static/watermelon/set_number_of_sth/index.js

// set_number_of_sth
var ws = new WebSocket("ws://0.0.0.0:7860/watermelon/ws");
ws.onmessage = function (event) {
    var messages = document.getElementById('messages')
    messages.innerText = event.data
};
function sendMessage(event) {
    var command = document.getElementById("command")
    var target = document.getElementById("target")
    var number = document.getElementById("number")

    var myobj = {
        url: "set_number_of_sth",
        data: {
            command: command.value,
            target: target.value,
            integer: number.value
        }
    }
    ws.send(JSON.stringify(myobj))
    event.preventDefault()
}