How to use the wagtail.core.fields.StreamField function in wagtail

field=models.BooleanField(default=False, verbose_name='Uganda'),
        ),
        migrations.AlterField(
            model_name='countryprofilessetting',
            name='ZA',
            field=models.BooleanField(default=True, verbose_name='South Africa'),
        ),
        migrations.AlterField(
            model_name='countryprofilessetting',
            name='ZM',
            field=models.BooleanField(default=False, verbose_name='Zambia'),
        ),
        migrations.AlterField(
            model_name='explainersteps',
            name='steps',
            field=wagtail.core.fields.StreamField([('step', wagtail.core.blocks.StructBlock([('title', wagtail.core.blocks.CharBlock(required=False)), ('brief', wagtail.core.blocks.TextBlock(required=False)), ('color', wagtail.core.blocks.CharBlock(help_text='Background colour.', required=False)), ('body', wagtail.core.blocks.RichTextBlock(required=False)), ('sidebar', wagtail.core.blocks.RichTextBlock(required=False))], icon='user'))]),
        ),
        migrations.AlterField(
            model_name='faq',
            name='cta_one_url',
            field=models.URLField(default='https://takwimu.zendesk.com/', verbose_name="'Find Out More' button URL"),
        ),
        migrations.AlterField(
            model_name='faq',
            name='cta_two_name',
            field=models.TextField(blank=True, verbose_name='Second button Name (optional)'),
        ),
        migrations.AlterField(
            model_name='faq',
            name='cta_two_url',
            field=models.URLField(blank=True, verbose_name='Second button URL (optional)'),
        ),

"videos.Videos",
    ]
    template = "home.html"

    # Content fields
    subtitle = TextField(max_length=250, blank=True, default="")
    button_text = CharField(max_length=30, blank=True, default="")
    button_url = CharField(max_length=2048, blank=True, default="")
    image = ForeignKey(
        "mozimages.MozImage",
        null=True,
        blank=True,
        on_delete=SET_NULL,
        related_name="+",
    )
    featured = StreamField(
        StreamBlock(
            [
                (
                    "post",
                    PageChooserBlock(
                        target_model=(
                            "articles.Article",
                            "externalcontent.ExternalArticle",
                        )
                    ),
                ),
                (
                    "content_page",
                    PageChooserBlock(target_model=("content.ContentPage",)),
                ),
                ("external_page", FeaturedExternalBlock()),

import wagtail.core.blocks
import wagtail.core.fields


class Migration(migrations.Migration):

    dependencies = [("externalcontent", "0016_auto_20190731_1226")]

    operations = [
        migrations.RenameField(
            model_name="externalvideo", old_name="video_duration", new_name="duration"
        ),
        migrations.AddField(
            model_name="externalvideo",
            name="speakers",
            field=wagtail.core.fields.StreamField(
                [
                    (
                        "speaker",
                        wagtail.core.blocks.PageChooserBlock(
                            page_type=["people.Person"], required=False
                        ),
                    )
                ],
                blank=True,
                null=True,
            ),

from django.db import migrations
import wagtail.core.blocks
import wagtail.core.fields


class Migration(migrations.Migration):

    dependencies = [
        ('diamm_site', '0009_auto_20161218_2149'),
    ]

    operations = [
        migrations.AlterField(
            model_name='publicationpage',
            name='pricing',
            field=wagtail.core.fields.StreamField((('price', wagtail.core.blocks.StructBlock((('description', wagtail.core.blocks.CharBlock()), ('price', wagtail.core.blocks.DecimalBlock())), template='website/blocks/pricing_field.jinja2')),)),
        ),

@hooks.register("register_page_listing_buttons")
def page_listing_buttons(page, page_perms, is_parent=False):
    if isinstance(page, ElectionIndexPage):
        yield wagtailadmin_widgets.PageListingButton(
            "Import Election", "/goes/to/a/url/", priority=10
        )


class ElectionIndexPage(RoutablePageMixin, Page):
    subpage_types = ["CandidatePage"]
    electionName = models.CharField(max_length=255)
    electionID = models.IntegerField()

    panels = StreamField([("three_cards", ThreeCardBlock())], null=True)

