djangocms-cascade 0.11.0

Collection of extendible plugins for DjangoCMS >3.3 for adding various widgets to any CMS placeholder

djangocms-cascade

DjangoCMS-Cascade is the Swiss army knife for working with Django-CMS plugins.

Why Use DjangoCMS-Cascade?

DjangoCMS-Cascade is a collection of plugins for Django-CMS placeholders. Instead of creating one database model for each CMS plugin, Cascade shares one database model for all of them. This is possible by storing the payload inside a JSON field instead of declaring each attribute explicitly, and it prevents us to handle all kind of nasty database migration problems.

Since Cascade keeps track on the widths of all columns, <img> and <picture> elements can be rendered in a responsive way, so that the browser only loads the image required for the visible viewport.

Using a JSON field to store the payload gives us much more flexibility. We can for instance enrich our plugins with additional attributes, configured during runtime. This can be used to optionally share attributes across different plugins (referenced by an alias name), add CSS classes and styles, or offer alternative rendering templates.

Another nice aspect of this approach is, that we can override the functionality used to set links onto pages which are not part of the CMS. This is specially useful, since we do not want to re-implement this functionality for all plugins, which require links, ie. images, pictures, buttons and text-links.

Since the payload of plugins is already serialized, we can even copy them from one site to another site supporting djangocms-cascade.

Documentation

Find detailed documentation on ReadTheDocs.

Please see the Release Notes before upgrading from an older version.

News for version 0.11

Instead of adding a list of PartialFormFields named glossary_fields, we now can add these fields to the plugin class, as we would in a Django forms.Form or models.Model, for instance

class MyPlugin(CascadePluginBase):
    name = "My Plugin"
    ... other attributes ...
    some_attr = GlossaryField(a_widget, label="A Label", initial=some_value)

instead of

class MyPlugin(CascadePluginBase):
    name = "My Plugin"
    ... other attributes ...
    glossary_fields = (
        PartialFormField('some_attr', a_widget, label="A Label", initial=some_value),
        ...
    )

Don’t forget run ./manage.py migrate cmsplugin_cascade after upgrading to version 0.11.x.

Caveats

Currently DjangoCMS-Cascade does not work with djangocms-text-ckeditor >= 3.1. Please stay with version 3.0.1 until this issue hase been fixed.

Architecture

It’s pluggable

DjangoCMS-Cascade is very modular, keeping its CMS modules in functional groups. These groups have to be activated independently in your settings.py. It also is possible to activate only certain plugins out of a group. One such group is cmsplugin_cascade.bootstrap3, but it could be replaced by a future Bootstrap-4, the Foundation, Angular Material or whatever other CSS framework you prefer.

Configurable individually

Each Cascade plugin can be styled individually. The site-administrator can specify which CSS styles and CSS classes can be added to each plugin. Then the page-editor can pick one of the allowed styles to adopt his elements accordingly.

Reuse your data

Each Cascade plugin can be configured by the site-administrator to share some or all of its data fields. This for instance is handy, to keep references onto external URLs in a central place. Or is can be used to resize all images sharing a cetrain property in one go.

Segment the DOM

It is even possible to group plugins into seperate evaluation contexts. This for instance is used to render different Plugins, depending on whether a user is authenticated or anonymous.

Responsive Images

In modern web development, images must adopt to the column width in which they are rendered. Therefore the <img ...> tag, in addition to the well known src attribute, also accepts additional srcset’s, one for each media query. Here djangocms-cascade calculates the required widths for each image, depending on the current column layout considering all media breakpoints.

This is also implemented for the <picture> element with all of it’s children, normally <source srcset="...">.

It also supports resolutions of more than one physical pixel per logical pixel as found in Retina displays.

Other Features

• Use the scaffolding technique from the preferred CSS framework to subdivide a placeholder into a grid system.

• Make full usage of responsive techniques, by allowing stacked to horizontal classes per element.

• Use styled buttons to add links.

• Wrap special content into a Jumbotron or a Carousel.

• Add <img> and <picture> elements in a responsive way, so that more than one image URL point onto the resized sources, one for each viewport using the srcset tags or the <source> elements.

• Use segmentation to conditionally render parts of the DOM.

• It is very easy to integrate additional elements from the preferred CSS framework. For instance, implementing the Bootstrap Carousel, required only 50 lines of Python code and two simple Django templates.

• Since all the data is stored in JSON, no database migration is required if a field is added, modified or removed from the plugin.

• Currently Bootstrap-3.x is supported, but other CSS frameworks can be easily added in a pluggable manner.

• It follows the “batteries included” philosophy, but still remains very modular.

In addition to easily implement any kind of plugin, DjangoCMS-Cascade makes it possible to add reusable helpers. Such a helper enriches a plugin with an additional, configurable functionality:

• By making some of the plugin fields sharable, one can reuse these values for other plugins of the same kind. This for instance is handy for the image and picture plugin, so that images always are resized to predefined values.

• By allowing extra fields, one can add an optional id tag, CSS classes and inline styles. This is configurable on a plugin and site base.

• It is possible to customize the rendering templates shipped with the plugins.

• Since all data is JSON, you can dump the content of one placeholder and insert it into another one, even on a foreign site. This for instance is useful to transfer pages from the staging site to production.

Help needed

If someone wants to start a subproject for a CSS framework, other than Bootstrap-3.

If you are a native English speaker, please check the documentation for spelling mistakes and grammar, since English not my mother tongue.