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To The right are the taxonomies, under them are the different terms, based on the radio selection of the terms..... i have to filter and display the car models.......

The Live working can be found here, follow the link

  • it can be done only through database interaction or it can be done with WordPress functions ? Commented Jun 4, 2012 at 11:47

2 Answers 2


Here's how you do it,

<form name="filterby" action="" method="GET">

    <input type="radio" name="cartype" value="bentley" OnChange="document.filterby.submit()" /> Bentley<br />
    <input type="radio" name="cartype" value="bmw" OnChange="document.filterby.submit()"/> BMW
    <input type="radio" name="cartype" value="bugatti" OnChange="document.filterby.submit()"/> Bugatti



$selection  = $_GET['cartype']?$_GET['cartype']:'bentley';

$args = array_merge( $wp_query->query, array( 

        'post_type' => 'cars',
        'taxonomy' => $selection,
        'order' => desc



query_posts( $args );

if (have_posts()) : while (have_posts()) : the_post(); ?>

    // do your desired output here

<?php endwhile; endif; ?>

What's happening in this code?

First of all, the form above contains your radio input buttons representing your desired cars or taxonomies.

You'll notice the following,


...what this does, is submit the form via the use of JavaScript as opposed to having to have a separate submit button to process the selection. You can always remove that in place of a submit button if you desire.

The form itself uses the GET method, instead of POST when processing the form, as we want to get the value from the user selection and pass it to our query/loop.

Upon selection the $_GET['cartype'] value is stored within a variable called $selection. We then use this variable within our query and in this case pass it along to the taxonomy property as the taxonomy for which we want to retrieve posts from.

You'll notice that withint he $selection variable that $_GET['cartype'] seems to be declared twice. This is not an error and let's break down the variable to understand why,

$selection  = $_GET['cartype']             // store the user selection 
              ?                            // OR ELSE
              $_GET['cartype']:'bentley';  // show posts from *bentley* taxonomy by default

Fairly self explanatory in that if there is no user input, such as when the user first lands on that page, they would not have made a selection from radio buttons yet, then we show a default list of posts from a desired taxonomy by assigning a taxonomy to the...


...if not there would be taxonomy name held within the $selection variable for which we pass along to our query. In turn, our query/loop would produce no results until input. This may produce an undesirable user experience.

While this is not necessary, its recommended, unless you are running a more complicated loop/query for which modify things according to your taste, otherwise set a default taxonomy to show cars from (which might be Aston Martin if you want to go via Alphabetic order).

All of the above goes into the template file for which is controlling your view/layout.

Hopefully this helps you.

  • Thanks a lot for ur generous help.... below is the code what i have tried after going through your code. kindly check once am i on the right track or not.... Commented Jun 20, 2012 at 13:07

I did like this................

function implement_ajaxaa() {
if(isset($_GET['manu_catidd']) && isset($_GET['trans_catidd']) && isset($_GET['fuel_catidd']))
 $bodytype_arg = array(
    'taxonomy' => 'bodytype',
    'terms' => array($_GET['manu_catidd']),
    'field' => 'slug',
    'compare' => '==',

if(isset($_GET['manu_catidd'])&& $GET['manu_catidd']=='undefined')
$bodytype_arg1 = '';
$bodytype_arg1 =$bodytype_arg;

$transmission_arg = array(
    'taxonomy' => 'transmission',
    'terms' => array($_GET['trans_catidd']),
    'field' => 'slug',
    'compare' => '==',

if(isset($_GET['trans_catidd']) && $GET['trans_catidd']=='undefined')
$transmission_arg1 = '';
$transmission_arg1 =$transmission_arg;

    'taxonomy' => 'fueltype',
    'terms' => array($_GET['fuel_catidd']),
    'field' => 'slug',
    'compare' => '==',

$args = array(
'post_type' => 'newcars','numberposts'=>20,     
'tax_query' => array(
'relation' => 'AND',

    'taxonomy' => 'model',
    'terms' => 'aston-martin',
    'field' => 'slug',
    'compare' => '==',


$query = new WP_Query( $args );

while ( $query->have_posts() ) : $query->the_post();
echo '<li>';
echo '<a href="';
echo the_permalink(); 
echo '" >';
echo '</a>';
echo '</li>';
add_action('wp_ajax_my_special_ajax_callab', 'implement_ajaxaa');
add_action('wp_ajax_nopriv_my_special_ajax_callab', 'implement_ajaxaa');//for users that are not logged in.


but retrieving of the posts is what im having the problem.... any more modifications ?

  • Can you provide more information as to what you mean by "retrieving of the posts"? Describe what's happening, or rather what's not happening. Also, where are you placing this code? I suggest testing your code incrementally first. So I'd first strip away the ajax function and test this snippet within the template file to ensure that all of my conditional elements are functioning as they should be, such as the correct form values being passed along to variables etc. I also use a plugin called BlackBox which shows you all the $_GET values
    – Adam
    Commented Jun 21, 2012 at 8:28
  • ...during development. This helps you track down any errors. Also please provide the html form code you are using. If its too big to paste here then use PasteBin and provide a link for evaluation.
    – Adam
    Commented Jun 21, 2012 at 8:29
  • @userabuser hi, here is the complete code pastebin.com/EUvz6Fa6 For a test purpose im retrieving all the posts, i'll replace all the posts with an image of the car brand later Commented Jun 21, 2012 at 9:20

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