Extensions get used even if document doesn't match

As mentioned here, Lemminx-Maven’s “participants” (eg. DiagnosticParticipant) seems to be still used even if the document doesn’t match.

Our implementation of IXMLExtension.match() looks like:

	public static boolean match(DOMDocument document) {
		return document.getDocumentURI().endsWith(pom.xml);
	}

As a workaround, I’m going to try adding the following to each “participant” to prevent processing a non-pom.xml file:

if (!MavenPlugin.match(...)) {
  return;
}

I haven’t looked into how IXMLExtension.match() is being used, but I imagine it’s used to determine whether or not an extension should be started up or not. Perhaps it should also be used when going through the extension registry to determine if an extension’s “participant” function should be called or not.

[angelozerr]

I totally agree that a kind of matcher must be provided because we do that for instance to avoid validating a XML file with the XSD validator which validate syntax of XML Schema (xs:element, etc) and should not be applied for a simple XML file. See https://github.com/eclipse/lemminx/blob/d0a94fd0a9a588450e63f9c2b622c90b0b09b743/org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/extensions/xsd/participants/diagnostics/XSDDiagnosticsParticipant.java#L32

I already thought about and my idea was:

• provide a new interface IDocumentSelector:

package org.eclipse.lemminx.services.extensions;

import org.eclipse.lemminx.dom.DOMDocument;

public interface IDocumentSelector {

	boolean match(DOMDocument document);
}

• implement this interface

public class MavenDocumentSelector implements IDocumentSelector  {

	public boolean match(DOMDocument document) {
             return "pom.xml".equals(document.getDocumentURI());
        }
}

• use it when you register participant on the IXMlExtension#start

registry.registerDiagnosticsParticipant(mavenDocumentSelector, diagnosticsParticipant);

[AObuchow]

since Match is already defined in the IXMLExtension interface,

No it doesn’t define this match method

You’re right, my mistake. We just happen to have it defined in our class which implements the IXMLExtension interface.