1 .. _portlethowto:

     2 

     3 

     4 How to create a new Portlet?

     5 ============================

     6 

     7 **Portlets** are pluggable user interface software components that are managed and displayed in a web portal,

     8 for example an enterprise portal or a web CMS. A portlet can aggregate (integrate) and personalize content from

     9 different sources within a web page. A portlet responds to requests from a web client and generates dynamic content

    10 (*reference:* `Wiki portlet`_).

    11 

    12 .. _`wiki portlet`: https://en.wikipedia.org/wiki/Portlet

    13 

    14 

    15 **PyAMS Portal** provides the portal engine but only a very small set of predefined portlets that can be used to compose

    16 and organize the structure of a web page; additional portlets are provided by other packages, like

    17 :ref:`pyams_content`.

    18 

    19 

    20 1. Define portlet settings

    21 ''''''''''''''''''''''''''

    22 

    23 Portlet settings interface are defined in ``interfaces.py``, you can use :py:class:`pyams_portal.interfaces.IPortletSettings`

    24 or extend the interface by adding additional properties for example:

    25 

    26 .. code-block:: python

    27 

    28     from zope.schema import Text

    29 

    30     NEW_PORTLET_NAME = 'new.portlet'

    31 

    32     class INewPortletSettings(IPortletSettings):

    33 

    34         comment = Text(title=_("Comment"),

    35                        required=True)

    36 

    37 

    38 A :py:class:`pyams_portal.portlet.PortletSettings` persistent subclass then implements what IPortletSettings describes:

    39 

    40 .. code-block:: python

    41 

    42     @implementer(INewPortletSettings)

    43     class NewPortletSettings(PortletSettings):

    44         """Portlet settings"""

    45 

    46         comment = FieldProperty(INewPortletSettings['comment'])

    47 

    48 

    49 2. Create Portlet

    50 '''''''''''''''''

    51 

    52 The Portlet component is a utility, which implements the :py:class:`pyams_portal.interfaces.IPortlet` interface and is

    53 registered by the :py:func:`pyams_portal.portlet.portlet_config` decorator;

    54 

    55 .. code-block:: python

    56 

    57     @portlet_config(permission=VIEW_PERMISSION)

    58     class ImagePortlet(Portlet):

    59         """Image portlet"""

    60 

    61         name = NEW_PORTLET_NAME

    62         label = _("New portlet")

    63 

    64         toolbar_image = None

    65         toolbar_css_class = 'fa fa-fw fa-2x fa-picture-o'

    66 

    67         settings_class = NewPortletSettings

    68 

    69 

    70 Where:

    71  - **permission**: permission required to display this portlet content

    72  - **name**: internal name given to this portlet. This name must be unique between all portlets, so using your own

    73    namespace into this name is generally a good option!

    74  - **label**: user label given to this portlet

    75  - **toolbar_image**: URL of an image used to display portlet button into ZMI toolbar, if any

    76  - **toolbar_css_class**: CSS class used to display portlet button into ZMI toolbar, if any

    77  - **settings_class**: class used to store portlet settings.

    78 

    79 

    80 3. Create portlet settings edit form

    81 ''''''''''''''''''''''''''''''''''''

    82 

    83 Portlet settings have to be updated through management interface via a :py:class:`pyams_portal.zmi.portlet.PortletSettingsEditor`

    84 subform:

    85 

    86 .. code-block:: python

    87 

    88     @pagelet_config(name='properties.html', context=INewPortletSettings, layer=IPyAMSLayer,

    89                     permission=VIEW_SYSTEM_PERMISSION)

    90     class NewPortletSettingsEditor(PortletSettingsEditor):

    91         """New portlet settings editor"""

    92 

    93         settings = INewPortletSettings

    94 

    95 

    96     @adapter_config(name='properties.json', context=(INewPortletSettings, IPyAMSLayer), provides=IPagelet)

    97     class NewPortletSettingsAJAXEditor(AJAXEditForm, NewPortletSettingsEditor):

    98         """New portlet settings editor, JSON renderer"""

    99 

   100 

   101 4. Previewing portlet content

   102 '''''''''''''''''''''''''''''

   103 

   104 A *previewer* is used into ZMI to display portlet content into portal template definition page:

   105 

   106 .. code-block:: python

   107 

   108     @adapter_config(context=(Interface, IPyAMSLayer, Interface, INewPortletSettings), provides=IPortletPreviewer)

   109     @template_config(template='my-portlet-preview.pt', layer=IPyAMSLayer)

   110     class NewPortletPreviewer(PortletPreviewer):

   111         """New portlet previewer"""

   112 

   113 

   114 The previewer template is a Chameleon template:

   115 

   116 .. code-block:: genshi

   117 

   118     <tal:var define="settings view.settings">

   119         <tal:if condition="settings.visible">

   120             <div tal:content="settings.comment">Comment</div>

   121         </tal:if>

   122         <tal:if condition="not settings.visible">

   123             <div class="text-center padding-y-5">

   124                 <span class="fa-stack fa-lg">

   125                     <i class="fa fa-eye fa-stack-1x"></i>

   126                     <i class="fa fa-ban fa-stack-2x text-danger"></i>

   127                 </span>

   128             </div>

   129         </tal:if>

   130     </tal:var>

   131 

   132 Here we check if portlet is visible or not to display a small icon when hidden; otherwise we display entered comment.

   133 

   134 

   135 5. Rendering portlet content

   136 ''''''''''''''''''''''''''''

   137 

   138 A *renderer* is used to display portlet content into rendered page content:

   139 

   140 .. code-block:: python

   141 

   142     @adapter_config(context=(IPortalContext, IPyAMSLayer, Interface, INewPortletSettings), provides=IPortletRenderer)

   143     @template_config(template='my-portlet-render.pt', layer=IPyAMSLayer)

   144     class NewPortletRenderer(PortletRenderer):

   145         """New portlet renderer"""

   146 

   147         label = _("Default comment renderer")

   148 

   149 

   150 Each renderer template is also a Chameleon template:

   151 

   152 .. code-block:: genshi

   153 

   154     <div class="comment" tal:content="view.settings.comment">Comment</div>

   155 

   156 

   157 This is the configuration of a *default* renderer defined for this portlet; you can provide several renderers for a

   158 given portlet by given distinct names to the adapters:

   159 

   160 .. code-block:: python

   161 

   162     @adapter_config(name='another-renderer',

   163                     context=(IPortalContext, IPyAMSLayer, Interface, INewPortletSettings), provides=IPortletRenderer)

   164     @template_config(template='my-portlet-render-2.pt', layer=IPyAMSLayer)

   165     class AnotherNewPortletRenderer(PortletRenderer):

   166         """Another new portlet renderer"""

   167 

   168         label = _("Another comment renderer")