As standard, Wagtail organises panels for pages into three tabs: 'Content', 'Promote' and 'Settings'. For snippets Wagtail puts all panels into one page. Depending on the requirements of your site, you may wish to customise this for specific page types or snippets - for example, adding an additional tab for sidebar content. This can be done by specifying an ``edit_handler`` attribute on the page or snippet model. For example:
Wagtail provides a general-purpose WYSIWYG editor for creating rich text content (HTML) and embedding media such as images, video, and documents. To include this in your models, use the :class:`~wagtail.core.fields.RichTextField` function when defining a model field:
:class:`~wagtail.core.fields.RichTextField` inherits from Django's basic ``TextField`` field, so you can pass any field parameters into :class:`~wagtail.core.fields.RichTextField` as if using a normal Django field. This field does not need a special panel and can be defined with ``FieldPanel``.
However, template output from :class:`~wagtail.core.fields.RichTextField` is special and needs to be filtered in order to preserve embedded content. See :ref:`rich-text-filter`.
By default, the rich text editor provides users with a wide variety of options for text formatting and inserting embedded content such as images. However, we may wish to restrict a rich text field to a more limited set of features - for example:
* The field might be intended for a short text snippet, such as a summary to be pulled out on index pages, where embedded images or videos would be inappropriate;
* When page content is defined using :ref:`StreamField <streamfield>`, elements such as headings, images and videos are usually given their own block types, alongside a rich text block type used for ordinary paragraph text; in this case, allowing headings and images to also exist within the rich text content is redundant (and liable to result in inconsistent designs).
We have few additional feature identifiers as well. They are not enabled by default, but you can use them in your list of identifiers. These are as follows:
On loading, Wagtail will search for any app with the file ``image_formats.py`` and execute the contents. This provides a way to customise the formatting options shown to the editor when inserting images in the :class:`~wagtail.core.fields.RichTextField` editor.
To begin, import the ``Format`` class, ``register_image_format`` function, and optionally ``unregister_image_format`` function. To register a new ``Format``, call the ``register_image_format`` with the ``Format`` object as the argument. The ``Format`` class takes the following constructor arguments:
Any class names you provide must have CSS rules matching them written separately, as part of the front end CSS code. Specifying a ``classnames`` value of ``left`` will only ensure that class is output in the generated markup, it won't cause the image to align itself left.