Package: emacs;
Reported by: Eshel Yaron <me <at> eshelyaron.com>
Date: Sat, 17 Jun 2023 11:08:01 UTC
Severity: normal
Tags: patch
Done: Eli Zaretskii <eliz <at> gnu.org>
Bug is archived. No further changes may be made.
Message #17 received at submit <at> debbugs.gnu.org (full text, mbox):
From: Eshel Yaron <me <at> eshelyaron.com> To: Eshel Yaron via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs <at> gnu.org> Cc: 64126 <at> debbugs.gnu.org, Eli Zaretskii <eliz <at> gnu.org> Subject: Re: bug#64126: [PATCH] New command 'eww-copy-alternate-url' Date: Wed, 21 Jun 2023 09:01:03 +0300
Hi all,
Any further comments about this addition?
> I'm attaching yet another updated patch (v3), the difference compared to
> the former patch is that now the alignment of completion candidate
> annotations is based on `string-pixel-width` and `display` text
> properties instead of padding with spaces.
>
> This deals better with more exotic strings that may appear in the link's
> title (again gnu.org is a good example here, as there are alternate link
> titles in different languages). Still I wonder if there's a more
> principled way to align such annotations, any suggestions?
>
> From 2337ba007e2d0512b2a4445e6749ef51df343417 Mon Sep 17 00:00:00 2001
> From: Eshel Yaron <me <at> eshelyaron.com>
> Date: Sat, 17 Jun 2023 13:48:51 +0300
> Subject: [PATCH v3] New command 'eww-copy-alternate-url'
>
> This adds a new command to EWW that copies an alternate link to the
> currently visited page into the kill ring. This is useful for
> subscribing to website feeds, etc.
>
> * lisp/net/eww.el (eww--alternate-urls)
> (eww-read-alternate-url): New functions.
> (eww-copy-alternate-url): New command.
> (eww-mode-map): Bind it to 'A'.
>
> * doc/misc/eww.texi (Basics): Document it.
>
> * etc/NEWS: Announce it.
> ---
> doc/misc/eww.texi | 15 +++++++++
> etc/NEWS | 5 +++
> lisp/net/eww.el | 79 +++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 99 insertions(+)
>
> diff --git a/doc/misc/eww.texi b/doc/misc/eww.texi
> index c02e9db11c9..cff48bd601e 100644
> --- a/doc/misc/eww.texi
> +++ b/doc/misc/eww.texi
> @@ -115,6 +115,21 @@ Basics
> @kbd{w} calls @code{eww-copy-page-url}, which will copy the current
> page's URL to the kill ring instead.
>
> +@findex eww-copy-alternate-url
> +@kindex A
> + The @kbd{A} command (@code{eww-copy-alternate-url}) copies the URL
> +of an alternate link of the current page into the kill ring. If the
> +page specifies multiple alternate links, this command prompts for one
> +of them in the minibuffer, with completion. Alternate links are
> +references that an @acronym{HTML} page may include to point to other
> +documents that act as its alternative representations. Notably,
> +@acronym{HTML} pages can use alternate links to point to their
> +translated versions and to @acronym{RSS} feeds. Alternate links
> +appear in the @samp{<head>} section of @acronym{HTML} pages as
> +@samp{<link>} elements with @samp{rel} attribute equal to
> +@samp{``alternate''}, they are part of the page's metadata and are not
> +visible in its rendered content.
> +
> @findex eww-open-in-new-buffer
> @kindex M-RET
> The @kbd{M-@key{RET}} command (@code{eww-open-in-new-buffer}) opens the
> diff --git a/etc/NEWS b/etc/NEWS
> index 61e6e161665..7c94c3efa89 100644
> --- a/etc/NEWS
> +++ b/etc/NEWS
> @@ -253,6 +253,11 @@ The interactive minibuffer prompt when invoking 'eww' now provides
> completions from 'eww-suggest-uris'. 'eww-suggest-uris' now includes
> bookmark URIs.
