StreamField block reference¶

Block options and methods¶

All block definitions accept the following optional keyword arguments or Meta class attributes:

• default

  • The default value (or a callable that returns the value) that a new ‘empty’ block should receive.

• label

  • The label to display in the editor interface when referring to this block - defaults to a prettified version of the block name (or, in a context where no name is assigned - such as within a ListBlock - the empty string).

• icon

  • The name of the icon to display for this block type in the editor. For more details, see our icons overview.

• template

  • The path to a Django template that will be used to render this block on the front end. See Template rendering

• group

  • The group used to categorize this block. Any blocks with the same group name will be shown together in the editor interface with the group name as a heading.

StreamField blocks can have previews that will be shown inside the block picker. To accommodate the feature, all block definitions also accept the following options:

• preview_value

  • The placeholder value (or a callable that returns the value) that will be used for rendering the preview. See get_preview_value() for more details.

• preview_template

  • The template that is used to render the preview. See get_preview_template() for more details.

• description

  • The description of the block to be shown to editors. See get_description() for more details.

All block definitions have the following methods and properties that can be overridden:

class wagtail.blocks.Block(*args, **kwargs)¶

get_context(value, parent_context=None)¶

Return a dict of context variables (derived from the block value and combined with the parent_context) to be used as the template context when rendering this value through a template. See the usage example for more details.

get_template(value=None, context=None)¶

Return the template to use for rendering the block if specified. This method allows for dynamic templates based on the block instance and a given value. See the usage example for more details.

get_preview_value()¶

Return the placeholder value that will be used for rendering the block’s preview. By default, the value is the preview_value from the block’s options if provided. If it’s a callable, it will be evaluated at runtime. If preview_value is not provided, the default is used as fallback. This method can also be overridden to provide a dynamic preview value.

get_preview_context(value, parent_context=None)¶

Return a dict of context variables to be used as the template context when rendering the block’s preview. The value argument is the value returned by get_preview_value(). The parent_context argument contains the following variables:

• request: The current request object.

• block_def: The block instance.

• block_class: The block class.

• bound_block: A BoundBlock instance representing the block and its value.

If the global preview template is used, the block will be rendered as the main content using {% include_block %}, which in turn uses get_context(). As a result, the context returned by this method will be available as the parent_context for get_context() when the preview is rendered.

get_preview_template(value, context=None)¶

Return the template to use for rendering the block’s preview. The value argument is the value returned by get_preview_value(). The context argument contains the variables listed for the parent_context argument of get_preview_context() above (and not the context returned by that method itself).

Note that the preview template is used to render a complete HTML page of the preview, not just an HTML fragment for the block. The method returns the preview_template attribute from the block’s options if provided, and falls back to the global preview template otherwise.

If the global preview template is used, the block will be rendered as the main content using {% include_block %}, which in turn uses get_template().

get_description()¶

Return the description of the block to be shown to editors as part of the preview. For field block types, it will fall back to help_text if not provided.

is_previewable¶

Determine whether the block is previewable in the block picker. By default, it automatically detects when a custom template is used or the the global preview template is overridden and a preview value is provided. If the block is previewable by other means, override this property to return True. To turn off previews for the block, set it to False.

Field block types¶

class wagtail.blocks.FieldBlock(*args, **kwargs)¶

Bases: Block

A block that wraps a Django form field

The parent class of all StreamField field block types.

class wagtail.blocks.CharBlock(*args, **kwargs)¶

Bases: FieldBlock

A single-line text input. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• required – If true (the default), the field cannot be left blank.

• max_length – The maximum allowed length of the field.

• min_length – The minimum allowed length of the field.

• help_text – Help text to display alongside the field.

• search_index – If false (default true), the content of this block will not be indexed for searching.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.TextBlock(*args, **kwargs)¶

Bases: FieldBlock

A multi-line text input. As with CharBlock, the following keyword arguments are accepted in addition to the standard ones:

Parameters:

• required – If true (the default), the field cannot be left blank.

• max_length – The maximum allowed length of the field.

