CF7 conditional logic [closed]

The only way to achieve this is to use a custom script file.

Load the script on the page where your form is being loaded using the following back-end function in your functions.php file,

add_action( 'wp_enqueue_scripts','register_custom_script');
//its important to register the script, else it will not load properly.
function register_custom_script(){
   wp_register_script( 'custom-cf7-script', <url to your script file>, array( 'jquery' ), null, true );
}
add_filter( 'do_shortcode_tag','load_custom_script', 10,3);
function load_custom_script($output, $tag, $args){
    if('contact-form-7' != $tag){
      return $output; //not a cf7 form shortcode.
    }
    if(!isset($attr['id']) || <yourform-id> != $attr['id']){
      return $output; //not your form
    }
    //load your custom script that you previously registered.
    wp_enqueue_script( 'custom-cf7-script');
}

in your custom script you’ll want to do something like,

(function($){
  $(document).ready(function(){
    var $select = $('#language-drop-down');
    var $hidden = $('#textfield1');
    $select.on('change',function(){
      if("spanish"==this.value) $hidden = "/filedirectory/for/spanish/templatefile";
    });
  })
})(jQuery)