Flask_Scss not compiling scss file in simple app - python

I'm trying to use Flask-Scss to compile a scss file in my flask app. Here is my app:
from flask import Flask, jsonify, render_template, request
from flask_scss import Scss
app = Flask(__name__)
app.debug = True
Scss(app, static_dir='static', asset_dir='assets/scss/')
#app.route('/')
def index():
return render_template('index.html')
if __name__ == '__main__':
app.run(debug=True)
This file is in a directory that also contains a static directory and assets directory. Furthermore, assets contains a scss directory, which holds the file test.scss. When I run the app, I don't see any css files getting created inside of static. Can someone please tell me what I'm doing wrong?

You have to put absolute path for it to work. Assuming your structure is app/init.py then this should be your code:
Scss(app, static_dir='app/static', asset_dir='app/assets/scss')
NOTE: Don't forget to reload the page for the compiling to happen. If you don't reload the page then scss files will not be compiled to css.

I recommend using libsass, it works for both Sass and SCSS files. After you import sass simply use the compile function with the dirname keyword argument, like this:
sass.compile(dirname=('path/to/source', 'path/to/target'))
You also have the option to set the output style, for example:
sass.compile(dirname=('path/to/source', 'path/to/target'), output_style='compressed')
If you want to watch a file or directory for automatic compilation on every edit use boussole.

Related

Having trouble with Flask in python, either says render_template doesn't exist, or that my template doesn't exist

