Serve stylesheet with webapp2 outside of Google App Engine - python

So I have successfully deployed an app using webapp2/jinja2 and a Paste server, but am having trouble serving static stylesheets.
I have had luck accessing static files via this method, as well as implementing a StaticFileHandler I found with some google-fu:
import os
import mimetypes
import webapp2
import logging
class StaticFileHandler(webapp2.RequestHandler):
def get(self, path):
abs_path = os.path.abspath(os.path.join(self.app.config.get('webapp2_static.static_file_path', 'static'), path))
if os.path.isdir(abs_path) or abs_path.find(os.getcwd()) != 0:
self.response.set_status(403)
return
try:
f = open(abs_path, 'r')
self.response.headers.add_header('Content-Type', mimetypes.guess_type(abs_path)[0])
self.response.out.write(f.read())
f.close()
except:
self.response.set_status(404)
where my main app routing looks like:
app = webapp2.WSGIApplication([('/', HelloWorld),
(r'/display', DisplayHandler),
(r'/static/(.+)', StaticFileHandler)
], debug=True)
My css files are in a folder under the app root: /static/css/main.css
I can access the file via direct url, and even link it as a stylesheet, but the styles won't apply. Any ideas? Is there another way to serve stylesheets? Some way to implement an app.yaml similar to GAE?

you dont need a static file handler.
upload the app with the static file folder by adding this to your app.yaml
- url: /static/
static_dir: static
docs are here: https://developers.google.com/appengine/docs/python/config/appconfig#Static_Directory_Handlers
edit:
see answer below in comments

#Mnemon, hats off to you for solving my problem. I would upvote you but I'm not allowed to do that. You convinced me that if it's not the only webapp2 way without GAE, it's at least a way that will work.
But also I can contribute that your solution is now installable as "pip install webapp2_static", from pipi--- by an author who seems to be using his real name... you I'm sure. Other webapp2 docs that I found helpful are available here.
I'm implementing your code on a Linux desktop development server, using paste, which you also used:
def main():
from paste import httpserver
httpserver.serve(app, host='127.0.0.1', port='8080')
But with the code as you have it above (which appears to be utterly identical to that of webapp2_static.py file), I don't find that putting my css files in a folder named static in the app root works as you said.
For example, I have /home/user/proj/public_html/app/app.py, where the py file contains your code plus other "views" for my ultra-simple site. (I don't know how paste really works, so maybe for now the public_html is just in there for reference so that I don't become confused when I'm uploading stuff onto the production server.)
So if I put the css stylesheets into a folder named /static, then, if I put /static in as either a subdirectory of /app or of /public_html I find that neither location works; I must instead make it a subdirectory of /proj.
I wasn't expecting that, but the cure for me is to change the default 'static' in your app.configure.get(..., 'static') call, to 'public_html/app/static'. Then it works, with the /static folder inside /app.
Similarly using the pipi code with './app/static/ in place of the default 'static' doesn't work; I found that I need ./public_html/app/static instead (or maybe it was just /public_html/app/static or even public_html/app/static... I forgot... one of those worked).
I tested how your computation of abs_path works and have reworked it in the code below, in which I have junked your approach in favor of something more Djangoesque. To wit, in my one app py file I put at the top the following:
STATIC_DIR = os.sep + 'tostatic' + os.path.abspath(os.path.dirname(__file__)) + os.sep + 'static'
Then in the page to which I want to add css, my Home page in my case, I put a very readable:
<link href="{{STATIC_DIR}}/dist/css/bootstrap.min.css" rel="stylesheet" type="text/css">
For the "view" that generates my Home page I have (env is a jinja2 Environment object that takes a template loader as an argument):
class Home(webapp2.RequestHandler):
def get(self):
template = env.get_template('index.html')
template_values = {'STATIC_DIR': STATIC_DIR }
self.response.write(template.render(template_values))
And finally the URL routing is as in:
app = webapp2.WSGIApplication(
[
(r'/', Home),
(r'/tostatic/(.+)', StaticView),
], debug=True)
The view for the static file serving is now:
class StaticView(webapp2.RequestHandler):
def get(self, path):
path = os.sep + path
try:
f = open(path, 'r')
self.response.headers.add_header('Content-Type', mimetypes.guess_type(path)[0])
self.response.out.write(f.read())
f.close()
except Exception, e:
print 'Problem in StaticView:', e
self.response.set_status(404)
To finally close, the problem that I had with your approach is the one that I and other near noobs have with the departure of URLs from the legacy association with the file system. In your approach "static" is both a sub-directory and a string between slashes at the front of the URL that tells the interpreter which view (which webapp2.RequestHandler subclass) to run. You take the /static from the rest of the URL and then later hard-code it back on. And when it comes time to decide what to put in for href in the tag the HTML page coder has to remember that duplicity. With the {{STATIC_DIR}} template variable approach it's clear what to do. And it's easy to redefine the location of the static files--- only the STATIC_DIR declaration has to be changed.
I found that self.response.set_status(404) shows up in Firebug, but not Firefox. Evidently with webapp2 you must provide and serve your own HTTP status code pages.

