Merge pull request #78 from astrofrog/load-fits

Added support for displaying FITS data

.travis.yml

@@ -13,7 +13,7 @@ env:
   global:
     - SETUP_XVFB=True
     - CONDA_CHANNELS="astrofrog/label/dev"
-    - CONDA_DEPENDENCIES="astropy qtpy traitlets ipywidgets>=7.0 ipyevents widgetsnbextension pyqt pytest requests nomkl matplotlib beautifulsoup4 lxml jupyterlab"
+    - CONDA_DEPENDENCIES="astropy qtpy traitlets ipywidgets>=7.0 ipyevents widgetsnbextension pyqt pytest requests nomkl matplotlib beautifulsoup4 lxml jupyterlab flask flask-cors"
     - PIP_DEPENDENCIES="sphinx-automodapi numpydoc sphinx_rtd_theme pytest-faulthandler"
   matrix:
     - PYTHON_VERSION=2.7

CHANGES.rst

@@ -1,6 +1,8 @@
 0.4.0 (unreleased)
 ------------------
 
+- Added ``load_fits_data`` method for Qt and Jupyter clients. [#78]
+
 - Fix compatibility with Jupyter Lab. [#63, #65]
 
 - Added GUI controls for imagery layers. [#64]

appveyor.yml

@@ -12,7 +12,7 @@ environment:
                         # to the matrix section.
 
       CONDA_CHANNELS: "astrofrog/label/dev conda-forge"
-      CONDA_DEPENDENCIES: "astropy qtpy traitlets ipywidgets>=7.0 ipyevents widgetsnbextension pyqt pytest requests matplotlib"
+      CONDA_DEPENDENCIES: "astropy qtpy traitlets ipywidgets>=7.0 ipyevents widgetsnbextension pyqt pytest requests matplotlib flask flask-cors"
       PIP_DEPENDENCIES: "pytest-faulthandler"
 
   matrix:

lib/wwt.js

@@ -24,19 +24,9 @@ var WWTView = widgets.DOMWidgetView.extend({
         // page. We use the same HTML file as for the Qt client.
         var div = document.createElement("div");
 
-        try {
-          // This should work for Jupyter notebook
-          nbextensions = requirejs.s.contexts._.config.paths.nbextensions;
-        } catch(e) {
-          // We should get here in Jupyter lab
-          nbextensions = null;
-        }
+        this.wwt_base_url = require('@jupyterlab/coreutils').PageConfig.getBaseUrl();
 
-        if (nbextensions == null) {
-          div.innerHTML = "<iframe width='100%' height='400' style='border: none;' src='wwt.html'></iframe>"
-        } else {
-          div.innerHTML = "<iframe width='100%' height='400' style='border: none;' src='" + nbextensions + "/pywwt/wwt.html'></iframe>"
-        }
+        div.innerHTML = "<iframe width='100%' height='400' style='border: none;' src='" + this.wwt_base_url + "wwt/wwt.html'></iframe>"
 
         this.el.appendChild(div);
 
@@ -122,6 +112,10 @@ var WWTView = widgets.DOMWidgetView.extend({
         }
       }
 
+      if (msg['url'] != null && msg['url'].slice(4) == '/wwt') {
+        msg['url'] = this.wwt_base_url + msg['url'];
+      }
+
       this.wwt_window.wwt_apply_json_message(this.wwt_window.wwt, msg);
 
     }

pywwt/core.py

@@ -1,3 +1,4 @@
+import os
 from traitlets import HasTraits, observe, validate, TraitError
 from astropy import units as u
 from astropy.time import Time
@@ -266,8 +267,8 @@ def _validate_scale(self, proposal):
 
     def track_object(self, obj):
         """
-        Focus the viewer on a particular object while in solar system mode. 
-        Available objects include the Sun, the planets, the Moon, Jupiter's 
+        Focus the viewer on a particular object while in solar system mode.
+        Available objects include the Sun, the planets, the Moon, Jupiter's
         Galilean moons, and Pluto.
 
         Parameters
@@ -308,7 +309,7 @@ def set_view(self, mode):
                      'panorama']
         ss_levels = ['solar_system', 'milky_way', 'universe']
         ss_mode = '3D Solar System View'
-        
+
         if mode in available:
             self._send_msg(event='set_viewer_mode', mode=mode)
             if mode == 'sky' or mode == 'panorama':
@@ -320,12 +321,12 @@ def set_view(self, mode):
             self.current_mode = mode
         else:
             raise ValueError('the given mode does not exist')
-        
+
         self.reset_view()
 
