Assign “div id” value to the variable php

Question

I have a div on my page '.php'

<div id="force_id"></div>

This prints an id for each product on the page. Ex: 126500

How do I assign this value of the other PHP variable (not click, on load for example)

I use it here :

$limit = ??????   (Value should be the id value here. For example 126500)
$plans = mysql_fetch_array(mysql_query("select * from motors WHERE prod_id = '$limit'"));

Thank you in advance ...

Answer 1

If you are looking for something on-load then you will need to use Javascript with some sort of Ajax call.

Your javascript would need to grab the id and then pass that to .php as a POST or GET variable.

However, it would probably be better for you to pass the ID with the page request. So your link to .php would look like this:

<a href='page.php?id=126500'>Link</a>

Obviously you can auto generate these. Then in .php you just get the value from GET:

$limit = $_GET['id']

Then you can use it in your SQL query (you should look at PDO rather than mysql_query to protect yourself from SQL injection hacks).

---

Some more detail on the GET option.
Your initial HTML for the menu choice of products to look at would look like this:

<h1>Select the Product you want to see</h1>
<ul>
<?php
$result = /*  SELECT MY PRODUCT CODES */

foreach($result AS $row){
    echo "<li><a href='product.php?id=".$row['id']."'>Product  ".$row['name']."</a></li>";
}
?>
</ul>

Then your product.php file would have this:

if(isset($_GET['id'])){
    $limit=$_GET['id'];
    $plans= /* SELECT FROM MOTORS USING $limit */
    foreach($plans AS $row){
            echo 'Product name:'.$row['name'];
            echo "<img src='".$row['img_path']."' />";
            ...
     }

}else{
    echo 'Sorry, unrecognised product';
}

You should do further validation on $_GET['id']; for example check that it is a number and within a range that you would expect for your product_id's

---

More detail on the POST option using Javascript & JQuery. If you have a specific reason for wanting to do POST, or for some reason you only want to publish the ID code on the one page then you could do it like this:

In your HTML I would use a data attribute in a div:

<div id='product' data-id='12650'></div>

In Javascript (I've assumed JQuery but the approach would be the same with other libraries) you would add to your 'onload' function (ie do this after the page has loaded):

$('#product').each(function(){
     var id=$(this).data('id');
     $.ajax({
        type: 'POST',
        url: 'product_content.php',
        data: {'id':id},
        success: function(msg){
             $(this).html(msg);
         },
        error: function(msg, status,err){
             $(this).html("Product not Found");             
         }
     });            
});

Finally you need a page to respond to the Ajax call product_content.php :

$limit=$_POST['id'];
/* DO SOME VALIDATION ON $limit HERE OR USE PDO AS PROTECTION */
$plans= /* SELECT FROM MOTORS USING $limit*/
 foreach($plans AS $row){
    echo 'Product name:'.$row['name'];
    echo "<img src='".$row['img_path']."' />";
    ...
}

I should point out I've not tested this code, so keep an eye out for typo's if you copy it directly.

Answer 2

If you're using form, you can put the div's value inside an input[hidden] inside the form. Something like this:

  $('#your_form').on('submit', function(){
    your_div = $('#your_div').attr('id');
    $('#hidden_field_used_on_form').val(your_div);
    return true;
  })