Loop elegantly through a JavaScript Array

I’ve been reading JavaScript Enlightenment to try and understand the language. There is beauty, and power, hiding behind the covers of JavaScript, but I haven’t clicked yet. I still don’t really get prototypal inheritance and what ‘this’ really means. There is power in understanding closure and scope, too, I am sure. This small book is recommended to see where the beauty is.

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I’d like to share one bit of code which I found elegant: looping through an array:

var myArray = ['blue','green','orange','red'];

var counter = myArray.length;

while (counter--) {
    console.log(myArray[counter]);
}

It relies on the fact that integer values that are not 0 or -0 are ‘truthy’.

Visually document the dependency tree of Script Libraries in your database with one click

The two ugly sisters of software quality are documentation and testing. Both are sure-fire indicators of how easy a piece of software is going to be to maintain. They are not sexy, though, and most customers or end users don’t care about them.

Nor pay for them.

Bad documentation and missing testing routines makes their hit on quality insidiously, as codebases become incrementally more complex, more difficult to decipher, and changes to the software become, apparently unexplainably, more and more costly, and risky, until it reaches the ‘legacy’ status – change me at your own risk and peril, bwoa-ha-ha-ha!

Manually generated documentation is useless. It’s almost immediately out of date. The only real documentation is the code itself, and that’s why any kind of documentation should be automatic, taken from the actual application. JavaDoc is superb, as was Mikkel Heisterberg’s lsdoc.org (which is sadly not online anymore – please join me in bribing Mikkel to reinstate it).

The Domino Designer Plug-in Dependency Documenter is a modest contribution to help you document IBM Notes applications. Once the plug-in is installed, a click of the button will make a diagram showing how the database’s script libraries depend on each other.

The practical application is to help fight the compilation problems that sometimes happens when Notes gets confused about time-stamps (Generic LSE Failure (no information), anybody?), and a sure way to work this around is to re-save the script libraries in reverse order of dependency. The diagram helps you to find out where to start.

Final Result

Please note that the heavy lifting of the diagram generation is done by Graphviz, which you’ll need to install separately on your development machine. Graphviz is a free, open source library which does a remarkably good job of making clear diagrams based on a simple inputted text file.

The plugin itself is still somewhat rough around the edges, and I’d welcome any kind of feedback or any feature requests you might find useful.

All of this would not have been possible without the previous work of Karsten Lehmann (mindoo), René Winkelmeyer (midpoints), Ulrich Krause (BCC Consulting) and Ralf Petters (Artweger GmbH), all of whom contributed fantastic presentations and blog entries on creating Notes Plug-ins. A special thanks to Ralf, who held my hand whilst I was trying to set up the development environment for plug-in development.

Tim Tripcony’s incinerate function elegantly batch recycles Domino Objects in Java

I recently was surfing through Stackoverflow and I hit a response from Tim Tripcony on this post: What is the best way to recycle Domino Objects in Java Beans

He published a small helper function to recycle an arbitrary number of Domino objects. It’s so simple, and so well written, that I thought it deserved a post of its own. Here it is in all its glory:

private void incinerate(Object... dominoObjects) {
    for (Object dominoObject : dominoObjects) {
        if (null != dominoObject) {
            if (dominoObject instanceof Base) {
                try {
                    ((Base)dominoObject).recycle();
                } catch (NotesException recycleSucks) {
                    // optionally log exception
                }
            }
        }
    }
}

And it’s used like this:

   Database wDb = null;
    View wView = null;
    Document wDoc = null;
    try {
// your code here
    } catch (NotesException ne) {
 // do error handling
    } finally {
        incinerate(wDoc, wView, wDb);
}

I find the function elegant in many ways; the function and the variables are clearly named, Tim uses variable-length argument lists (thats the Object… part with the ellipsis), the new for-each iteration, plus there is some humour. Thanks, Tim.

SSJS is an abomination born out of IBM’s misguided condescension

Scott Souder was recently extolling the skill of the IBM developers and added as an aside “these are not your average domino developers”. I flinched at the statement and thought defensively “does he mean me?”

The more I think of it, though, and it becomes obvious that this is a central assumption that affected the design of XPages. It’s even there, in the introduction to the mastering XPages book.

