Function: shr--extract-best-source
shr--extract-best-source is a byte-compiled function defined in
shr.el.gz.
Signature
(shr--extract-best-source DOM &optional URL PREF)
Documentation
Extract the best :src property from <source> blocks in DOM.
Source Code
;; Defined in /usr/src/emacs/lisp/net/shr.el.gz
(defun shr--extract-best-source (dom &optional url pref)
"Extract the best `:src' property from <source> blocks in DOM."
(setq pref (or pref -1.0))
(let (new-pref)
(dolist (elem (dom-non-text-children dom))
(when (and (eq (dom-tag elem) 'source)
(< pref
(setq new-pref
(shr--get-media-pref elem))))
(setq pref new-pref
url (dom-attr elem 'src))
;; libxml's html parser isn't HTML5 compliant and non terminated
;; source tags might end up as children. So recursion it is...
(dolist (child (dom-non-text-children elem))
(when (eq (dom-tag child) 'source)
(let ((ret (shr--extract-best-source (list child) url pref)))
(when (< pref (cdr ret))
(setq url (car ret)
pref (cdr ret)))))))))
(cons url pref))