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Title: webbrowser default browser detection and/or public API for _trylist.
Type: enhancement Stage: resolved
Components: Versions: Python 3.6
Status: closed Resolution: fixed
Dependencies: Superseder:
Assigned To: ncoghlan Nosy List: berker.peksag, daves, jaysinh.shukla, ncoghlan, r.david.murray, vstinner
Priority: normal Keywords: patch

Created on 2015-05-19 13:43 by daves, last changed 2022-04-11 14:58 by admin. This issue is now closed.

File name Uploaded Description Edit
preferredbrowser.diff daves, 2015-07-18 01:03 Prioritize the default desktop browser review
Pull Requests
URL Status Linked Edit
PR 85 merged daves, 2017-02-18 12:56
PR 288 merged ncoghlan, 2017-02-25 07:49
PR 342 merged berker.peksag, 2017-02-27 14:40
Messages (14)
msg243590 - (view) Author: David Steele (daves) * Date: 2015-05-19 13:43
When calling*(), the module goes through a list of installed browsers, and uses the first one that succeeds, to process the request.

The first 'browsers' in the 'X' list are 'xdg-open' and others of that ilk. The problem is that they only have one 'open' behavior - the 'new' parameter is ignored ('same window', 'new window', 'new tab').

I can get the fully supported default browser in GNOME with e.g.

def browser():
    app = Gio.app_info_get_default_for_type('x-scheme-handler/https', True)
    bpath = app.get_filename()

    for candidate in webbrowser._tryorder:
        if candidate in bpath:
            return webbrowser.get(using=candidate)

    return webbrowser.get()

... but this code accesses a private list.

The problems are:

1) webbrowser does not determine and return the current default browser.

2) There is no public interface for determining the current/installed browser type list.

The problem can be mitigated by resolving (1) and/or (2).

Also, the browser type list in the documentation is missing many entries.

Checked on 2.7 and 3.4. I believe this is valid across all supported versions.
msg243593 - (view) Author: R. David Murray (r.david.murray) * (Python committer) Date: 2015-05-19 14:19
Any change is going to be an enhancement, so it will only go in 3.6 (at this point...beta/feature freeze for 3.5 is this weekend).

Would you like to propose a patch?
msg243598 - (view) Author: David Steele (daves) * Date: 2015-05-19 14:43
On Tue, May 19, 2015 at 10:19 AM, R. David Murray
<> wrote:
> Would you like to propose a patch?

My preferred solution would be a bit intrusive - check for and use
xdg-settings or gi.repository.Gio to identify the default browser, and
match the result against the type list. I'm not sure that would get
approval, nor am I sure of the best standard-library-compliant way to
go about it.
msg246874 - (view) Author: David Steele (daves) * Date: 2015-07-18 01:03
Patch attached, to sort the desktop default browser to the top of _tryorder.
msg287731 - (view) Author: David Steele (daves) * Date: 2017-02-14 02:57
msg288077 - (view) Author: Jaysinh shukla (jaysinh.shukla) * Date: 2017-02-18 13:04
Hello David,
    I hope you are still working on I tried to add few suggestions. Please write back on any confusions. Thanks!
msg288078 - (view) Author: David Steele (daves) * Date: 2017-02-18 13:11

Thanks for the feedback. I'm adding the documentation now.

As I noted in github, I'm not sure what the preferred exception handling would be for xdg-settings.
msg288539 - (view) Author: Nick Coghlan (ncoghlan) * (Python committer) Date: 2017-02-25 05:00
To summarise the changes that were made during the PR review, here's the eventual commit message for the merged PR:

 bpo-24241: Improve preferred webbrowser handling (#85)

- Add 'preferred' argument to webbrowser.register
- Use xdg-settings to specify preferred X browser

The first change replaces the existing undocumented tri-state
'try_order' parameter with the documented boolean keyword-only
'preferred' parameter. Setting it to True places the browser at the
front of the list, preferring it as the return to a subsequent get() call.