I am doing an assignment to integrate a python script with HTML templates, and while the IDE is giving me no errors, when I try to actually run the website it gives me an "internal server error" and in the debug menu it says either that it doesn't recognize the Flask command "render_template" or doesn't recognize the HTML file it's supposed to render. The HTML file is stored both in the same folder as the python file and a copy is stored in a seperate "templates" folder located in the same folder as the python file. I really have no idea what's going on, the teacher has been no help.
I tried renaming the files, spell checked the imports repeated, checked all the commands, made copies of the python and Html files to see if the directorry was the problem. I really am not sure what else to try
...from flask import Flask
...from flask import render_template
...from flask import request
...from flask import flash
...import datetime
...app = Flask(__name__)
```#app.route('/')
...#the home page
...def home():
... return render_template('home_page.html')
```#app.route('/clock/')
...#the clock site
...def time_site():
... return date_and_time()
...def date_and_time():
... cur_time = str(datetime.now())
...return render_template('clock.html', cur_time)
```if __name__ == "__main__":
...app.run()

How to remove older css files after webassets rebuilds the scss for a python flask app?

I have a Python 3.9 flask app which uses the flask_assets library.
My flask init.py file looks like:
import logging
import os
from flask import Flask, request, current_app
from config import Config
from flask_assets import Environment
from app.utils.assets import bundles
def create_app(config_class=Config):
app = Flask(__name__)
app.config.from_object(config_class)
assets = Environment(app)
assets.debug = True
assets.versions = 'timestamp'
# assets.cache = False
from app.main import bp as main_bp
app.register_blueprint(main_bp)
assets.register(bundles)
if not app.debug and not app.testing:
app.logger.setLevel(logging.INFO)
app.logger.info('Application starting.')
return app
Since flask_assets is built on top of webassets, I import the Environment and a css Bundle I created which compiles my scss code to css.
Here is how my Bundle looks like:
from flask_assets import Bundle
bundles = {
'css': Bundle (
'scss/_main.scss',
'scss/_base.scss',
'scss/_typography.scss',
'scss/_page_home.scss',
'scss/_page_technote.scss',
filters='pyscss',
depends=('**/*.scss'),
output='css/style.%(version)s.scss.css'
)
}
The problem I have:
Every time I make a change to my scss files, the css successfully rebuilds with a new version for cache busting. However, the older css files remain.
What's the best automatic way to remove them every time a rebuild happens? Is there any reason for keeping the older files?
Also - side question - is it possible for the Bundle object to automatically consider all files of certain type in a directory? Rather than me listing every file individually?
Here is how my files look like:
Thank you!
You can use rmtree. Even though I believe a better way exists, this does it.
from os.path import join
from shutil import rmtree
app = Flask(__name__)
rmtree(join(app.static_folder, 'css'), ignore_errors=True)
You can improve this by checking the file meta by date or similar to not delete the unchanged ones.

How do I pass libsass configuration variables into a flask_assets bundle?

My goal is to set LIBSASS_STYLE="expanded" via flask_assets.Bundle. The webassets libsass documentation says I can do it, but doesn't say how.
My base app controller looks like the following.
from flask import Flask, render_template
from flask_assets import Environment, Bundle
app = Flask(__name__)
# ... Typical flask controller stuff
if __name__ == "__main__":
assets = Environment(app)
css = Bundle(
'sass/*.scss', # input scss files
filters='libsass', # to be compiled by libsass
output='css/style.css' # and outputed to style.css
)
assets.register("asset_css", css)
app.run(debug=True)
This outputs a valid css file (which is great) but not in the format that I desire since I simply have no idea where I can slip any libsass options.
Any help on this issue is greatly welcome. Thanks!
You need to instantiate libsass filter explicitly to pass options to it
from flask_assets import Bundle
from webassets.filter import get_filter
libsass = get_filter(
'libsass',
as_output=True,
style='compressed',
)
css = Bundle(
'sass/*.scss',
filters=(libsass),
output='css/style.css'
)

Change static folder from config in Flask

Has anyone tried this snippet flask config based static folder code cnippet?
The code:
import flask
class MyFlask(flask.Flask):
#property
def static_folder(self):
if self.config.get('STATIC_FOLDER') is not None:
return os.path.join(self.root_path,
self.config.get('STATIC_FOLDER'))
#static_folder.setter
def static_folder(self, value):
self.config.get('STATIC_FOLDER') = value
# Now these are equivalent:
app = Flask(__name__, static_folder='foo')
app = MyFlask(__name__)
app.config['STATIC_FOLDER'] = 'foo'
In my case in complains about this line:
self.config.get('STATIC_FOLDER') = value
The error message: Can't assign to function call
Does anyone how to set the static_folder from the config.py file in Flask?
Okay, I assume you want to use a custom path to the static folder for whatever reason. I wanted to do the same for the sake of better app modularity.
Here's my app folder structure:
instance/
core/
|_templates/
|_static/
|_views.py
run.py
config.py
As you can see, my static folder is inside the core folder.
In run.py, you can do the following:
app = Flask(__name__, static_url_path=None)
if __name__ == '__main__':
app.config.from_object('config')
# config file has STATIC_FOLDER='/core/static'
app.static_url_path=app.config.get('STATIC_FOLDER')
# set the absolute path to the static folder
app.static_folder=app.root_path + app.static_url_path
print(app.static_url_path)
print(app.static_folder)
app.run(
host=app.config.get('HOST'),
port=app.config.get('PORT'),
threaded=True
)
This is what I did, and it works perfectly fine. I'm using flask 0.12.
I don't know anything about that snippet, but
some_function(...) = some_value
is never valid Python (Python doesn't have l-values). It looks like config has a dict-like interface, so the offending line should probably just be
self.config['STATIC_FOLDER'] = value
Probably a copy-and-paste error from the getter definition above the setter.
app = Flask(__name__, static_url_path="/STATIC_FOLDER", static_folder='STATIC_FOLDER')
Yes, In one of my projects I am using/setting a custom path for STATIC_FOLDER. You can set the path to STATIC_FOLDER in config.py like below:
STATIC_PATH = '<project-name>/<path-to-static-folder>/'
ex:
STATIC_PATH = 'myApp/static/'
If you can write your project structure then I can answer it as per your requirements.
FYI if you want your directory to be outside of the server directory the best solutions I found so far are either to make a copy of your directory into the server directory before startup in your main(), or to create a symlink.

Flask: How to serve static html?

I am trying to serve a static html file, but returns a 500 error
(a copy of editor.html is on .py and templates directory)
This is all I have tried:
from flask import Flask
app = Flask(__name__, static_url_path='/templates')
#app.route('/')
def hello_world():
#return 'Hello World1!' #this works correctly!
#return render_template('editor.html')
#return render_template('/editor.html')
#return render_template(url_for('templates', filename='editor.html'))
#return app.send_static_file('editor.html') #404 error (Not Found)
return send_from_directory('templates', 'editor.html')
This is the response:
Title: 500 Internal Server Srror
Internal Server Error
The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.
Reducing this to the simplest method that'll work:
Put static assets into your static subfolder.
Leave Flask set to the default, don't give it a static_url_path either.
Access static content over the pre-configured /static/ to verify the file works
If you then still want to reuse a static file, use current_app.send_static_file(), and do not use leading / slashes:
from flask import Flask, current_app
app = Flask(__name__)
#app.route('/')
def hello_world():
return current_app.send_static_file('editor.html')
This looks for the file editor.html directly inside the static folder.
This presumes that you saved the above file in a folder that has a static subfolder with a file editor.html inside that subfolder.
Some further notes:
static_url_path changes the URL static files are available at, not the location on the filesystem used to load the data from.
render_template() assumes your file is a Jinja2 template; if it is really just a static file then that is overkill and can lead to errors if there is actual executable syntax in that file that has errors or is missing context.
All the answers are good but what worked well for me is just using the simple function send_file from Flask. This works well when you just need to send an html file as response when host:port/ApiName will show the output of the file in browser
#app.route('/ApiName')
def ApiFunc():
try:
#return send_file('relAdmin/login.html')
return send_file('some-other-directory-than-root/your-file.extension')
except Exception as e:
logging.info(e.args[0])```
send_from_directory and send_file need to be imported from flask.
Your code sample would work if you do the following:
from flask import Flask, send_from_directory
app = Flask(__name__, static_url_path='/templates')
#app.route('/')
def hello_world():
return send_from_directory('templates', 'editor.html')
However, remember if this file loads other files e.g. javascript, css, etc. you would have to define routes for them too.
Also, as far as I understand, this is not the recommended method on production because it's slow.

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