cpython/Lib/webbrowser.py
Fred Drake 3f8f1643c8 Remove some false comments.
Reorganize so the initialization sequences does not bite us in the foot.
(There is no good reason to discard classes that clients may want to
subclass.)
2001-07-19 03:46:26 +00:00

317 lines
9.5 KiB
Python

"""Interfaces for launching and remotely controlling Web browsers."""
import os
import sys
__all__ = ["Error", "open", "get", "register"]
class Error(Exception):
pass
_browsers = {} # Dictionary of available browser controllers
_tryorder = [] # Preference order of available browsers
def register(name, klass, instance=None):
"""Register a browser connector and, optionally, connection."""
_browsers[name.lower()] = [klass, instance]
def get(using=None):
"""Return a browser launcher instance appropriate for the environment."""
if using:
alternatives = [using]
else:
alternatives = _tryorder
for browser in alternatives:
if browser.find('%s') > -1:
# User gave us a command line, don't mess with it.
return GenericBrowser(browser)
else:
# User gave us a browser name.
try:
command = _browsers[browser.lower()]
except KeyError:
command = _synthesize(browser)
if command[1] is None:
return command[0]()
else:
return command[1]
raise Error("could not locate runnable browser")
# Please note: the following definition hides a builtin function.
def open(url, new=0, autoraise=1):
get().open(url, new, autoraise)
def open_new(url):
get().open(url, 1)
def _synthesize(browser):
"""Attempt to synthesize a controller base on existing controllers.
This is useful to create a controller when a user specifies a path to
an entry in the BROWSER environment variable -- we can copy a general
controller to operate using a specific installation of the desired
browser in this way.
If we can't create a controller in this way, or if there is no
executable for the requested browser, return [None, None].
"""
if not os.path.exists(browser):
return [None, None]
name = os.path.basename(browser)
try:
command = _browsers[name.lower()]
except KeyError:
return [None, None]
# now attempt to clone to fit the new name:
controller = command[1]
if controller and name.lower() == controller.basename:
import copy
controller = copy.copy(controller)
controller.name = browser
controller.basename = os.path.basename(browser)
register(browser, None, controller)
return [None, controller]
ret
def _iscommand(cmd):
"""Return true if cmd can be found on the executable search path."""
path = os.environ.get("PATH")
if not path:
return 0
for d in path.split(os.pathsep):
exe = os.path.join(d, cmd)
if os.path.isfile(exe):
return 1
return 0
PROCESS_CREATION_DELAY = 4
class GenericBrowser:
def __init__(self, cmd):
self.name, self.args = cmd.split(None, 1)
self.basename = os.path.basename(self.name)
def open(self, url, new=0, autoraise=1):
command = "%s %s" % (self.name, self.args)
os.system(command % url)
def open_new(self, url):
self.open(url)
class Netscape:
"Launcher class for Netscape browsers."
def __init__(self, name):
self.name = name
self.basename = os.path.basename(name)
def _remote(self, action, autoraise):
raise_opt = ("-noraise", "-raise")[autoraise]
cmd = "%s %s -remote '%s' >/dev/null 2>&1" % (self.name,
raise_opt,
action)
rc = os.system(cmd)
if rc:
import time
os.system("%s &" % self.name)
time.sleep(PROCESS_CREATION_DELAY)
rc = os.system(cmd)
return not rc
def open(self, url, new=0, autoraise=1):
if new:
self._remote("openURL(%s, new-window)"%url, autoraise)
else:
self._remote("openURL(%s)" % url, autoraise)
def open_new(self, url):
self.open(url, 1)
class Konqueror:
"""Controller for the KDE File Manager (kfm, or Konqueror).
See http://developer.kde.org/documentation/other/kfmclient.html
for more information on the Konqueror remote-control interface.