    @route(r"^$")  # will override the default Page serving mechanism
    def post_404(self, request):
        raise Http404

    @route(r"^([^\/]*)\/$")
    def election_page(self, request, name, *args, **kwargs):
        print(name)
        context = self.get_context(request)
        try:
            page = ElectionIndexPage.objects.live().get(electionName=name)
        except ElectionIndexPage.DoesNotExist:
            raise Http404
        return page.serve(request, *args, **kwargs)

    @route(r"^(.*)\/(.*)\/$")

import wagtail.embeds.blocks
import wagtail.core.blocks
import wagtail.snippets.blocks


class Migration(migrations.Migration):

    dependencies = [
        ('home', '0010_auto_20160704_1313'),
    ]

    operations = [
        migrations.AlterField(
            model_name='homepage',
            name='body_da',
            field=wagtail.core.fields.StreamField((('image', wagtail.images.blocks.ImageChooserBlock(icon='image')), ('info_block', wagtail.core.blocks.StructBlock((('title', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text', wagtail.core.blocks.RichTextBlock(required=False)), ('button', wagtail.core.blocks.StructBlock((('internal_link', wagtail.core.blocks.PageChooserBlock(required=False)), ('external_link', wagtail.core.blocks.URLBlock(required=False)), ('link_text', wagtail.core.blocks.TextBlock(required=False))), required=False)), ('highlight', wagtail.core.blocks.ChoiceBlock(help_text='How should this block be displayed?', required=False, choices=[('', 'None'), ('highlight', 'Highlight (blue)'), ('boxed', 'Boxed'), ('boxed2', 'Boxed Variation'), ('highlight-purple', 'Highlight (purple)')], icon='cup')), ('alignment', wagtail.core.blocks.ChoiceBlock(help_text='How should the text and image be aligned?', default='vertical', choices=[('vertical', 'vertical'), ('horizontal', 'horizontal')], icon='cup'))))), ('video_block', wagtail.core.blocks.StructBlock((('title', wagtail.core.blocks.CharBlock(classname='full title')), ('video', wagtail.embeds.blocks.EmbedBlock())))), ('news_block', wagtail.core.blocks.StructBlock((('title', wagtail.core.blocks.CharBlock(classname='full title')), ('news', wagtail.core.blocks.CharBlock(classname='full title'))))), ('rss_feed', wagtail.core.blocks.StructBlock((('feed', wagtail.snippets.blocks.SnippetChooserBlock(target_model=home.models.snippets.RSSImport, required=True)),))), ('column_block', wagtail.core.blocks.StructBlock((('title_col1', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image_col1', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text_col1', wagtail.core.blocks.RichTextBlock(required=False)), ('title_col2', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image_col2', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text_col2', wagtail.core.blocks.RichTextBlock(required=False)), ('title_col3', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image_col3', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text_col3', wagtail.core.blocks.RichTextBlock(required=False)))))), null=True, blank=True),
        ),
        migrations.AlterField(
            model_name='homepage',
            name='body_de',
            field=wagtail.core.fields.StreamField((('image', wagtail.images.blocks.ImageChooserBlock(icon='image')), ('info_block', wagtail.core.blocks.StructBlock((('title', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text', wagtail.core.blocks.RichTextBlock(required=False)), ('button', wagtail.core.blocks.StructBlock((('internal_link', wagtail.core.blocks.PageChooserBlock(required=False)), ('external_link', wagtail.core.blocks.URLBlock(required=False)), ('link_text', wagtail.core.blocks.TextBlock(required=False))), required=False)), ('highlight', wagtail.core.blocks.ChoiceBlock(help_text='How should this block be displayed?', required=False, choices=[('', 'None'), ('highlight', 'Highlight (blue)'), ('boxed', 'Boxed'), ('boxed2', 'Boxed Variation'), ('highlight-purple', 'Highlight (purple)')], icon='cup')), ('alignment', wagtail.core.blocks.ChoiceBlock(help_text='How should the text and image be aligned?', default='vertical', choices=[('vertical', 'vertical'), ('horizontal', 'horizontal')], icon='cup'))))), ('video_block', wagtail.core.blocks.StructBlock((('title', wagtail.core.blocks.CharBlock(classname='full title')), ('video', wagtail.embeds.blocks.EmbedBlock())))), ('news_block', wagtail.core.blocks.StructBlock((('title', wagtail.core.blocks.CharBlock(classname='full title')), ('news', wagtail.core.blocks.CharBlock(classname='full title'))))), ('rss_feed', wagtail.core.blocks.StructBlock((('feed', wagtail.snippets.blocks.SnippetChooserBlock(target_model=home.models.snippets.RSSImport, required=True)),))), ('column_block', wagtail.core.blocks.StructBlock((('title_col1', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image_col1', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text_col1', wagtail.core.blocks.RichTextBlock(required=False)), ('title_col2', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image_col2', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text_col2', wagtail.core.blocks.RichTextBlock(required=False)), ('title_col3', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image_col3', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text_col3', wagtail.core.blocks.RichTextBlock(required=False)))))), null=True, blank=True),