The second change adds a private `_os_preferred_browser` setting
and then uses that to make the default browser reported by
`xdg-settings` first in the try list when running under X (or
another environment that sets the `DISPLAY` variable).
This avoids the problem where the first entry in the tryorder
queue otherwise defaults to xdg-open, which doesn't support
the "new window" option.
msg288541 - (view) Author: Nick Coghlan (ncoghlan) * (Python committer) Date: 2017-02-25 05:45
After merging this, I belatedly realised that codecov's complaint about the lack of code coverage for the diff was actually valid: now that "preferred" is a public API, it should have a cross-platform test case.

That should be a fairly straightforward test to write, as it can just use an arbitrary string, and then poke around in _tryorder directly to make sure it is updated as expected - it doesn't need to use a valid browser reference.
msg288550 - (view) Author: Nick Coghlan (ncoghlan) * (Python committer) Date: 2017-02-25 08:15
Second PR merged with the missing test case.
msg290366 - (view) Author: Berker Peksag (berker.peksag) * (Python committer) Date: 2017-03-24 23:37
New changeset 370f7a956cef5895c93ca5a53fc26b04df973aaf by Berker Peksag in branch 'master':
bpo-24241: Add versionchanged directive to the documentation (#342)
msg290401 - (view) Author: Nick Coghlan (ncoghlan) * (Python committer) Date: 2017-03-24 23:46
New changeset 56a8eccc43c66ae51c5a6bfc89635b1998fd419e by Nick Coghlan in branch 'master':
bpo-24241: Add dedicated webbrowser.register test case (#288)
msg290404 - (view) Author: Nick Coghlan (ncoghlan) * (Python committer) Date: 2017-03-24 23:46
New changeset e3ce69522ffd7c0354d6e70d18f42bce325ed97e by Nick Coghlan (David Steele) in branch 'master':
bpo-24241: Improve preferred webbrowser handling (#85)
msg318167 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2018-05-30 11:23
It seems like this issue introduced a regression: bpo-33693.
Date User Action Args
2022-04-11 14:58:17adminsetgithub: 68429
2018-05-30 12:37:14berker.peksagsetpull_requests: - pull_request1099
2018-05-30 11:23:16vstinnersetnosy: + vstinner
messages: + msg318167
2017-03-31 16:36:38dstufftsetpull_requests: + pull_request1099
2017-03-24 23:46:59ncoghlansetmessages: + msg290404
2017-03-24 23:46:14ncoghlansetmessages: + msg290401
2017-03-24 23:37:01berker.peksagsetnosy: + berker.peksag
messages: + msg290366
2017-02-27 14:40:51berker.peksagsetpull_requests: + pull_request296
2017-02-25 08:15:11ncoghlansetstatus: open -> closed

messages: + msg288550
stage: test needed -> resolved
2017-02-25 07:49:29ncoghlansetpull_requests: + pull_request258
2017-02-25 05:45:20ncoghlansetassignee: ncoghlan
2017-02-25 05:45:02ncoghlansetstatus: closed -> open

messages: + msg288541
stage: resolved -> test needed
2017-02-25 05:00:33ncoghlansetnosy: + ncoghlan
messages: + msg288539
2017-02-25 04:58:32ncoghlansetstatus: open -> closed
resolution: fixed
stage: needs patch -> resolved
2017-02-18 13:11:21davessetmessages: + msg288078
2017-02-18 13:04:02jaysinh.shuklasetnosy: + jaysinh.shukla
messages: + msg288077
2017-02-18 12:56:44davessetpull_requests: + pull_request123
2017-02-14 02:57:57davessetmessages: + msg287731
2015-07-18 01:03:44davessetfiles: + preferredbrowser.diff
keywords: + patch
messages: + msg246874
2015-05-19 14:43:54davessetmessages: + msg243598
2015-05-19 14:19:09r.david.murraysetversions: + Python 3.6
type: behavior -> enhancement

nosy: + r.david.murray
title: webbrowser (very often) doesn't support the 'new' parameter -> webbrowser default browser detection and/or public API for _trylist.
messages: + msg243593
stage: needs patch
2015-05-19 13:43:02davescreate