When you invoke the Hook window, it needs to identify the current document, resource, or context. If Hook cannot identify the current context, the status bar message will say,
No linkable item found in
App. Learn more
where “App” is the name of the app. For example, “No linkable item found in Mail.”
There are four likely explanations for this situation.
1. The foreground document has not been saved
It is impossible to link to (or from) a document until it is saved. Some applications (e.g. Notes.app, Bear, nvALT) save new documents as soon as they’re created, but many applications (e.g. TextEdit, BBEdit, Photoshop) let you open a new window and start writing or modifying new documents which don’t exist in the file system and cannot be hooked until they are saved.
Tip: Save new documents before trying to hook them.
2. The message is a draft email, or the email app does not have automation
Hook normally identifies emails by their standard “Message-ID” , per Section 3.6.4 of RFC 2822.
Until an email message is sent, the message does not have an ID. Therefore it cannot be referenced.
If you happen to use the Spark email client by Readdle, as of 2019-12-05 it still does not support automation to get the name and ID of emails. Mail.app, MailMate and Airmail 3 and even Outlook do support automation.
Tip: Use an email app that supports automation, and make sure you are dealing with a message that has been sent.
3. No document is selected, open or loaded in the frontmost window
The context is determined by the contents of the frontmost window. If another window is in front, Hook won’t identify the correct context.
If you have accessed a web page that has not yet loaded, it is not possible for apps (including Hook) to tell what the address or name of the web page is.
Tip: Ensure that the correct window is frontmost, and that the desired document is open or selected.
4. The Application is unsupported
Most macOS applications work with Hook but some require special support for their integration.
Tip: Learn more about integrating Hook with unsupported applications.
Ongoing and future developments
CogSci Apps, with the help of its savvy forum members, keep increasing the reach of Hook. The Hook contextual window will soon provide links even in the context of apps that don’t support adequate automation.