Quick XPages Utility: Keep Alive and Alert

  • Aug 30, 2016

For one of my projects recently, I put together a small custom control that I sure wish I had thought to do years ago: a "keep alive and alert" control. For a long time now, the Extension Library has had a "keepAlive" control, which keeps a page session (and, usually, authentication) alive while the user has the browser window open, avoiding the otherwise-common issue of someone sitting on a page "too long" and having it break underfoot. However, that doesn't cover the edge cases: the user putting their computer to sleep and waking it with the same page open, the server rebooting, a server cluster failover, expiring SSO token, or so forth. In those cases, the problem will fall more or less "silently" to the JavaScript console, and the page will just be mysteriously unresponsive.

This control has a similar starting point, where it will ping the server periodically (every 10 seconds in this case), but will also display a Bootstrap modal alert when things go awry. It's not too picky about the cause of the problem: since usually the only practical solution is to reload the page, it just says that and leaves it there. This could also be redone to be more efficient like the ExtLib one (which would avoid the page recomputation inherent in the partial refresh), and it may not cover the case of authorization expiring in an app that allows anonymous access, but it should do the job nicely in the normal case:

<?xml version="1.0" encoding="UTF-8"?>
<xp:view xmlns:xp="http://www.ibm.com/xsp/core">
	<xp:div id="keepAliveAndAlert" style="display: none"></xp:div>
	<xp:scriptBlock><xp:this.value><![CDATA[
		window.__keepAliveAndAlert = setInterval(function() {
			XSP.partialRefreshGet("#{id:keepAliveAndAlert}", {
				onComplete: function() {
					// Good!
				},
				onError: function() {
					jQuery(dojo.byId("#{id:keepAliveAndAlertError}")).modal({
						backdrop: 'static'
					});
					
					clearInterval(window.__keepAliveAndAlert);
					window.__keepAliveAndAlert = null;
				}
			});
		}, 10 * 1000);
	]]></xp:this.value></xp:scriptBlock>
	<xp:div style="display: none" id="keepAliveAndAlertError" styleClass="modal fade error-modal" role="dialog">
		<div class='modal-dialog'><div class='modal-content'>
			<div class='modal-header'><h4 class='modal-title'>Page Session Expired</h4></div>
			<div class='modal-body'>
				<p>Your page session has expired.</p>
				<p>Please&#160;<a href="javascript:location.reload()">reload</a>&#160;the page to continue working.</p>
			</div>
		</div></div>
	</xp:div>
</xp:view>

Change Is In The Air

  • Aug 26, 2016

During last week’s MWLUG, there was a clear sense that things are a little different this year. Dave Navarre dubbed the technical implications “platform agnosticism”, while I geared my presentation towards the feeling that change is in the air.

This is not totally new. Red Pill Now cast aside the XPages UI layer and most of the assumptions of Domino development to move to a new level; PSC's presentations have long developed a polyglot tone, and this ramped up this year; and people like Paul Withers have been growing with tools like Vaadin.

It's not too important to dive into the specifics of market forces or the shifting sands of technology, and the platform defensiveness that we tend to wear as a cozy blanket doesn't serve anyone properly. Our beloved Domino app-dev platform has grown pretty long in the tooth and it doesn’t seem like it’s in for a revitalization.

The situation is, fortunately, an opportunity.

One of the things I hoped to convey in my presentation is that, though the prospect of learning some of the ever-changing array of modern development tools is daunting, it is also exhilarating and profitable both professionally and personally. As insane as the tangled web of server frameworks, JS optimizers, language transpilers, automation tools, dependency managers, and so forth may seem, particularly compared to the simple days of Notes client development, there is a great deal of good news.

The popular tools are awash in documentation, with clear examples for doing basically whatever you will want to do. There's also a lot of conceptual overlap and familiarity: if your tool of choice loses favor, it won't be a start from square one to learn the next. And it's not required to learn every single thing that comes along. If you build yourself a Java web stack using, say, Spring that does the job, it's not also necessary to learn every single new client-side JS app framework that comes along.

