如何在ajax函数中调用php文件？

Question

I've got this problem that I can't solve. Partly because I can't explain it with the right terms. I'm new to this so sorry for this clumsy question.

Below you can see an overview of my goal.I tried to get all category id's in a dynamic dropdown list ,the second dropdown list is based on the first dropdown list selection for this i find some code its working fine in local but i tried inside magento its not working Why ?

Here is my code

<tr>
                <td class="tdpadfirst">
                <label for="category" class="rightgap"><?php echo Mage::helper('marketplacepartner')->__('Product Category') ?>:</label>
                <span class="required starimp">&nbsp;&nbsp;&nbsp;&nbsp;</span>
                    </td>

                <td class="tdpadfirst">
                <select id="category" class="myinput-text required-entry widthinput" name="category" onChange="updateCategory(this.value)">
                <option value="">--Select Categories--</option>
                <?php
                include('db.php');
                $sql=mysql_query("select entity_id from catalog_category_entity where level='2';");
                while($row=mysql_fetch_array($sql)) {
                $id=$row['entity_id'];
                $data=$row['parent_id'];?>
                <!--echo '<option value="'.$entity_id.'">'.$parent_id.'</option>';-->
                <option value="<?php echo $id ?>"><?php echo $id ?></option>
                <?php  } ?>
                </select>
                <select name="city" class="city">
                <option selected="selected">--Select subcategory--</option>
                </select></td></tr>

<script type="text/javascript" src="http://ajax.googleapis.com/
ajax/libs/jquery/1.4.2/jquery.min.js"></script>
  <script type="text/javascript">
$(document).ready(function() {
   $(".country").change(function() {
    var id=$(this).val();
    var dataString = 'id='+ id;
    $.ajax ({
    type: "POST",
    url: "ajax_city.php",
    data: dataString,
    cache: false,
    success: function(html) {
       $(".city").html(html);
    }
    });
});
});

ajax_city.php is :

   <?php
include('db.php');
if($_POST['id']) {
   $id=$_POST['id'];
    $sql=mysql_query("select entity_id from catalog_category_entity where parent_id='$id'");
    while($row=mysql_fetch_array($sql)) {
        $id=$row['entity_id'];
        $data=$row['parent_id'];
        echo '<option value="'.$data.'">'.$id.'</option>';
    }
}

?>

And db.php is :

   <?php
$mysql_hostname = "localhost";
$mysql_user = "root";
$mysql_password = "admin";
$mysql_database = "magento16";
$bd = mysql_connect($mysql_hostname, $mysql_user, $mysql_password) 
or die("Opps some thing went wrong");
mysql_select_db($mysql_database, $bd) or die("Opps some thing went wrong");

?>

Answer 1

Could use specify what you mean by "its working fine in local but i tried inside magento its not working?"

I'm not 100% sure if you have done this based on your question. Try replacing the php code in ajax_city.php with just html you might be able to isolate the issue.

You may need to allow the cross domian access depending on your setup. Try adding this code to your ajax_city.php page.

header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, POST');  

On an unrelated note, the way you have written your ajax_city.php file you have left yourself vulnerable to SQL injection. Assuming your "$id" value in your sql is supposed to be an integer you can simply force the typecasting to prevent the sql injection.

...entity_id from catalog_category_entity where parent_id='$id'");

Change:

$id=$_POST['id'];

To:

$id=intval($_POST['id']);

Hope this helps!

Answer 2

Are you sure the path to ajax file is correct, the way i see magento has a base .htaccess. Check if the ajax file you are calling is actually being called by checking NET requests sent in your browser, probably using firebug in firefox or chromes default debugger. If its working fine outside magento and path to file is still correct and data is not showing up try making up a simple module in magento by using mage::catalog_category Model. I hope it may help.. :)