NSF ODP Tooling 2.0

Jesse Gallagher | 2 weeks ago | Comments
The other week, version 2.0 of the NSF ODP Tooling project was released. This project allows for the compilation and generation of on-disk-project representations of NSFs without the use of Designer, and as part of a tree of Maven projects. This release has several important improvements:

- Full round-trip fidelity for NSFs<->ODPs to match Designer's behavior
- Local compilation and export on platforms supported by the Notes client or Domino
- Improvements to the Eclipse tooling to provide Design Element categories and XML editor hooks for DXL files
- Automatic generation of missing .metadata files; for example, for new XPages or resources added to the project outside of Designer
- Maven-side generation of plugin files for cross-IDE compatibility

I've recorded a video going over the example project included in the repository, which is itself available on GitHub.


Request for Action: Project Steering Committee

Paul Withers | 4 weeks ago | Comments
OpenNTF has had a steady stream of contributions over recent years, adding to a large corpus of contributions during this century. There is also renewed focus on Domino, potential for new markets of JavaScript developers with Domino, imminent new releases of Sametime, Connections in the process of being acquired by HCL, and a number of other products already in ownership or being acquired by HCL. The board have appreciated the need for revisiting project approaches and management of key projects, to ensure greater scalability for the future, reach beyond traditional project categories and ensure better consumption of quality projects. After all, OpenNTF pre-dates YouTube (2005) and GitHub (2008), as well as most currently-active ICS-related blogs.

But we want you, our OpenNTF community, to be involved in building this future. We have some ideas, but we want to form a Project Steering Committee to review those ideas and come up with a formal proposal to the board. This will touch all aspects of the contributor process and probably resurrect or modernise existing roles like committers. The Project Steering Committee is expected to evolve into product-specific committees, ensuring review and overseeing of key projects for those products. But this inaugural committee will have a different focus, on recommendations only, and there is no obligation on your time beyond the adoption of the recommendations. However, this is an opportunity to get involved at the earliest stage.

We would like to move quite quickly, formalising the proposals before autumn if possible. As an initial step, the team will be brought together in a private Slack channel. So please reach out to one of the board members in the general channel of OpenNTF's Slack if you wish to be involved.

This is your community, and we can only function if there is a committed community of active participants. So please take this opportunity.

AbstractCompiledPage, Missing Plugins, and MANIFEST.MF in FP10 and V10.x

Jesse Gallagher | 2 months ago | Comments
(This entry is cross-posted from frostillic.us)

Since 9.0.1 FP 10, and including V10 because it's largely identical for this purpose, I've encountered and seen others encountering a couple strange problems with compiling XPages projects. This is a perfect opporunity for me to spin a tale about the undergirding frameworks, but I'll start out with the immediate symptoms and their fixes.

The Symptoms

There are three broad categories of problems I've seen:

- "AbstractCompiledPage cannot be resolved to a type"
- Missing third-party XPages libraries, such as ODA, resulting in messages like "The import org.openntf cannot be resolved"
- Complaints about MANIFEST.MF, like "MANIFEST.MF has no main section" and others

The first two are usually directly related and have the same fix, while the second can also be caused by some other sources, and the last one is entirely distinct.

Fix #1: The Target Platform

For the first two are based on problems in the active Target Platform, namely one or both of the standard platform components go missing. The upshot is that you want your Target Platform preferences to look something like this:

Working target platform

There should be a selected platform (the name doesn't matter, but "Running Platform" is the default name) with entries at least for ${eclipse_home} and for a directory inside your Notes data dir, here C:\Notes\Data\workspace\applications\eclipse. If they're missing, modify an existing platform or create a new one and add an "Installation"-type entry for ${eclipse_home} and a "Directory"-type one for the eclipse directory within your data dir.

Fix #2: Broken Plugins, Particularly ODA

Though V10 didn't change much when it comes to XPages, there are a few small differences. One in particular bit ODA: we had a dependency on the com.ibm.domino.commons plugin, which was in the standard Notes environment previously but is not as of V10 (though it's still present on the server). We fixed that one in the V10 release, and so you should update your ODA version if you hit this trouble. I don't think I've seen other plugins with this issue in the V10 transition, but it's a possibility if Fix #1 doesn't do it.

Fix #3: MANIFEST.MF

This one barely qualifies as a "fix", but it worked for me: if you see Designer complaining about MANIFEST.MF, you can usually beat it into submission by cleaning/rebuilding the project in question. The trouble is that Designer is, for some reason, skipping a step of the XPages compilation process, and cleaning usually kicks it into gear.