self.response.headers.add_header('Content-Type', mimetypes.guess_type(abs_path)[0])
self.response.headers['Content-Type'] = mimetypes.guess_type(abs_path)[0]

Related

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-Uploads URL is always a 404

I'm using Flask-Uploads to upload a file and output the URL. However, for some reason the URL always points to a 404! I can see the file in the correct folder, but the URL seems to not be able to find it. Here are the configurations I'm using...
UPLOADS_DEFAULT_URL = os.environ.get("UPLOADS_URL", "http://localhost:5000/")
UPLOADS_DEFAULT_DEST = "app/uploads"
I also have an Upload set defined as:
productUploadSet = UploadSet('plist', extensions=('xlsx', 'csv', 'xls'))
The file is found in "app/uploads/plist/filename.csv" and I'll get a url returned to me like "http://localhost:5000/productlist/filename.csv" but whenever I open the URL it is always a 404. I know that the url method from Flask-Uploads doesn't actually check fi the file exists, but I can see the file is actually there. Is it looking in the wrong place somehow? Thanks for any help.
From Flask's guide to uploading files:
Now one last thing is missing: the serving of the uploaded files. As of Flask 0.5 we can use a function that does that for us:
from flask import send_from_directory
#app.route('/uploads/<filename>')
def uploaded_file(filename):
return send_from_directory(app.config['UPLOAD_FOLDER'],
filename)
Alternatively you can register uploaded_file as build_only rule and use the SharedDataMiddleware. This also works with older versions of Flask:
from werkzeug import SharedDataMiddleware
app.add_url_rule('/uploads/<filename>', 'uploaded_file',
build_only=True)
app.wsgi_app = SharedDataMiddleware(app.wsgi_app, {
'/uploads': app.config['UPLOAD_FOLDER']
})
Without implementing one of these, Flask has no idea how to serve the uploaded files.

Different translations of the same static html file: how is it possible to force the user's browser to select one of them?

I have several translations (into different languages) of the same static html file. Those were obtained via Sphinx-Python, using the internationalization feature, which ends up with mo files. All this works fine.
However, I have no clue on how to allow the user's browser to choose the proper translation that corresponds to the Accept-Languages header sent by the browser itself.
The static files will be served via Flask's send_static_file.
Thanks a lot for any hint on how it's possible to force the browser to select the "good" translation from a bunch of static files.
I have a solution that I'd like to share.
I have followed the instructions given here, that are applicable as long as the production server is Apache. The following lines are added for every translation of the same Sphinx files.
Alias /doc_en /location/of/sphinx/english_version/html
<Directory /location/of/sphinx/english_version/html>
Order deny,allow
Allow from all
</Directory>
From the Flask's side, one can steer the user to the most appropriate translation (as defined by user's browser), with the help of Flask-Babel extension:
app = Flask(__name__)
app.config.from_pyfile('mysettings.cfg')
babel = Babel(app)
#babel.localeselector
def get_locale():
bestl = request.accept_languages.best_match(['de', 'fr', 'en'])
if bestl:
return request.accept_languages.best_match(['de', 'fr', 'en'])
else:
return "en"
Then, static file is served via send_static_file:
#app.route('/<dir>/<filename>', methods=['GET'])
def doc(dir, filename):
path = os.path.join(dir, filename)
return app.send_static_file(path)
#app.route('/help')
def docs():
return redirect(url_for('doc', dir = 'doc_'+get_locale(), filename='index.html'))

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.