        ),
        migrations.AlterField(
            model_name='homepage',
            name='body_en',
            field=wagtail.core.fields.StreamField((('image', wagtail.images.blocks.ImageChooserBlock(icon='image')), ('info_block', wagtail.core.blocks.StructBlock((('title', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text', wagtail.core.blocks.RichTextBlock(required=False)), ('button', wagtail.core.blocks.StructBlock((('internal_link', wagtail.core.blocks.PageChooserBlock(required=False)), ('external_link', wagtail.core.blocks.URLBlock(required=False)), ('link_text', wagtail.core.blocks.TextBlock(required=False))), required=False)), ('highlight', wagtail.core.blocks.ChoiceBlock(help_text='How should this block be displayed?', required=False, choices=[('', 'None'), ('highlight', 'Highlight (blue)'), ('boxed', 'Boxed'), ('boxed2', 'Boxed Variation'), ('highlight-purple', 'Highlight (purple)')], icon='cup')), ('alignment', wagtail.core.blocks.ChoiceBlock(help_text='How should the text and image be aligned?', default='vertical', choices=[('vertical', 'vertical'), ('horizontal', 'horizontal')], icon='cup'))))), ('video_block', wagtail.core.blocks.StructBlock((('title', wagtail.core.blocks.CharBlock(classname='full title')), ('video', wagtail.embeds.blocks.EmbedBlock())))), ('news_block', wagtail.core.blocks.StructBlock((('title', wagtail.core.blocks.CharBlock(classname='full title')), ('news', wagtail.core.blocks.CharBlock(classname='full title'))))), ('rss_feed', wagtail.core.blocks.StructBlock((('feed', wagtail.snippets.blocks.SnippetChooserBlock(target_model=home.models.snippets.RSSImport, required=True)),))), ('column_block', wagtail.core.blocks.StructBlock((('title_col1', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image_col1', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text_col1', wagtail.core.blocks.RichTextBlock(required=False)), ('title_col2', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image_col2', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text_col2', wagtail.core.blocks.RichTextBlock(required=False)), ('title_col3', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image_col3', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text_col3', wagtail.core.blocks.RichTextBlock(required=False)))))), null=True),
        ),
        migrations.AlterField(
            model_name='homepage',
            name='body_fr',
            field=wagtail.core.fields.StreamField((('image', wagtail.images.blocks.ImageChooserBlock(icon='image')), ('info_block', wagtail.core.blocks.StructBlock((('title', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text', wagtail.core.blocks.RichTextBlock(required=False)), ('button', wagtail.core.blocks.StructBlock((('internal_link', wagtail.core.blocks.PageChooserBlock(required=False)), ('external_link', wagtail.core.blocks.URLBlock(required=False)), ('link_text', wagtail.core.blocks.TextBlock(required=False))), required=False)), ('highlight', wagtail.core.blocks.ChoiceBlock(help_text='How should this block be displayed?', required=False, choices=[('', 'None'), ('highlight', 'Highlight (blue)'), ('boxed', 'Boxed'), ('boxed2', 'Boxed Variation'), ('highlight-purple', 'Highlight (purple)')], icon='cup')), ('alignment', wagtail.core.blocks.ChoiceBlock(help_text='How should the text and image be aligned?', default='vertical', choices=[('vertical', 'vertical'), ('horizontal', 'horizontal')], icon='cup'))))), ('video_block', wagtail.core.blocks.StructBlock((('title', wagtail.core.blocks.CharBlock(classname='full title')), ('video', wagtail.embeds.blocks.EmbedBlock())))), ('news_block', wagtail.core.blocks.StructBlock((('title', wagtail.core.blocks.CharBlock(classname='full title')), ('news', wagtail.core.blocks.CharBlock(classname='full title'))))), ('rss_feed', wagtail.core.blocks.StructBlock((('feed', wagtail.snippets.blocks.SnippetChooserBlock(target_model=home.models.snippets.RSSImport, required=True)),))), ('column_block', wagtail.core.blocks.StructBlock((('title_col1', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image_col1', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text_col1', wagtail.core.blocks.RichTextBlock(required=False)), ('title_col2', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image_col2', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text_col2', wagtail.core.blocks.RichTextBlock(required=False)), ('title_col3', wagtail.core.blocks.CharBlock(required=False, classname='full title')), ('image_col3', wagtail.images.blocks.ImageChooserBlock(required=False)), ('text_col3', wagtail.core.blocks.RichTextBlock(required=False)))))), null=True, blank=True),
        ),

