L. Leo L. Leo - 13 days ago 3
Ajax Question

Integrating dynamic dependent select box into WordPress

I want to add part search into a website powered by WordPress. I have currently achieved the function, but I have trouble of integrating it into WordPress. I tried several ways but the dynamic dependent select box still not working.

I followed this tutorial: Dynamic Dependent Select Box using jQuery, Ajax and PHP

Below are my code which works well outside WordPress.

index.php


<head>
<script src="http://code.jquery.com/jquery-3.1.1.min.js"></script>
<script src="js/ajax-ps.js"></script>
</head>

<body>
<form class="select-boxes" action="ps-result.php" method="POST">
<?php
include('dbConfig.php');
$query = $db->query("SELECT * FROM ps_manufact WHERE status = 1 ORDER BY manufact_name ASC");
$rowCount = $query->num_rows;
?>
<select name="manufacturer" id="manufact" class="col-md-2 col-sm-2 col-xs-10" onchange="manufactText(this)">
<option value="">Select Manufacturer</option>
<?php
if($rowCount > 0){
while($row = $query->fetch_assoc()){
echo '<option value="'.$row['manufact_id'].'">'.$row['manufact_name'].'</option>';
}
}else{
echo '<option value="">Manufacturer Not Available</option>';
}
?>
</select>
<input id="manufacturer_text" type="hidden" name="manufacturer_text" value=""/>
<script type="text/javascript">
function manufactText(ddl) {
document.getElementById('manufacturer_text').value = ddl.options[ddl.selectedIndex].text;
}
</script>

<select name="type" id="type" class="col-md-2 col-sm-2 col-xs-10" onchange="typeText(this)">
<option value="">Select Manufacturer First</option>
</select>
<input id="type_text" type="hidden" name="type_text" value=""/>
<script type="text/javascript">
function typeText(ddl) {
document.getElementById('type_text').value = ddl.options[ddl.selectedIndex].text;
}
</script>

<select name="year" id="year" class="col-md-2 col-sm-2 col-xs-10" onchange="yearText(this)">
<option value="">Select Type First</option>
</select>
<input id="year_text" type="hidden" name="year_text" value=""/>
<script type="text/javascript">
function yearText(ddl) {
document.getElementById('year_text').value = ddl.options[ddl.selectedIndex].text;
}
</script>

<select name="model" id="model" class="col-md-2 col-sm-2 col-xs-10" onchange="modelText(this)">
<option value="">Select Year First</option>
</select>
<input id="model_text" type="hidden" name="model_text" value=""/>
<script type="text/javascript">
function modelText(ddl) {
document.getElementById('model_text').value = ddl.options[ddl.selectedIndex].text;
}
</script>

<input type="submit" name="search" id="search" class="col-md-2 col-sm-2 col-xs-10" value="Search">
</form>
</body>


ajax-ps.js


$(document).ready(function(){
$('#manufact').on('change',function(){
var manufactID = $(this).val();
if(manufactID){
$.ajax({
cache: false,
type:'POST',
url:'ajax-data.php',
data:'manufact_id='+manufactID,
success:function(type_data){
$('#type').html(type_data);
$('#year').html('<option value="">Select Type First</option>');
}
});
}else{
$('#type').html('<option value="">Select Manufact First</option>');
$('#year').html('<option value="">Select Type First</option>');
}
});

$('#type').on('change',function(){
var typeID = $(this).val();
if(typeID){
$.ajax({
cache: false,
type:'POST',
url:'ajax-data.php',
data:'type_id='+typeID,
success:function(year_data){
$('#year').html(year_data);
$('#model').html('<option value="">Select Year First</option>');
}
});
}else{
$('#year').html('<option value="">Select Type First</option>');
$('#model').html('<option value="">Select Year First</option>');
}
});

$('#year').on('change',function(){
var yearID = $(this).val();
if(yearID){
$.ajax({
cache: false,
type:'POST',
url:'ajax-data.php',
data:'year_id='+yearID,
success:function(model_data){
$('#model').html(model_data);
}
});
}else{
$('#model').html('<option value="">Select Year First</option>');
}
});
});


ajax-data.php


include('dbConfig.php');

if(isset($_POST["manufact_id"]) && !empty($_POST["manufact_id"])){
$query = $db->query("SELECT * FROM ps_type WHERE manufact_id = ".$_POST['manufact_id']." AND status = 1 ORDER BY type_name ASC");