I would like to humbly submit to IBM that domino developers nowadays are not an unskilled community, and that its modeling of who domino developers are needs some updating, in the hope that this will positively affect further design decisions. We’re not the Samanthas of the programming world.

It’s immediately obvious at any notes gathering that we are not the youngest community – I rarely see anybody in their twenties, for instance. It’s therefore obvious that we are all experienced. Even those without a computer science background (and this applies to me) has learnt, the hard way, that it’s the maintenance and debugging of code which is complex, not the writing. I learned, the hard way, that copy-pasting code is a shortcut which kills you a couple of years later. I learned that structuring code cleanly, with small functions doing a single thing, ends up being far easier to maintain than two thousand lines of procedural code. Making the switch from procedural code to object oriented code helped tremendously, along with the concept of separating business logic from the displaying logic.

XPages was confusing to me at the beginning. It seemed like a step backwards. Squirreling bits of JavaScript into the XML code, into what clearly should strictly be a presentation layer, mixing business logic with presentation logic, after spending years moving code from buttons and hotspots in forms into script libraries? It doesn’t make sense – until you understand the central assumption of IBM, which was that we would not get Java. Too difficult. The dumbo domino developers will never get it. They only get quick-and-dirty RAD.

Then, in the course of my XPages learning curve I stumbled into managed beans, and everything clicked into place. This is where the beauty lies, this is where I can put my layered, easily debuggable, easily testable code. It’s easy to bind to the XML source, and the Expression Language is concise and powerful. And yet these sections are under-documented, the know-how gleaned from stack overflow and numerous blog entries on the subject made by us, dummy domino developers.

In the face of the obvious scarcity of resources that IBM has devoted to the Notes platform, it is such a crying shame to have invested so much into SSJS and the whole formulation of formula language as JavaScript functions. (An impressive achievement, but a misguided one in my opinion).

The resources could have been better spent elsewhere. Learning java is but one of the challenges of learning XPages, and it’s a challenge for which there are tons of documentation.

There’s often a picture made about misguided security in IT – a brand-new lock on a rotten door doesn’t increase your security. Here there is a parallel with misguided condescension – Removing Java out of the learning curve is just a small contribution to making XPages simpler. There’s a plethora of new stuff that we must learn, we must get our heads around conflicting terminology (e.g. Notes View, JSF View, Eclipse View), a lot of functionality comes from knowing that the CSS class you need is called ‘lotusInlinelist lotusUtility’, there are missing tools such as JUnit, refactoring, renaming so you end up having to do a lot of things manually…

SSJS annoys me because of the underlying assumption – I am dumb.

SSJS also annoys me architecturally. It breaks the MVC model pretty badly. It probably also affects performance and scalability (although I have no figures to support this)

And it’s also a misnomer: It’s not at all JavaScript being run on the server (like node.js would do, blindingly fast on top of Google’s V8 engine). At runtime it’s really running as Java. Guess why it takes so long to build your projects? Our poor computers have to interpret the ‘JavaScript’ and translate this into Java code. And your guess is as good as mine when it comes to the new versions of JavaScript – will IBM update too, to ECMA 5 Strict, say?

My tip: circumvent SSJS as soon as you can and go straight to Java.

Powerful searches in DDE: Regex for ‘all bar that don’t start with foo’

Regexes are wonderful. There’s a learning curve, and they are very cryptical to be able to read, let alone write, but once you get the hang of it they are wonderful.

I was doing some refactoring and I wanted to see all instances of a function called ‘AddButton’ – and my results got saturated with another function ClickAddbutton.

Which Regex to use to ask for ‘Show me all AddButtons but ignore ClickAddButton’?

The trick here is to use negative lookbehind:

(?<!textIDontWantPrefixed)TextIAmLookingFor

so in my example this was what to input in the search box in DDE:

(?<!Click)AddButton

This is the way it works:

1. Search for ‘AddButton’

2.When you’ve found ‘AddButton’, look if there is a naughty prefix (‘Click’) which invalidates the search.

This is the lookbehind part. It’s slightly confusing because a lookbehind is going to look at the bits to the left of the word, which one would typically call ‘before’. The regex convention is that forwards is the direction of parsing and behind is the other direction.

3. if the naughty prefix isn’t there, return a match.

That’s the negative part.

