NPE prevents Import > Install Tern Modules wizard initialization

[demonfiddler]

For me, the import wizard never actually gets displayed. The error log shows the following exception:

java.lang.NullPointerException
at tern.eclipse.ide.tools.internal.ui.wizards.repository.InstallTernModulesSelectionWizardPage.validate(InstallTernModulesSelectionWizardPage.java:286)
at tern.eclipse.ide.tools.internal.ui.wizards.TernWizardPage.dialogChanged(TernWizardPage.java:80)
at tern.eclipse.ide.tools.internal.ui.wizards.TernWizardPage.createControl(TernWizardPage.java:71)
at org.eclipse.jface.wizard.Wizard.createPageControls(Wizard.java:175)
at org.eclipse.jface.wizard.WizardDialog.createPageControls(WizardDialog.java:705)
at org.eclipse.jface.wizard.WizardDialog.setWizard(WizardDialog.java:1153)
at org.eclipse.jface.wizard.WizardDialog.updateForPage(WizardDialog.java:1211)

It would appear that the preceding call at line 285 to InstallTernModulesSelectionWizardPage.modulesBlock.getCheckedModules() returns null as a consequence of having been called prematurely; that is to say, before any call to TernModulesBlock.setCheckedModules(Collection) has been made.

[angelozerr]

@demonfiddler this module import is was just a POC. I will fix this bug, but if you wish to have this feature, we need to finalize ternjs/tern#424

[demonfiddler]

Thanks for the (very) quick response @angelozerr. I'd seen the #195 thread, which is how I learnt of the wizard's existence. Then I found it in my installed tern-feature.feature.group_1.0.0.201508302102 and tried to use it.

Actually, I'm writing an Eclipse plug-in to add support for a large (2.5 MB) custom library that is generated from XSDs. I found JSDT's content assist somewhat flakey and incomplete and wondered whether Tern Eclipse IDE could do a better job. So I was really looking for an Eclipse extension point by which my Eclipse plug-in could contribute a simple Tern plug-in that loads a JSON module definition (created by condense) - both would be packaged within my Eclipse plug-in. This would avoid requiring the user to configure their IDE manually by downloading the module using your wizard.

[incidental] Anyhow, this all turns out to be largely academic since condense does not emit JSDoc-derived metadata for type members, which from an end-user's perspective is exactly the same limitation as suffered by native JSDT content assist (although for different reasons). See #321 and https://bugs.eclipse.org/bugs/show_bug.cgi?id=333712 respectively.

[angelozerr]

So I was really looking for an Eclipse extension point by which my Eclipse plug-in could contribute a simple Tern plug-in that loads a JSON module definition (created by condense) - both would be packaged within my Eclipse plug-in.

Today it doesn't exists this extension point. I would like to do that, please create an issue for that.

This would avoid requiring the user to configure their IDE manually by downloading the module using your wizard.

I understand. If you wish to test your JSON Type Definition inside tern.java, you have 2 choices :

• copy/paste your JSON Type Definition in your root project and go at JavaScript / Tern / Developement and check "Loading local plugin?". Apply your project preferences and reopen it. You should see your JSON Type Definition in the Tern / Modules. Seelct it adn you should use it.
• otherwise, go at ternjs folder (in your ECLIPSE_HOME/plugins/ternjs_**) create you a folder tern-myfwk, (like https://github.com/angelozerr/tern.java/tree/master/core/ternjs/node_modules) which must contains myfwk.json, packages.json which define in the main fields your myfwk.json. You can too create a metadata file which brings some informations like icon, description, dependencies, etc. The extension point will update this folder when it will exists.

[incidental] Anyhow, this all turns out to be largely academic since condense does not emit JSDoc-derived metadata for type members, which from an end-user's perspective is exactly the same limitation as suffered by native JSDT content assist (although for different reasons).

I'm writing a JSDoc -> Tern generator that I'm using to generate Phaser. If you wish I could commit my work and explain you how it works, but it's not very clean for the moment. My future idea is to provide this generator inside tern.java.

[demonfiddler]

Thanks for your responses and kind offer to commit your generator. I won't trouble you to do this for now, as I need to consult with my management as to whether we'll be taking our efforts any further at this juncture - it's been quite time-consuming and we haven't achieved the results we'd hoped for.

One further thought: the default tern repository currently enumerates Tern modules as children of the node_modules/tern folder within the ternjs Eclipse plug-in. A binary plug-in's installed image should be treated as a read-only location. Eclipse plug-ins have a writable 'state location' (see Plugin.getStateLocation() : IPath), which would be an appropriate place for maintaining user-downloaded modules. So it might be better to aim for a 'composed repository' that presents the contents of several repositories as if they were a single repository. That way, you could still read the built-in modules from the ternjs binary plug-in image, read downloaded custom modules from the plug-in state location, and read additional repositories contributed by 3rd party Eclipse plug-ins via the proposed extension point from within their contributing plug-ins.