server/middleware: download files

API.md

@@ -106,6 +106,13 @@ Requests that upload files must use `multipart/form-data` encoding. JSON
 metadata must then be included as field of name `metadata`, whereas files must
 be included as separate fields with names specific to each request type.
 
+Alternatively, the server can download the files from the Internet on client's
+behalf. In that case, the request doesn't need to be specially encoded in any
+way. The files, however, should be passed as regular fields appended with `Url`
+suffix. For example, to download a file named `content` from
+`http://example.com/file.jpg`, the client should pass
+`{"contentUrl":"http://example.com/file.jpg"}` as part of the message body.
+
 ## Error handling
 
 All errors (except for unhandled fatal server errors) send relevant HTTP status

server/szurubooru/api/context.py

@@ -1,5 +1,6 @@
 import falcon
 from szurubooru import errors
+from szurubooru.func import net
 
 class Context(object):
     def __init__(self):
@@ -13,11 +14,13 @@ class Context(object):
         return name in self.input
 
     def has_file(self, name):
-        return name in self.files
+        return name in self.files or name + 'Url' in self.input
 
     def get_file(self, name, required=False):
         if name in self.files:
             return self.files[name]
+        if name + 'Url' in self.input:
+            return net.download(self.input[name + 'Url'])
         if not required:
             return None
         raise errors.MissingRequiredFileError(

server/szurubooru/tests/api/test_context.py

@@ -1,5 +1,7 @@
+import unittest.mock
 import pytest
 from szurubooru import api, errors
+from szurubooru.func import net
 
 def test_has_param():
     ctx = api.Context()
@@ -13,6 +15,15 @@ def test_get_file():
     assert ctx.get_file('key') == b'content'
     assert ctx.get_file('key2') is None
 
+def test_get_file_from_url():
+    with unittest.mock.patch('szurubooru.func.net.download'):
+        net.download.return_value = b'content'
+        ctx = api.Context()
+        ctx.input = {'keyUrl': 'example.com'}
+        assert ctx.get_file('key') == b'content'
+        assert ctx.get_file('key2') is None
+        net.download.assert_called_once_with('example.com')
+
 def test_getting_list_parameter():
     ctx = api.Context()
     ctx.input = {'key': 'value', 'list': ['1', '2', '3']}