Voilà!

P.S. an excellent tool for Regexes is RegExBuddy (Windows only though). Really recommended, saved me loads and loads of time. I wouldn’t do regexes without it.

Leave Code in the state you would like to find it in.

It’s been one of my principles since I started being an independent developer. Much of my work is maintaining old codebases, and there are many horror stories that I could recount.

The temptation is there to do a quick-and-dirty modification, a quick patch, but one should resist the temptation.

Customers generally do not understand the concept of refactoring and I have to this date never been able to persuade any customer of parting with cash for refactoring. Arguments about less work down the line just fall on deaf ears.

So the refactoring is included in my normal style of coding – on-the-fly refactoring, if you will. I generally find that it’s well worth refactoring badly written code as you are trying to read it.Renaming variables is my first step at reading the code, then creating subfunctions that have a clear purpose in separate functions. If the code is complex I’ll generally do the step of converting it to object-oriented code. It might seem like a waste of time or even overzealousness, but on the long run it’s well worth it, also for your client, for his maintenance costs are going to go down.

So, whenever I am within a function that I need to update or correct, I make sure that I leave the code in a state that won’t make me cringe. This usually means renaming variables (naming them for what the content is, not the container – i.e. docPurchaseOrder instead of doc), adding error trapping, and deleting stuff.

I love deleting stuff. The fewer design elements, the fewer functions there are, the better, if you ask me.

In the past, if you were a Notes developer without access to third-party tools, coding was very much an accretive process. Need a lookup view? Create a new one. Need a slightly different function? copy-paste. Since we had no visibility about dependencies, it was really dangerous to remove things – so the convention was just to add things.

Over the years this results in a terrible mess.

Thankfully there are some tools one still can use. One of my favourites is Teamstudio’s lscalls, a small exe that lists out functions that are no longer called by any other function. This is a really powerful and safe way to identify functions ready for deletion.

Teamstudio no longer posts it on their website (too legacy-ish, presumably) but they will send you the file if you e-mail them and ask nicely.

Just for me, here is an example of the syntax.

C:\Program Files (x86)\IBM\Notes>lscalls “C:\Program Files (x86)\IBM\Notes\Data\Development\eFSR\eFSR3_0\Efsr_(3_0)_Field_Service_Local_Dev.nsf” -o “c:\temp\lscallsoutput.csv”

You will need to place lscalls.exe in your notes program directory.

A little caveat: if a function is shared between multiple databases with inherited script libraries, you might want to make a check on all databases sharing the common code.

Finding comments from Tim or Jens in forums and blogs

Every now and then, on my searches in the interwebs, I find a comment or an answer by Tim or Jens, and different emotions hit me:

There is a moment of shock, a ‘speaking from the dead’ frisson, then sadness at their deaths, and then, also, gratitude and a sense of wonder that they are still helping me out.

Jens never missed an event, be it in Switzerland or abroad (where the both of us were sometimes the only attendees coming from Switzerland). I found him to be exact, friendly, helpful and in the last few years he had been a driving force within SNOUG, the Swiss notes user group and had organised a few weeks before his death a very enjoyable day for us locals.

I only met Tim in person once, at the ILUG in Cardiff (where he delivered his infamous Star-Wars themed session with Paul Withers). Blattschuss. What a wonderful session.

I regularly read his blog, and I was always impressed about his creative energy, always pushing at the boundaries of what is possible, and I always wondered – Where does he find the time for all of this?

We had a long chat walking to the restaurant and I discovered that he also sung in his spare time – a hobby that I share with him, and Julian Woodward. I had imagined us singing a trio together, for a laugh and hopefully for a bit of a surprise. He was enthusiastic about the idea. It would have been lovely, he had such a deep bass voice, almost effortless, Julian is a Tenor, and I am a baritone, so it would have been perfect.

Tim was also surprisingly accessible, and, his evident acumen notwithstanding, never made me feel silly. His explanations always left me thinking ‘so that’s how you do it’ instead of the unfortunately far more common ‘that went miles over my head, I’d better just nod as if I understood’.

At the moment I just feel grateful to have such a wonderful job, to have so many talented persons pooling their knowledge without any financial reward, to work in an environment that is so fast-paced, and being able to discover such persons as Jens and Tim.