>
> ++++
> +*** New command 'eww-copy-alternate-url'.
> +It copies an alternate link to the page currently visited in EWW into
> +the kill ring.
> +
> ** go-ts-mode
>
> +++
> diff --git a/lisp/net/eww.el b/lisp/net/eww.el
> index 61f0f47373d..89f7ba37cc1 100644
> --- a/lisp/net/eww.el
> +++ b/lisp/net/eww.el
> @@ -1086,6 +1086,7 @@ eww-mode-map
> "&" #'eww-browse-with-external-browser
> "d" #'eww-download
> "w" #'eww-copy-page-url
> + "A" #'eww-copy-alternate-url
> "C" #'url-cookie-list
> "v" #'eww-view-source
> "R" #'eww-readable
> @@ -2576,4 +2577,82 @@ eww-bookmark-jump
>
> (provide 'eww)
>
> +;;; Alternate links (RSS and Atom feeds, etc.)
> +
> +(defun eww--alternate-urls (dom &optional base)
> + "Return an alist of alternate links in DOM.
> +
> +Each element is a list of the form (URL TYPE TITLE) where URL is
> +the href attribute of the link expanded relative to BASE, TYPE is
> +its type attribute, and TITLE is its title attribute. If any of
> +these attributes is absent, the corresponding element is nil."
> + (let ((alternates
> + (seq-filter
> + (lambda (attrs) (string= (alist-get 'rel attrs)
> + "alternate"))
> + (mapcar #'dom-attributes (dom-by-tag dom 'link)))))
> + (mapcar (lambda (alternate)
> + (list (url-expand-file-name (alist-get 'href alternate)
> + base)
> + (alist-get 'type alternate)
> + (alist-get 'title alternate)))
> + alternates)))
> +
> +(defun eww-read-alternate-url ()
> + "Get the URL of an alternate link of this page.
> +
> +If there is just one alternate link, return its URL. If there
> +are multiple alternate links, prompt for one in the minibuffer
> +with completion. If there are none, return nil."
> + (when-let ((alternates (eww--alternate-urls
> + (plist-get eww-data :dom)
> + (plist-get eww-data :url))))
> + (let ((url-max-width
> + (seq-max (mapcar #'string-pixel-width
> + (mapcar #'car alternates))))
> + (title-max-width
> + (seq-max (mapcar #'string-pixel-width
> + (mapcar #'caddr alternates))))
> + (sep-width (string-pixel-width " ")))
> + (if (cdr alternates)
> + (let ((completion-extra-properties
> + (list :annotation-function
> + (lambda (feed)
> + (let* ((attrs (alist-get feed
> + alternates
> + nil
> + nil
> + #'string=))
> + (type (car attrs))
> + (title (cadr attrs)))
> + (concat
> + (propertize " " 'display
> + `(space :align-to
> + (,(+ sep-width
> + url-max-width))))
> + title
> + (when type
> + (concat
> + (propertize " " 'display
> + `(space :align-to
> + (,(+ (* 2 sep-width)
> + url-max-width
> + title-max-width))))
> + "[" type "]"))))))))
> + (completing-read "Alternate URL: " alternates nil t))
> + (caar alternates)))))
> +
> +(defun eww-copy-alternate-url ()
> + "Copy an alternate URL of the current page into the kill ring.
> +
> +Alternate links are references that an HTML page may include to
> +point to its alternative representations, such as a translated
> +version or an RSS feed."
> + (interactive nil eww-mode)
> + (if-let ((url (eww-read-alternate-url)))
> + (progn
> + (kill-new url)
> + (message "Copied %s to kill ring" url))
> + (user-error "No alternate links found on this page!")))
> +
> ;;; eww.el ends here
--
Thanks,
Eshel
GNU bug tracking system
Copyright (C) 1999 Darren O. Benham,
1997,2003 nCipher Corporation Ltd,
1994-97 Ian Jackson.