Merge pull request #128 from Zsailer/extension-browser-open

[MRG] add open_browser trait to ExtensionApp

jupyter_server/extension/application.py

@@ -4,7 +4,8 @@
 from traitlets import (
     Unicode, 
     List, 
-    Dict, 
+    Dict,
+    Bool,
     default, 
     validate
 )
@@ -80,6 +81,12 @@ def _preparse_for_stopping_flags(Application, argv):
         app.exit(0)
 
 
+flags['no-browser']=(
+    {'ExtensionApp' : {'open_browser' : True}},
+    _("Prevent the opening of the default url in the browser.")
+)
+
+
 class ExtensionApp(JupyterApp):
     """Base class for configurable Jupyter Server Extension Applications.
 
@@ -176,6 +183,11 @@ def _config_file_name_default(self):
         help=_("The default URL to redirect to from `/`")
     )
 
+    open_browser = Bool(
+        True,
+        help=_("Should the extension open a browser window?")
+    )
+
     custom_display_url = Unicode(u'', config=True,
         help=_("""Override URL shown to users.
 
@@ -335,7 +347,7 @@ def start(self):
         # Override the server's display url to show extension's display URL.
         self.serverapp.custom_display_url = self.custom_display_url
         # Override the server's default option and open a broswer window.
-        self.serverapp.open_browser = True
+        self.serverapp.open_browser = self.open_browser
         # Hijack the server's browser-open file to land on
         # the extensions home page.
         self.serverapp._write_browser_open_file = self._write_browser_open_file