Read a file on App Engine with Python?

Is it possible to open a file on GAE just to read its contents and get the last modified tag?
I get a IOError: [Errno 13] file not accessible:
I know that i cannot delete or update but i believe reading should be possible
Has anyone faced a similar problem?
os.stat(f,'r').st_mtim
You've probably declared the file as static in app.yaml. Static files are not available to your application; if you need to serve them both as static files and read them as application files, you'll need to include 2 copies in your project (ideally using symlinks, so you don't actually have to maintain an actual copy.)
Update Nov 2014:
As suggested in the comments, you can now do this with the application_readable flag:
application_readable
Optional. By default, files declared in static file handlers are
uploaded as static data and are only served to end users, they cannot
be read by an application. If this field is set to true, the files are
also uploaded as code data so your application can read them. Both
uploads are charged against your code and static data storage resource
quotas.
See https://cloud.google.com/appengine/docs/python/config/appconfig#Static_Directory_Handlers
You can read files, but they're on Goooogle's wacky GAE filesystem so you have to use a relative path. I just whipped up a quick app with a main.py file and test.txt in the same folder. Don't forget the 'e' on st_mtime.
import os
from google.appengine.ext import webapp
from google.appengine.ext.webapp import util
class MainHandler(webapp.RequestHandler):
def get(self):
path = os.path.join(os.path.split(__file__)[0], 'test.txt')
self.response.out.write(os.stat(path).st_mtime)
def main():
application = webapp.WSGIApplication([('/', MainHandler)],
debug=True)
util.run_wsgi_app(application)
if __name__ == '__main__':
main()
+1 for the new "application_readable: true" feature. Before using this new feature I did run into an issue with GAEs' "wacky" file system while getting the NLP Montylingua to import.
Issue: Monty uses the open(filename,'rb') and a file pointer to file_ptr.read() in bytes from the static files. My implementation worked on my local windows system but failed upon deployment!
The fix: Specify the expected bytes to read file_ptr.read(4) #4 binary bytes
Appears to be something related to the 64 bit GAE server wanting to read in more (8 by default) bytes. Anyways, took a while to find that issue. Montylingua loads now.
I came up strange but working solution :) Jinja :)
Serving static files directly sometimes become a headache with GAE. Possible trade-off from performance let you move straigh forward with Jinja
- url: /posts/(.*\.(md|mdown|markdown))
mime_type: text/plain
static_files: static/posts/\1
upload: posts/(.*\.(md|mdown|markdown))
from jinja2 import Environment
from jinja2.loaders import FileSystemLoader
posts = Environment(loader=FileSystemLoader('static/posts/')) # Note that we use static_files folder defined in app.yaml
post = posts.get_template('2013-11-13.markdown')
import markdown2 # Does not need of course
class Main(webapp2.RequestHandler):
def get ( self ):
self.response.headers[ 'Content-Type' ] = 'text/html'
self.response.write ( markdown2.markdown( post.render()) ) # Jinja + Markdown Render function
Did you get it ;) I tested and It worked.
With webapp2, supposing you have pages/index.html at the same path as main.py:
#!/usr/bin/env python
import webapp2, os
class MainHandler(webapp2.RequestHandler):
def get(self):
path = os.path.join(os.path.split(__file__)[0], 'pages/index.html')
with open(path, 'r') as f:
page_content = f.read()
self.response.write(page_content)
app = webapp2.WSGIApplication([
('/', MainHandler)
], debug=True)
I can't see an answer for when the file hasn't been marked as static, and you're trying to read it in mode 'rt'; apparently that doesn't work. You can however open files just fine in mode 'rb', or just plain 'r'. (I wasted about 10 minutes on that 't'.)

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