Get cookies

[mawoka-myblock]

Hello everyone, do you know a way to read a cookie or the localStorage for example and get this variable in the python thread, session? Thanks for your help!

[wang0618]

You can use pywebio.session.run_js and pywebio.session.eval_js to deal with cookies or localStorage with js.

This is an example to write and read the localStorage:

key = 'name'
value = 'pywebio'

run_js("localStorage.setItem(key, value)", key=key, value=value)
val = eval_js("localStorage.getItem(key)", key=key)

Since there is no direct functions to manipulate cookies in js, you need some helper functions:

# https://stackoverflow.com/questions/14573223/set-cookie-and-get-cookie-with-javascript
run_js("""
window.setCookie = function(name,value,days) {
    var expires = "";
    if (days) {
        var date = new Date();
        date.setTime(date.getTime() + (days*24*60*60*1000));
        expires = "; expires=" + date.toUTCString();
    }
    document.cookie = name + "=" + (value || "")  + expires + "; path=/";
}
window.getCookie = function(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for(var i=0;i < ca.length;i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1,c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
    }
    return null;
}
""")

run_js("setCookie(key, value)", key='name', value='pywebio')
val = eval_js("getCookie(key)", key='name')

run_js("setCookie(key, value)", key='hello', value='world')
val = eval_js("getCookie(key)", key='hello')

[mawoka-myblock]

It works in Firefox but not in Chromium-Based stuff (Brave) (I mean your stuff)

[mawoka-myblock]

At the top is Brave and at the bottom Firefox Dev edition with this script:

import pywebio

from pywebio.input import *
from pywebio.output import *
from pywebio.session import *


def main():
    already_logged_in = actions("Already logged in?", ["Yes", "No"])
    if already_logged_in == "Yes":
        val = eval_js("localStorage.getItem('login_id')")
        put_text('login_id', val)

    hold()


if __name__ == '__main__':
    pywebio.start_server(main, port=8080, debug=True)

[mawoka-myblock]

Oh man, it was the Stupid cache!!! Btw: do you know a way to disable the cache in Firefox?

[wang0618]

Turning off the cache doesn't seem like a good idea, it can make pages load slowly.

In chrome, I usually use Empty Cache and Hard Reload to clear the cache for current page.

[mon6912640]

key = 'name'
value = 'pywebio'

run_js("localStorage.setItem(key, value)", key=key, value=value)
val = eval_js("localStorage.getItem(key)", key=key)
print(val)

# output:<coroutine object to_coroutine at 0x0461A540>

It doesn't work. @wang0618

=============
It works. I added 'await' before 'eval_js' calling.

key = 'name'
value = 'pywebio'

run_js("localStorage.setItem(key, value)", key=key, value=value)
val = await eval_js("localStorage.getItem(key)", key=key)
print(val)

# output:pywebio