Fix typo in docs and add example application for file uploading (#476)

docs/request.md

@@ -206,9 +206,9 @@ class ProfileIn(Schema):
 
 @app.post('/profiles')
 @app.input(ProfileIn, location='form_and_files')
-def create_profile(files_data):
-    avatar_file = files_data['avatar']
-    name = files_data['name']
+def create_profile(form_and_files_data):
+    avatar_file = form_and_files_data['avatar']
+    name = form_and_files_data['name']
 
     avatar_filename = secure_filename(avatar_file.filename)
     avatar_file.save(os.path.join(the_path_to_uploads, avatar_filename))

examples/README.md

@@ -9,6 +9,7 @@
 - Token auth example: [/examples/auth/token_auth/app.py][_token_auth]
 - Basic auth example: [/examples/auth/basic_auth/app.py][_basic_auth]
 - Dataclass example (with marshmallow-dataclass): [/examples/dataclass/app.py][_dataclass]
+- File upload example: [/examples/file_upload/app.py][_file_upload]
 
 [_basic]: https://github.com/apiflask/apiflask/tree/main/examples/basic/app.py
 [_cbv]: https://github.com/apiflask/apiflask/tree/main/examples/cbv/app.py
@@ -19,6 +20,7 @@
 [_token_auth]: https://github.com/apiflask/apiflask/tree/main/examples/auth/token_auth/app.py
 [_basic_auth]: https://github.com/apiflask/apiflask/tree/main/examples/auth/basic_auth/app.py
 [_dataclass]: https://github.com/apiflask/apiflask/tree/main/examples/dataclass/app.py
+[_file_upload]: https://github.com/apiflask/apiflask/tree/main/examples/file_upload/app.py
 
 If you have built an application with APIFlask, feel free to submit a pull request to add the source link here.
 

examples/file_upload/app.py

@@ -0,0 +1,41 @@
+import os
+
+from werkzeug.utils import secure_filename
+from apiflask import APIFlask, Schema
+from apiflask.fields import File, String
+
+app = APIFlask(__name__)
+
+upload_dir = './upload'
+
+
+class Image(Schema):
+    image = File()
+
+
+class ProfileIn(Schema):
+    name = String()
+    avatar = File()
+
+
+@app.post('/images')
+@app.input(Image, location='files')
+def upload_image(files_data):
+    f = files_data['image']
+
+    filename = secure_filename(f.filename)
+    f.save(os.path.join(upload_dir, filename))
+
+    return {'message': f'file {filename} saved.'}
+
+
+@app.post('/profiles')
+@app.input(ProfileIn, location='form_and_files')
+def create_profile(form_and_files_data):
+    avatar_file = form_and_files_data['avatar']
+    name = form_and_files_data['name']
+
+    avatar_filename = secure_filename(avatar_file.filename)
+    avatar_file.save(os.path.join(upload_dir, avatar_filename))
+
+    return {'message': f"{name}'s profile created."}