John Davidson

Message:

PHP variables doesn't keep their values when AJAX loads a content.

index.php Here is my code in index.php:

<?php

    if (empty($_GET["j"])) {@$_GET["j"] = "en";}

    $lang = htmlspecialchars($_GET["j"]);

 

    if (empty($_GET["as"])) {@$_GET["as"] = "home";}

    $page = htmlspecialchars($_GET["as"]);

 

    require_once("/scripts/header.php");

    require("/scripts/languages.php");

?>



    <div id="page">

        <?php 

            if (file_exists("pages/".$page.".php")) {

                include("pages/".$page.".php");

            } 

        ?>

    </div>

    

    <nav>

        <a href="/cs/home" class="link">Domů</a>

        <a href="/en/contact" class="link">Kontakt</a>

    </nav>

    

    <script src="/scripts/loader.js"></script>

.htaccess I need the URL to be rewrited by this rule:

RewriteEngine on

 

RewriteCond %{REQUEST_FILENAME} !-d

RewriteCond %{REQUEST_FILENAME} !-f

RewriteRule ^(.*)/(.*)$ index.php?j=$1&as=$2 [QSA]

languages.php - There I have some languages variables which I need to use in loaded content by ajax in #page div

<?php

    if ($lang== "cs") {

        $headline = "This is title in another language";

        $text = "

            <p>This is long text in another language.</p>

            <p>This is second paragraph in another language.</p>

        ";

    }

    else {

        $headline = "This is title";

        $text = "

            <p>This is long text.</p>

            <p>This is second paragraph.</p>

        ";

    }

?>

loader.js - Ajax loader:

$(document).ready(function() {

    $('nav a.link').click(ChangePage);

});

 

function ChangePage() {

    var Link = $(this).attr('href');

    var Page = Link.substring(4);

    var Lang= Link.substring(1, 3);

    var Path = "/pages/" + Page+ ".php";

    

    $.ajax({

        url: Path,

        type: "POST",

        success: function(result){

            $("#page").html(result);

            document.title = $('#page_wrap').data('title');

        },

        error: function() {

            alert("there is some error");

        }

    });

    

    return false;

}

home.php - I have this files like home, contact etc. which I need to load into #page div

<div id="page_wrap" data-title="Home - Site Name">HOME</div>

<?php 

    echo "

        <br>This is lang: ".$lang."

        <br>Headline: ".$headline."

        <br>Text: ".$text."

    "; 

?>

If I load page for first time it works. After I load content by clicking on nav link the variable of $lang is undefined.. How can I fix it please? I've even tried php session, but it didn't work at all. Is there any way how to fix it?

---

My Answer:
't need to be declared with a specific data type in JavaScript. You can simply use the "var", "let", or "const" keywords to declare a variable and assign a value to it. JavaScript is a dynamically typed language, which means that variables can hold values of any data type and can be reassigned to different data types at any time.

For example:

javascript
var myVar = 10; // declaring a variable and assigning a number value
let myString = "Hello, world!"; // declaring a variable and assigning a string value
const PI = 3.14; // declaring a constant variable with a number value

myVar = "JavaScript"; // reassigning the variable to a string value


In the above example, "myVar" is initially assigned a number value, but it can be reassigned to a string value later on. The "let" keyword is used to declare variables that can be reassigned, while the "const" keyword is used to declare constants that cannot be reassigned.