"""
def __init__(self):
if _iscommand("konqueror"):
self.name = self.basename = "konqueror"
else:
self.name = self.basename = "kfm"
def _remote(self, action):
cmd = "kfmclient %s >/dev/null 2>&1" % action
rc = os.system(cmd)
if rc:
import time
if self.basename == "konqueror":
os.system(self.name + " --silent &")
else:
os.system(self.name + " -d &")
time.sleep(PROCESS_CREATION_DELAY)
rc = os.system(cmd)
return not rc
def open(self, url, new=1, autoraise=1):
# XXX Currently I know no way to prevent KFM from
# opening a new win.
self._remote("openURL %s" % url)
open_new = open
class Grail:
# There should be a way to maintain a connection to Grail, but the
# Grail remote control protocol doesn't really allow that at this
# point. It probably neverwill!
def _find_grail_rc(self):
import glob
import pwd
import socket
import tempfile
tempdir = os.path.join(tempfile.gettempdir(),
".grail-unix")
user = pwd.getpwuid(_os.getuid())[0]
filename = os.path.join(tempdir, user + "-*")
maybes = glob.glob(filename)
if not maybes:
return None
s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
for fn in maybes:
# need to PING each one until we find one that's live
try:
s.connect(fn)
except socket.error:
# no good; attempt to clean it out, but don't fail:
try:
os.unlink(fn)
except IOError:
pass
else:
return s
def _remote(self, action):
s = self._find_grail_rc()
if not s:
return 0
s.send(action)
s.close()
return 1
def open(self, url, new=0, autoraise=1):
if new:
self._remote("LOADNEW " + url)
else:
self._remote("LOAD " + url)
def open_new(self, url):
self.open(url, 1)
class WindowsDefault:
def open(self, url, new=0, autoraise=1):
os.startfile(url)
def open_new(self, url):
self.open(url)
#
# Platform support for Unix
#
# This is the right test because all these Unix browsers require either
# a console terminal of an X display to run. Note that we cannot split
# the TERM and DISPLAY cases, because we might be running Python from inside
# an xterm.
if os.environ.get("TERM") or os.environ.get("DISPLAY"):
_tryorder = ("mozilla","netscape","kfm","grail","links","lynx","w3m")
# Easy cases first -- register console browsers if we have them.
if os.environ.get("TERM"):
# The Links browser <http://artax.karlin.mff.cuni.cz/~mikulas/links/>
if _iscommand("links"):
register("links", None, GenericBrowser("links %s"))
# The Lynx browser <http://lynx.browser.org/>
if _iscommand("lynx"):
register("lynx", None, GenericBrowser("lynx %s"))
# The w3m browser <http://ei5nazha.yz.yamagata-u.ac.jp/~aito/w3m/eng/>
if _iscommand("w3m"):
register("w3m", None, GenericBrowser("w3m %s"))
# X browsers have more in the way of options
if os.environ.get("DISPLAY"):
# First, the Netscape series
if _iscommand("netscape") or _iscommand("mozilla"):
if _iscommand("mozilla"):
register("mozilla", None, Netscape("mozilla"))
if _iscommand("netscape"):
register("netscape", None, Netscape("netscape"))
# Next, Mosaic -- old but still in use.
if _iscommand("mosaic"):
register("mosaic", None, GenericBrowser("mosaic %s >/dev/null &"))
# Konqueror/kfm, the KDE browser.
if _iscommand("kfm") or _iscommand("konqueror"):
register("kfm", Konqueror, Konqueror())
# Grail, the Python browser.
if _iscommand("grail"):
register("grail", Grail, None)
class InternetConfig:
def open(self, url, new=0, autoraise=1):
ic.launchurl(url)
def open_new(self, url):
self.open(url)
#
# Platform support for Windows
#
if sys.platform[:3] == "win":
_tryorder = ("netscape", "windows-default")
register("windows-default", WindowsDefault)
#
# Platform support for MacOS
#
try:
import ic
except ImportError:
pass
else:
# internet-config is the only supported controller on MacOS,
# so don't mess with the default!
_tryorder = ("internet-config")
register("internet-config", InternetConfig)
# OK, now that we know what the default preference orders for each
# platform are, allow user to override them with the BROWSER variable.
#
if os.environ.has_key("BROWSER"):
# It's the user's responsibility to register handlers for any unknown
# browser referenced by this value, before calling open().
_tryorder = os.environ["BROWSER"].split(":")
for cmd in _tryorder:
if not _browsers.has_key(cmd.lower()):
if _iscommand(cmd.lower()):
register(cmd.lower(), None, GenericBrowser("%s %%s" % cmd.lower()))
_tryorder = filter(lambda x: _browsers.has_key(x.lower())
or x.find("%s") > -1, _tryorder)
# what to do if _tryorder is now empty?