WP_List_Table::get_column_info() WordPress Method

	protected function get_column_info() {
		// $_column_headers is already set / cached.
		if ( isset( $this->_column_headers ) && is_array( $this->_column_headers ) ) {
			/*
			 * Backward compatibility for `$_column_headers` format prior to WordPress 4.3.
			 *
			 * In WordPress 4.3 the primary column name was added as a fourth item in the
			 * column headers property. This ensures the primary column name is included
			 * in plugins setting the property directly in the three item format.
			 */
			$column_headers = array( array(), array(), array(), $this->get_primary_column_name() );
			foreach ( $this->_column_headers as $key => $value ) {
				$column_headers[ $key ] = $value;
			}

			return $column_headers;
		}

		$columns = get_column_headers( $this->screen );
		$hidden  = get_hidden_columns( $this->screen );

		$sortable_columns = $this->get_sortable_columns();
		/**
		 * Filters the list table sortable columns for a specific screen.
		 *
		 * The dynamic portion of the hook name, `$this->screen->id`, refers
		 * to the ID of the current screen.
		 *
		 * @since 3.1.0
		 *
		 * @param array $sortable_columns An array of sortable columns.
		 */
		$_sortable = apply_filters( "manage_{$this->screen->id}_sortable_columns", $sortable_columns );

		$sortable = array();
		foreach ( $_sortable as $id => $data ) {
			if ( empty( $data ) ) {
				continue;
			}

			$data = (array) $data;
			if ( ! isset( $data[1] ) ) {
				$data[1] = false;
			}

			$sortable[ $id ] = $data;
		}

		$primary               = $this->get_primary_column_name();
		$this->_column_headers = array( $columns, $hidden, $sortable, $primary );

		return $this->_column_headers;
	}