webui: Split "handers/configs.py" from "handlers/websocket.py"

Split "ConfigsHandler" from "FG21simWSHandler" as "handlers/configs.py"

1 files changed, 265 insertions, 0 deletions

diff --git a/fg21sim/webui/handlers/configs.py b/fg21sim/webui/handlers/configs.py
new file mode 100644
index 0000000..2e6c3a9
--- /dev/null
+++ b/fg21sim/webui/handlers/configs.py
@@ -0,0 +1,265 @@
+# Copyright (c) 2016 Weitian LI <liweitianux@live.com>
+# MIT license
+
+"""
+Handle the configurations operations with the client.
+"""
+
+import os
+import logging
+
+from ...errors import ConfigError
+
+
+logger = logging.getLogger(__name__)
+
+
+class ConfigsHandler:
+    """
+    Handle the "configs" type of messages from the client.
+    """
+    def __init__(self, configs):
+        self.configs = configs
+
+    def handle_message(self, msg):
+        """
+        Handle the message of type "configs", which request to get or
+        set some configurations by the client.
+
+        TODO:
+        * improve the description ...
+        * split these handling functions into a separate class in a module
+
+        Parameters
+        ----------
+        msg : dict
+            A dictionary parsed from the incoming JSON message, which
+            generally has the following syntax:
+            ``{"type": "configs", "action": <action>, "data": <data>}``
+            where the ``<action>`` is ``set`` or ``get``, and the ``<data>``
+            is a list of config keys or a dict of config key-value pairs.
+
+        Returns
+        -------
+        response : dict
+            A dictionary parsed from the incoming JSON message, which
+            generally has the following syntax:
+            ``{"type": "configs", "action": <action>,
+               "data": <data>, "errors": <errors>}``
+            where the ``<action>`` is the same as input, the ``<data>`` is
+            a list of config keys or a dict of config key-value pairs, and
+            ``<errors>`` contains the error message for the invalid config
+            values.
+        """
+        try:
+            msg_type = msg["type"]
+            msg_action = msg["action"]
+            response = {"type": msg_type, "action": msg_action}
+            logger.info("WebSocket: handle message: " +
+                        "type: {0}, action: {1}".format(msg_type, msg_action))
+            if msg_action == "get":
+                # Get the values of the specified options
+                try:
+                    data, errors = self._get_configs(keys=msg["keys"])
+                    response["success"] = True
+                    response["data"] = data
+                    response["errors"] = errors
+                except KeyError:
+                    response["success"] = False
+                    response["error"] = "'keys' is missing"
+            elif msg_action == "set":
+                # Set the values of the specified options
+                try:
+                    errors = self._set_configs(data=msg["data"])
+                    response["success"] = True
+                    response["data"] = {}  # be more consistent
+                    response["errors"] = errors
+                except KeyError:
+                    response["success"] = False
+                    response["error"] = "'data' is missing"
+            elif msg_action == "reset":
+                # Reset the configurations to the defaults
+                self._reset_configs()
+                response["success"] = True
+            elif msg_action == "load":
+                # Load the supplied user configuration file
+                try:
+                    success, error = self._load_configs(msg["userconfig"])
+                    response["success"] = success
+                    if not success:
+                        response["error"] = error
+                except KeyError:
+                    response["success"] = False
+                    response["error"] = "'userconfig' is missing"
+            elif msg_action == "save":
+                # Save current configurations to file
+                try:
+                    success, error = self._save_configs(msg["outfile"],
+                                                        msg["clobber"])
+                    response["success"] = success
+                    if not success:
+                        response["error"] = error
+                except KeyError:
+                    response["success"] = False
+                    response["error"] = "'outfile' or 'clobber' is missing"
+            else:
+                logger.warning("WebSocket: " +
+                               "unknown action: {0}".format(msg_action))
+                response["success"] = False
+                response["error"] = "unknown action: {0}".format(msg_action)
+        except KeyError:
+            # Received message has wrong syntax/format
+            response = {"success": False,
+                        "type": msg_type,
+                        "error": "no action specified"}
+        #
+        logger.debug("WebSocket: response: {0}".format(response))
+        return response
