I am developing a location based web app/website. The website involves an HTML webpage, which has a button which when clicked by the user should:
Extract the user location coordinates
Run a python Program whose input will be the extracted user location, perform some manipulation.
Finally display real-time results back to the html webpage/ i.e. user computer screen.
The python Program is currently accepting the user location by using geocoder function. The program is successfully running on my system/PC.
I have an AWS EC2 Ubuntu server, to which the location of the vehicle GPS device is being sent.
Finally once everything is set up, I will be hosting/deploying the website so that individual users can test it on their system. I am aware of the hosting part.
Can someone please tell me how do I get along with the task of running the python program on an HTML button click and sending back real time results (which is the output of the python program) back to the html webpage?
To run python code on a buttonClick, you can set a href attribute to a link, which you catch in your flask backend. For example <a href="http://myapp/runthiscode"/> in the HTML and app.rout("/runthiscode") in flask. After that, the manipulation, you can give the updated variables to the page, by redirecting with redirect("/", args=args). args are the updated variables, which you can use in the HTML. For example like this: <a> {{ args }} </a>
The simplest way I can think of doing this is creating a basic API endpoint to do this data processing and return it to your frontend.
The process will look like:
User clicks button
Grab the user's longitutde and latitude (most likely using this, though from the sounds you might be able to do this already)
Submit a POST request to your Flask backend
Render the response in the frontend
Jonas answer gives you a rough sense of what this would look like; the only thing I would add is a tutorial. This one from FreeCodeCamp looks great.
Related
So I had a number of amino acid sequence strings that I wanted to use as input into a tool that studies its interactions with certain components of the human immune system (http://www.cbs.dtu.dk/services/NetMHCcons/).
I wanted to ask what, if any, would be a way of accessing, inputting data and getting the output, via a script (R or python preferably). My main issue was I had a lot of sequences that need to be queried separately so wanted to automate the whole thing. The website has one field that reads "Submission" which takes in the string input. There is another field "select species/loci" which gives a drop down menu from which an option needs to be selected. Lastly there's a "submit" button. The output simply loads on the page after hitting submit.
I've tentatively poked around with RSelenium and Rcurl but wanted to ask if there was a more efficient method.
I took a look at what it'd take to send a POST request to this service from Python, and it looks possible:
this form takes in "multipart/form-data" (see: How to send a "multipart/form-data" with requests in python?), you'll need to send your data in this format. You could inspect a request from the browser (using the dev tools) and copy the fields from there as a starting point.
once the form is submitted, it doesn't give you the result right away. You'd need to get your job ID from the response, and then poll the URL: http://www.cbs.dtu.dk/cgi-bin/webface2.fcgi?jobid={your_job_id}&wait=20 until it gives you the result
the result will then need to be downloaded and parsed
This tool is however available as a portable version for linux/mac: https://services.healthtech.dtu.dk/software.php
Perhaps downloading this version would make it easier?
Try this :
Submitting to a web form using python
This link is an answer to how to send web forms in python, using urllib. Check your source code and extract the necessary data using re module from the source code of the link you have put up, and send the request.
save the HTML source code of http://www.cbs.dtu.dk/services/NetMHCcons/ in the python file as
source_code = '''...'''
The HTML can be found by using CTRL+U in firefox.
I tried web.seeother("link"), but this does not open it in a new tab. Now I can generate a link with a _blank tag, but then the user has to click on the link separately that is separate button for generating the link and another button to follow that link. I want to perform both with a single click. A server side method to do this would be best.
I am using the web.py framework.
As the document says web.seeother() is used for redirecting a user to another page. So a more clear way for asking your question is: "how to make web.seeother() open a link in a new tab"?
As I have observed the documents, There is no way to do that on server-side.
Not a web.py issue. Cannot be done from server-side by any python or non-python framework, must be done in the Client.
From the client, you can set target="_blank" in the HTML, or use javascript with something like window.open(url). Javascript will allow you to set size and position of second window.
I have a Python script that accepts text from a user, interprets that text and then produces a text response for that user. I want to create a simple web interface to this Python script that is accessible to multiple people at once. By this I mean that person A can go to the website for the script and begin interacting with the script and, at the same time, person B can do the same. This would mean that the script is running in as many processes/sessions as desired.
What would be a good way to approach this?
Maybe you should try a python web framework like django or flask .etc
Make a simple website that offers a webpage that contians a form to input text ,and when people visit the url, put their text in the form and submit, your code can handle it and return a webpage to show the result.
So I am attempting to use bottle.py and twitter bootstrap together to make a small website. I need to be able to insert a reasonable amount of data at various points in the HTML using Python but I am not really sure I understand how the HTML and python are communicating.
Here is an example of twitter and bottle working together.
He mentions linking a couple of .js files in the html and I can see where he does that but I am not really sure how that affects how the python interacts with the html. Is there a callback from the Javascript that the python catches using request.GET.get().strip():?
Also one of the last lines is:
return template('templates/gpio.tpl', colour1=colour1, colour2=colour2, colour3=colour3)
I am not sure how the templates/gpio.tpl is connected to the html he mentions below. I understand that the colour# variables are referenced in the html (I assume this happens with the {{}} syntax) but I am not sure how the html gets called at all.
