Custom display API

tensorboard/notebook.py

@@ -49,19 +49,32 @@
 _CONTEXT_COLAB = "_CONTEXT_COLAB"
 _CONTEXT_IPYTHON = "_CONTEXT_IPYTHON"
 _CONTEXT_NONE = "_CONTEXT_NONE"
+_CONTEXT_CUSTOM = "_CONTEXT_CUSTOM"
+
+_custom_display = None
+
+
+def register_custom_display(func):
+    global _custom_display
+    _custom_display = func
 
 
 def _get_context():
     """Determine the most specific context that we're in.
 
     Returns:
+      _CONTEXT_CUSTOM: If user has registered a custom display function.
       _CONTEXT_COLAB: If in Colab with an IPython notebook context.
       _CONTEXT_IPYTHON: If not in Colab, but we are in an IPython notebook
         context (e.g., from running `jupyter notebook` at the command
         line).
       _CONTEXT_NONE: Otherwise (e.g., by running a Python script at the
         command-line or using the `ipython` interactive shell).
     """
+
+    if _custom_display is not None:
+        return _CONTEXT_CUSTOM
+
     # In Colab, the `google.colab` module is available, but the shell
     # returned by `IPython.get_ipython` does not have a `get_trait`
     # method.
@@ -145,7 +158,7 @@ def start(args_string):
     except ImportError:
         IPython = None
 
-    if context == _CONTEXT_NONE:
+    if context == _CONTEXT_NONE or context == _CONTEXT_CUSTOM:
         handle = None
         print("Launching TensorBoard...")
     else:
@@ -314,6 +327,7 @@ def _display(port=None, height=None, print_message=False, display_handle=None):
             pass
 
     fn = {
+        _CONTEXT_CUSTOM: _custom_display,
         _CONTEXT_COLAB: _display_colab,
         _CONTEXT_IPYTHON: _display_ipython,
         _CONTEXT_NONE: _display_cli,

tensorboard/notebook_test.py

@@ -0,0 +1,79 @@
+# Copyright 2017 The TensorFlow Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+from tensorboard import notebook
+from tensorboard import manager
+from tensorboard import test as tb_test
+
+try:
+    # python version >= 3.3
+    from unittest import mock
+except ImportError:
+    import mock  # pylint: disable=unused-import
+
+
+class CustomDisplayAPITest(tb_test.TestCase):
+    """Tests for `notebook.register_custom_display()`."""
+
+    counter = 0
+
+    # Mock a StartLaunched result to prevent starting a Tensorboard process
+    # when calling notebook.start()
+    _info = manager.TensorBoardInfo(
+        version="x.x",
+        start_time=0,
+        pid=0,
+        port=6006,
+        path_prefix="prefix",
+        logdir="dir",
+        db="db",
+        cache_key="key",
+    )
+    _startup_result = manager.StartLaunched(info=_info)
+
+    def custom_display(self, port, height, display_handle):
+        del port
+        del height
+        del display_handle
+        self.counter = 1
+
+    def reset(self):
+        self.counter = 0
+
+    def test_get_context(self):
+        notebook.register_custom_display(self.custom_display)
+        self.assertEqual(notebook._get_context(), "_CONTEXT_CUSTOM")
+
+    def test_display(self):
+        notebook.register_custom_display(self.custom_display)
+        notebook.display(6006)
+        self.assertEqual(self.counter, 1)
+        self.reset()
+
+    def test_start(self):
+        with mock.patch(
+            "tensorboard.manager.start", lambda _: self._startup_result
+        ):
+            notebook.register_custom_display(self.custom_display)
+            notebook.start("--logdir test")
+        self.assertEqual(self.counter, 1)
+        self.reset()
+
+
+if __name__ == "__main__":
+    tb_test.main()