I've also seen others have success by deleting the error entry in the Errors view (which is actually a thing that you can do) and never seeing it again. I suspect that the real fix here is the same as above: during the next build, Designer creates the file properly and it goes away on its own.

The Causes

So what are the sources of these problems? The root reason is that Designer is a sprawling mountain of code, built on ancient frameworks and maintained by a diminished development team, but the immediate causes have to do with OSGi.

The first type of trouble - the target platform - most likely has to do with a change in the way Eclipse manages target platforms (look at the same prefs screen in 9.0.1 stock and you'll see it's quite different), and I suspect that there's a bug in the code that migrates between the two formats, possibly due to the dramatic age difference in the underlying Eclipse versions.

The second type of trouble - the MANIFEST.MF - is due to a behind-the-scenes switch in how Designer (and maybe the server) handles dependencies in XPages projects.

Target Platforms

The mechanism that OSGi projects - such as XPages applications - use for determining their dependencies at build time is the notion of a "Target Platform". The "target" refers to the notion that this is the platform that is expected to be available at runtime for what you're building - loosely equivalent to a basic Java classpath. An OSGi project is checked against this Target Platform to determine which classes are available based on their bundle names and versions.

This is distinct from the related concept of a "Running Platform". Designer, being based on Eclipse, is itself built on and runs using OSGi. Internally, it uses the same mechanisms that an XPages application does to determine what plugins it knows about and what services those plugins provide.

This distinction has historically been hidden from XPages developers due to the way the default Target Platform is set up, pointing at the same Running Platform it's using. So Designer itself has the core XPages plugins running, and it also exposes them to XPages applications as the Target. Similarly, the way we install XPages Libraries like ODA is to install them outright into the Designer Running Platform. This allows Designer to know about the library service provided, which it uses to populate the list of available plugins in the Xsp Properties editors.

However, as our trouble demonstrates, they're not inherently the same thing. In standalone OSGi development in Eclipse, it's often useful to have a Target Platform distinct from the Running Platform - such as the XPages environment for plugins - to ensure that you only depend on plugins that will be available at runtime. But when the two diverge in Designer, you end up with situations like this, where Designer-the-application knows about the XPages runtime and plugins and constructs an XPages project and translates XSP to Java using them, but then the compilation process with its empty Target Platform has no idea how to actually compile the generated code.

MANIFEST.MF

I've mentioned that an OSGi project "determines its dependencies" out of the Target Platform, but didn't mention the way it does that. The specific mechanism has changed over time (which is the source of our trouble), but the idea is that, in addition to the Java classes and resources, an OSGi bundle (or plugin) has a file that declares the names of the plugins it needs, including potentially a version range. So, for example, a plugin might say "I need org.apache.httpcomponents.httpclient at least version 4.5, but not 5.0 or higher". The compiler uses the Target Platform to find a matching plugin to compile the code, and the runtime environment (Domino in our case) does the same with its Running Platform when loading.

(Side note: you can also specify Java packages to include from any plugin instead of specific plugin names, but Designer does not do that, so it's not important for this purpose.)

(Other side note: this distinction comes, I believe, from Eclipse's switch from its own mechanism to OSGi in its 3.0 release, but I use "OSGi" to cover the general concept here.)

The old way to do this was in a file called "plugin.xml". If you look inside any XPages application in Package Explorer, you'll see this file and the contents will look something like this:

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.0"?>
<plugin class="plugin.Activator"
  id="Galatea2dVCC_2fIKSG_dev5csyncagent_nsf" name="Domino Designer"
  provider="TODO" version="1.0.0">
  <requires>
    <!--AUTOGEN-START-BUILDER: Automatically generated by null. Do not modify.-->
    <import plugin="org.eclipse.ui"/>
    <import plugin="org.eclipse.core.runtime"/>
    <import optional="true" plugin="com.ibm.commons"/>
    <import optional="true" plugin="com.ibm.commons.xml"/>
    <import optional="true" plugin="com.ibm.commons.vfs"/>
    <import optional="true" plugin="com.ibm.jscript"/>
    <import optional="true" plugin="com.ibm.designer.runtime.directory"/>
    <import optional="true" plugin="com.ibm.designer.runtime"/>
    <import optional="true" plugin="com.ibm.xsp.core"/>
    <import optional="true" plugin="com.ibm.xsp.extsn"/>
    <import optional="true" plugin="com.ibm.xsp.designer"/>
    <import optional="true" plugin="com.ibm.xsp.domino"/>
    <import optional="true" plugin="com.ibm.notes.java.api"/>
    <import optional="true" plugin="com.ibm.xsp.rcp"/>
    <import optional="true" plugin="org.openntf.domino.xsp"/>
    <!--AUTOGEN-END-BUILDER: End of automatically generated section-->
  </requires>
</plugin>

