How do I receive data, like numbers and text, through the GET method in MicroPython? #10981

alekthegenius · 2023-03-08T16:18:56Z

alekthegenius
Mar 8, 2023

Recently, I have been working on a project using an ESP32 and MicroPython. However, I have not found much documentation concerning MicroPython's urllib.urequest or the sockets library, specifically on how to go about transmitting data through an HTML form via the GET method and receiving it as a variable.

It's in essence the same problem as this one How can I get the named parameters from a URL using Flask? but because that solution only works for the Flask module, it does not answer my question on doing the same with micropython.

Retrieving form parameters via GET in regular Python is as simple as requesting the arguments using Flask's request library, like so:

value = request.args['argument']

And then sending a request in HTML:

<form action="/" method="get" target="_blank">
  <label for="argument">Argument:</label>
  <input type="text" id="argument" name="argument"><br><br>
  <input type="submit" value="Submit">
</form>

Which then outputs something like this:

http://IPADDR:PORT/?argument=value

However, there is no such attribute in MicroPython's urllib.urequest nor in the sockets library.

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'module' object has no attribute 'args'

Does anyone know how to get the results from micropython?

Answered by sethstenzel

Mar 8, 2023

So like I said before, I just parse it myself. There may be a library out there that can do it, but here is some of my code that I've adapted to your example quick.

import network
import time
import socket


def network_connect(network_name, network_password):
    station = network.WLAN(network.STA_IF)
    station.active(True)
    station.connect(network_name, network_password)

    timeout = 60
    while not station.isconnected() and timeout > 0:
        time.sleep_ms(1000)
        timeout -= 1
    if station.isconnected():
        ips_and_mask = station.ifconfig()
        print(ips_and_mask)
        my_ip = ips_and_mask[0]
        return my_ip
    return False


  
def page_data():
    …

View full answer

sethstenzel · 2023-03-08T17:01:26Z

sethstenzel
Mar 8, 2023

Greetings, I'm new to MicroPython, but I am trying to help out folks since so many have helped me out. So my apologies if my answers are a bit rough.

I'm a little confused by your post; I think you are talking about two different types of requests. the urequests module would be used to make a request, whereas the request.args that is being referenced in the flask answer is the request object from flask, which is hosting the html/website. That answer is for getting the parameters of a request that flask has received from a client.

Is your ESP32 the client, the server, or both in your question?

If you are the server, and you are using sockets, you should be able to parse them manually, that is what I've done in the past.

Is your code online anywhere?

2 replies

alekthegenius Mar 8, 2023
Author

My apologies for any confusion on my part, the ESP32 is hosting the server and not the client. I see now that the request library is for making requests and not receiving them. My question is how do you get the parameters from a GET request from the client, using the sockets module?

I would like to be able to set the time on the ESP32 from the webpage.

Here is an example of my code:

import gc
gc.collect()

try:
  import usocket as socket
except:
  import socket
  
import network
from machine import RTC

rtc = RTC()

addr = socket.getaddrinfo('0.0.0.0', 80)[0][-1]
s = socket.socket()
s.bind(addr)
s.listen(5)

def web_page(page):
    year = str(rtc.datetime()[0])
    month = str(rtc.datetime()[1])
    day = str(rtc.datetime()[2])
    weekday = str(rtc.datetime()[3])
    hours = str(rtc.datetime()[4])
    minutes = str(rtc.datetime()[5])
    seconds = str(rtc.datetime()[6])
    subseconds = str(rtc.datetime()[7])
    
    index = """<!DOCTYPE html>
    <html>
        <head> <title>Project Title</title> </head>
        <body>
            <h1>Project</h1>
            <a href="?run\"><button class="button">Run</button></a>
            
            <form action="/" method="get" target="_self">
                <label for="time">Change Time:</label><br>
                <input type="time" id="time" name="time">
                <input type="submit" value="Set Time">
            </form>
            <h3>Year: {year}, Month: {month}, Day: {day}, Weekday: {weekday}, Hours: {hours}, Minutes: {minutes}, Seconds: {seconds}, Subseconds: {subseconds}</h3>
            
