Multitail is something I mentioned on my Enterprise Geeks slot with Craig Cmehil and allows you to tail more than one file at once. Very useful for keeping an eye on all those log files in the instance work directory!

And screen is one of those great utilities that I put in the same class as putty and vim: absolutely essential. It allows you to maintain multiple persistent sessions on a remote *nix host. Great for disconnecting and reconnecting (especially on dodgy ‘net connections) and being able to continue exactly where you left off.

I realised that people might benefit from these too, so I thought I’d offer them for you to download in binary form, so you can avoid going through the hassle of firing up the package manager and wrestling with repositories and dependencies, or building from source. I built them from source on an 64bit SUSE Linux VM ‘nplhost’ straight from SAP, so they should work if you’re using the same as the standard VM recommended for the trial. If you’ve decided on a Windows VM to run Gateway, then you’re out of luck, in more ways than one

They’re available here: http://www.pipetree.com/~dj/2012/04/nplhost/

Download them to npladm’s home directory to run them from there. Don’t forget to (a) chmod +x each of the binaries, and (b) rename the _ to .  for each of the dotfiles.

Share and enjoy!

Here’s the post: “DJ Adams and a trip down technology lane“. If you’re after the audio file directly, it’s here.

I had a lot of fun. Thanks Craig!

Everything is a resource

There’s an idea that has been a long time in gestation – the idea of a loose coupling of data storage, front end apps, and backend command line environments. Firebase, an offering still in beta, with some features pending, has come along and seems to be delivering that. With style. Style not only in the actual UX, but in the design approach. In a recent talk on SAP NetWeaver Gateway at the SAP Developers Kick-Off Meeting (DKOM) in Karlsruhe, I had a slide that simply said:

Everything is a resource

This is a key tenet that underpins the values of REST and related directions in information architecture: that if a piece of data (or, indirectly, a business function, for that matter) is important, you should give it a name, an address – make it a first class citizen on the web. From there, everything else follows. You can manipulate it, you can describe it, and you can link to it.

With Firebase, each piece of JSON data you store in the backend gets its own URL. Each object, array, element and attribute is automatically given an address, as you create them. You can manipulate the data via the Javascript library, through a REST API and also through a lovely graphical debugger that looks like this:

Firebase Graphical Debugger

Firebase Graphical Debugger

With the debugger you can manipulate the data directly too. What I’m guessing, through the way that the Debugger operates, is that the Debugger itself is powered by Firebase. When data in the data set that you’re viewing is changed – whether that change is initiated via the REST API or activity in a Firebase-powered application, the view in the debugger is automatically updated to show that change.

Event system

Which brings me on to the other part of Firebase that’s important – the event system. Reading data from Firebase in your Javascript application is done by attaching asynchronous callbacks to a data location. These callbacks are triggered on data events like ‘value’, ‘child_added’, ‘child_changed’ and so on. So a very simple setup to be able to show when a new record was added to a dataset would be as simple as:

• Instantiating a new Firebase object, pointing to the URL of the data set
• Associating a callback function to the ‘child_added’ event, to receive, unpack and use the new record

Like this:

var dataRef = new Firebase('http://demo.firebase.com/[...]299148/[...]QULZ4snBB/');

dataRef.on('child_added', function(snapshot) {
  var data = snapshot.val();
  // ...
}

Screencast: Stupid Firebase and SAPUI5 Tricks

On Saturday evening I had a little hack around, and found developing with Firebase fun as well as interesting. I put together a little screencast “Stupid Firebase and SAPUI5 tricks“. I have been investigating the SAP UI Development Toolkit for HTML5 (aka SAPUI5) for a short while now, and thought it would be an interesting exercise to hook up some data events powered by Firebase with an SAPUI5 DataTable. And throw my favourite environment – the Unix command line – into the mix too.
 

 
As I didn’t speak over the screencast, I thought I’d provide an annotation here.

