I have been following the custom-column instructions – https://docs.admincolumns.com/article/21-how-to-create-my-own-column

I’ve downloaded the template, replaced placeholder values and enabled the plugin.

“That’s it, your column type plugin is ready for testing!”

But the new column does not appear in any ACP dropdowns.

Even if I leave the placeholder values, I don’t see COLUMN_LABEL anywhere.

What am I doing wrong?

I’ve seemingly got classes/Free/my_column.php functioning well.

But I’m confused about how to enabling sorting, filtering, editing etc. The column header is not active for clicking
and my column doesn’t appear in filters.

What more is necessary in classes/sorting/my_column.php… ?

			// Start editing here.

			// Put all the column logic here to retrieve the value you need
			// For example: $value = get_post_meta( $id, '_my_custom_field_example', true );

			$value = $this->column->get_raw_value( $id );

			// Stop editing.

It’s not clear what is meant by “logic”. Why isn’t $value simply taken from get_raw_value()?

Code below…

I also don’t understand what, if anything, I should be doing with classes/Pro/my_column.php

<?php

namespace mynamespace\Column\Free;

class my_column extends \AC\Column {

	public function __construct() {

		// Identifier, pick an unique name. Single word, no spaces. Underscores allowed.
		$this->set_type( 'column-my_column' );

		// Default column label.
		$this->set_label( __( 'My Column', 'ac-my_column' ) );
	}

	/**
	 * Returns the display value for the column.
	 *
	 * @param int $id ID
	 *
	 * @return string Value
	 */
	public function get_value( $post_id ) {

		// get raw value
		$value = $this->get_raw_value( $post_id );

		if ($value) {
			// optionally you can change the display of the value. In this example we added a post link.
			$value = '<a href="' . esc_url( get_permalink( $post_id ) ) . '">' . $value . '</a>';
		} else {
			$value = '–';
		}

		return $value;
	}

	/**
	 * Get the raw, underlying value for the column
	 * Not suitable for direct display, use get_value() for that
	 * This value will be used by 'inline-edit' and get_value().
	 *
	 * @param int $id ID
	 *
	 * @return mixed Value
	 */
	public function get_raw_value( $post_id ) {

		$connected_post_id = get_post($post_id)->post_parent;
		
		// Get all terms of post attached to this image
		$post_term = get_the_terms( $connected_post_id, 'topic' );

		// If there are any terms
		if ( $post_term ) {
			$value = $post_term[0]->name;
			return $value;
		}

		
	}

	/**
	 * (Optional) Create extra settings for you column. These are visible when editing a column. You can remove this function is you do not use it!
	 * Write your own settings or use any of the standard available settings.
	 */
	protected function register_settings() {

		// NOTE! When you use any of these settings, you should remove the get_value() method from this column, because the value will be rendered by the AC_Settings_Column_{$type} classes.

		// Display an image preview size settings screen
		// $this->add_setting( new \AC\Settings\Column\Image( $this ) );

		// Display an excerpt length input field in words
		// $this->add_setting( new \AC\Settings\Column\WordLimit( $this ) );

		// Display an excerpt length input field in characters
		// $this->add_setting( new \AC\Settings\Column\CharacterLimit( $this ) );

		// Display a date format settings input field
		// $this->add_setting( new \AC\Settings\Column\Date( $this ) );

		// Display before and after input fields
		// $this->add_setting( new \AC\Settings\Column\BeforeAfter( $this ) );

		// Displays a dropdown menu with user display formats
		// $this->add_setting( new \AC\Settings\Column\User( $this ) );

		// Displays a dropdown menu with post display formats
		// $this->add_setting( new \AC\Settings\Column\Post( $this ) );
	}

	/**
	 * (Optional) Is valid. You can remove this function is you do not use it!
	 * This determines whether the column should be available. If you want to disable this column
	 * for a particular post type you can set this to false.
	 * @return bool True/False Default should be 'true'.
	 */
	public function is_valid() {

		// Example: if the post type does not support thumbnails then return false
		// if ( ! post_type_supports( $this->get_post_type(), 'thumbnail' ) ) {
		//    return false;
		// }

		return true;
	}

	/*
	 * (Optional) Enqueue CSS + JavaScript on the admin listings screen. You can remove this function is you do not use it!
	 *
	 * This action is called in the admin_head action on the listings screen where your column values are displayed.
	 * Use this action to add CSS + JavaScript
	 */
	public function scripts() {

		wp_enqueue_script( 'ac-my_column', plugin_dir_url( __FILE__ ) . "../../../js/column.js" );
		wp_enqueue_style( 'ac-my_column', plugin_dir_url( __FILE__ ) . "../../../css/column.css" );
	}

}