Actual situation:
The client downloads a small pythonscript that is executable.
The client executes it. The script gathers information from the computer and sends the data to the webserver vià POST-Method.
Wanted Situation:
After the webserver recived the data, it should forward the information to the website-session of the client. And the website should display the information.
This is a visual example of the principle:
There is also a example of this principle on Can You Run It.
How can I realize this?
A common way of implementing this is using a RESTful API. Basically the API does not care if the request is from a script or web browser, it just passes data structures to and from clients. The only tricky part to your example is when there are multiple users involved because a secret must be shared between the browser and script. I believe Can You Run It puts this unique secret into the program they ask you to download.
Look into Django Rest Framework for examples of how to implement this.
Related
I'm trying to get some tables with specific filters on this qlikview page, for future analysis: http://transferenciasabertas.planejamento.gov.br/QvAJAXZfc/opendoc.htm?document=painelcidadao.qvw&lang=en-US&host=QVS%40srvbsaiasprd01&anonymous=true
I don't want to do it manually (downloading tables for every filter). Therefore, I searched for API's for Python on qlikview website, but only found qliksense API's for SSE (like this https://github.com/qlik-oss/server-side-extension).
Is there any chance that I could automate the retrieving process that I explained using Python?
Server side extensions are used for something else. They extend Qlik's functionality to process data (for example running some statistical functions on top of the displayed data if such functions do not exists in Qlik natively)
Interestingly is that the portal link (http://transferenciasabertas.planejamento.gov.br) is a QlikView app that later redirects to a Qlik Sense app(s). It seems that anonymous users are allowed on the platform (which makes automating data retrieval easier).
Qlik Sense communicates with the browser via web sockets. So the answer to your question is - yes. You can used Python to connect to the underlying Qlik Sense Engine and make some selections and get the data back.
The not very good news is that I dont think there is dedicated Python library so you'll have to send the raw web socket requests by yourself. The documentation for the Engine API can be found at Qlik's help site
If you are open for JS solution then you can use Qlik's enigma.js library for Engine communication.
The web sockets traffic can be monitored from the browser (to view what data is being send/received and its format)
I have JS running and essentially getting user entries from my HTML session storage and pushing these to a DB. I also need to use a HTTP request to pass a json object containing the entries to a python file hosted somewhere else.
Does anyone have any idea of documentation I could look at, or perhaps how to get JSON objects from JS to Python.
My client does not want me to grab the variables directly from the DB.
You have to create some sort of communication channel between the javascript and python code. This could be anything, SOAP, HTTP, RPC, any number of and flavor of message queue.
If nothing like that is in place, it's quite the long way around. A complex application might warrant you doing this, think micro services communicating across some sort of service bus. It's a sound strategy and perhaps that's why your client is asking for it.
You already have Firebase, though! Firebase is a real-time database that already has many of the characteristics of a queue. The simplest and most idiomatic thing to do would be to let the python code be notified of changes by Firebase: Firebase as service bus is a nice strategy too!
I'm looking for a bit of web development advice. I'm fairly new to the area but I'm sure there are some gurus out there willing to part with some wisdom.
Objective: I'm interested in controlling a Python application on my computer from my personal web hosted site. I know, this question has been asked several times before but in each case the requirements were a bit different from my own. To reduce the length of this post I'll summarize my objective in a few bullet points:
Personal site is hosted by a web hosting company
Site uses HTML, PHP, MySQL, Python and JavaScript, the majority of everything is coded by me from the ground up
An application that is coded in Python will run on a PC within my home and will communicate with an Arduino board
The app will receive commands from the internet to control actuation via the Arduino, and will transmit sensor data back to the site (such as temperature)
Looking for the communication to be bi-directional, fast and secure
Securing the connection between site and Python app would be most ideal
I'm not looking to connect to the Python application directly, the web server must serve as the 'middle man'
So far I've considered HTTP Post and HTML forms, using sockets (Python app would run as a web server), an IRC bot and reading/writing to a text file stored on the web server.
I was also hoping to have a way to communicate with the Python app without needing to refresh the webpage, perhaps using AJAX or JavaScipt? Maybe with Flash?
Is there something I'm not considering? I feel like I'm missing something. Thanks in advance for the advice!
Just thinking out loud for how I would start out with this. First, regarding the website itself, you can just use what's easiest to you, or to the environment you're in. For example, a basic PHP page will do just fine, but if you can get a site running in Python as well, I'd prefer using the same language all over.
That said, I'm not sure why you would need to use a hosted website? Given that you're already forced to have a externally accessible PC at home for the communication, why not run a webserver on that directly (Apache, Nginx, or even something like CherryPy should do)? That webserver can then communicate with the python process that is running to control your Arduino (by using e.g. Python's xmlrpclib). If you would run things via the hosting company, you would still need some process that can handle external requests securely... something a webserver is quite good at. Just running it yourself gives you all the freedom you want, and simplifies things by lessening the number of components in your solution.