     def reset_view(self):
         """
-        Reset the current view mode's coordinates and field of view to 
+        Reset the current view mode's coordinates and field of view to
         their original states.
         """
         if self.current_mode == 'sky':
@@ -345,7 +346,7 @@ def reset_view(self):
                                       fov=1e14*u.deg, instant=False)
         if self.current_mode == 'panorama':
             pass
-        
+
     def load_image_collection(self, url):
         """
         Load a collection of layers for possible use in the viewer.
@@ -489,3 +490,12 @@ def add_collection(self, points, **kwargs):
         """
         collection = CircleCollection(self, points, **kwargs)
         return collection
+
+    def _validate_fits_data(self, filename):
+        if not os.path.exists(filename):
+            raise Exception("File {0} does not exist".format(filename))
+        from astropy.wcs import WCS
+        wcs = WCS(filename)
+        projection = wcs.celestial.wcs.ctype[0][4:]
+        if projection != '-TAN':
+            raise ValueError("Only -TAN FITS files are supported at the moment")

pywwt/data_server.py

@@ -0,0 +1,88 @@
+import os
+import time
+import socket
+import logging
+from hashlib import md5
+from threading import Thread
+
+__all__ = ['get_data_server']
+
+
+def get_data_server(verbose=True):
+    """
+    This starts up a flask server and returns a handle to a DataServer
+    object which can be used to register files to serve.
+    """
+
+    from flask import Flask
+    from flask_cors import CORS
+
+    class FlaskWrapper(Flask):
+
+        port = None
+        host = None
+
+        def run(self, *args, **kwargs):
+            self.host = kwargs.get('host', None)
+            self.port = kwargs.get('port', None)
+            try:
+                super(FlaskWrapper, self).run(*args, **kwargs)
+            finally:
+                self.host = None
+                self.port = None
+
+    app = FlaskWrapper('DataServer')
+    CORS(app)
+    if verbose:
+        log = logging.getLogger('werkzeug')
+        log.setLevel(logging.ERROR)
+
+    class DataServer(object):
+
+        def __init__(self):
+            self._files = {}
+            self._thread = Thread(target=self.start_app)
+            self._thread.daemon = True
+            self._thread.start()
+            self._app = app
+            while self._app.host is None and self._app.port is None:
+                time.sleep(0.1)
+
+        @property
+        def port(self):
+            return self._app.port
+
+        @property
+        def host(self):
+            return self._app.host
+
+        def start_app(self):
+            host = socket.gethostbyname('localhost')
+            for port in range(8000, 9000):
+                try:
+                    return app.run(host=host, port=port)
+                except Exception:
+                    pass
+            raise Exception("Could not start up data server")
+
+        def serve_file(self, filename, real_name=True, extension=''):
+            with open(filename, 'rb') as f:
+                content = f.read()
+            if real_name:
+                hash = os.path.basename(filename)
+            else:
+                hash = md5(content).hexdigest() + extension
+            self._files[hash] = os.path.abspath(filename)
+            return 'http://' + self.host + ':' + str(self.port) + '/data/' + hash
+
+        def get_file_contents(self, hash):
+            with open(self._files[hash], 'rb') as f:
+                return f.read()
+
+    ds = DataServer()
+
+    @app.route("/data/<hash>")
+    def data(hash):
+        return ds.get_file_contents(hash)
+
+    return ds

pywwt/jupyter.py

@@ -13,6 +13,7 @@
     from ipyevents import Event as DOMListener
 
 from .core import BaseWWTWidget
+from .jupyter_server import serve_file
 
 __all__ = ['WWTJupyterWidget']
 
@@ -49,6 +50,19 @@ def _default_layout(self):
     def _send_msg(self, **kwargs):
         self.send(kwargs)
 
+    def load_fits_data(self, filename):
+        """
+        Load a FITS file.
+
+        Paramters
+        ---------
+        filename : str
+            The filename of the FITS file to display.
+        """
+        self._validate_fits_data(filename)
+        url = serve_file(filename, extension='.fits')
+        self._send_msg(event='load_fits', url=url)
+
     @property
     def layer_controls(self):
         if self._controls is None:

pywwt/jupyter_server.py

@@ -1,34 +1,73 @@
 import os
+import json
+from hashlib import md5
+from tornado import web
 from notebook.utils import url_path_join
 from notebook.base.handlers import IPythonHandler
 
 __all__ = ['load_jupyter_server_extension']
 
 
 STATIC_DIR = os.path.join(os.path.dirname(__file__), 'nbextension', 'static')
+CONFIG = os.path.expanduser('~/.pywwt')
 
 
-class WWTHTMLHandler(IPythonHandler):
-    def get(self):
-        with open(os.path.join(STATIC_DIR, 'wwt.html')) as f:
-            content = f.read()
-        self.finish(content)
+class WWTFileHandler(IPythonHandler):
+
+    def get(self, filename):
+
+        filename = os.path.basename(filename)
 