• min_length – The minimum allowed length of the field.

• help_text – Help text to display alongside the field.

• search_index – If false (default true), the content of this block will not be indexed for searching.

• rows – Number of rows to show on the textarea (defaults to 1).

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.EmailBlock(*args, **kwargs)¶

Bases: FieldBlock

A single-line email input that validates that the value is a valid e-mail address. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• required – If true (the default), the field cannot be left blank.

• help_text – Help text to display alongside the field.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.IntegerBlock(*args, **kwargs)¶

Bases: FieldBlock

A single-line integer input that validates that the value is a valid whole number. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• required – If true (the default), the field cannot be left blank.

• max_value – The maximum allowed numeric value of the field.

• min_value – The minimum allowed numeric value of the field.

• help_text – Help text to display alongside the field.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.FloatBlock(*args, **kwargs)¶

Bases: FieldBlock

A single-line Float input that validates that the value is a valid floating point number. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• required – If true (the default), the field cannot be left blank.

• max_value – The maximum allowed numeric value of the field.

• min_value – The minimum allowed numeric value of the field.

• help_text – Help text to display alongside the field.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.DecimalBlock(*args, **kwargs)¶

Bases: FieldBlock

A single-line decimal input that validates that the value is a valid decimal number. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• required – If true (the default), the field cannot be left blank.

• help_text – Help text to display alongside the field.

• max_value – The maximum allowed numeric value of the field.

• min_value – The minimum allowed numeric value of the field.

• max_digits – The maximum number of digits allowed in the number. This number must be greater than or equal to decimal_places.

• decimal_places – The number of decimal places to store with the number.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.RegexBlock(*args, **kwargs)¶

Bases: FieldBlock

A single-line text input that validates a string against a regular expression. The regular expression used for validation must be supplied as the first argument, or as the keyword argument regex.

blocks.RegexBlock(regex=r'^[0-9]{3}$', error_messages={
    'invalid': "Not a valid library card number."
})

The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• regex – Regular expression to validate against.

• error_messages – Dictionary of error messages, containing either or both of the keys required (for the message shown on an empty value) or invalid (for the message shown on a non-matching value).

• required – If true (the default), the field cannot be left blank.

• help_text – Help text to display alongside the field.

• max_length – The maximum allowed length of the field.

• min_length – The minimum allowed length of the field.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.URLBlock(*args, **kwargs)¶

Bases: FieldBlock

A single-line text input that validates that the string is a valid URL. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• required – If true (the default), the field cannot be left blank.

• max_length – The maximum allowed length of the field.

• min_length – The minimum allowed length of the field.

• help_text – Help text to display alongside the field.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.BooleanBlock(*args, **kwargs)¶

Bases: FieldBlock

A checkbox. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• required – If true (the default), the checkbox must be ticked to proceed. As with Django’s BooleanField, a checkbox that can be left ticked or unticked must be explicitly denoted with required=False.

• help_text – Help text to display alongside the field.

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.DateBlock(*args, **kwargs)¶

Bases: FieldBlock

A date picker. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• format – Date format. This must be one of the recognized formats listed in the DATE_INPUT_FORMATS setting. If not specified Wagtail will use the WAGTAIL_DATE_FORMAT setting with fallback to "%Y-%m-%d".

• required – If true (the default), the field cannot be left blank.

• help_text – Help text to display alongside the field.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.TimeBlock(*args, **kwargs)¶

Bases: FieldBlock

A time picker. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• format – Time format. This must be one of the recognized formats listed in the TIME_INPUT_FORMATS setting. If not specified Wagtail will use the WAGTAIL_TIME_FORMAT setting with fallback to "%H:%M".

• required – If true (the default), the field cannot be left blank.

• help_text – Help text to display alongside the field.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.DateTimeBlock(*args, **kwargs)¶

Bases: FieldBlock

A combined date/time picker. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• format – Date/time format. This must be one of the recognized formats listed in the DATETIME_INPUT_FORMATS setting. If not specified Wagtail will use the WAGTAIL_DATETIME_FORMAT setting with fallback to "%Y-%m-%d %H:%M".

