webui: Add "ProductsAJAXHandler" to manipulate the products manifest

TODO: some actions currently not implemented yet

1 files changed, 173 insertions, 0 deletions

diff --git a/fg21sim/webui/handlers/products.py b/fg21sim/webui/handlers/products.py
new file mode 100644
index 0000000..5c9e0c8
--- /dev/null
+++ b/fg21sim/webui/handlers/products.py
@@ -0,0 +1,173 @@
+# Copyright (c) 2016 Weitian LI <liweitianux@live.com>
+# MIT license
+
+"""
+Handle the AJAX requests from the client to manage the simulation products.
+"""
+
+
+import os
+import logging
+
+import tornado.ioloop
+from tornado.escape import json_decode, json_encode
+
+from .base import BaseRequestHandler
+
+
+logger = logging.getLogger(__name__)
+
+
+class ProductsAJAXHandler(BaseRequestHandler):
+    """
+    Handle the AJAX requests from the client to manage the simulation products.
+
+    Attributes
+    ----------
+    from_localhost : bool
+        ``True`` if the request is from the localhost, otherwise ``False``.
+    """
+    def initialize(self):
+        """Hook for subclass initialization.  Called for each request."""
+        self.products = self.application.products
+        if self.request.remote_ip == "127.0.0.1":
+            self.from_localhost = True
+        else:
+            self.from_localhost = False
+
+    def get(self):
+        """
+        Handle the READ-ONLY products manifest manipulations.
+
+        Supported actions:
+        - get: Get the current products manifest
+        - download: TODO
+        - open: TODO
+        """
+        action = self.get_argument("action", "get")
+        if action == "get":
+            response = {
+                "manifest": self.products.manifest,
+                "localhost": self.from_localhost,
+            }
+            success = True
+        else:
+            # ERROR: bad action
+            success = False
+            reason = "Bad request action: {0}".format(action)
+        #
+        if success:
+            logger.debug("Response: {0}".format(response))
+            self.set_header("Content-Type", "application/json; charset=UTF-8")
+            self.write(json_encode(response))
+        else:
+            logger.warning("Request failed: {0}".format(reason))
+            self.send_error(400, reason=reason)
+
+    @tornado.web.authenticated
+    def post(self):
+        """
+        Handle the READ-WRITE products manifest manipulations.
+
+        Supported actions:
+        - load: Load the products manifest from file
+        - save: Save the current products manifest to file
+        - reset: Reset existing products manifest
+        - convert: Convert the product from HEALPix map to HPX image
+        """
+        request = json_decode(self.request.body)
+        logger.debug("Received request: {0}".format(request))
+        action = request.get("action")
+        if action == "load":
+            # Load the manifest from supplied file
+            try:
+                success, reason = self._load_products(request["manifestfile"])
+            except KeyError:
+                success = False
+                reason = "'manifestfile' is missing"
+        elif action == "save":
+            # Save current products manifest to file
+            try:
+                success, reason = self._save_products(request["outfile"],
+                                                      request["clobber"])
+            except KeyError:
+                success = False
+                reason = "'outfile' or 'clobber' is missing"
+        elif action == "reset":
+            # Reset existing products manifest
+            success = self._reset_products()
+        elif action == "convert":
+            # Convert the product from HEALPix map to HPX image
+            raise NotImplementedError("TODO")
+        else:
+            # ERROR: bad action
+            success = False
+            reason = "Bad request action: {0}".format(action)
+        #
+        if success:
+            response = {"action": action, "success": success}
+            logger.debug("Response: {0}".format(response))
+            self.set_header("Content-Type", "application/json; charset=UTF-8")
+            self.write(json_encode(response))
+        else:
+            logger.warning("Request failed: {0}".format(reason))
+            self.send_error(400, reason=reason)
+
+    def _reset_products(self):
+        """Reset the existing products manifest."""
+        self.products.reset()
+        return True
+
+    def _load_products(self, manifestfile):
+        """
+        Load the products manifest from file.
+
+        Parameters
+        ----------
+        manifestfile: str
+            The path to the products manifest 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(manifestfile)):
+            self.products.load(manifestfile)
+            success = True
+        else:
+            error = "Not an absolute path"
+        return (success, error)
+
+    def _save_products(self, outfile, clobber=False):
+        """
+        Save current products manifest to file.
+
+        Parameters
+        ----------
+        outfile: str
+            The filepath to the output manifest 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.products.dump(outfile, clobber=clobber)
+            success = True
+        except (ValueError, OSError) as e:
+            error = str(e)
+        return (success, error)