Python method for retrieving the list of environment names from the s…

…erver (fossasia#463)

Summary:
Introduces a way to get a list of all of the environment names from the server. Could be useful to make some python tooling around sorting and deleting environments, and also later around downloading and saving environments.

Implements fossasia#445

Tested by running in terminal

<img width="493" alt="screen shot 2018-08-29 at 11 19 51 pm" src="https://user-images.githubusercontent.com/1276867/44827666-12baf100-abe2-11e8-9151-56bce8a49f84.png">

<!--- What types of changes does your code introduce? Put an `x` in all the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

<!--- Go over all the following points, and put an `x` in all the boxes that apply. -->
<!--- If you're unsure about any of these, don't hesitate to ask. We're here to help! -->
- [x] My code follows the code style of this project.
- [x] My change requires a change to the documentation.
- [x] I have updated the documentation accordingly.
- [ ] For JavaScript changes, I have re-generated the minified JavaScript code.
Pull Request resolved: fossasia#463

Differential Revision: D9616314

Pulled By: JackUrb

fbshipit-source-id: e04d21fc3da1cff7ce7e96b31766eb44dbeb2595

README.md

@@ -291,6 +291,7 @@ vis._send({'data': [trace], 'layout': layout, 'win': 'mywin'})
 - [`vis.close`](#visclose)    : close a window by id
 - [`vis.delete_env`](#visdelete_env) : delete an environment by env_id
 - [`vis.win_exists`](#viswin_exists) : check if a window already exists by id
+- [`vis.get_env_list`](#visget_env_list) : get a list of all of the environments on your server
 - [`vis.win_hash`](#viswin_hash): get md5 hash of window's contents
 - [`vis.get_window_data`](#visget_window_data): get current data for a window
 - [`vis.check_connection`](#vischeck_connection): check if the server is connected
@@ -626,6 +627,10 @@ This function returns a bool indicating whether or not a window `win` exists on
 Optional arguments:
 - `env`: Environment to search for the window in. Default is `None`.
 
+#### vis.get_env_list
+
+This function returns a list of all of the environments on the server at the time of calling. It takes no arguments.
+
 #### vis.win_hash
 
 This function returns md5 hash of the contents of a window `win` if it exists on the server. Returns None otherwise.

py/visdom/__init__.py

@@ -561,6 +561,13 @@ def _win_exists_wrap(self, win, env=None):
             'eid': env,
         }, endpoint='win_exists', quiet=True)
 
+    def get_env_list(self):
+        """
+        This function returns a list of all of the env names that are currently
+        in the server.
+        """
+        return json.loads(self._send({}, endpoint='env_state', quiet=True))
+
     def win_exists(self, win, env=None):
         """
         This function returns a bool indicating whether

py/visdom/server.py

@@ -157,6 +157,7 @@ def __init__(self, port=DEFAULT_PORT, env_path=DEFAULT_ENV_PATH,
             (r"/win_data", DataHandler, {'app': self}),
             (r"/delete_env", DeleteEnvHandler, {'app': self}),
             (r"/win_hash", HashHandler, {'app': self}),
+            (r"/env_state", EnvStateHandler, {'app': self}),
             (r"/(.*)", IndexHandler, {'app': self}),
         ]
         super(Application, self).__init__(handlers, **tornado_settings)
@@ -671,6 +672,25 @@ def post(self):
         )
         self.wrap_func(self, args)
 
+
+class EnvStateHandler(BaseHandler):
+    def initialize(self, app):
+        self.app = app
+        self.state = app.state
+
+    @staticmethod
+    def wrap_func(handler, args):
+        # TODO if an env is provided return the state of that env
+        all_eids = list(handler.state.keys())
+        handler.write(json.dumps(all_eids))
+
+    def post(self):
+        args = tornado.escape.json_decode(
+            tornado.escape.to_basestring(self.request.body)
+        )
+        self.wrap_func(self, args)
+
+
 class HashHandler(BaseHandler):
     def initialize(self, app):
         self.app = app