Learn Wagtail CMS Course

StreamField Deep Dive: How to find undocumented options

Writing a StreamField without a custom class

For simple StreamFields you do not need to create custom classes. If you want to, that's 100% OK to do. Below you will see an example of a CharBlock that uses most of the available CharBlock kwargs.

from wagtail.core.fields import StreamField
from wagtail.core.models import Page
from wagtail.core import blocks as streamfield_blocks

class FlexPage(Page):
    """Flexible page class."""

    content = StreamField(
            ("char_block", streamfield_blocks.CharBlock(
                help_text="Oh wow this is help text!!",

If you're wondering how I know we can use these fields:

  • required
  • help_text
  • min_length
  • max_length
  • template

Well the TL;DR version is: I went to the source code https://github.com/wagtail/wagtail/blob/master/wagtail/core/blocks/field_block.py#L97

If you want to know how I found this, you'll need to watch the video and about half way through I start talking about how to find the source code by working backwards from my current code.

The Git Commit