how to use multiple dispatchers in same cherrypy application? - cherrypy

I have a cherrypy application like this:
import cherrypy
from controllers import UsersController
class Root(object):
exposed = True
def index(self):
return 'welcome'
if __name__ == '__main__':
root = Root()
root.users = UsersController()
cherrypy.tree.mount(
root,
'/',
{
'/users' : {'request.dispatch' : cherrypy.dispatch.MethodDispatcher()}
}
)
cherrypy.engine.start()
cherrypy.engine.block()
Now I wish to use MethodDispatcher() for providing REST api to /users resource and I want a default dispatcher for '/' path (where a call to root.index() is expected). Instead of writing own RoutesDispatcher() is there any way to achieve this? (e.g. using MethodDispatcher() for '/users' as shown and something like DefaultDispatcher() for '/')? BTW, the error I am getting is 'Root' object is not callable.

Since your Root is to be served with a normal dispatcher, it should be index.exposed = True.

Related

Python Flask Blueprint inject a variable value to all contexts globally?

I have the following app.py:
def create_app(env_name) -> Flask:
app = Flask(__name__)
app.register_blueprint(foo1, url_prefix="/foo1")
app.register_blueprint(foo2, url_prefix="/foo2")
app.register_blueprint(foo3, url_prefix="/foo3")
return app
and the following main.py:
from .app import create_app
app = create_app(env_name)
app.run(HOST, PORT)
and inside the individual blueprints / controllers / contexts, I defined a function which is needed by the template of the application:
foo1app = Blueprint("foo1", __name__)
#foo1app.context_processor
def inject_now():
return {'now': datetime.utcnow()}
Currently I copy-paste the code snippet above to ALL blueprints / controllers / contexts. Is there a way to inject the now globally without this code duplication? Thanks.
foo1app = Blueprint("foo1", __name__)
#foo1app.app_context_processor
def inject_now():
return {'now': datetime.utcnow()}
From the Blueprint class:
context_processor: Like Flask.context_processor but for a blueprint. This function is only executed for requests handled by a blueprint.
app_context_processor: Like Flask.context_processor but for a blueprint. Such a function is executed each request, even if outside of the blueprint.

Adding query parameter for every flask GET request

Trying to figure out the right mechanism to use here.
I want to modify the flask request coming in every time.
I think the request is immutable, so I am trying to figure out if this mechanism exists.
Basically, I want to append a string onto the end of the request coming in.
I can hook into the request and the right time in a before_request handler like this:
#app.before_app_request
def before_request_custom():
# Get the request
req = flask.request
method = str(req.method)
if method == "GET":
# Do stuff here
pass
But I am not sure what to actually do to add this in, and don't see a way to accomplish it...I guess i could redirect, but that seems silly in this case. Any ideas?
The request object is immutable (https://werkzeug.palletsprojects.com/en/1.0.x/wrappers/#base-wrappers), but request.args or request.form can be set from ImmutableOrderedMultiDict to just OrderedMultiDict using Subclassing on Flask (https://flask.palletsprojects.com/en/1.1.x/patterns/subclassing/). Here's an example of how you could add that filter[is_deleted]=False URL param:
from flask import Flask, request, Request
from werkzeug.datastructures import OrderedMultiDict
class MyRequest(Request):
parameter_storage_class = OrderedMultiDict
class MyApp(Flask):
def __init__(self, import_name):
super(MyApp, self).__init__(import_name)
self.before_request(self.my_before_method)
def my_before_method(self):
if "endpoint" in request.base_url:
request.args["filter[is_deleted]"] = "False"
app = MyApp(__name__)
app.request_class = MyRequest
#app.route('/endpoint/')
def endpoint():
filter = request.args.get('filter[is_deleted]')
return filter
This way you can modify request.args before you actually send the request.
How about this?
from flask import g
#app.before_request
def before_request():
# Get the request
req = flask.request
method = str(req.method)
if method == "GET":
g.my_addon = "secret sauce"
return None
Then, g.my_addon is available in every view function:
from flask import g
#app.route('/my_view')
def my_view():
if g.my_addon == "secret sauce":
print('it worked!')
Using test_request_context() you can make the trick.
Related: https://flask.palletsprojects.com/en/1.1.x/quickstart/#accessing-request-data

