Medium-Term Ways to Improve XPages

Aug 28, 2019 1:18 PM

Tags: xpages
  1. What Makes XPages "Not Modern"?
  2. Medium-Term Ways to Improve XPages

Following up on my jeremiad the other day, I've been thinking about some of the short- to medium-term ways that XPages could be improved. I'm not fully sold on the idea that it should be massively improved in-place due to some of the systemic decisions and the general goal of future-proofing, but some improvements that HCL could make in the near future would make everyday XPages development better and would help people like me in our tasks of bringing in other tools.

The big caveat here is that I'm labeling these as small-scale tasks in theory. Since I don't know about all the workings of the lowest layers, in particular the way the XPages stack interacts with traditional nHTTP, this could easily fall into "this should be easy!" territory for reasons I can't know.

The other caveat is that I'm largely going to leave out bringing in new runtimes as a stated goal: no integrating Open Liberty, no cramming in a Node runtime, or so forth. The most expedient fix for some of this may actually be to do something like that, depending on how the "WebSphere" parts of Domino work to begin with, but that would be an implementation detail for the purposes of this list.

With those out of the way, let's proceed!

Servlet API

This has been a bugbear for a long time, and being able to bump up the Servlet API version would be huge for both its immediate features and for compatibility with newer standards and third-party libraries. I'm not sure what the source of the limitation is - it could be primarily to do with the deprecated web app part of Equinox Domino uses or it could be due to nHTTP-side C code.

Remove or Don't Export Apache Commons Logging From the JSF Libs Plugin

This may seem overly specific at first, but it's been the source of an outsized amount of hair-pulling for me and others.

I'm referring here to the "com.ibm.designer.lib.jsf" plugin that's a central part of the XPages stack. In addition to the obligatory "jsf-api" and "jsf-impl" JARs, it also contains very-old versions Apache Commons BeanUtils, Collections, Digester, and Logging. The trouble is that the Logging packages are made available outside this bundle and then these are automatically on the classpath of every XPages application and plugin. In a void, that's not terrible, but logging packages are a source of tremendous heartache when developing XPages and Java agents, and in particular they can often end up in jvm/lib/ext and cause ClassLoader trouble by mixing with the version in this plugin.

Ideally, it'd be removed outright or taken out of the exported packages and instead included just where it's needed. Next best would be to include newer versions as proper OSGi bundles with package-version information (more on that next).

Add version information to exported packages

What I'm referring to here is the OSGi mechanism for assigning versions not just to a bundle as a whole, but also to individual packages. As an example, here's a trimmed-down and cleaned-up version of the export list from the aforementioned JSF libs plugin:

Export-Package: javax.faces,
 org.apache.commons.logging,
 org.apache.commons.logging.impl

With version information (including a made-up "1.3" version to differentiate XPages JSF), it'd be more like:

Export-Package: javax.faces;version="1.3.0",
 org.apache.commons.logging;version="1.0.3",
 org.apache.commons.logging.impl;version="1.0.3"

Doing this across the board would make the XPages runtime much more OSGi-friendly.

Provide Public or OpenNTF-Permission-Gated p2 and Maven Access (With Javadoc!)

I've been on this soap box for a long while, and it comes up pretty frequently: because the XPages runtime exists solely as a component of Notes and Domino, you have to jump through hoops to depend on it as part of an external project. The "Update Site for Build Management" was a good step, in that it became one place to get a nicely-formatted p2 repository, but that was never updated past 9.0.1 and even then was just a ZIP download, not an HTTP-accessible p2 site like you'd get with things like Eclipse. Additionally, there's never been a Mavenized version of these artifacts, meaning anyone wanting to use XPages JARs without PDE or Tycho has to reinvent the wheel.

I made tools to automate these processes, but it'd be up to HCL to give the legal approval to make the results of that available generally (or to authenticated OpenNTF users who agreed to an EULA).

Shared-Source the Stack

Open-sourcing XPages would likely be a large task just because of the legal side of it, but perhaps just giving read-only access to licensed customers would be an easier step to take. There's so much about the inner workings of XPages that are effectively a black box, and it's very difficult to figure out how to accomplish a lot of advanced tasks. Having source access would make this sort of thing much, much smoother.

Support WABs or Similar

Alongside XPages came the ability to deploy servlets and JEE web apps via OSGi, but these use the deprecated Equinox extension points and an IBM-Expeditor-specific point, respectively. From what I gather, the more-normal way to do this in OSGi is via Web Application Bundles. That wouldn't necessarily change the capabilities of development for Domino dramatically, but it'd make it a smaller step to go from "normal web app" to deploying on Domino, and wouldn't necessarily involve a full revamp of the Expeditor layers.


That's it for this list, at least for now. I may end up thinking of enough for another one of these posts, but I wouldn't want to load HCL up with too much homework right after the summer break.

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Stephan Koops - Aug 29, 2019 4:20 AM

This sounds very good !! HCL, do the job !

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Bernd Gewehr - Aug 29, 2019 3:04 PM

  1. We are doing fantastic things with domino and xPages
  2. good to see you think about its future
  3. if HCL does not follow you, they must be crazy! Thank you for being so engaged on these things for such a long time!
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