• required – If true (the default), the field cannot be left blank.

• help_text – Help text to display alongside the field.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.RichTextBlock(*args, **kwargs)¶

Bases: FieldBlock

A WYSIWYG editor for creating formatted text including links, bold / italics etc. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• editor – The rich text editor to be used (see WAGTAILADMIN_RICH_TEXT_EDITORS).

• features – Specifies the set of features allowed (see Limiting features in a rich text field).

• required – If true (the default), the field cannot be left blank.

• max_length – The maximum allowed length of the field. Only text is counted; rich text formatting, embedded content and paragraph / line breaks do not count towards the limit.

• min_length – The minimum allowed length of the field. Only text is counted; rich text formatting, embedded content and paragraph / line breaks do not count towards the limit.

• search_index – If false (default true), the content of this block will not be indexed for searching.

• help_text – Help text to display alongside the field.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.RawHTMLBlock(*args, **kwargs)¶

Bases: FieldBlock

A text area for entering raw HTML which will be rendered unescaped in the page output. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• required – If true (the default), the field cannot be left blank.

• max_length – The maximum allowed length of the field.

• min_length – The minimum allowed length of the field.

• help_text – Help text to display alongside the field.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

Warning

When this block is in use, there is nothing to prevent editors from inserting malicious scripts into the page, including scripts that would allow the editor to acquire administrator privileges when another administrator views the page. Do not use this block unless your editors are fully trusted.

class wagtail.blocks.BlockQuoteBlock(*args, **kwargs)¶

Bases: TextBlock

A text field, the contents of which will be wrapped in an HTML <blockquote> tag pair in the page output. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• required – If true (the default), the field cannot be left blank.

• max_length – The maximum allowed length of the field.

• min_length – The minimum allowed length of the field.

• help_text – Help text to display alongside the field.

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.ChoiceBlock(*args, **kwargs)¶

Bases: BaseChoiceBlock

A dropdown select box for choosing one item from a list of choices. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• choices – A list of choices, in any format accepted by Django’s choices parameter for model fields, or a callable returning such a list.

• required – If true (the default), the field cannot be left blank.

• help_text – Help text to display alongside the field.

• search_index – If false (default true), the content of this block will not be indexed for searching.

• widget – The form widget to render the field with (see Django Widgets).

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

ChoiceBlock can also be subclassed to produce a reusable block with the same list of choices everywhere it is used. For example, a block definition such as:

blocks.ChoiceBlock(choices=[
    ('tea', 'Tea'),
    ('coffee', 'Coffee'),
], icon='cup')

Could be rewritten as a subclass of ChoiceBlock:

class DrinksChoiceBlock(blocks.ChoiceBlock):
    choices = [
        ('tea', 'Tea'),
        ('coffee', 'Coffee'),
    ]

    class Meta:
        icon = 'cup'

StreamField definitions can then refer to DrinksChoiceBlock() in place of the full ChoiceBlock definition. Note that this only works when choices is a fixed list, not a callable.

class wagtail.blocks.MultipleChoiceBlock(*args, **kwargs)¶

Bases: BaseChoiceBlock

A select box for choosing multiple items from a list of choices. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• choices – A list of choices, in any format accepted by Django’s choices parameter for model fields, or a callable returning such a list.

• required – If true (the default), the field cannot be left blank.

• help_text – Help text to display alongside the field.

• search_index – If false (default true), the content of this block will not be indexed for searching.

• widget – The form widget to render the field with (see Django Widgets).

• validators – A list of validation functions for the field (see Django Validators).

• form_classname – A value to add to the form field’s class attribute when rendered on the page editing form.

• form_attrs – A dictionary of additional attributes to add to the form field’s wrapper element when rendered on the page editing form.

class wagtail.blocks.PageChooserBlock(*args, **kwargs)¶

Bases: ChooserBlock

A control for selecting a page object, using Wagtail’s page browser. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• required – If true (the default), the field cannot be left blank.

