[Zope] 'Cookie crumb trail' navigation

[Mike Renfro]

On Fri, Mar 22, 2002 at 03:19:28PM -0800, Iago wrote:

>   Here's the code for recursiveLinks:

You'll drive yourself insane mixing logic ("how do I get a list of my
parent folders to build a breadcrumb trail?") and presentation ("I
want each element of my breadcrumb trail to be hotlinked, with '>'
characters between each one").

That having been said, I have a snippet of code at my Python/ZPT
sitemap example (http://www.zope.org/Members/mwr/python_zpt_sitemap)
that generates a list of folders similar to what you want:

  ###
  ### list_parent_folders
  ###
  results=[]

  # Find parent folders from the current folder
  ids2=[]
  for id in context.REQUEST.PARENTS[:-1]:
    ids2.append(id.id)

    ids2.reverse()

  for id in ids2:
    object=getattr(context,id)
    if hasattr(object.aq_explicit,'menu_entry'):
      results.append(object)

  return results

The script does check for the existence of a 'menu_entry' property on
each container, but you could remove that check if you want.

ZPT that should accomplish the breadcrumbs might look like (completely
untested, but built off of my known-working example):

  <div id="breadcrumbs"
       tal:define="sequence python:here.list_parent_folders()">
    <tal:block repeat="item sequence">
      <span class="crumb"
            tal:condition="python:here!=item or template.id!='index_html'">
        <a href="link url"
           tal:attributes="href item/absolute_url"
           tal:content="item/title_or_id">link to some folder</a> --
      </span>
      <span class="crumb"
            tal:condition="python:here==item and template.id=='index_html'">
        <strong><span tal:replace="item/title_or_id">current folder (not linked)</span></strong>
      </span>
    </tal:block>
  </div>

And I think that'll give you a breadcrumb trail that looks like:

<a href="/a">Title A</a> -- <a href="/a/b">Title B</a> -- <strong>Title C</strong>

if you were in the folder /a/b/c

Hope that works, or that you can use it as a starting point.

-- 
Mike Renfro  / R&D Engineer, Center for Manufacturing Research,
931 372-3601 / Tennessee Technological University -- renfro@tntech.edu