将jQuery变量回显到PHP

Question

I have this code to export an image:

$(document).ready(function(e){
    var frontPlateClass = $('.choose-front-plate-size').find('a.active').parent().prop('className'),
    // alert(frontPlateClass);
});


$image = $_POST['plate_image'];
$ebay_username = $_POST['ebay_username'];
$decoded = base64_decode(str_replace('data:image/png;base64,', '', $image));
$date = date('m-d-Y', time());
$name = $ebay_username."-front-" . $date .".png";
file_put_contents("/var/makeaplate.justapplications.co.uk/cart/" . $name, $decoded);
$full_path = "/var/wmakeaplate.justapplications.co.uk/cart/" . $name;
imageCreateCorners($full_path, $name, 25);
$name1 = 'cart/'.$name;
echo '<div class="content-btns">';
echo "<img src='$name1' alt='image' id='front_img' />";
echo '<p class="download-btn"><a href="download.php?ebay_username='.$ebay_username.'&img=' . $name1 .'">Download front plate</a></p>';
echo '</div>';

As you can see I have 1 jQuery variable frontPlateClass . How can I add this in php with echo?

Answer 1

PHP is executed before there is content on the screen, at the server. jQuery / HTML is rendered by the browser once the page is sent to the client.

The only way you can do this (passing a JS variable to PHP) is by doing an AJAX call to a PHP file after the document has loaded, sending the variable as the data.

Answer 2

You cant do it like that.

One thing that you have to know, it the difference between server side and client side.

Server side generate the html, the javascript etc... Php is executed on the server side.

Client side come after, it receive all html/javascript/etc... generate through the server. Once it receive all this text, browser have mechanisms to parse the javascript and execute it.

The solution for your problem:

You can use ajax, it gonna create a request to a php script on the server side. Ajax is generated from the client side. So you will be able to send the content of frontPlateClass to a php script.

Answer 3

Develop following structure;

function.php

<?php
    $frontPlateClass = $_POST["frontPlateClass"];
    // Now you can use this vaiable anywhere you want
    $image = $_POST['plate_image'];
    $ebay_username = $_POST['ebay_username'];
    $decoded = base64_decode(str_replace('data:image/png;base64,', '', $image));
    $date = date('m-d-Y', time());
    $name = $ebay_username."-front-" . $date .".png";
    file_put_contents("/var/makeaplate.justapplications.co.uk/cart/" . $name, $decoded);
    $full_path = "/var/wmakeaplate.justapplications.co.uk/cart/" . $name;
    imageCreateCorners($full_path, $name, 25);
    ........
?>

In your html:

$(document).ready(function(e){
    var frontPlateClass = $('.choose-front-plate-size').find('a.active').parent().prop('className'),
    $.ajax({
       url: "path_to_function.php",
       method: "POST",
       data: "frontPlateClass=" + frontPlateClass,
      success: function(response) {} 
    });
});

By doing this, you can send js variable to php. And you can use that value in php side

Answer 4

You can't 'echo' it using PHP. I would add a blank div using HTML in your PHP code and then have JQuery populate it.

So in your HTML something like this..

<div class="inner">Goodbye</div>

Then in your script something like this.

$( ".inner" ).append( frontPlateClass );

Hope this puts you in the right direction.