And, in the mean time, there's a lot of great work left to do with Domino. There are XPages applications in use and development, and these will go a very long way. Domino remains a very capable platform, and the path through XPages can be a very natural lead-in to other technologies, especially if you focus on the aspects that carry on: Java, data separation, REST services, and so forth.

For my part, I, too, still have great work to do on Domino and XPages, but I'm also expanding beyond it with eyes open. As I mention frequently, I believe that Darwino is the best path for a number of reasons. When I have the opportunity, I plan to start getting into the meat-and-potatoes reasons why and examples of how to actually use the thing. Time permitting, I hope to have a series at some point for converting my blog over to a Darwino+JEE application, and I'll share my process of picking my tools and replicating with its current NSF form as I go. If all goes well, it should serve as an example of taking an existing XPages app and transforming it into something new.

This is an opportunity, and it's an exciting time.


Postscript: This is the optimistic take, granted, and some people’s situations are a bit more dire. Admins, I imagine, are in a strange spot (I hope you’ve been brushing up on ancillary tools!), and a lot of companies are doing a lot of hand-wringing about the future for app dev and maintenance as well, particularly those with a heavy Notes-client dependency. My point is that it’s not necessary to get too mired in the doom and gloom.

MWLUG 2016 Slides

  • Aug 20, 2016

I just returned from this year's MWLUG, held in surprisingly-rainy Austin, Texas. As every year, MWLUG is an outstanding event, particularly for a development crowd (though I think admins get tons of material too). I'm definitely looking forward to next year's in DC, and not merely because that's a pretty quick drive for me.

I'll have some more to write later to follow up on the themes of this year's event, but in the mean time I've uploaded the slides from my presentation:

AD106 - Expand Your Apps And Skills To The Wider World

This was a fun one to present, and should lead into a lot of good blog material in the future.

MWLUG 2016

  • Aug 15, 2016

MWLUG 2016 is happening this week, down in I'm-sure-it's-not-deathly-hot Austin, Texas. MWLUG has really proven to be a top-tier conference for our community, and I'm looking forward to it again this year. To be fair, part of that is that I'll be presenting on Friday, with a session entitled "Expand Your Apps And Skills To The Wider World":

The technological world has changed, but the work done by your Domino apps has not. Rather than discarding your old applications in a distruptive process, it is possible to extend them forward into the modern world: native mobile applications, modern web technologies, and integration with new platforms. This session will demonstrate using active open-source technologies to build new, mobile-enabled UIs, run smoothly on Bluemix, integrate with Watson, perform deep reporting with DashDB, and integrate authentication in Connections Cloud. These examples use Darwino for Domino connectivity and app structure, and this session will also introduce the forthcoming Darwino.org open-source community.

This will be something of a followup to my previous sessions about becoming familiar first with Java in XPages and then eventually with Maven. It's an interesting time to be in the spot we are, and I hope to make some sense of one of the paths we can take.

So, please join me Friday at 11:30 - 12:30 (where hopefully we won't be too ravenous for lunch) and all week to catch up and talk shop.

Release Weekend: ODA and Darwino

  • Aug 2, 2016

This past weekend was a nice one for releases to a couple of the projects I work on: the OpenNTF Domino API and Darwino.

The ODA release is something of a "consolidation" release over 2.0.0: it fixes a few of the bugs that cropped up since then, adds some important lower-level tweaks, and brings the graph REST API into the mainline release. One note with the REST API is that, due to making use of a recently-added extension to the core code, it requires a recent release of the Extension Library, 9.0.1_17 or higher.

The Darwino release is something of a preparatory release, containing some significant improvements since the initial 1.0 earlier this year. A lot of the features will warrant a proper announcement post, but the ones I find most intriguing (or worked on the most) are significantly-improved Domino replication, a new scheduling framework, and some nice cloud-deployment improvements, such as Watson integration tools and proper support for Microsoft Azure. This also sets the ground for a number of features in the next major release, which exist in initial form now, but need some final polish.

Should I have time (it continued to be a very-busy summer), both of these will warrant some more discussion. But, in the mean time, give the new versions a shot!