1 Breadcrumbs (:mod:`cubicweb.web.views.ibreadcrumbs`)

     1 Breadcrumbs

     2 ----------------------------------------------------

     2 -----------

     3 XXX feedme

     3 

     4 Breadcrumbs are a navigation component to situate the user in the

     5 arborescence's site.

     6 

     7 

     8 Display

     9 ~~~~~~~

    10 

    11 Breadcrumbs are displayed by default in the header section (see

    12 :ref:`the_main_template_sections`).  With the default base template,

    13 the header section is composed by the logo, the application name,

    14 breadcrumbs and, at the most right, the login box. Breadcrumbs are

    15 displayed just next to the application name, thus breadcrumbs begin

    16 with a separator.

    17 

    18 Here is the header section of the CubicWeb's forge:

    19 

    20 .. image:: ../../../images/breadcrumbs_header.png

    21 

    22 There are three breadcrumbs components defined in

    23 ``cubicweb/web/views/ibreadcrumbs.py`` file:

    24 

    25 - BreadCrumbEntityVComponent: displayed for a result set with one line

    26   if the entity implements the ``IBreadCrumbs`` interface.

    27 - BreadCrumbETypeVComponent: displayed for a result set with more than

    28   one line, but with all entities of the same type which implement the

    29   ``IBreadCrumbs`` interface.

    30 - BreadCrumbAnyRSetVComponent: displayed for any other result set.

    31 

    32 Implementation

    33 ~~~~~~~~~~~~~~

    34 

    35 The ``IBreadCrumbs`` interface is defined in the

    36 ``cubicweb/interfaces.py`` file. It specifies that an entity which

    37 implements this interface must have a ``breadcrumbs`` method.

    38 

    39 Here is the API of the ``breadcrumbs`` method:

    40 

    41 .. automethod:: cubicweb.interfaces.IBreadCrumbs.breadcrumbs

    42 

    43 

    44 If the breadcrumbs method return a list of entities, the

    45 ``cubicweb.web.views.ibreadcrumbs.BreadCrumbView`` is used to display

    46 the first elements and the

    47 ``cubicweb.web.views.ibreadcrumbs.BreadCrumbTextView`` is used to

    48 display the last one.

    49 

    50 By default, for any entity, if recurs=True, breadcrumbs method returns

    51 a list of entities, else a list of a simple string.

    52 

    53 In order to see a hierarchical breadcrumbs, entities must have a

    54 ``parent`` method which returns the parent entity. By default this

    55 method doesn't exist on entity, given that it can not be guessed.

    56 

    57 XXX To change the default separator, you have to monkeypatch the

    58 ``BreadCrumbEntityVComponent.separator`` class attribute.

    59 

    60 XXX  add_to_breadcrumbs = False on an EntityView