[mizzinc]

Hello,

I would like to know the correct method to add a filter in a child theme for a template function.

For this example lets use ‘bbp_get_user_subscribe_link()’

I would like to insert

<icon class="icon-user"></i>

into the following before the %s

<span id="subscribe-%d"  %s>%s

$html = sprintf( '%s<span id="subscribe-%d"  %s>%s</span>%s', $r['before'], $topic_id, $sub, $url, $topic_id, $text, $r['after'] );

of this function bbp_get_user_subscribe_link()

	function bbp_get_user_subscribe_link( $args = '', $user_id = 0, $wrap = true ) {
		if ( !bbp_is_subscriptions_active() )
			return;

		// Parse arguments against default values
		$r = bbp_parse_args( $args, array(
			'subscribe'   => __( 'Subscribe',   'bbpress' ),
			'unsubscribe' => __( 'Unsubscribe', 'bbpress' ),
			'user_id'     => 0,
			'topic_id'    => 0,
			'before'      => ' | ',
			'after'       => ''
		), 'get_user_subscribe_link' );

		// Validate user and topic ID's
		$user_id  = bbp_get_user_id( $r['user_id'], true, true );
		$topic_id = bbp_get_topic_id( $r['topic_id'] );
		if ( empty( $user_id ) || empty( $topic_id ) ) {
			return false;
		}

		// No link if you can't edit yourself
		if ( !current_user_can( 'edit_user', (int) $user_id ) ) {
			return false;
		}

		// Decide which link to show
		$is_subscribed = bbp_is_user_subscribed( $user_id, $topic_id );
		if ( !empty( $is_subscribed ) ) {
			$text       = $r['unsubscribe'];
			$query_args = array( 'action' => 'bbp_unsubscribe', 'topic_id' => $topic_id );
		} else {
			$text       = $r['subscribe'];
			$query_args = array( 'action' => 'bbp_subscribe', 'topic_id' => $topic_id );
		}

		// Create the link based where the user is and if the user is
		// subscribed already
		if ( bbp_is_subscriptions() ) {
			$permalink = bbp_get_subscriptions_permalink( $user_id );
		} elseif ( bbp_is_single_topic() || bbp_is_single_reply() ) {
			$permalink = bbp_get_topic_permalink( $topic_id );
		} else {
			$permalink = get_permalink();
		}

		$url  = esc_url( wp_nonce_url( add_query_arg( $query_args, $permalink ), 'toggle-subscription_' . $topic_id ) );
		$sub  = $is_subscribed ? ' class="is-subscribed"' : '';
		$html = sprintf( '%s<span id="subscribe-%d"  %s>%s</span>%s', $r['before'], $topic_id, $sub, $url, $topic_id, $text, $r['after'] );

		// Initial output is wrapped in a span, ajax output is hooked to this
		if ( !empty( $wrap ) ) {
			$html = '<span id="subscription-toggle">' . $html . '</span>';
		}

		// Return the link
		return apply_filters( 'bbp_get_user_subscribe_link', $html, $r, $user_id, $topic_id );
	}

So how would I construct my_custom_bbp_get_user_subscribe_link() function to add_filter( ‘bbp_get_user_subscribe_link’, ‘my_custom_bbp_get_user_subscribe_link’ ); ?

I hope the answer will serve as a general example to correctly add filters to many other template functions.

Thanks for your assistance.

[Stephen Edgar]

Out of luck at the moment due to your choice of bbp_user_subscribe_link for your example.

See bbPress Trac Ticket #2418

Generally though take a look in the Codex, there are a few examples to help you out:
eg https://codex.bbpress.org/bbp_show_lead_topic/

[mizzinc]

Cheers Stephen and thanks for taking the time to respond.