如何从js调用php方法？

Question

I am working on project of Counter service where I need to control the flow the customers, each customer can have 5mins in the counter. On the other hand, the system should control 5 counters.

Here is my attempt to solve the problem. Look at my MWE:

  //this is part of the code where I set the timer for each counter. function increment() { if (running == 1) { setTimeout(function() { time++; var mins = Math.floor(time / 10 / 60); var secs = Math.floor(time / 10); var tenths = time % 10; if (mins == 5) { //after 5 mins is over the system should call php deQueue() method to dequeue the current and point out to next customer. document.getElementById("message").innerHTML = "Currently, Counters are available... Next Customer..." deQueue(); //this is my php method. available(); } document.getElementById("timer").innerHTML = mins + ":" + secs + ":" + tenths; increment(); }, 100) } } 

 //And this is my php file. <?php public function deQueue(){ if (!$this->isEmpty()) { $this->front = ($this->front+1) %5; $this->size--; }else{ echo "The Counter is empty! <br>"; } } ?> 

Answer 1

Now you will need to use an ajax request to your php file like this:

function increment() {
    if (running == 1) {
        setTimeout(function() {
            time++;
            var mins = Math.floor(time / 10 / 60);
            var secs = Math.floor(time / 10);
            var tenths = time % 10;
            if (mins == 5) ajaxDequeue(mins);
            document.getElementById("timer").innerHTML = mins + ":" + secs + ":" + tenths;
            increment();
        }, 100)
    }
}

function ajaxDequeue(mins){ 
    $.ajax({  
        url: 'ajax.php?minutes=' + mins,  
        beforeSend: function() 
        {
            document.getElementById("message").innerHTML = "Currently, Counters are available... Next Customer..."
        },  
        success: function(response)
        {
            document.getElementById("message").innerHTML = response;
        }      
    });
}

then in your ajax.php file set it to check for value of minutes

<?php
    $minutes = $_GET["minutes"];

    if (isset($minutes)) deQueue();

    public function deQueue(){
            if (!$this->isEmpty()) {
                $this->front = ($this->front+1) %5;
                $this->size--;
            }else{
                echo "The Counter is empty! <br>";
            }
        }
?>

Answer 2

To me it looks like you are trying to directly call a PHP function from JavaScript. To describe it in easy words, these two languages usually need an extra layer to communicate, called the HTTP , because PHP runs on the webserver and JavaScript runs on the webbrowser.

To execute a JavaScript function "after a certain time" you can use setTimeout .

To open a communication to PHP (webserver) you can use AJAX .