            <script>
            setTimeout(() => {{
                document.location.reload();
            }}, 30000);
            </script>
        </body>
    </html>
    """.format(year=year, month=month, day=day, weekday=weekday, hours=hours, minutes=minutes, seconds=seconds, subseconds=subseconds)
    
    running = """<!DOCTYPE html>
    <html>
        <head> <title>Running</title> </head>
        <body>
            <h1>Running</h1>
            <a href="/"><button class="button">Return Back</button></a>
        </body>
    </html>
    """
    
    if page=="main":
        return index
    elif page=="running":
        return running

ap = network.WLAN(network.AP_IF)
ap.active(True)
ap.config(essid='network_name', authmode=4, password='password')

def feed():
    pass

while True:
    try:
        if gc.mem_free() < 102000:
            gc.collect()
        conn, addr = s.accept()
        conn.settimeout(3.0)
        
        print('Received HTTP GET connection request from %s' % str(addr))
        
        request = conn.recv(1024)
        conn.settimeout(None)
        request = str(request)
        
        print('GET Request Content = %s' % request)
        
        run = request.find('/?run')

        if run == 6:
            response = web_page(page="running")
            feed()
        else:
            response = web_page(page="main")
            pass

        conn.send('HTTP/1.1 200 OK\n')
        conn.send('Content-Type: text/html\n')
        conn.send('Connection: close\n\n')
        conn.sendall(response)
        conn.close()
    except OSError as e:
        conn.close()
        print('Connection closed')

alekthegenius Mar 8, 2023
Author

I am also new, not really to the python programming language, but to the server side of things, like handling connections and making and receiving requests, so thank you very much for your help and time.

sethstenzel · 2023-03-08T18:25:19Z

sethstenzel
Mar 8, 2023

So like I said before, I just parse it myself. There may be a library out there that can do it, but here is some of my code that I've adapted to your example quick.

import network
import time
import socket


def network_connect(network_name, network_password):
    station = network.WLAN(network.STA_IF)
    station.active(True)
    station.connect(network_name, network_password)

    timeout = 60
    while not station.isconnected() and timeout > 0:
        time.sleep_ms(1000)
        timeout -= 1
    if station.isconnected():
        ips_and_mask = station.ifconfig()
        print(ips_and_mask)
        my_ip = ips_and_mask[0]
        return my_ip
    return False


  
def page_data():
    html = """
        <!DOCTYPE HTML>
        <html>
            <head>
                <title>get params</title>
            </head>
            <body>
                <form action="/" method="get" target="_blank">
                <label for="argument">Argument1:</label>
                <input type="text" id="argument1" name="argument1"><br>
                <label for="argument2">Argument2:</label>
                <input type="text" id="argument2" name="argument2"><br>
                <label for="argument3">Argument3:</label>
                <input type="text" id="argument3" name="argument3"><br>
                <input type="submit" value="Submit">
                </form>
            </body>
        </html>"""
    return html

def parse_params(part):
    parameters = {}
    for piece in part.split(" "):
        if "/?" in piece:
            piece = piece.replace("/?", "")
            amp_split = piece.split("&")
            for param_set in amp_split:
                eq_split = param_set.split("=")
                parameters[eq_split[0]] = eq_split[1]
    return parameters

def server(my_ip="", my_port=80):
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.bind((f'{my_ip}', my_port))
    s.listen(1)
    print("\nstarting server")
    print(f"http://{my_ip}/\n")
    while True:
        try:
            if gc.mem_free() < 102000:
                gc.collect()
            conn, addr = s.accept()
            conn.settimeout(3.0)
            print(f'\nGot a connection from {str(addr)}')
            request = conn.recv(1024)
            conn.settimeout(None)
            request = str(request).replace("b'","").replace("'","")
            request = request.split("\\r\\n")
            
            for part in request:
                print(part)

            for part in request:
                if "/?" and "GET" in part:
                    params = parse_params(part)
            
            if params:
                print(f"Params: {params}\n")
            
            response = page_data()
            conn.send('HTTP/1.1 200 OK\n')
            conn.send('Content-Type: text/html\n')
            conn.send('Connection: close\n\n')
            conn.sendall(response)
            conn.close()
        except OSError as e:
            conn.close()
            print('Connection closed\n')


network_name = "<hidden>"
network_password = "<hidden>"

connection = network_connect(network_name, network_password)

if connection:
    my_ip = connection
    my_port = 80
    server(my_ip, my_port)

and here is an example of the response I get and the params I can use:

Got a connection from ('10.0.1.90', 60782)
GET /?argument1=apples&argument2=grapes&argument3=bananas HTTP/1.1
Host: 10.0.1.207
Connection: keep-alive
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.7      
Referer: http://10.0.1.207/
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9


Params: {'argument2': 'grapes', 'argument3': 'bananas', 'argument1': 'apples'}

1 reply

alekthegenius Mar 8, 2023
Author

Thank you for your time and explanation on parsing the parameters.

kjm1102 · 2023-03-15T07:04:35Z

kjm1102
Mar 15, 2023

If you're looking to set time on the esp32 from the date returned returned by a server you can just grab the date from a server reply in urequests by inserting a line after l=s.readline() in the urequests lib

l=s.readline()
if 'Date' in l: global date; date=l.decode().split('Date')[1]

saves all that pfaffing about with ntp servers.

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MicroPython

How do I receive data, like numbers and text, through the GET method in MicroPython? #10981

alekthegenius Mar 8, 2023

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sethstenzel Mar 8, 2023

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