Add basic support for "download" and "rawbytes" API views

tailbone/api/master2.py

@@ -2,7 +2,7 @@
 ################################################################################
 #
 #  Rattail -- Retail Software Framework
-#  Copyright © 2010-2020 Lance Edgar
+#  Copyright © 2010-2021 Lance Edgar
 #
 #  This file is part of Rattail.
 #
@@ -26,6 +26,7 @@ Tailbone Web API - Master View (v2)
 
 from __future__ import unicode_literals, absolute_import
 
+from pyramid.response import FileResponse
 from cornice import resource, Service
 
 from tailbone.api import APIMasterView
@@ -41,6 +42,8 @@ class APIMasterView2(APIMasterView):
     editable = True
     deletable = True
     supports_autocomplete = False
+    supports_download = False
+    supports_rawbytes = False
 
     @classmethod
     def establish_method(cls, method_name):
@@ -85,6 +88,48 @@ class APIMasterView2(APIMasterView):
         self.Session.delete(obj)
         self.Session.flush()
 
+    ##############################
+    # download
+    ##############################
+
+    def download(self):
+        """
+        GET view allowing for download of a single file, which is attached to a
+        given record.
+        """
+        obj = self.get_object()
+
+        filename = self.request.GET.get('filename', None)
+        if not filename:
+            raise self.notfound()
+        path = self.download_path(obj, filename)
+
+        response = self.file_response(path)
+        return response
+
+    def download_path(self, obj, filename):
+        """
+        Should return absolute path on disk, for the given object and filename.
+        Result will be used to return a file response to client.
+        """
+        raise NotImplementedError
+
+    def rawbytes(self):
+        """
+        GET view allowing for direct access to the raw bytes of a file, which
+        is attached to a given record.  Basically the same as 'download' except
+        this does not come as an attachment.
+        """
+        obj = self.get_object()
+
+        filename = self.request.GET.get('filename', None)
+        if not filename:
+            raise self.notfound()
+        path = self.download_path(obj, filename)
+
+        response = self.file_response(path, attachment=False)
+        return response
+
     @classmethod
     def defaults(cls, config):
         cls._defaults(config)
@@ -137,5 +182,24 @@ class APIMasterView2(APIMasterView):
         if cls.supports_autocomplete:
             autocomplete = Service(name='{}.autocomplete'.format(route_prefix),
                                    path='{}/autocomplete'.format(collection_url_prefix))
-            autocomplete.add_view('GET', 'autocomplete', klass=cls)
+            autocomplete.add_view('GET', 'autocomplete', klass=cls,
+                                  permission='{}.list'.format(permission_prefix))
             config.add_cornice_service(autocomplete)
+
+        # download
+        if cls.supports_download:
+            download = Service(name='{}.download'.format(route_prefix),
+                               # TODO: probably should allow for other (composite?) key fields
+                               path='{}/{{uuid}}/download'.format(object_url_prefix))
+            download.add_view('GET', 'download', klass=cls,
+                              permission='{}.download'.format(permission_prefix))
+            config.add_cornice_service(download)
+
+        # rawbytes
+        if cls.supports_rawbytes:
+            rawbytes = Service(name='{}.rawbytes'.format(route_prefix),
+                               # TODO: probably should allow for other (composite?) key fields
+                               path='{}/{{uuid}}/rawbytes'.format(object_url_prefix))
+            rawbytes.add_view('GET', 'rawbytes', klass=cls,
+                              permission='{}.download'.format(permission_prefix))
+            config.add_cornice_service(rawbytes)

tailbone/views/core.py

@@ -2,7 +2,7 @@
 ################################################################################
 #
 #  Rattail -- Retail Software Framework
-#  Copyright © 2010-2020 Lance Edgar
+#  Copyright © 2010-2021 Lance Edgar
 #
 #  This file is part of Rattail.
 #
@@ -166,7 +166,7 @@ class View(object):
         return render_to_response('json', data,
                                   request=self.request)
 
-    def file_response(self, path, filename=None):
+    def file_response(self, path, filename=None, attachment=True):
         """
         Returns a generic FileResponse from the given path
         """
@@ -174,11 +174,12 @@ class View(object):
             return self.notfound()
         response = FileResponse(path, request=self.request)
         response.content_length = os.path.getsize(path)
-        if not filename:
-            filename = os.path.basename(path)
-            if six.PY2:
-                filename = filename.encode('ascii', 'replace')
-        response.content_disposition = str('attachment; filename="{}"'.format(filename))
+        if attachment:
+            if not filename:
+                filename = os.path.basename(path)
+                if six.PY2:
+                    filename = filename.encode('ascii', 'replace')
+            response.content_disposition = str('attachment; filename="{}"'.format(filename))
         return response
 
     def get_quickie_context(self):