• page_type – Restrict choices to one or more specific page types; by default, any page type may be selected. Can be specified as a page model class, model name (as a string), or a list or tuple of these.

• can_choose_root – Defaults to false. If true, the editor can choose the tree root as a page. Normally this would be undesirable since the tree root is never a usable page, but in some specialized cases, it may be appropriate. For example, a block providing a feed of related articles could use a PageChooserBlock to select which subsection of the site articles will be taken from, with the root corresponding to ‘everywhere’.

class wagtail.documents.blocks.DocumentChooserBlock(*args, **kwargs)¶

Bases: BaseDocumentChooserBlock

A control to allow the editor to select an existing document object, or upload a new one. The following additional keyword argument is accepted:

Parameters:

required – If true (the default), the field cannot be left blank.

class wagtail.images.blocks.ImageBlock(*args, **kwargs)¶

Bases: StructBlock

An usage of ImageChooserBlock with support for alt text. For backward compatibility, this block overrides necessary methods to change the StructValue to be an Image model instance, making it compatible in places where ImageChooserBlock was used.

An accessibility-focused control to allow the editor to select an existing image, or upload a new one. This has provision for adding alt text and indicating whether images are purely decorative, and is the Wagtail-recommended approach to uploading images. The following additional keyword argument is accepted:

Parameters:

required – If true (the default), the field cannot be left blank.

ImageBlock incorporates backwards compatibility with ImageChooserBlock. A block initially defined as ImageChooserBlock can be directly replaced with ImageBlock - existing data created with ImageChooserBlock will be handled automatically and changed to ImageBlock’s data format when the field is resaved.

class wagtail.images.blocks.ImageChooserBlock(*args, **kwargs)¶

Bases: ChooserBlock

A control to allow the editor to select an existing image, or upload a new one. The following additional keyword argument is accepted:

Parameters:

required – If true (the default), the field cannot be left blank.

class wagtail.snippets.blocks.SnippetChooserBlock(*args, **kwargs)¶

Bases: ChooserBlock

A control to allow the editor to select a snippet object. Requires one positional argument: the snippet class to choose from. The following additional keyword argument is accepted:

Parameters:

required – If true (the default), the field cannot be left blank.

class wagtail.embeds.blocks.EmbedBlock(*args, **kwargs)¶

Bases: URLBlock

A field for the editor to enter a URL to a media item (such as a YouTube video) to appear as embedded media on the page. The following keyword arguments are accepted in addition to the standard ones:

Parameters:

• required – If true (the default), the field cannot be left blank.

• max_width – The maximum width of the embed, in pixels; this will be passed to the provider when requesting the embed.

• max_height – The maximum height of the embed, in pixels; this will be passed to the provider when requesting the embed.:param max_length: The maximum allowed length of the field.

• min_length – The minimum allowed length of the field.

• help_text – Help text to display alongside the field.

Structural block types¶

class wagtail.blocks.StaticBlock(*args, **kwargs)¶

Bases: Block

A block that just ‘exists’ and has no fields.

A block which doesn’t have any fields, thus passes no particular values to its template during rendering. This can be useful if you need the editor to be able to insert some content that is always the same or doesn’t need to be configured within the page editor, such as an address, embed code from third-party services, or more complex pieces of code if the template uses template tags. The following additional keyword argument is accepted:

Parameters:

admin_text – A text string to display in the admin when this block is used. By default, some default text (which contains the label keyword argument if you pass it) will be displayed in the editor interface, so that the block doesn’t look empty, but this can be customized by passing admin_text:

blocks.StaticBlock(
    admin_text='Latest posts: no configuration needed.',
    # or admin_text=mark_safe('<b>Latest posts</b>: no configuration needed.'),
    template='latest_posts.html')

