bbPress.org

meta boxes are used in the backend, but you are most of the way there.

so to add the dropdown you can use

add_action(‘bbp_theme_before_reply_content’, ‘so_additional_content’);

(there is a bbp_theme_after_reply_content action as well)

and then in the function put the drop down stuff – I’ve not checked your code, so you’ll need to tidy and correct the following if it doesn’t work

so

function so_additional_content () {
?>
<label>Choose the size of the element : </label>
<select name=”custom_element_grid_class” id=”custom_element_grid_class”>
<option value=”normal” <?php selected( $meta_element_class, ‘normal’ ); ?>>normal</option>
<option value=”square” <?php selected( $meta_element_class, ‘square’ ); ?>>square</option>
<option value=”wide” <?php selected( $meta_element_class, ‘wide’ ); ?>>wide</option>
<option value=”tall” <?php selected( $meta_element_class, ‘tall’ ); ?>>tall</option>
</select>
<?php 
}

Then when the user presses submit a function in bbpress called ‘new reply handler’ takes over.

that has a hook

do_action( ‘bbp_new_reply_post_extras’, $reply_id );

which you can link to, to do the save.

so you would have

add_action ( 'bbp_new_reply_post_extras' , 'so_save' ) ;

function so-save ($reply_id) {
$meta_element_class = $_POST[‘custom_element_grid_class’];
update_post_meta($reply_id, ‘custom_element_grid_class_meta_box’, $meta_element_class);
}

again your code is not checked.

you will need to add functionality if you want users to edit their replies and change the dropdown selection

I’ll let you play with the above, and do come back with a first version if you need extra help.

If you fix it, then PLEASE post your solution here to help others

ok, I’ve ONLY edited this to correct syntax, but try it and then come back

add_action( 'bbp_theme_before_reply_form_content', 'so_additional_content' );
function so_additional_content($post){
	$reply_id = bbp_get_reply_id();
    $meta_element_class = get_post_meta($reply_id, 'custom_element_grid_class_meta_box', true); //true ensures you get just one value instead of an array
     echo '<label>Choose the size of the element :  </label>' ;
	?> 
    <select name="custom_element_grid_class" id="custom_element_grid_class">
      <option value="normal" <?php selected( $meta_element_class, 'normal' ); ?>>normal</option>
      <option value="square" <?php selected( $meta_element_class, 'square' ); ?>>square</option>
      <option value="wide" <?php selected( $meta_element_class, 'wide' ); ?>>wide</option>
      <option value="tall" <?php selected( $meta_element_class, 'tall' ); ?>>tall</option>
    </select>'
    <?php
}
 

 
add_action('bbp_new_reply_post_extras', 'so_save_metabox');

function so_save_metabox(){ 
    global $post;
    if(isset($_POST["custom_element_grid_class"])) {
         //check the capability: if ( !current_user_can( 'edit_post', $post->ID ))  return $post->ID;
        $meta_element_class = $_POST['custom_element_grid_class'];
        //END OF UPDATE

        update_post_meta($reply_id, 'custom_element_grid_class_meta_box', $meta_element_class);
        //print_r($_POST);
		
    }
}

add_action('bbp_theme_before_reply_content', 'so_show_metabox');

function so_show_metabox() {
  $meta_element_class = get_post_meta($reply_id, 'custom_element_grid_class_meta_box', true);
  // the problem is "Field 1" appear in every reply post
  echo "Field 1: ". $meta_element_class."<br>";  
}

easier to start again

this works

add_action( 'bbp_theme_before_reply_form_content', 'rew_additional_field' );
function rew_additional_field($post){
	?>
	<select name="rew_additional_field" id="rew_additional_field">
		<option value="enqury">Enquiry</option>
		<option value="complaint">Complaint</option>
		<option value="feedback">Feedback</option>
	</select>
	<?php
}
 

add_action('bbp_new_reply_post_extras', 'rew_save_additional_field');

function rew_save_additional_field($reply_id){ 
    global $post;
    if(isset($_POST["rew_additional_field"])) {
        update_post_meta ($reply_id, 'rew_additional_field', $_POST["rew_additional_field"]) ;
	}
}

add_action('bbp_theme_before_reply_content', 'rew_show_additional_field');

function rew_show_additional_field () {
$reply_id = bbp_get_reply_id();
  $field = get_post_meta($reply_id, 'rew_additional_field', true);
  if (!empty ($field)) {
	echo "Type: ". ucfirst($field)."<br>";  
  }
}

I just amended the above, so try it again in case you loaded the wrong version !

It is all quite doable, but sorry, you well into design and beyond free help in a support forum.