Add a way to use an external command to download HTML in eww

* doc/misc/eww.texi (Advanced): Document it.

* lisp/net/eww.el (eww-retrieve): New function.
(eww-reload): Use it.
(eww): Ditto.
(eww-retrieve-command): New variable.

1 files changed, 17 insertions, 0 deletions

diff --git a/doc/misc/eww.texi b/doc/misc/eww.texi
index 85be112402c..e814d0ac486 100644
--- a/doc/misc/eww.texi
+++ b/doc/misc/eww.texi
@@ -212,6 +212,23 @@ in an external browser by customizing
 @node Advanced
 @chapter Advanced
 
+@findex eww-retrieve-command
+  EWW normally uses @code{url-retrieve} to fetch the @acronym{HTML}
+before rendering it. It can sometimes be convenient to use an external
+program to do this, and @code{eww-retrieve-command} should then be a
+list that specifies a command and the parameters.  For instance, to
+use the Chromium browser, you could say something like this:
+
+@lisp
+(setq eww-retrieve-command
+      '("chromium" "--headless"
+		    "--virtual-time-budget=3000"
+		    "--dump-dom"))
+@end lisp
+
+The command should return the @acronym{HTML} on standard output, and
+the data should use @acronym{UTF-8} as the charset.
+
 @findex eww-view-source
 @kindex v
 @cindex Viewing Source