Help for creating an AJAX event

With the help of our friend @Givanildo R. de Oliveira, we were able to solve the problem and only bring the products related to the selected Category.

Below the working code:

<?php include "conexao.php"; ?>

<div id="produtos" class="sections full-width-wrapper bg_4">
    <div class="centered-wrapper">

        <div class="section-header">
            <?php include 'menu_pags.php';?>            
        </div>

<div id="produtos-content">

    <!-- Listando os Categorias -->
    <?php
    $nome_cat = $_POST['nome_cat'];
    $img_cat = $_POST['img_cat'];
    $query_categoria = mysql_query("SELECT * FROM categoria");
    while($res = mysql_fetch_array($query_categoria)){
    ?>
    <div style="float:left; width:112px; height:133px; padding:2px 10px;" id="cats-list">
        <a class="cat-link" href="?nome_cat=<?php echo $res['nome_cat']; ?>#produtos" title="<?php echo $res['nome_cat']; ?>">
        <img style="position:relative; top:50%; transform:translateY(-50%);"
            src="img_cate/<?php echo $res['img_cat']; ?>" width="100"
            title="<?php echo $res['nome_cat']; ?>" />
        </a>
        <div style="background:#2f2140; ; width:880px;z-index:999;border-radius:25px; <?php echo $res['nome_cat']==$_GET['nome_cat'] ? 'display:block;' : ''; ?>" class="single-cat">
            <h1 align="center" style="width:830px; margin-top:-40px;"><?php echo $res['nome_cat']; ?></h1>
            <div style="margin-left:357px;width:50px;" class="cat-links">
                <a class="close-btn" href="javascript:;" title="Voltar">
                    <img src="img/fechar.jpg" />
                </a>
            </div>

<!-- Listando os produtos -->
<?php
$nome_cat = $_GET['nome_cat'];
$query_produtos = mysql_query("SELECT * FROM produtos WHERE nome_cat = '$nome_cat'") or die(mysql_error());
while($res = mysql_fetch_array($query_produtos)){

$codigo = $_POST['codigo'];
$img_prod = $_POST['img_prod'];
$titulo = $_POST['titulo'];
$descricao = $_POST['descricao'];
$nome_cat = $_POST['nome_cat'];
?>

    <div style="float:left; width:112px; height:133px; padding:2px 10px;" id="songs-list">
            <a class="song-link" href="javascript:;" title="">
            <img style="position:relative; top:50%; transform:translateY(-50%);" src="img_prod/<?php echo $res['img_prod']; ?>" width="100" title="<?php echo $res['titulo']; ?>" /></a>

        <div style=" margin-top:120px;z-index:999;border-bottom-right-radius:25px;border-top-right-radius:25px;" class="single-song">
            <div style="width:50px;margin-left:300px;" class="song-links">
            <a class="close-btn" href="javascript:;" title="Voltar">
                <img src="img/fechar.jpg" />
            </a>
                <div class="song-sides">
                    <img style="margin:40px 0 0 -142px;" src="img_prod/<?php echo $res['img_prod']; ?>" width="369" />
                </div>
            </div>

            <meta http-equiv="Content-Type" content="text/html; charset=windows-1252" />

            <h1> <?php echo $res['titulo']; ?> </h1>
            <div class="entry" style="overflow-y: hidden; padding: 0px; width: 100px;">
            <p style="font-family:Verdana, Geneva, sans-serif; size:14px; font-weight:bold; color:#ccc;">
            <?php echo nl2br($res['descricao']); ?>
            </p>
            <div class="jspContainer" style="width: 100px; height: auto;">
            <div class="jspPane" style="padding: 0px; top: 0px; width: 100px;">
            </div></div></div>
            <span class="song-sides left-side"></span>
        </div>
    </div>
<?php
}
?>

        </div>
    </div>
    <?php
    }
    ?>
</div>

</div></div></div>

I hope you can help other users with the same problem.

With jQuery you can simply use the post method to request your * .php file to receive the data from it.

You will have to separate your * .php file and answer the client-side with some sort of separate string somehow representing the values of the $nome_cat and $img_cat variables. You can answer the client-side with JSON and interpret it with the JSON.parse method (if you are going to send strings that include quotation marks, declare "\" before the quotation mark, or simply: $value= str_replace('"', '\"', $value); ).

To answer the client-side you declare echo or printf with some argument string in PHP.

Now you can use $.post to execute the file next to the server and receive a response from it in a callback function, success in the 1st parameter, which occurs when the request is made successively.

$.post({
    /* Coloque os dados de postagem e seus valores no objeto 'data' */
    data: {
        codigo: null,
        descricao: null,
        img_prod: null,
        nome_cat: null,
        titulo: null
    },
    success: function(reply) {
        var data = JSON.parse(reply),
            $link = $('.cat-link');

        $link.attr("title", data.nome_cat);

        var catImage = $link[0].getElementsByTagName("img")[0];
        catImage.setAttribute("title", data.nome_cat);
        catImage.src = "img_cate/" + data.img_cat;
    },
    url: "script.php"
});

In PHP, you could answer the client-side in this way if you use JSON:

echo '{'.
     '"codigo":'.$codigo.
     '"descricao":'.$descricao.
     '"img_prod":'.$img_prod.
     '"nome_cat":'.$nome_cat.
     '"titulo":'.$titulo.
     '}';

With this, you will have to ignore the use of PHP in some cases.