Acquire target during already-active prompt

[woolsweater]

Can Embark be used to get a target into the minibuffer after a command has already been started? In effect, "yanking" into the minibuffer, but directly from a regular buffer, not from the kill ring.

As a concrete example, say I'm looking at the Magit status view for a repo, and I decide I want to check out a particular commit by its hash. So I hit b b, running magit-checkout, which wants to read the hash value in the minibuffer. Then I realize I have the hash already written out in another open buffer. I switch to that buffer and run embark-act on the hash. The magit-checkout prompt is still active and Embark has the value I want. But how can I put them together?

It looks like this might be possible in embark's design, if I could get embark--act to target the current, active minibuffer when running a non-interactive function. If I'm reading the code correctly. But I figured I'd ask; this doesn't seem to have come up in Issues before that I can see. Not so much a feature request as a usage help request. 🙂

[minad]

You can write a custom embark-inject action and bind it in the embark-general-map. Then in the other buffer, press C-. I on the target you want to inject into the currently active minibuffer (assuming that C-. is bound to embark-act).

(defun embark-inject (str)
  (interactive "sString: ")
  (let ((win (active-minibuffer-window)))
    (unless win
      (user-error "No active minibuffer"))
    (select-window win)
    (delete-minibuffer-contents)
    (insert str)))

(define-key embark-general-map "I" #'embark-inject)

I think it isworth to add this functionality with the description of the use case to the wiki. I wouldn't add the action to Embark itself since it seems to be too rarely useful, since you can just use kill (w = embark-copy-as-kill) and yank in the minibuffer instead.

[woolsweater]

Ah, that's great. I didn't think it would be so simple to get the previous command's minibuffer. Thanks!