Custom Field Second Dropdown Based On Previous Dropdown's Selection

@Artemis Obauldi Did you ever get get this implemented?

 

Here is my workaround for a dynamic drop down based on a previous drop down selection

Install this addon
https://xenforo.com/community/resources/multiple-choice-fields-by-waindigo.3825/

Run the following SQL in phpMyAdmin to add a new field called multiple_choice_waindigo to the xf_nflj_showcase_custom_field

Code:

ALTER TABLE  `xf_nflj_showcase_custom_field` ADD  `multiple_choice_waindigo` TINYINT UNSIGNED NOT NULL DEFAULT  '0'

Create a new showcase drop down custom field



Create the drop down choices for the first and second drop down by separating the entries by a pipe "|".

In this example, the first drop down contains the companies Honda, BMW and Chevrolet. The second drop down will then be dynamically generated based on the company selected and will display the respective models from the selected company.
So if BMW is selected, the second drop down will contain M3, M4 and M5.



Go back to phpMyAdmin and set the multiple_choice_waindigo field in the xf_nflj_showcase_custom_field to 1

Code:

UPDATE  `showcase`.`xf_nflj_showcase_custom_field` SET  `multiple_choice_waindigo` =  '1' WHERE  `xf_nflj_showcase_custom_field`.`field_id` =  'vehicle';

When creating a new showcase only the first drop down is initially shown


Company selection



Once the company is selected, the models show up

Model has been selected


Submitted showcase item

The vehicle shows up as BMW|M5. See next post on how to remove the "|".

 

The "|" separating the make and model can be removed with a template callback

In the library folder create a new folder called Custom

Create a new empty file called Showcase.php


Add the following code, which will replace the "|" with a space, to the Showcase.php file

Code:

<?php

class Custom_Showcase
{
    public static function renderVehicle()
    {
        $val = func_get_arg(1);
        return  str_replace("|"," ", $val);
    }
}

?>

Change the display location of the vehicle custom field to Self Placement


Edit the nflj_showcase_item_field_group template and add the following before the </xen:contentcheck> tag

Code:

<xen:if is="{$item.customFields.vehicle}">
    <div class="customShowcaseFields tab1">
        <dl class="customShowcaseFieldvehicle">
            <dt>Vehicle:</dt>
            <dd><xen:callback class="Custom_Showcase" method="renderVehicle"   params="{xen:helper showcaseFieldValue, $item, 'vehicle', {$item.customFields.vehicle}}"></xen:callback></dd>
        </dl>
    </div>
</xen:if>

End result

 

Conditional fields (SC & AMS)