make helm-list-elisp-packages use cache

Question

Every time I use the command helm-list-elisp-packages it downloads all the index files from melpa, gnu etc. Is there a way to make it rely on the previous cache of the index files ?

I know there is package-list-packages-no-fetch which does what I want but it doesn't have the nice helm interface.

Answer 1

Actually, helm-list-elisp-package already does what you want: it only downloads descriptions of all configured ELPA packages for the first time.

Even without downloading, It may still looks slow because of a great number of packages. In this case, you can use helm-resume to resurrect previously invoked helm-list-elisp-package, it is much faster.

Please also see the implementation of helm-list-elisp-package and the docstring of helm-resume.

Update

Don't fetch the updated list of packages:

(defun helm-list-elisp-packages-no-fetch ()
  (interactive)
  (setq helm-el-package--initialized-p t)
  (helm-list-elisp-packages nil))

Do fetch the updated list of packages:

C-u M-x helm-list-elisp-packages

Only fetch for the first time during one Emacs session and don't refetch for the rest time:

M-x helm-list-elisp-packages