1. We start out with a view of the Firebase Graphical Debugger showing a data set at a given URL. The data set contains a number of nodes, each node has an identifier which is used in forming that node’s unique URL
2. On the Unix command line, I use cURL – a great command line HTTP client – to effectively remove the data, by making an HTTP PUT to the data set’s URL, supplying an empty JSON stucture as the payload. As you can see, the data disappeared immediately in the Graphical Debugger, as the event triggered the Javascript function to remove the data from the display to reflect the snapshot stored at the backend
3. A simple SAPUI5 DataTable is revealed in another window, empty, with three columns for some data we’re going to see appear there; data based on the standard Apache access log (source IP address, relative path of URL requested, and status code)
4. We go back to the Unix command line, and use a combination of tail, perl and some core bash shell features to pull some data out of my web server’s access log, turn it into JSON, and make HTTP POST requests to the data set stored by Firebase
5. Before we actually complete and execute that command pipeline, we have a quick look at the SAPUI5 and Firebase Javascript behind the DataTable, showing the relationship between the DataTable fields and what we’re expecting in the ‘child_added’ Firebase data event
6. Finally we execute the command pipeline and see immediately that not only the Graphical Debugger is updated to show the records that were added to the data set at that URL, but also the DataTable receives the data as intended.

There really is little merit in this experiment; what was important for me was to see Firebase in action, and to learn something about the philosophy of the framework. I really liked what I’ve seen so far.

As I mentioned at the start, there are some features still missing from Firebase – most notably security. So you’re completely at liberty right now to read those URLs from the screencast and start hacking with my demo data. But why do that? Better to get yourself down to the Firebase tutorial pages and build some samples for yourself.

Share and enjoy!

This week I had the great honour of being invited to, and speaking at SAP DKOM (Development Kick-Off Meeting) in Karlsruhe. It was a truly great event – thousands of SAP developers attending many tracks and sessions on everything from Analytics, through Database & Technology, to Cloud, and more besides. As I sit here in Frankfurt airport on my way home, I’ve been reflecting on perhaps the best single takeaway from this event. Yes the content of the talks was great (and I enjoyed giving my session on SAP NetWeaver Gateway too). Yes the venue and organisation was second to none. Yes it was great to see the SAP Mentor wolfpack and our illustrious leader Mark Finnern.

But most of all, I saw, felt, and experienced something that I last remember from over 20 years ago in my SAP career: The Developer Connection.

Back in the day, when I was (more) innocent, certainly a lot younger, and waist-deep in IBM mainframe tech, I moved around implementing and supporting R/2 installations in the UK and Europe. Esso Petroleum in London, Deutsche Telekom in Euskirchen, and so on. In those days you could catch up with all the OSS notes on your favourite topics over a couple of coffees. Most importantly however, you had connections to the developers at SAP who were building and shipping the code that you were implementing. We knew each other’s names, and in many cases, shared phone numbers or email addresses too. There was a strong bond between customers and developers – and we worked together to make the software better.

That connection lost its way over the next few years, when SAP (consciously or unconsiously) built barriers between us. It became almost impossible in some cases to even find out the name of the developer or team responsible, let alone contact them directly.

Well – that connection is back. And better than ever before. Both at SAP TechEd Madrid, and this week at DKOM, developers were coming and saying hello. Developers who are building the great stuff we’re exploring and using, like SAPUI5 and NetWeaver Gateway. People like you and me. We are connecting again. I think there are a number of reasons for this.

First, there’s the amazing community called the SAP Community Network (SCN – although for me it will always be the SAP Developer Network – SDN) that brings together developers from all sources. Then there’s SAP’s re-focus on developers, and the corresponding coupling of empowerment and responsibility that SAP is giving directly to those developers. Further, there’s the inexorable turning inside out manoeuvre that SAP began a few years ago now, moving cautiously at first but now gathering pace as more and more technology directions that SAP are following are from outside the SAP universe, not inside. SAP developers naturally are connecting with the wider development community in general.

Whatever the reason, it’s a great sign that the future looks exciting for SAP development as a whole. Connections, collaboration and cooperation is returning. The Developer Connection is here again.

I thought it would be a nice exercise to take one of the SAPUI5 controls for a spin, namely the SearchField. It has a great many options, and wraps some jQuery functions to provide a comfortable way to expose ‘intellisense’ style results as you type. It’s over there on the right, in the sidebar.

SDN Forum Search

From the Javascript, here’s the instantiation:

var oSdnSearch = new sap.ui.commons.SearchField("sdnSearch", {
  startSuggestion: 2,
  search: function (oEvent) {
    var topic = oEvent.getParameter("query");
    window.open(oSdnAreaMap[topic], '_blank');
  },
  suggest: doSuggest
});

Simple as that. I’ve pulled the SDN Forum names and URLs into an object oSdnAreaMap, and have a doSuggest() function that handles the suggest event by deriving matches and filling the search results.

