Library that works with Flask (version 1 or 2) and SqlAlchemy to store files on your server & in your database
Read the docs: Documentation
Please install the latest release:
pip install flask-file-uploadIf you are updating from >=0.1 then please read the upgrading instruction
(Important: The below configuration variables need to be set before initiating FileUpload)
from flask_file_upload.file_upload import FileUpload from os.path import join, dirname, realpath # This is the directory that flask-file-upload saves files to. Make sure the UPLOAD_FOLDER is the same as Flasks's static_folder or a child. For example: app.config["UPLOAD_FOLDER"] = join(dirname(realpath(__file__)), "static/uploads") # Other FLASK config varaibles ... app.config["ALLOWED_EXTENSIONS"] = ["jpg", "png", "mov", "mp4", "mpg"] app.config["MAX_CONTENT_LENGTH"] = 1000 * 1024 * 1024 # 1000mb app.config["SQLALCHEMY_DATABASE_URI"] = "postgresql://localhost:5432/blog_db"We can either pass the instance to FileUpload(app) or to the init_app(app) method:
from flask_file_upload import FileUpload app = Flask(__name__, static_folder="static") # IMPORTANT: This is your root directory for serving ALL static content! db = SQLAlchemy() file_upload = FileUpload() # An example using the Flask factory pattern def create_app(): db.init_app(app) # Pass the Flask app instance as the 1st arg & # the SQLAlchemy object as the 2nd arg to file_upload.init_app. file_upload.init_app(app, db) # If you require importing your SQLAlchemy models then make sure you import # your models after calling `file_upload.init_app(app, db)` or `FileUpload(app, db)`. from .model import * # Or we can pass the Flask app instance directly & the Flask-SQLAlchemy instance: db = SQLAlchemy(app) # Pass the Flask app instance as the 1st arg & # the SQLAlchemy object as the 2nd arg to FileUpload file_upload = FileUpload(app, db) app: Flask = NoneFlask-File-Upload (FFU) setup requires each SqlAlchemy model that wants to use FFU library to be decorated with @file_upload.Model .This will enable FFU to update your database with the extra columns required to store files in your database. Declare your attributes as normal but assign a value of file_upload.Column. This is easy if you are using Flask-SqlAlchemy:
from flask_sqlalchemy import SqlAlchemy db = SqlAlchemy()Full example:
from my_app import file_upload @file_upload.Model class blogModel(db.Model): __tablename__ = "blogs" id = db.Column(db.Integer, primary_key=True) # Use flask-file-upload's `file_upload.Column()` to associate a file with a SQLAlchemy Model: my_placeholder = file_upload.Column() my_video = file_upload.Column()# A common scenario could be a video with placeholder image. # So first lets grab the files from Flask's request object: my_video = request.files["my_video"] placeholder_img = request.files["placeholder_img"]To add files to your model, pass a dict of keys that reference the attribute name(s) defined in your SqlAlchemy model & values that are your files. For Example:
file_upload.add_files(blog_post, files={ "my_video": my_video, "placeholder_img": placeholder_img, }) # Now commit the changes to your db db.session.add(blog_post) db.session.commit()It's always good practise to commit the changes to your db as close to the end of your view handlers as possible (we encourage you to use add_files over the save_files method for this reason).
