Class DataFormatter

source code

                   object --+                    
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 base.structure.StructureBase --+                
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                   object --+   |                
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           base.common.Parser --+                
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base.structure.ParseableStructure --+            
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             base.structure.Structure --+        
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                           object --+   |        
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      base.structure.RestrictionMixin --+        
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                   rscdef.procdef.ProcDef --+    
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                       rscdef.procdef.ProcApp --+
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                                               DataFormatter

A procedure application that renders data in a processed service.

These play the role of the renderer, which for datalink is ususally trivial. They are supposed to take descriptor.data and return a pair of (mime-type, bytes), which is understood by most renderers.

When no dataFormatter is given for a core, it will return descriptor.data directly. This can work with the datalink renderer itself if descriptor.data will work as a nevow resource (i.e., has a renderHTTP method, as our usual products do). Consider, though, that renderHTTP runs in the main event loop and thus most not block for extended periods of time.

The following names are available to the code:

• descriptor -- whatever the DescriptorGenerator returned
• args -- all the arguments that came in from the web.

In addition to the usual names available to ProcApps, data formatters have:

• Page -- base class for resources with renderHTTP methods.
• IRequest -- the nevow interface to make Request objects with.
• File(path, type) -- if you just want to return a file on disk, pass its path and media type to File and return the result.
• TemporaryFile(path, type) -- as File, but the disk file is unlinked after use
• soda -- the protocols.soda module