+        # First we check if this is a standard file in the static directory
+        if os.path.exists(os.path.join(STATIC_DIR, filename)):
+            path = os.path.join(STATIC_DIR, filename)
+        else:
+            # If not, we open the config file which should contain a JSON
+            # dictionary with filenames and paths.
+            if not os.path.exists(CONFIG):
+                raise web.HTTPError(404)
+            with open(CONFIG) as f:
+                config = json.load(f)
+            if filename in config['paths']:
+                path = config['paths'][filename]
+            else:
+                raise web.HTTPError(404)
 
-class WWTJSHandler(IPythonHandler):
-    def get(self):
-        with open(os.path.join(STATIC_DIR, 'wwt_json_api.js')) as f:
+        with open(path, 'rb') as f:
             content = f.read()
+
         self.finish(content)
 
 
+def serve_file(path, extension=''):
+
+    if not os.path.exists(path):
+        raise ValueError("Path {0} does not exist".format(path))
+
+    hash = md5(path.encode('utf-8')).hexdigest() + extension
+
+    with open(CONFIG) as f:
+        config = json.load(f)
+
+    if hash not in config['paths']:
+
+        config['paths'][hash] = os.path.abspath(path)
+
+        with open(CONFIG, 'w') as f:
+            json.dump(config, f)
+
+    return '/wwt/' + hash
+
+
 def load_jupyter_server_extension(nb_server_app):
 
     web_app = nb_server_app.web_app
     host_pattern = '.*$'
 
-    route_pattern = url_path_join(web_app.settings['base_url'], '/wwt.html')
-    web_app.add_handlers(host_pattern, [(route_pattern, WWTHTMLHandler)])
+    if not os.path.exists(CONFIG):
+        config = {'paths': {}}
+        with open(CONFIG, 'w') as f:
+            json.dump(config, f)
 
-    route_pattern = url_path_join(web_app.settings['base_url'], '/wwt_json_api.js')
-    web_app.add_handlers(host_pattern, [(route_pattern, WWTJSHandler)])
+    route_pattern = url_path_join(web_app.settings['base_url'], '/wwt/(.*)')
+    web_app.add_handlers(host_pattern, [(route_pattern, WWTFileHandler)])

pywwt/nbextension/static/wwt_json_api.js

@@ -55,6 +55,10 @@ function wwt_apply_json_message(wwt, msg) {
       wwt.gotoRaDecZoom(msg['ra'], msg['dec'], msg['fov'], msg['instant']);
       break;
 
+    case 'load_fits':
+      wwt.loadFits(msg['url']);
+      break;
+
     case 'setting_set':
       var name = msg['setting'];
       wwt.settings["set_" + name](msg['value']);

pywwt/qt.py

@@ -13,6 +13,7 @@
 
 from .core import BaseWWTWidget
 from .logger import logger
+from .data_server import get_data_server
 
 __all__ = ['WWTQtClient']
 
@@ -96,15 +97,15 @@ def _check_ready(self):
 
 class WWTQtWidget(QtWidgets.QWidget):
 
-    def __init__(self, parent=None):
+    def __init__(self, url=None, parent=None):
 
         super(WWTQtWidget, self).__init__(parent=parent)
 
         self.web = QWebEngineView()
         self.page = WWTQWebEnginePage()
         self.page.setView(self.web)
         self.web.setPage(self.page)
-        self.web.setHtml(WWT_HTML)
+        self.web.setUrl(QtCore.QUrl(url))
 
         layout = QtWidgets.QVBoxLayout()
         layout.setContentsMargins(0, 0, 0, 0)
@@ -162,7 +163,11 @@ def __init__(self, block_until_ready=False, size=None):
             if app is None:
                 app = QtWidgets.QApplication([''])
 
-        self.widget = WWTQtWidget()
+        self._data_server = get_data_server()
+        self._data_server.serve_file(WWT_JSON_FILE, real_name=True)
+        wwt_url = self._data_server.serve_file(WWT_HTML_FILE, real_name=True)
+
+        self.widget = WWTQtWidget(url=wwt_url)
         if size is not None:
             self.widget.resize(*size)
         self.widget.show()
@@ -186,6 +191,19 @@ def _send_msg(self, async=True, **kwargs):
         msg = json.dumps(kwargs)
         return self.widget._run_js("wwt_apply_json_message(wwt, {0});".format(msg), async=async)
 
+    def load_fits_data(self, filename):
+        """
+        Load a FITS file.
+
+        Paramters
+        ---------
+        filename : str
+            The filename of the FITS file to display.
+        """
+        self._validate_fits_data(filename)
+        url = self._data_server.serve_file(filename, extension='.fits')
+        self._send_msg(event='load_fits', url=url)
+
     def render(self, filename):
         """
         Saves a screenshot of the viewer's current state.