$return the first parameter, it is a boolean and controls whether or not the breadcrumb trail is returned or echoed. Set to true to return the assembled breadcrumb trail string. It defaults to false if no value is passed in.
$linked the second parameter, it is a boolean and controls whether or not the breadcrumbs in the breadcrumb trail are linked (if anchors are generated or not). Set to false to get a string without anchors. It defaults to true if no value is passed in.
$reverse the third parameter, it is a boolean and controls the order the breadcrumbs are arranged within the trail. Set to true to have the current item’s breadcrumb show up first in the breadcrumb trail (this is revered of the normal behavior). It defaults to false if no value is passed in.
$force the fourth parameter, it is a boolean and controls whether or not generation of the breadcrumb trail should be forced (e.g. should the internal caching mechanism be bypassed). It defaults to false if no value is passed in. This parameter was introduced in Breadcrumb NavXT 5.6.0.
bcn_display_list() accepts the same parameters as bcn_display(). The difference is in how the breadcrumb trail is assembled. bcn_display() places a breadcrumb separator between breadcrumbs in the trail. bcn_display_list() wraps each breadcrumb with <li> tags.
Since version 3.0.0, Breadcrumb NavXT has shipped with a built in WordPress sidebar widget. In Breadcrumb NavXT version 3.5.0 the included widget was rewritten and is multi instance capable. The widget allows you to place a breadcrumb trail in your theme without touching any of your theme’s files. Since Breadcrumb NavXT has a two different display functions (bcn_display() and bcn_display_list()), along with three input variables for these functions ($return, $linked, $reverse), the widget has a few settings available to the user.
Currently, the following settings are available:
A field to enter a title for the output widget, this works just like the title on any other widget.
Whether to output the trail as a list or not. If checked, the output trail will be placed in an unordered list, with each breadcrumb belonging to its own list element.
Whether to link the breadcrumbs or not. If checked (default), each of the breadcrumbs in the breadcrumb trail will have a hyperlink.
Whether to reverse the order of the trail or not. If checked, the breadcrumb trail will be output in reverse order (the leftmost breadcrumb (or first breadcrumb in a list output) will be the breadcrumb for current page).
Whether to hide the trail on the front page or not. If checked, the breadcrumb trail for the front page of your site will not be displayed (e.g. when is_front_page() evaluates to true).
The widget still uses the settings values specified in the Breadcrumb NavXT settings page to define its behavior while filling the breadcrumb trail.
This filter is applied within the bcn_breadcrumb_trail class in the post_hierarchy() function. This filter was introduced in version 5.4 with three parameters. In version 5.5 a fourth parameter was added. It receives four parameters:
$term – (WP_Term|boolean)(required) The term object returned by bcn_breadcrumb_trail::pick_post_terms() to filter (note that this parameter may be the boolean value false)
$id – (id)(optional) The ID of the post this term is for
$type – (string)(optional) The post type name for the post represented by the ID in the second parameter
$taxonomy – (string)(optional) The name of the taxonomy the term belongs to