If you wish to let flask-file-upload handle adding & committing to the current session then use file_upload.save_files - this method is only recommended if you are sure nothing else needs committing after you have added you files. For example:
file_upload.save_files(blog_post, files={ "my_video": my_video, "placeholder_img": placeholder_img, })
blog_post = file_upload.update_files(blog_post, files={ "my_video": new_my_video, "placeholder_img": new_placeholder_img, })Deleting files from the db & server can be non trivial, especially to keep both in sync. The file_upload.delete_files method can be called with a kwarg of clean_up & then depending of the string value passed it will provide 2 types of clean up functionality:
fileswill clean up files on the server but not update the modelmodelwill update the model but not attempt to remove the files from the server. See delete_files Docs for more details
# Example using a SqlAlchemy model with an appended # method that fetches a single `blog` blogModel = BlogModel() blog_results = blogModel.get_one() # We pass the blog & files blog = file_upload.delete_files(blog_result, files=["my_video"]) # If parent kwarg is set to True then the root primary directory & all its contents will be removed. # The model will also get cleaned up by default unless set to `False`. blog_result = file_upload.delete_files(blog_result, parent=True, files=["my_video"]) # If the kwarg `commit` is not set or set to True then the updates are persisted. # to the session. And therefore the session has been commited. blog = file_upload.delete_files(blog_result, files=["my_video"]) # Example of cleaning up files but not updating the model: blog = file_upload.delete_files(blog_result, files=["my_video"], clean_up="files")file_upload.stream_file(blog_post, filename="my_video")file_upload.get_file_url(blog_post, filename="placeholder_img")Example for getting file urls from many objects:
# If blogs_model are many blogs: for blog in blog_models: blog_image_url = file_upload.get_file_url(blog, filename="blog_image") setattr(blog, "blog_image", blog_image_url)The majority of requests will require many entities to be returned & these entities may have SQLAlchemy backrefs with relationships that may also contain Flask-File-Upload (FFU) modified SQLAlchemy models. To make this trivial, this method will set the appropriate filename urls to your SQLAlchemy model objects (if the transaction hasn't completed then add_file_urls_to_models will complete the transaction by default).
The first argument required by this method is models - the SQLAlchemy model(s).
Then pass in the required kwarg filenames which references the parent's FFU Model values - this is the file_upload.Model decorated SQLALchemy model
file_upload.Column()method.
Important! Also take note that each attribute set by this method postfixes a _url tag. e.g blog_image becomes blog_image_url
Example for many SQLAlchemy entity objects (or rows in your table)::
@file_upload.Model class BlogModel(db.Model): blog_image = file_upload.Column()Now we can use the file_upload.add_file_urls_to_models to add file urls to each SQLAlchemy object. For example::
blogs = add_file_urls_to_models(blogs, filenames="blog_image") # Notice that we can get the file path `blog_image` + `_url` assert blogs[0].blog_image_url == "path/to/blogs/1/blog_image_url.png"To set filename attributes to a a single or multiple SQLAlchemy parent models with backrefs to multiple child SQLAlchemy models, we can assign to the optional backref kwarg the name of the backref model & a list of the file attributes we set with the FFU Model decorated SQLAlchemy model.
To use backrefs we need to declare a kwarg of backref & pass 2 keys: - name: The name of the backref relation - filenames: The FFU attribute values assigned to the backref model
For example::
# Parent model @file_upload.Model class BlogModel(db.Model): # The backref: blog_news = db.relationship("BlogNewsModel", backref="blogs") blog_image = file_upload.Column() blog_video = file_upload.Column() # Model that has a foreign key back up to `BlogModel @file_upload.Model class BlogNewsModel(db.Model): # The foreign key assigned to this model: blog_id = db.Column(db.Integer, db.ForeignKey("blogs.blog_id")) news_image = file_upload.Column() news_video = file_upload.Column()The kwarg backref keys represent the backref model or entity (in the above example this would be the BlogNewsModel which we have named blog_news. Example::
blogs = add_file_urls_to_models(blogs, filenames=["blog_image, blog_video"], backref={ "name": "blog_news",` "filenames": ["news_image", "news_video], })WARNING: You must not set the relationship kwarg: lazy="dynamic"! If backref is set to "dynamic" then back-referenced entity's filenames will not get set. Example::
# This will work blog_news = db.relationship("BlogNewsModel", backref="blog") # this will NOT set filenames on your model class blog_news = db.relationship("BlogNewsModel", backref="blog", lazy="dynamic")The arguments below will also run if you're using vanilla Alembic.
export FLASK_APP=flask_app.py # Path to your Flask app # with pip flask db stamp head flask db migrate flask db upgrade # with pipenv pipenv run flask db stamp head pipenv run flask db migrate pipenv run flask db upgradeYou will need to create a migration script with the below column name changes:
[you_file_name]__file_typebecomes[you_file_name]__mime_type[you_file_name]__mime_typebecomes[you_file_name]__ext[you_file_name]__file_namestays the same