From what I understand (which so far isnt a whole lot) this is how it goes:
User enters "server:port/gpio" into a webbrowser
The python decorator gets called by bottle and the function is run returning the template at the bottom.
This is where I get confused.
A) How does the python script know to call the html?
B) How does the gpio.tpl template code get sent to the html?
C) Is it safe to assume that the python arguements sent to the template function can be referenced using the {{}} syntax or is there more to it?
D) How does the html call back to the python to update the buttons he shows at the bottom?
D.1) does the JS linked at the top have something to do with this?
Lastly: If anyone has a another/better example of linking bootstrap and bottle I would be very happy to see it.
This is quite a loaded post. Thank you for your patience. :D
You'd really need to first learn how the HTTP protocol works... But let's try to quickly answer your main question:
how the HTML and python are communicating
Quite simply: they don't. What happens is:
your client (usually your browser) send an HTTP request to your site
the front web server (Apache, Nginx, whatever) sends this request to the bottle.py application
the bottle.py app dispatch the request to the right controller function matching the url's path portion and request's method against the defined routes)
the controller function does what it has to do and returns an HTTP response to the front web server
the front web server send this response to your client
Usually - but not necessarily - the HTTP response contains HTML content, generated by the controller using a template. IOW : bottle.py uses the template to generate html that is sent back to the client.
Once the response is sent, there's no more "communication" until the client sends another request.
So if I wanted to make an html button that changed something on the page how would I send that response back to bottle.py regenerate the page with the change?
It depends on what you want to change...
For example, pushing the button could trigger a new HTTP request, you should then define a new feature in your code.
Let's take the previous example, and imagine you want to add a switchOff button.
You have to add the following button somewhere in the gpio.tpl :
<input type="submit" class="btn" name="LedsOff" value="Turn off the leds!">
Then, modify the function gpio() to add a new condition with the following :
elif request.GET.get('LedsOff','').strip():
from quick2wire.gpio import Pin, exported
with exported(Pin(12, Pin.Out)) as out1, exported(Pin(13, Pin.Out)) as out2:
out1.value = 0
out2.value = 0
I have a python script that, once executed from command line, performs the needed operations and exit. If, during the execution, the program is not able to perform a choice, he prompts the user and asks them to take a decision!
Now I have to implement a web interface, and here comes the problems ... I created an htm file with a simple form that, once the user "submits" he passes the parameters to a cgi script that contains just one line and runs my python program ! And it seems to work.
My question is: if it happens that the program needs to ask the user for a choice, how can I return this value to my python script? To prompt the user for a choice I need to create a webpage with the possible choices ... Does anybody know how can I open a webpage with python ?
The second and most important question is: how can I return a value from a web page to my "original" python module? In python I would simply make a
return choice
but with a web page I have no idea how to do it.
Recap:
Starting from a web page, I run a cgi script ! Done
This CGI script runs my python program... Done
If the program is not able to take a decision,
3a create a web page with the possible choices I can do it
3b display the created web page ????????
3c return the response to the original python module ????????
"Does anybody know how can I open a webpage with python ? The second and most important question is: how can I return a value from a web page to my "original" python module ??"
This is all very simple.
However, you need to read about what the web really is. You need to read up on web servers, browsers and the HTTP protocol.
Here's the golden rule: A web server responds to HTTP requests with a web page.
The second part of that rules is: A Request is a URL and a method (GET or POST). There's more to a request, but that's the important part.
That's all that ever happens. So, you have to recast your use case into the above form.
Person clicks a bookmark; browser makes an empty request (to a URL of "/") and gets a form.
Person fills in the form, clicks the button; browser POST's the request (to the URL in the form) and gets one of two things.
If your script worked, they get their page that says it all worked.
If your script needed information, they get another form.
Person fills in the form, clicks the button; browser POST's the request (to the URL in the form) and gets the final page that says it all worked.
You can do all of this from a "CGI" script. Use mod_wsgi and plug your stuff into the Apache web server.
Or, you can get a web framework. Django, TurboGears, web.py, etc. You'll be happier with a framework even though you think your operation is simple.
I think you could modify the Python script to return an error if it needs a choice and accept choices as arguments. If you do that, you can check the return value from your cgi script and use that to call the python script appropriately and return the information to the user.
Is there a reason why you can't call the python script directly? I suspect you'd end up with a neater implementation if you were to avoid the intermediate CGI.
What webserver are you using? What cgi language? Perl maybe?
Web pages don't return values, and they aren't programs - a web page is just a static collection of HTML or something similar which a browser can display. Your CGI script can't wait for the user to send a response - it must send the web page to the user and terminate.
However, if the browser performs a second query to your CGI program (or a different CGI program) based on the data in that page, then you can collect the information that way and continue from that point.
Probably easier if you write your cgi in python then call your python script from the cgi script.
Update your script to separate the UI from the logic.
Then it should be relatively easy to interface your script with the (python) cgi script.
For python cgi reference:
Five minutes to a Python CGI
http://docs.python.org/library/cgihttpserver.html
I think first off you need to separate your code from your interface. When you run a script, it spits out a page. You can pass arguments to it using url parameters. Ideally you want to do your logic, and then pass the results into a template that python prints to the cgi.