Protesilaos Stavrou

Emacs: the next version of Denote will support custom identifiers

There are a lot of developments happening in denote and the various other extensions for it that I maintain. I will share more details in the release notes, hopefully before the end of this month. Just to give you a forewarning about a potentially massive boost for advanced users or developers: the ability to specify a completely custom identifier scheme for Denote file names.

By default, Denote constructs a file name to have, at minimum, an identifier as a compact representation of the date and time. It looks like this: 20250920T120924. The default file will also have a title and keywords, based on user input at the relevant minibuffer prompts, so it will look like this:

20250920T120924--denote-custom-identifiers__emacs_programming.txt

Instead of hardcoding the scheme of an identifier as a compact representation of a date and time, we provide the variable denote-get-identifier-function. Its value is the symbol of a function, which is called to yield an identifier, as a string.

I have written a few examples of this in the Denote manual, grouped under this section: https://protesilaos.com/emacs/denote#h:3048f558-7d84-45d6-9ef2-53055483e801. Read the documentation of denote-get-identifier-function for the remaining technicalities.

The identifier can be anything from an automatic incremental numbering scheme to something that always asks for user input to produce a more information-dense result. To illustrate the potential of the latter concept, the manual elaborates on the use-case of recording data about academic publications, such as the editor, authors, and publisher, through a series of minibuffer prompts. The end result is a unique identifier with the help of some extra helper functions.

Custom identifiers are prefixed with the @@ file name component separator. This way they are unambiguous and can be retrieved with certainty. More so since the Denote file name components can be presented in any order, per the user option denote-file-name-components-order.

Custom identifiers are the culmination of many changes over the years to make the Denote file-naming scheme as flexible as possible. It is super effective out-of-the-box and can then be particularised to specific workflows with ease. These are not mutually exclusive, as users can still rely on the regular Denote functionality for most cases and only deviate from it with bespoke functions where necessary. For instance, to have a special variant of denote-rename-file that applies a custom identifier scheme instead of the default, users can write a wrapper command like this:

(defun my-denote-rename-file-with-my-custom-identifier ()
  "Like `denote-rename-file' but use `my-denote-get-custom-identifier' instead."
  (interactive)
  (let ((denote-get-identifier-function #'my-denote-get-custom-identifier))
    (call-interactively 'denote-rename-file)))

Imagine doing this for files in a specific folder where the standard identifier provided by Denote does not add much value (beside being a unique match for the linking mechanism, that is).

The Denote manual is full of examples like the above. These sort of small and elegant extensions are possible owning to the design of the code into easily adaptable functions.

We keep going from strength to strength and I am delighted with the results. I hope you make good use of the tools on offer. Let me know if there is anything more you need: I am confident we can make it happen.

Much of the thought and work that went is to this project is thanks to user mentalisttraceur and long-time contributor Jean-Philippe Gagné Guay.

About Denote

Denote is a simple note-taking tool for Emacs. It is based on the idea that notes should follow a predictable and descriptive file-naming scheme. The file name must offer a clear indication of what the note is about, without reference to any other metadata. Denote basically streamlines the creation of such files while providing facilities to link between them.

Denote’s file-naming scheme is not limited to “notes”. It can be used for all types of file, including those that are not editable in Emacs, such as videos. Naming files in a consistent way makes their filtering and retrieval considerably easier. Denote provides relevant facilities to rename files, regardless of file type.

[ I have a page with all my Emacs packages, which includes all the Denote extensions I maintain: https://protesilaos.com/emacs. ]

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