This was a short hack started on the hotel room balcony and finished off in the airport. One thing I haven’t got to the bottom of yet is controlling the number of displayed matches. Hope to get that nailed down soon.

Update 30 Mar 2012

After some collaboration with Ethan Jewett I’ve put the code on github, and it now also matches anywhere in the string, rather than the match being anchored at the start. Share and enjoy!

Web Programming with SAP’s Internet Communication Framework with DJ Adams from Prohyena on Vimeo.

If you’re interested in attending the next instance of the course, which is in May this year, please sign up!

In preparation for the previous instance of the course last year, we shot a video with yours truly explaining what the course was about and why you should attend.

Omniversity : Web Programming with SAP’s Internet Communication Framework from Madlab on Vimeo.

Madlab have their own semi-resident video expert and in the run up to the next course we’re going to shoot a new video with lots of exciting content! Well, I guess you might call it exciting if you are into SAP tech and seeing debugging activity in slow motion.

Anyway, watch this space – next week I’m over at Madlab again for the shoot. Perhaps I should get a haircut. Or a wig.

His team has an enormous scope, covering Mobile, In-Memory, On-Demand, HANA and more. While the word “Marketing” might be auto-filtered by a techie’s radar-filter, what became clear very quickly is that this group is totally developer focused. His group is already building a brand-new Developer Center (I wrote about this earlier this week) and is focused on helping the developer help themselves. What’s more, the group is staffed with developers. I’ve not managed to find anyone in TIP yet that doesn’t have a developer background.

DJ Adams interviews Aiaz Kazi at SAP TechEd Live 2011

Hasso is reported to have said “developers are the key to success”, and of course, we all know that Developers Are The New Kingmakers. What becomes clear in this interview, is that there’s a re-focus on the developer in the space that spans the distance between mobile and enterprise. This re-focus is long overdue in our industry, so I applaud SAP for having the courage to lead on this. Yes, SAP will benefit because one of the keys to a successful mobile platform is a host of developers in the non traditional-SAP space. But if the message and focus builds, the developer at large will benefit even more.

Perhaps this is a milestone along the way to the upcoming Developer Renaissance?

The interview is here: http://www.sapvirtualevents.com/teched/sessiondetails.aspx?sId=841

HTML5 is one of those technologies. While not so much a surprise, what’s more revealing, and encouraging, is that it’s being given decent coverage at SAP TechEd this year. The adoption of HTML5 as the core of a new UI library (originally codenamed “Phoenix”) for app front-ends is something that has a voice here. Look at the TechEd sessions available:

• CD202 HTML5 for Lightweight SAP Applications
• MOB264 Building & Customising a Mobile Application Without Writing Code
• MM220 How to Customise a Mobile Application with HTML5 and Javascript
• EXP443 HTML5 @ SAP

That’s not to say that this is breaking news – Thomas Jung (an SAP Mentor from SAP Labs) made reference to Phoenix in an interview with Jon Reed a few months ago. Furthermore, in a very useful chat with SAP’s Chris Whealy on Monday after InnoJam, I got to understand more about the philosophy and approach of SAP NetWeaver Gateway’s exposure of data objects and their relationships in a way that would make HATEOAS pay attention. And Chris used an early version of the UI library to present the exposed data. This seems to be a common theme internally in SAP, at least.

So what’s the deal? In EXP443 I learned that the library is built upon jQuery. So SAP are avoiding the NIH syndrome, that’s good. But there were other attendees that were questioning SAP’s decision to build Yet Another Javascript Ui Library. At the very least, the model implementation of the library’s MVC framework gives the wily Javascript hacker a head-start on using and consuming Gateway services. And in my opinion that’s the deal. Yes, we have a very nice UI library (and no, it’s not available until 2Q12, before you ask!) but we also have code that speaks the language of thousands of front-end developers on the one hand, and eases the connection to the proprietary back-end on the other.

SAP’s future lies with developers, and they’re embracing those developers in many different ways (the Technology & Innovation Platform team is one group that is making seriously good moves in this direction — but that’s a story for another time). HTML5 adoption by SAP was most likely part of a scratching of an internal itch, but it implicitly embraces non-SAP developers in potentially far-reaching ways. Great stuff.