The updates on your site I'd keep quite basic: commands you want to run can be handled in the request handlers of the webserver by just calling the relevant (xmlrpclib) calls. Dynamically updating the page is best done by some AJAX calls I reckon. Based on your story, these updates are easily put in a JSON object, suitable for periodically updating only the relevant segments of your page.
I would like to generate reports in pdf format with following scenario: people would enter information on a web site and after submitting, data would be transfered to jasper reports server and pdf would be created.
Python would be language of choice for my task.
Is this scenario plausible with current jasper reports software (open source or similar), could it be done, and what would be steps in the right direction ?
Is this scenario plausible with current jasper reports software (open source or similar),
Yes.
could it be done
Yes.
and what would be steps in the right direction ?
Write a web server in Python. Your web server will allow a user to enter information on a web site and after submitting, data would be transfered to jasper reports server and pdf would be created. Your web server would provide the PDF back to the user.
You need to pick a framework, install the components, write the unit tests, write the code, debug the code and transition the code to production.
It's hard (given the question) to determine what part of this you actually need help with.
Write the interface for the user with the language of your choice. Then, having the data from the user, make an API request to the jasperserver's API requesting the report.
Make sure to account for the time the report may need to be generated if you want to make it synchronous.
Otherwise, the API allows you to generate a report and poll for it's completion. When it's done, just send the file to the user.
If you use the second approach, don't point the client ajax polling mechanism to the jasperserver as you might not want it to be accessible from the internet directly. You should do that in the backend of your app.
More information about the REST web services for Jasper Server here: https://community.jaspersoft.com/documentation/jasperreports-server-web-services-guide/v550/rest-web-services-overview
Good luck! :)
Use jasper reports server to publish the report and use its rest interface to produce the output. See Render HTML to PDF in Django site that shows a practical implementation of a python rest client
For my final year project I plan to code a cloud in Python. The client will be written in Java by the other member of my team. The client will have a tabbed interface and it will provide a text editor, a media player, a couple of small Java based games and a maybe a few more services.
The server will work like this:
1) Validate the user.
2) Send a file, called "dump" to the user. Dump will contain all the file names and file types that the user created by himself or the files which the user can read/write. This info will be fetched from the database.
3) The tabs in the client will display the file types associated with the tab application. e.g the media tab will only select and show the media files from the dump readable by user. The text editor tab will show only the txt files from the dump readable by the user.
4) A request to open the file will send the file back to client, which the associated application will open.
5) All the changes made to the files and all the actions (overwriting, saving, deleting etc.) will be sent back to the server along with the new object. Something similar will be done to the newly created objects.
My Questions are:
What are the best approaches for the communication between the client and the server. For the dump I plan to use some sort of encrypted XML file. For the other way round, I don't have a clue :/.
For easy integration with the database, I was planning to use Django (which I started few days back). How can I send my requests from the client to the server (without Django I'd use SQL queries) and the files from the server to the client? Maybe GET and POST will work for the former problem? Any other suggestions?
Q1: how should I transfer data between client/server securely
A: HTTPS to support encryption & JSON to serialise objects between languages (Python/Java) seems to be the most natural. You could experiment with XML-RPC over SSL or TSL if you want to be creative.
Q2: How do I send queries to the server's db?
A: My first response is to say talk to the person coding the server, and see what's easiest on that end. However, I think that your client should stick to HTTP. The server developer would ensure the server supports RESTful URIs. Then your client only access a URI and have the results processed by the server.
At its most raw, this could be implemented like this:
https://www.example.com/db?q="SELECT * FROM docs"
There are smarter ways to do it, but you get the idea.
If you're going to use a web framework on the server, it makes sense to use an HTTP-based protocol. The downside is that only the client can initiate a connection (e.g., the client needs to first ask for the "dump" file), but a simple GET request will suffice (remember, the server can send anything in the HTTP response, including your XML file).
Regarding encryption, it's best to use an existing protocol like HTTPS. There are well-vetted libraries that will correctly establish a secure connection between your client and the server.
Overall, I'm advocating the highest-level protocols that are appropriate for your application. HTTP(S) goes hand-in-hand with your web-based architecture, so make use of it.
Stick to Django. It's really productive. I would use JSON instead of XML. More convenient. import json. This should help you in communicating between client-server.
Also cloud computing is just a recent word that's just thrown around for (client+server+some services). Oh by the way all that you want to do can be completely done in Django itself. No need to go to JAVA.
Django is Cool :)