$rowCount = $query->num_rows;

if($rowCount > 0){
echo '<option value="">Select Type</option>';
while($row = $query->fetch_assoc()){
echo '<option value="'.$row['type_id'].'">'.$row['type_name'].'</option>';
}
}else{
echo '<option value="">Type Not Available</option>';
}
}

if(isset($_POST["type_id"]) && !empty($_POST["type_id"])){
$query = $db->query("SELECT * FROM ps_year WHERE type_id = ".$_POST['type_id']." AND status = 1 ORDER BY year_name ASC");

$rowCount = $query->num_rows;

if($rowCount > 0){
echo '<option value="">Select Year</option>';
while($row = $query->fetch_assoc()){
echo '<option value="'.$row['year_id'].'">'.$row['year_name'].'</option>';
}
}else{
echo '<option value="">Year Not Available</option>';
}
}

if(isset($_POST["year_id"]) && !empty($_POST["year_id"])){
$query = $db->query("SELECT * FROM ps_model WHERE year_id = ".$_POST['year_id']." AND status = 1 ORDER BY model_name ASC");

$rowCount = $query->num_rows;

if($rowCount > 0){
echo '<option value="">Select Model</option>';
while($row = $query->fetch_assoc()){
echo '<option value="'.$row['model_id'].'">'.$row['model_name'].'</option>';
}
}else{
echo '<option value="">Model Not Available</option>';
}
}


Now the problem is, when select the first box, the second one becomes empty, nothing is returned from the database:

Capture - After select the first box

Really appreicate Christos Lytras to help me solve the previous problem.

I have a new problem with
action="ps-result.php"
in the line
<form class="select-boxes" action="ps-result.php" method="POST">
.

ps-result.php


<?php
if (isset($_POST['search'])) {
$clauses = array();
if (isset($_POST['manufacturer_text']) && !empty($_POST['manufacturer_text'])) {
$clauses[] = "`manufacturer` = '{$_POST['manufacturer_text']}'";
}
if (isset($_POST['type_text']) && !empty($_POST['type_text'])) {
$clauses[] = "`type` = '{$_POST['type_text']}'";
}
if (isset($_POST['year_text']) && !empty($_POST['year_text'])) {
$clauses[] = "`year` = '{$_POST['year_text']}'";
}
if (isset($_POST['model_text']) && !empty($_POST['model_text'])) {
$clauses[] = "`model` = '{$_POST['model_text']}'";
}
$where = !empty( $clauses ) ? ' where '.implode(' and ',$clauses ) : '';

$sql = "SELECT * FROM `wp_products` ". $where;
$result = filterTable($sql);
}
else {
$sql = "SELECT * FROM `wp_products` WHERE `manufacturer`=''";
$result = filterTable($sql);
}

function filterTable($sql) {
$con = mysqli_connect("localhost", "root", "root", "i2235990_wp2");
if (!$con) {
die('Could not connect: ' . mysqli_error($con));
}
$filter_Result = mysqli_query($con, $sql);
return $filter_Result;
}
?>

<?php get_header(); ?>

<div class="container">
...
</div>

<?php get_footer(); ?>


Now when I click
Search
, it returns

Fatal error: Call to undefined function get_header() in /Applications/MAMP/htdocs/wordpress/wp-content/themes/myTheme/inc/ps-result.php on line 42
.

Answer

The proper way to do this, is to create a wordpress shortcode and then use that shortcode wherever you want, page or post, but if you want to create something more specific, then you should create a small wordpress plugin. I won't get into this, but it’s really not a big deal to create a simple wordpress plugin having such functionality. I’ll go through the steps on how you can have this working in wordpress with the files and the code you already have. I assume you already have the tables of your example created. My tables are like this:

wp_citytours_dynsel_cities
wp_citytours_dynsel_states
wp_citytours_dynsel_countries

I have imported some data and I have all those tables filled with proper data. I can provide some sql files if you like, but I assume you already have your tables filled with the proper data for each table.

