Changeset 2586

Timestamp:

14/06/07 13:57:39 (12 years ago)

Author:

spascoe

Message:

First WMS GetMap? request working.

Location:

TI05-delivery/ows_framework/trunk/ows_server/ows_server

Files:

• controllers/csml_wms.py (modified) (4 diffs)
• lib/render.py (modified) (3 diffs)

TI05-delivery/ows_framework/trunk/ows_server/ows_server/controllers/csml_wms.py

@@ -7 +7 @@
 
 @author: Stephen Pascoe
+
 """
 from ows_server.lib.base import *
 from ows_server.controllers.csml_api import get_csml_doc
 from ows_server.lib.decorators import *
+from ows_server.lib import grid_util, render
+from ows_server.lib.csml_util import get_csml_doc
 import ows_server.lib.validators as V
 
@@ -20 +23 @@
 from ows_common.domain import ValuesUnit, PossibleValues
 
-from ows_server.lib.csml_util import get_csml_doc
-import ows_server.lib.validators as V
-
+import cdms
+import tempfile, os
+from cStringIO import StringIO
+import MA
 
 class CsmlWmsController(OwsController):
@@ -38 +42 @@
 
 
+    def _iterDimensions(self, feature):
+        """
+        Retrieve the non-geospatial dimensions of a feature.
+
+        @return: generator of dimension names
+
+        """
+        # Waiting for this feature to be implemented
+        #lat = feature.getLatitude()
+        #lon = feature.getLongitude()
+        lat = 'latitude'; lon = 'longitude'
+        
+        for axis_name in feature.getDomain():
+            if axis_name not in [lat, lon]:
+                yield axis_name
+
     def _loadFeatureDimensions(self, feature):
         dims = {}
-        #!WARNING
-        # This bit is a hack until the CSML API implements a mechanism
-        # to determine which elements of a domain are longitude and latitude.
-        for axis_name, axis in feature.getDomain().iteritems():
-            if axis_name in ['longitude', 'latitude']:
-                continue
+        domain = feature.getDomain()
+        for axis_name in self._iterDimensions(feature):
+            axis = domain[axis_name]
             dims[axis_name] = Dimension(possibleValues=PossibleValues.fromAllowedValues(axis),
-                                        #!TODO: this is a fudge until we can deduce UOM.
+                                        #!TODO: see ticket:770 for how to populate this
                                         valuesUnit=ValuesUnit(uoms=[''],
                                                               referenceSystems=['']))
@@ -115 +132 @@
                transparent=False, bgcolor=None, exceptions=None):
 
+        # Retrieve dataset and selected feature
         dataset = get_csml_doc(file)
+        feature = dataset.getFeature(layers)
+        if feature is None:
+            raise OWS_E.InvalidParameterValue('Layer not found', 'layers')
 
-        return Response('Operation done')
+        # Define the extraction selector
+        sel = dict(latitude=(bbox[1], bbox[3]), longitude=(bbox[0], bbox[2]))
+
+        # Parse dimensions.
+        for dim in self._iterDimensions(feature):
+            # For the moment hard-code time in.  We don't support any other dimension yet.
+            if dim.lower() != 'time':
+                raise ValueError('Only lat, lon and time are supported domain axes')
+            
+            try:
+                sel[dim] = request.params[dim]
+            except KeyError:
+                raise OWS_E.MissingParameterValue('%s dimension not specified' % dim, dim)
+            
+        # Subset the feature
+        (fd, filename) = tempfile.mkstemp('.nc', 'csml_wms_'); os.close(fd)
+        feature.subsetToGridSeries(ncname=os.path.basename(filename),
+                                   outputdir=os.path.dirname(filename),
+                                   time=sel['time'] # workarround for CSML bug
+                                   #**sel
+                                   )
+        d = cdms.open(filename)
+        #var = d(feature.name.CONTENT, squeeze=1)
+        var = d(feature.name.CONTENT, longitude=sel['longitude'], latitude=sel['latitude'],
+                squeeze=1)
         
+        # Deduce min and max
+        varmin = MA.minimum(var, None)
+        varmax = MA.maximum(var, None)
+
+        # Render variable to a PIL image
+        img = render.render_variable(var, bbox, width, height, varmin, varmax)
+
+        # Serialise it to PNG
+        buf = StringIO()
+        img.save(buf, 'PNG')
+
+        return Response(content=buf.getvalue(), mimetype='image/png')

TI05-delivery/ows_framework/trunk/ows_server/ows_server/lib/render.py

@@ -94 +94 @@
 
 
-def render_variable(var, bbox, width, height, cmap, varmin, varmax):
+def render_variable(var, bbox, width, height, varmin, varmax, cmap=None, ):
     """
     Creates RGBA PIL images with a selectable matplotlib colour scale.
 
+    @todo: This should be class really, but it came out of my brain as a function.
+    @todo: Transparent missing_value mask not working.
+
     """
+
+    if cmap is None:
+        cmap = cm.get_cmap()
 
 
@@ -118 +124 @@
         norm = colors.normalize(varmin, varmax)
         a = norm(var.getValue())
-
+        order = var.getOrder()
+        
         # Render the normalised variable by converting it into a byte array then to a PIL image
         img_buf = (cmap(a) * 255).astype('b')
         (y, x, c) = img_buf.shape
-        img = Image.frombuffer("RGBA", (x, y), img_buf.tostring(), "raw", "RGBA", 0. 1)
+
+        img = Image.frombuffer("RGBA", (x, y), img_buf.tostring(), "raw", "RGBA", 0, 1)
 
         # Ensure lat & lon increase from the bottom left
@@ -140 +148 @@
     # It is assumed that grid can wrap around in the longitude and therefore only
     # needs adjusting in the latitude.
-    if bbox != bboxObj.crs84:
+    if bbox != bbox_obj.crs84:
         img = Image.new('RGBA', (width, height))
-        (ox, oy) = bboxObj.getCrs84OffsetInImage(width, height)
-        nwidth, nheight = bboxObj.getCrs84ImageSize(width, height)
+        (ox, oy) = bbox_obj.getCrs84OffsetInImage(width, height)
+        nwidth, nheight = bbox_obj.getCrs84ImageSize(width, height)
         # If the image is too small just send a blank image
-        if bboxObj.crs84Width > abs(dlon) and bboxObj.crs84Height > abs(dlat):
+        if bbox_obj.crs84Width > abs(dlon) and bbox_obj.crs84Height > abs(dlat):
             img1 = render(var, width, nheight)
             img.paste(img1, (0, oy))