alternative to send JS data to a new PHP page to use the data

Question

Hello!

My knowledge in PHP is basic, but I will understand the explanations better.

My goal is to create a home page index.php where it gets the resolution of the user screen and this data X and Y are stored in variables and so in a form. The page would automatically call another page where the JS variable values are used by PHP.

I have not yet learned Mysql to formulate a database. I have seen several options to send variables even per link, but none worked properly.

The little I know of JS is enough to automatically get the Review through this code below:

<script>
var x = screen.availWidth;
var y = screen.availHeight;

alert("LARGURA: "+ x +"\nALTURA: " + y)
</script>

of course without Alert for the page come to be able to call another without user intervention.

I know in my researches that in a single file you can’t use the JS variables in PHP because PHP runs on the server and JS runs on the user

As you can see I thought of using a form that auto fills with the value of JS variables. The problem that in JS I am more than Noob. So in the other file called then php would use the data that is saved in the form.

I saw some alternatives here, but none I could actually use properly and it came to mind that this alternative will be faster.

Thank you in advance.

Answer 1

JAVASCRIPT jquery:

$(function() {
    $.post('alerta.php', { width: screen.width, height:screen.height }, function(json) {
        if(json.outcome == 'success') {
            // do something with the knowledge possibly?
        } else {
            alert('Impossível deixar o PHP saber a resolução da tela!');
        }
    },'json');
});

PHP (alert.php)

<?php
// Você pode fazer algo parecido com isto:
if(isset($_POST['width']) && isset($_POST['height'])) {
    $_SESSION['screen_width'] = $_POST['width'];
    $_SESSION['screen_height'] = $_POST['height'];
    echo json_encode(array('outcome'=>'success'));
} else {
    echo json_encode(array('outcome'=>'error','error'=>"Não é possível definir a resolução."));
}
?>

Source: https://stackoverflow.com/questions/1504459/getting-the-screen-resolution-using-php

Blz

Answer 2

In Javascript you can call the URL of the new page by passing the two values in the URL Query String. Ex.

http://seudominio.com.br/teste.php?width=" + screen.availWidth + "&height=" + screen.availHeight

In php these values will be available in the variable $_GET["height"] and $_GET["width"].

Now if these values are the only ones that need the ideal tool for this is to use Cookies, because they serve exactly for this, record small values that need to be sent to the server on each page call.

An example in php here. https://stackoverflow.com/questions/25775046/setcookie-with-get-method

Now... if you can improve the question, it will be easier to answer more specifically. What kind of application is it, if it runs on the server or if it runs on the client, what purpose of these values, etc... For example, in my applications I use xmlHttpRequest, but it is only to call a service in Php that returns a JSON and from there I continue in Javascript. Your need may be different.