How to serve static files in FastAPI

I am trying to serve static files that I have in a package_docs directory. When I open in the browzer:
http://127.0.0.1:8001/packages/docs/index.html , the page is running.
But I want to open the page: http://127.0.0.1:8001/packages/docs/
without the source file. And the output is 404 Not Found
app.mount("/packages/docs",
StaticFiles(directory=pkg_resources.resource_filename(__name__, 'package_docs')
),
name="package_docs")
#app.get("/packages/docs/.*", include_in_schema=False)
def root():
return HTMLResponse(pkg_resources.resource_string(__name__, "package_docs/index.html"))
app.include_router(static.router)
app.include_router(jamcam.router, prefix="/api/v1/cams", tags=["jamcam"])
How can I change my code? Any advice will be helpful. Thank you in advance.
There's a html option in Starlette that can be used within FastAPI. Starlette Documentation
This would let you have something such as:
app.mount("/site", StaticFiles(directory="site", html = True), name="site")
Which would parse /site to /site/index.html, /site/foo/ to /site/foo/index.html, etc.
The other answers can help you redirect if you want to change the folder names in a way not handled by using "directory = /foo", but this is the simplest option if you simply want to load the associated .html files.
You need to use FastAPI's TemplateResponse (actually Starlette's):
from fastapi import Request
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates
app.mount("/static", StaticFiles(directory="static"), name="static")
templates = Jinja2Templates(directory="package_docs")
#app.get("/items/{id}")
async def example(request: Request):
return templates.TemplateResponse("index.html", {"request": request})
Request as part of the key-value pairs in the context for Jinja2. So, you also have to declare it as query parameter. and you have to specify a html file you want to render it with Jinja ("your.html", {"request": request})
Also to return a HTMLResponse directly you can use HTMLResponse from fastapi.responses
from fastapi.responses import HTMLResponse
#app.get("/items/", response_class=HTMLResponse)
async def read_items():
return """
<html>
<head>
<title></title>
</head>
<body>
</body>
</html>
"""
You can read more about custom response from FastAPI Custom Responses
If app.mount is not an option,
you can always manually read the file and respond with its content...
For example, if your static files are inside /site then:
from os.path import isfile
from fastapi import Response
from mimetypes import guess_type
#app.get("/site/{filename}")
async def get_site(filename):
filename = './site/' + filename
if not isfile(filename):
return Response(status_code=404)
with open(filename) as f:
content = f.read()
content_type, _ = guess_type(filename)
return Response(content, media_type=content_type)
#app.get("/site/")
async def get_site_default_filename():
return await get_site('index.html')
From the docs
The first "/static" refers to the sub-path this "sub-application" will be "mounted" on. So, any path that starts with "/static" will be handled by it.
This means that you mount your directory at http://127.0.0.1:8001/packages/docs/ , but you then need to either specify a file in the URL, or add a handler as you did. The problem though, is that since you mounted the path first, it will not take into consideration the following paths that include part of the path.
A possibility is to first specify the path for http://127.0.0.1:8001/packages/docs/ so that it is handled by fastapi and then to mount the folder, serving static files.
Also, I would redirect users asking for http://127.0.0.1:8001/packages/docs/ to http://127.0.0.1:8001/packages/docs/index.html
▶️ 1. You don't need to create route to serve/render homepage/static-folder explicitly. When you mark a directory as static it will automatically get the first argument as route of the app.mount() in this case it's app.mount("/"). So, when you enter the base url like http://127.0.0.1:8000/ you will get the static files.
▶️ 2. app instance of the FastAPI() class. Yes, you can have as many instance as you want in a single FASTAPI app.
▶️ 3. api_app instance of the FastAPI() for other api related task.
The reason 2 & 3 need because if you want to stick with just app instance, when user req for the url http://127.0.0.1:8000/, user will get the the static file, then when user will req for http://127.0.0.1:8000/hello then the server will try to find hello inside static-folder, but there is no hello inside static-folder!, eventually it will be a not-found type response. That's why it's need to be created another instance of FastAPI api_app, and registered with prefix /api(▶️ -> 5), so every req comes from http://127.0.0.1:8000/api/xx, decorator #api_app (▶️ -> 4) will be fired!
instance declaration and mount() method calling order is important.
from fastapi import FastAPI
from fastapi.staticfiles import StaticFiles
from starlette.templating import Jinja2Templates
templates = Jinja2Templates(directory='homepage-app')
# for ui
# 🔽 -> 2
app = FastAPI(title="homepage-app")
# for api
# 🔽 -> 3
api_app = FastAPI(title="api-app")
# for api and route that starts with "/api" and not static
# 🔽 -> 5
app.mount("/api", api_app)
# for static files and route that starts with "/"
# 🔽 -> 1
app.mount("/", StaticFiles(directory="static-folder", html=True), name="static-folder")
# for your other api routes you can use `api_app` instance of the FastAPI
# 🔽 -> 4
#api_app.get("/hello")
async def say_hello():
print("hello")
return {"message": "Hello World"}

