Activate extension with workspaceContains when a matching file is added to the workspace

[roblourens]

If I have "workspaceContains:**/*.md" as an activationEvent, it would be useful for it to fire when a matching file is added to the workspace, not just when a workspace with matching file is opened.

#27665 (comment)

[1nVitr0]

Are there any plans to implement this?

I'd rather not have my extension running permanently to figure out if it can be activated. This would be the far better solution regarding performance.

[JustinGrote]

As a workaround, you can lazy-load extensions now, so you can lazy load just the detection logic and active that rest on detection change.

Ideally this is first party handled by vscode however.

[1nVitr0]

I was thrown for a loop by the now. You mean, that this has always been possible and can be implemented in any extension, regardless of the state of the vscode API?

[JustinGrote]

@1nVitr0 https://code.visualstudio.com/api/references/activation-events#onStartupFinished

onStartupFinished can be used to lazy load an extension in a way that minimizes vscode startup performance.

[1nVitr0]

@JustinGrote Right, that makes total sense. If combined with the proper workspaceContains selector, that should allow the extension to load immediately if necessary or listen for the files without impacting startup performance. Thanks!