My test theme root directory is:

/wp-content/themes/citytours/

I have created the directory under my theme root directory and I have included all the code files there, so we have 3 files:

/wp-content/themes/citytours/dynsel/index-partial.php

<?php
//Include database configuration file
include('dbConfig.php');

//Get all country data
$query = $db->query("SELECT * FROM wp_citytours_dynsel_countries WHERE status = 1 ORDER BY country_name ASC");

//Count total number of rows
$rowCount = $query->num_rows;
?>
<select name="country" id="country">
    <option value="">Select Country</option>
    <?php
    if($rowCount > 0){
        while($row = $query->fetch_assoc()){ 
            echo '<option value="'.$row['country_id'].'">'.$row['country_name'].'</option>';
        }
    }else{
        echo '<option value="">Country not available</option>';
    }
    ?>
</select>

<select name="state" id="state">
    <option value="">Select country first</option>
</select>

<select name="city" id="city">
    <option value="">Select state first</option>
</select>

<script type="text/javascript">
jQuery(function($) {
    $('#country').on('change',function(){
        var countryID = $(this).val();
        if(countryID){
            $.ajax({
                type:'POST',
                url:'<?php echo home_url('wp-content/themes/citytours/dynsel/ajaxData.php') ?>',
                data:'country_id='+countryID,
                success:function(html){
                    $('#state').html(html);
                    $('#city').html('<option value="">Select state first</option>'); 
                }
            }); 
        }else{
            $('#state').html('<option value="">Select country first</option>');
            $('#city').html('<option value="">Select state first</option>'); 
        }
    });

    $('#state').on('change',function(){
        var stateID = $(this).val();
        if(stateID){
            $.ajax({
                type:'POST',
                url:'<?php echo home_url('wp-content/themes/citytours/dynsel/ajaxData.php') ?>',
                data:'state_id='+stateID,
                success:function(html){
                    $('#city').html(html);
                }
            }); 
        }else{
            $('#city').html('<option value="">Select state first</option>'); 
        }
    });
});
</script>

/wp-content/themes/citytours/dynsel/dbConfig.php

<?php
//db details
$dbHost = 'localhost';
$dbUsername = 'xxxx';
$dbPassword = 'xxxx';
$dbName = 'xxxx';

//Connect and select the database
$db = new mysqli($dbHost, $dbUsername, $dbPassword, $dbName);

if ($db->connect_error) {
    die("Connection failed: " . $db->connect_error);
}
?>

/wp-content/themes/citytours/dynsel/ajaxData.php

<?php
//Include database configuration file
include('dbConfig.php');

if(isset($_POST["country_id"]) && !empty($_POST["country_id"])){
    //Get all state data
    $query = $db->query("SELECT * FROM wp_citytours_dynsel_states WHERE country_id = ".$_POST['country_id']." AND status = 1 ORDER BY state_name ASC");

    //Count total number of rows
    $rowCount = $query->num_rows;

    //Display states list
    if($rowCount > 0){
        echo '<option value="">Select state</option>';
        while($row = $query->fetch_assoc()){ 
            echo '<option value="'.$row['state_id'].'">'.$row['state_name'].'</option>';
        }
    }else{
        echo '<option value="">State not available</option>';
    }
}

if(isset($_POST["state_id"]) && !empty($_POST["state_id"])){
    //Get all city data
    $query = $db->query("SELECT * FROM wp_citytours_dynsel_cities WHERE state_id = ".$_POST['state_id']." AND status = 1 ORDER BY city_name ASC");

    //Count total number of rows
    $rowCount = $query->num_rows;

    //Display cities list
    if($rowCount > 0){
        echo '<option value="">Select city</option>';
        while($row = $query->fetch_assoc()){ 
            echo '<option value="'.$row['city_id'].'">'.$row['city_name'].'</option>';
        }
    }else{
        echo '<option value="">City not available</option>';
    }
}
?>

As you can see, the index-partial.php now contains only needed code, without <body>, <head> and script files included. Wordpress already includes jQuery to the application for most themes, but you should always check that. Now, you can add the functionality wherever you want, even at the theme index.php file, but always with caution. I have used theme's single post template file, which is single-post.php. I have included the example code, under the main post body inside a div. I just include the index-partial.php like this:

<div class="<?php echo esc_attr( $content_class ); ?>">
    <div class="box_style_1">
    ...
    </div><!-- end box_style_1 -->

    <div class="box_style_1">
        <?php include(__DIR__.'/dynsel/index-partial.php'); ?>
    </div>
</div><!-- End col-md-9-->

I also have used the wordpress home_url function, to have a proper url rooted for the ajaxData.php file like this:

url:'<?php echo home_url('wp-content/themes/citytours/dynsel/ajaxData.php') ?>'

Now, if you have followed all these steps, then you should have your code example working at under each post. You can now included it wherever you want by using that line of code <?php include(__DIR__.'/dynsel/index-partial.php'); ?>.

enter image description here

Please let me know if that worked for you.