You can see it here declaring a name for the pseudo-plugin that "is" the XPages application (oddly, "Domino Designer"), a couple other metadata bits, and, most importantly, the list of required plugins. This is the list that Designer historically (and maybe still; it's not clear) uses to populate the "Plug-in Dependencies" section in the Package Explorer view. It trawls through the Target Platform, finds a matching version of each of the named plugins (the latest version, since these have no specified ranges), adds it to the list, and recursively does the same for any re-exported dependencies of those plugins. "Re-exported" isn't exposed here as a concept, but it is a distinction in normal OSGi plugins.

Designer derives its starting points here from implicit required libraries in XPages applications (all those "org.eclipse" and "com.ibm" ones above) as well as through the special mechanism of XspLibrary extension contributions from plugins installed in the Running Platform. This is why a plugin like ODA has to be installed in Designer itself: in the runtime, it asks its plugins if they have any XspLibrary classes and uses those to determine the third-party plugin to load. Here, ODA declares that its library needs org.openntf.domino.xsp, so Designer adds that and its re-exported dependencies to the Plug-in Dependencies group.

With its switch to OSGi in the 3.x series circa 2005, most of the functionality of plugin.xml moved to a file called "META-INF/MANIFEST.MF". This starkly-named file is a standard part of Java, and OSGi extends it to include bundle/plugin metadata and dependency declarations. As of 9.0.1 FP10, Designer also generates one of these (or is supposed to) when assembling the XPages project. For the same project, it looks like this:

Manifest-Version: 1.0
Bundle-ManifestVersion: 2
Bundle-Name: Domino Designer
Bundle-SymbolicName: Galatea2dVCC_2fIKSG_dev5csyncagent_nsf;singleton:=true
Bundle-Version: 1.0.0
Bundle-Vendor: TODO
Require-Bundle: org.eclipse.ui,
  org.eclipse.core.runtime,
  com.ibm.commons,
  com.ibm.commons.xml,
  com.ibm.commons.vfs,
  com.ibm.jscript,
  com.ibm.designer.runtime.directory,
  com.ibm.designer.runtime,
  com.ibm.xsp.core,
  com.ibm.xsp.extsn,
  com.ibm.xsp.designer,
  com.ibm.xsp.domino,
  com.ibm.notes.java.api,
  com.ibm.xsp.rcp,
  org.openntf.domino.xsp
Eclipse-LazyStart: false

You can see much of the same information (though oddly not the Activator class) here, switched to the new format. This matches what you'll work with in normal OSGi plugins. For Eclipse/Equinox-targeted plugins, like XPages libraries, plugin.xml still exists, but it's reduced to just declaring extension points and contributions, and no longer includes dependency or name information.

Eclipse had moved to full OSGi by the time of Designer's pre-FP10 basis (2008's 3.4 Ganymede), but XPages's history goes back further, so I guess that the old-style Eclipse plugin.xml route is a relic of that. For a good while, Eclipse worked with the older-style plugins without batting an eye. FP10 brought a move to 2016's Eclipse 4.6 Neon, though, and I'm guessing that Eclipse dropped the backwards compatibility somewhere in the intervening eight years, so the XPages build process had to be adapted to generate both the older plugin.xml files for backwards compatibility as well as the newer MANIFEST.MF files.

I can't tell what the cause is, but, sometimes, Designer fails to populate the contents of this file. It might have something to do with the order of the builders in the internal Eclipse project file or some inner exception that manifests as an incomplete build. Regardless, doing a project clean and usually jogs Designer into doing its job.

Conclusion

The mix of layering a virtual Eclipse project over an NSF, the intricacies of OSGi, and IBM's general desire to insulate XPages developers from the black magic behind the scenes leads to any number of opportunities for bugs like these to crop up. Honestly, it's impressive that the whole things holds together as well as it does. Even though it doesn't seem like it to look at the user-visible changes, the framework changes in FP10 were massive, and it's not at all surprising that things like this would crop up. It's just a little unfortunate that the fixes are in no way obvious unless you've been stewing in this stuff for years.