above:

  1. Identify the core functionality
  2. Implement it using the simplest technology possible
  3. Enhance!

Implementing core functionality using the simplest technology possible – in the case of a website by using well-structured semantic HTML markup generated on the server – gives some expected benefits:

Plus it provides a strong foundation to take advantage of unexpected occurrences; those emerging properties mentioned earlier.

From brand new browsers to old browsers working in a new way, your well-structured HTML will deliver your content even if everything else fails. Support for new input types on a myriad of unimagined devices will be taken care of by the browser – rather than you having to find Yet Another JavaScript Component™ that adds the support you need. And as new APIs are added you can layer on support for these knowing the foundation of your site is rock solid.

Spending Technical Credit

So you’ve built your system carefully, thinking about the many ways in which it could fail. You’ve done ‘over and above the minimum necessary effort’ and can now sit back, confident in the hope that should a rainy day come you’ve accrued enough technical credit to weather the storm.

Performerjs.org – Standards-driven JavaScript Goodness

For a while now I’ve been using a library of little functions built on top of the prototype JavaScript framework which allow me to add some interactive goodness (yes, that means AJAX) to web pages using nothing but a few standard element attributes. I’ve written about this before a few times, but the time has come to push it out a bit further in the hope that it will help others. I call it Performer.

So I’ve bought a new domain names (extending my power on the web, mwahaha) and am in the process of getting the very latest, cutting edge version of Peformer on performerjs.org. There are still some bugs to figure out, particularly in Internet Exploder, but you can see the range of features Performer offers.

It’s released in a Creative Commons licence meaning basically you can use it for what you want, but don’t say you did it all yourself. You can even adapt, build, tweak and chop/change to your hearts content. But any changes you make must be released under a similar licence to help benefit everyone.

No doubt I’ll be writing more about Performer as I add new features and polish up what’s there, but for now just take a look at how a few standard attributes can turn a boring page into an all-singing, all-dancing Web 2.0 wonderpage!

Unobtrusive JavaScript password strength checker

I’ve added a couple of new functions to Performer – my easy to use JavaScript library. The two new functions allow you to check the strength of a password as it’s typed into a text box, and also check if a password and its confirmation match. Both update a notification element with a suitable message.

But that’s not all. Some of the older functions, such as the AJAX loader and tabbing functions, have got a little love as well. They now add extra classes to the elements they affect so you can style them easily. This stuff isn’t documented yet, but in a nutshell:

  • When loading some data from a remote page using the Loader function the element which is being updated will have the class ‘loaderloading’ while the loading is happening. Phew, a few too many ‘loader’s there.
  • When using the Tabber function to switch the visibility between different elements in a tag group, the link to the selected tab will have an additional class of ‘tabbercurrent’.
  • UPDATE: the Toggler function adds the class ‘toggleropen’ when the toggled element is being shown. That means you can easily do ‘open’ and ‘close’ CSS styles.

I’ve got lots more ideas for Performer, but time is short at the moment. However this little library – and the fantastic prototype library it’s built on – continue to make my life better.