pdoCrumbs

Snippet for building breadcrumb navigation.

Replaces BreadCrumb well, works with documents from any contexts and allows specifying various conditions for resource selection.

Snippet has high performance by selecting all needed elements from the database in a single query.

Parameters

Accepts all pdoTools parameters and some of its own:

Parameter	Default	Description
&showLog	0	Show extra snippet debug info. Only for users logged in to the "mgr" context.
&from	0	Resource id from which to build breadcrumbs. Usually the site root, i.e. «0».
&to		Resource id for which breadcrumbs are built. Default is current page id.
&exclude		List of resource IDs to exclude from selection.
&toPlaceholder		If set, the snippet stores all data in a placeholder with this name instead of outputting.
&outputSeparator	\n	Separator between crumbs
&tpl		Name chunk for displaying resource. If not set, resource fields will be printed to screen.
&tplCurrent		Chunk for formatting current document in navigation.
&tplMax		Chunk added at the start of results if there are more than &limit.
&tplHome		Chunk for formatting link to home page.
&tplWrapper		Wrapper chunk for all results. Accepts one placeholder: [[+output]]. Does not work with the parameter &toSeparatePlaceholders.
&wrapIfEmpty		Enables wrapper chunk output &tplWrapper even when no results.
&showCurrent	1	Output current document in navigation.
&showHome	0	Output link to home at start of navigation.
&showAtHome	1	Show breadcrumbs on the site home page.
&hideSingle	0	Don't output result if it is the only one.
&direction	ltr	Navigation direction: left to right «ltr» or right to left «rtl», e.g. for Arabic.

Templates

Template	Default
&tpl	@INLINE <li><a href="[[+link]]">[[+menutitle]]</a></li>
&tplCurrent	@INLINE <li class="active">[[+menutitle]]</li>
&tplMax	@INLINE <li class="disabled">&nbsp;...&nbsp;</li>
&tplHome
&tplWrapper	@INLINE <ul class="breadcrumb">[[+output]]</ul>

Examples

Generate breadcrumbs for current page:

[[pdoCrumbs]]

Generate with limit on number of items:

[[pdoCrumbs?
  &limit=`2`
]]

Snippet works well when called from pdoResources. For example, this chunk:

<h3>[[+pagetitle]]</h3>
<p>[[+introtext]]</p>
[[pdoCrumbs?
  &to=`[[+id]]`
  &showCurrent=`0`
]]

Generate Schema.org microdata in JSON-LD format

{'!pdoCrumbs' | snippet: [
  'showHome' => 1,
  'tplWrapper' => '@INLINE
    <script type="application/ld+json">
      {
        "@context": "http://schema.org",
        "@type": "BreadcrumbList",
        "itemListElement": [ {$output} ]
      }
    </script>
  ',
  'tplHome' => '@INLINE
    {
      "@type": "ListItem",
      "position": {$idx},
      "item": {
        "@id": "{$link}",
        "name": "{$menutitle}"
      }
    },
  ',
  'tplCurrent' => '@INLINE
    {
      "@type": "ListItem",
      "position": {$idx},
      "item": {
        "@id": "{$link}",
        "name": "{$menutitle}"
      }
    }
  ',
  'tpl' => '@INLINE
    {
      "@type": "ListItem",
      "position": {$idx},
      "item": {
        "@id": "{$link}",
        "name": "{$menutitle}"
      }
    },
  ',
]}

Demo

Working example of breadcrumb generation in search results mSearch2.