def _add_streamfields(cls: wagtailPage, node: str, dict_params: dict, app: str, prefix: str) -> None:
    from .types.streamfield import (
        block_handler,
        stream_field_handler,
    )

    for field in cls._meta.fields:
        if isinstance(field, StreamField):
            field_name = field.name
            stream_field_name = f"{node}{string.capwords(field_name, sep='_').replace('_', '')}"
            blocks = field.stream_block.child_blocks

            handlers = dict(
                (name, block_handler(block, app, prefix))
                for name, block in blocks.items()
            )

            f, resolve = stream_field_handler(
                stream_field_name,
                field_name,
                handlers
            )

            dict_params.update({

duration = CharField(
        max_length=30,
        blank=True,
        null=True,
        help_text=(
            "Optional video duration in MM:SS format e.g. “12:34”. Shown when the "
            "video is displayed as a card"
        ),
    )
    transcript = RichTextField(
        blank=True,
        default="",
        features=RICH_TEXT_FEATURES,
        help_text="Optional text transcript of the video, supports rich text",
    )
    video_url = StreamField(
        StreamBlock([("embed", EmbedBlock())], min_num=1, max_num=1, required=True),
        help_text=(
            "Embed URL for the video e.g. https://www.youtube.com/watch?v=kmk43_2dtn0"
        ),
    )
    speakers = StreamField(
        StreamBlock(
            [("speaker", PageChooserBlock(target_model="people.Person"))],
            required=False,
        ),
        blank=True,
        null=True,
        help_text="Optional list of people associated with or starring in the video",
    )

    # Card fields

serializes these as a list of strings taken from the name attribute of each
    tag.

    Example:

    "tags": ["bird", "wagtail"]
    """
    def to_representation(self, value):
        return list(value.all().order_by('name').values_list('name', flat=True))


class BaseSerializer(serializers.ModelSerializer):
    # Add StreamField to serializer_field_mapping
    serializer_field_mapping = serializers.ModelSerializer.serializer_field_mapping.copy()
    serializer_field_mapping.update({
        wagtailcore_fields.StreamField: StreamField,
    })
    serializer_related_field = RelatedField

    # Meta fields
    type = TypeField(read_only=True)
    detail_url = DetailUrlField(read_only=True)

    def to_representation(self, instance):
        data = OrderedDict()
        fields = [field for field in self.fields.values() if not field.write_only]

        # Split meta fields from core fields
        meta_fields = [field for field in fields if field.field_name in self.meta_fields]
        fields = [field for field in fields if field.field_name not in self.meta_fields]

        # Make sure id is always first. This will be filled in later