+
+    def _get_configs(self, keys=None):
+        """Get the values of the config options specified by the given keys.
+
+        Parameters
+        ----------
+        keys : list[str], optional
+            A list of keys specifying the config options whose values will
+            be obtained.
+            If ``keys=None``, then all the configurations values are dumped.
+
+        Returns
+        -------
+        data : dict
+            A dictionary with keys the same as the input keys, and values
+            the corresponding config option values.
+        errors : dict
+            When error occurs (e.g., invalid key), then the specific errors
+            with details are stored in this dictionary.
+
+        NOTE
+        ----
+        Do not forget the ``userconfig`` option.
+        """
+        if keys is None:
+            # Dump all the configurations
+            data = self.configs.dump(flatten=True)
+            data["userconfig"] = self.configs.userconfig
+            errors = {}
+        else:
+            data = {}
+            errors = {}
+            for key in keys:
+                if key == "userconfig":
+                    data["userconfig"] = self.configs.userconfig
+                else:
+                    try:
+                        data[key] = self.configs.getn(key)
+                    except KeyError as e:
+                        errors[key] = str(e)
+        #
+        return (data, errors)
+
+    def _set_configs(self, data):
+        """Set the values of the config options specified by the given keys
+        to the corresponding supplied data.
+
+        NOTE
+        ----
+        The ``userconfig`` needs special handle.
+        The ``workdir`` and ``configfile`` options should be ignored.
+
+        Parameters
+        ----------
+        data : dict
+            A dictionary of key-value pairs, with keys specifying the config
+            options whose value will be changed, and values the new values
+            to which config options will be set.
+            NOTE:
+            If want to set the ``userconfig`` option, an *absolute path*
+            must be provided.
+
+        Returns
+        -------
+        errors : dict
+            When error occurs (e.g., invalid key, invalid values), then the
+            specific errors with details are stored in this dictionary.
+        """
+        errors = {}
+        for key, value in data.items():
+            if key in ["workdir", "configfile"]:
+                # Ignore "workdir" and "configfile"
+                continue
+            elif key == "userconfig":
+                if os.path.isabs(os.path.expanduser(value)):
+                    self.configs.userconfig = value
+                else:
+                    errors[key] = "Not an absolute path"
+            else:
+                try:
+                    self.configs.setn(key, value)
+                except KeyError as e:
+                    errors[key] = str(e)
+        # NOTE:
+        # Check the whole configurations after all provided options are
+        # updated, and merge the validation errors.
+        __, cherr = self.configs.check_all(raise_exception=False)
+        errors.update(cherr)
+        return errors
+
+    def _reset_configs(self):
+        """Reset the configurations to the defaults."""
+        self.configs.reset()
+
+    def _load_configs(self, userconfig):
+        """Load configurations from the provided user configuration file.
+
+        Parameters
+        ----------
+        userconfig: str
+            The filepath to the user configuration file, which must be
+            an *absolute path*.
+
+        Returns
+        -------
+        success : bool
+            ``True`` if the operation succeeded, otherwise, ``False``.
+        error : str
+            If failed, this ``error`` saves the details, otherwise, ``None``.
+        """
+        success = False
+        error = None
+        if os.path.isabs(os.path.expanduser(userconfig)):
+            try:
+                self.configs.read_userconfig(userconfig)
+                success = True
+            except ConfigError as e:
+                error = str(e)
+        else:
+            error = "Not an absolute path"
+        return (success, error)
+
+    def _save_configs(self, outfile, clobber=False):
+        """Save current configurations to file.
+
+        Parameters
+        ----------
+        outfile: str
+            The filepath to the output configuration file, which must be
+            an *absolute path*.
+        clobber : bool, optional
+            Whether overwrite the output file if already exists?
+
+        Returns
+        -------
+        success : bool
+            ``True`` if the operation succeeded, otherwise, ``False``.
+        error : str
+            If failed, this ``error`` saves the details, otherwise, ``None``.
+        """
+        success = False
+        error = None
+        try:
+            self.configs.save(outfile, clobber=clobber)
+            success = True
+        except (ValueError, OSError) as e:
+            error = str(e)
+        return (success, error)