AttributeError: 'Request' object has no attribute 'params'

I'm getting error " AttributeError: 'Request' object has no attribute 'params' " in falcon library on python3, ubuntu.
request url = 127.0.0.1:8000/user?name=abc
from wsgiref import simple_server
import falcon
class user(object):
def on_get(self, req, resp):
print(req.params['name'])
api = application = falcon.API()
usr = user()
api.add_route('/user', usr)
if __name__ == '__main__':
http = simple_server.make_server('127.0.0.10', 8000, api)
http.serve_forever()
In the above code I'm unable to access req.params
If you are using version 1.0, be aware of the following breaking change:
An option was added to toggle automatic parsing of form params. Falcon
will no longer automatically parse, by default, requests that have the
content type "application/x-www-form-urlencoded"...
Applications that require this functionality must re-enable it
explicitly, by setting a new request option that was added for that
purpose, per the example below:
app = falcon.API()
app.req_options.auto_parse_form_urlencoded = True
https://github.com/falconry/falcon/blob/master/CHANGES.rst

CherryPy server name tag

When running a CherryPy app it will send server name tag something like CherryPy/version.
Is it possible to rename/overwrite that from the app without modifying CherryPy so it will show something else?
Maybe something like MyAppName/version (CherryPy/version)
This can now be set on a per application basis in the config file/dict
[/]
response.headers.server = "CherryPy Dev01"
Actually asking on IRC on their official channel fumanchu gived me a more clean way to do this (using latest svn):
import cherrypy
from cherrypy import _cpwsgi_server
class HelloWorld(object):
def index(self):
return "Hello World!"
index.exposed = True
serverTag = "MyApp/%s (CherryPy/%s)" % ("1.2.3", cherrypy.__version__)
_cpwsgi_server.CPWSGIServer.environ['SERVER_SOFTWARE'] = serverTag
cherrypy.config.update({'tools.response_headers.on': True,
'tools.response_headers.headers': [('Server', serverTag)]})
cherrypy.quickstart(HelloWorld())
This string appears to be being set in the CherrPy Response class:
def __init__(self):
self.status = None
self.header_list = None
self._body = []
self.time = time.time()
self.headers = http.HeaderMap()
# Since we know all our keys are titled strings, we can
# bypass HeaderMap.update and get a big speed boost.
dict.update(self.headers, {
"Content-Type": 'text/html',
"Server": "CherryPy/" + cherrypy.__version__,
"Date": http.HTTPDate(self.time),
})
So when you're creating your Response object, you can update the "Server" header to display your desired string. From the CherrPy Response Object documentation:
headers
A dictionary containing the headers of the response. You may set values in
this dict anytime before the finalize phase, after which CherryPy switches
to using header_list ...
EDIT: To avoid needing to make this change with every response object you create, one simple way to get around this is to wrap the Response object. For example, you can create your own Response object that inherits from CherryPy's Response and updates the headers key after initializing:
class MyResponse(Response):
def __init__(self):
Response.__init__(self)
dict.update(self.headers, {
"Server": "MyServer/1.0",
})
RespObject = MyResponse()
print RespObject.headers["Server"]
Then you can can call your object for uses where you need to create a Response object, and it will always have the Server header set to your desired string.

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