Source Code for Module gavo.web.productrender

 1  """ 
 2  Code dealing with product (i.e., fits file) delivery. 
 3  """ 
 4   
 5  #c Copyright 2008-2019, the GAVO project 
 6  #c 
 7  #c This program is free software, covered by the GNU GPL.  See the 
 8  #c COPYING file in the source distribution. 
 9   
10   
11  from nevow import inevow 
12   
13  from gavo import base 
14  from gavo import svcs 
15  from gavo.protocols import products 
16  from gavo.web import grend 
17   
18   
19 -class ProductRenderer(grend.ServiceBasedPage): 
20          """The renderer used for delivering products. 
21   
22          This will only work with a ProductCore since the resulting 
23          data set has to contain products.Resources.  Thus, you probably 
24          will not use this in user RDs. 
25          """ 
26          name = "get" 
27          pathFromSegments = "" 
28   
29 -        def renderHTTP(self, ctx): 
30                  request = inevow.IRequest(ctx) 
31                  try: 
32                          data = {"accref":  
33                                  products.RAccref.fromRequest(self.pathFromSegments, request)} 
34                  except base.NotFoundError: 
35                          raise base.ui.logOldExc(svcs.UnknownURI("No product specified")) 
36   
37                  # deferring here and going to all the trouble of running a core 
38                  # is probably overkill; currently, the main thing that'd require 
39                  # handwork is figuring out authentication in parallel with what 
40                  # needs to be done for tar files.  We should do better, indded. 
41                  return self.runServiceWithFormalData(data, ctx 
42                          ).addCallback(self._deliver, ctx) 
43           
44 -        def _deliver(self, result, ctx): 
45                  doPreview = result.queryMeta.ctxArgs.get("preview") 
46                  # SvcResult madness; clean up SvcResult and remove this. 
47                  result = getattr(result, "original", result) 
48                  product = result[0] 
49                  request = inevow.IRequest(ctx) 
50   
51                  # TODO: figure out a good way to see whether what we've got already is a 
52                  # preview. 
53                  if doPreview and not "Preview" in product.__class__.__name__: 
54                          return products.PreviewCacheManager.getPreviewFor(product 
55                                  ).addCallback(self._deliverPreview, product, request 
56                                  ).addErrback(self._deliverPreviewFailure, request) 
57   
58                  else: 
59                          return product 
60   
61 -        def _deliverPreview(self, content, product, request): 
62                  previewMime = product.pr["preview_mime"] or "image/jpeg" 
63                  request.setHeader("content-type", str(previewMime)) 
64                  request.setHeader("content-length", len(content)) 
65                  return content 
66           
67 -        def _deliverPreviewFailure(self, failure, request): 
68                  failure.printTraceback() 
69                  data = "Not an image (preview generation failed, please report)" 
70                  request.setResponseCode(500) 
71                  request.setHeader("content-type", "text/plain") 
72                  request.setHeader("content-length", str(len(data))) 
73                  return data 
74   
75 -        def locateChild(self, ctx, segments): 
76                  if segments: 
77                          self.pathFromSegments = "/".join(segments) 
78                  return self, () 
79