StaticBlock can also be subclassed to produce a reusable block with the same configuration everywhere it is used:

class LatestPostsStaticBlock(blocks.StaticBlock):
    class Meta:
        icon = 'user'
        label = 'Latest posts'
        admin_text = '{label}: configured elsewhere'.format(label=label)
        template = 'latest_posts.html'
        form_attrs = {
            'data-controller': 'magic',
            'data-action': 'click->magic#abracadabra',
        }

class wagtail.blocks.StructBlock(*args, **kwargs)¶

Bases: BaseStructBlock

A block consisting of a fixed group of sub-blocks to be displayed together. Takes a list of (name, block_definition) tuples as its first argument:

body = StreamField([
    # ...
    ('person', blocks.StructBlock([
        ('first_name', blocks.CharBlock()),
        ('surname', blocks.CharBlock()),
        ('photo', ImageBlock(required=False)),
        ('biography', blocks.RichTextBlock()),
    ], icon='user')),
])

Alternatively, StructBlock can be subclassed to specify a reusable set of sub-blocks:

class PersonBlock(blocks.StructBlock):
    first_name = blocks.CharBlock()
    surname = blocks.CharBlock()
    photo = ImageBlock(required=False)
    biography = blocks.RichTextBlock()

    class Meta:
        icon = 'user'

The Meta class supports the properties default, label, icon and template, which have the same meanings as when they are passed to the block’s constructor.

This defines PersonBlock() as a block type for use in StreamField definitions:

body = StreamField([
    ('heading', blocks.CharBlock(form_classname="title")),
    ('paragraph', blocks.RichTextBlock()),
    ('image', ImageBlock()),
    ('person', PersonBlock()),
])

The following additional options are available as either keyword arguments or Meta class attributes:

Parameters:

• form_classname – An HTML class attribute to set on the root element of this block as displayed in the editing interface, defaults to struct-block. When overriding, you may need to include the default struct-block class if you have custom code or use a third-party package that relies on it. See Adding custom classes and attributes.

• form_attrs – A dictionary of additional attributes to set on the root element of this block as displayed in the editing interface. See Adding custom classes and attributes.

• form_template – Path to a Django template to use to render this block’s form. See Customizing the template of StructBlock forms.

• collapsed – When true and the block is within another StructBlock, the block is initially collapsed. This can be useful for blocks with many sub-blocks, or blocks that are not expected to be edited frequently. See Customizing the initial collapsible state.

• value_class – A subclass of wagtail.blocks.StructValue to use as the type of returned values for this block. See Additional methods and properties on StructBlock values.

• search_index – If false (default true), the content of this block will not be indexed for searching.

• label_format – Determines the summary label shown after the label when the block is collapsed in the editing interface. By default, the value of the first sub-block in the StructBlock is shown, but this can be customized by setting a string here with block names contained in braces - for example label_format = "{surname}, {first_name}". If you wish to hide the summary label entirely, set this to the empty string "".

• form_layout – A list of block names or BlockGroup instances to determine the order in which sub-blocks are displayed in the editing interface. Alternatively, a BlockGroup instance can be provided instead of a list, to define a group of children and settings blocks. See Changing the order and grouping of child blocks and BlockGroup for more details.

get_form_layout() → BlockGroup¶

Return the BlockGroup representing the form layout for this StructBlock.

Added in version 7.3: The form_layout option and the get_form_layout method were added.

class wagtail.blocks.ListBlock(*args, **kwargs)¶

Bases: Block

A block consisting of many sub-blocks, all of the same type. The editor can add an unlimited number of sub-blocks, and re-order and delete them. Takes the definition of the sub-block as its first argument:

body = StreamField([
    # ...
    ('ingredients_list', blocks.ListBlock(blocks.CharBlock(label="Ingredient"))),
])

Any block type is valid as the sub-block type, including structural types:

body = StreamField([
    # ...
    ('ingredients_list', blocks.ListBlock(blocks.StructBlock([
        ('ingredient', blocks.CharBlock()),
        ('amount', blocks.CharBlock(required=False)),
    ]))),
])

The following additional options are available as either keyword arguments or Meta class attributes:

Parameters:

• form_classname – An HTML class attribute to set on the root element of this block as displayed in the editing interface.

• form_attrs – A dictionary of additional attributes to set on the root element of this block as displayed in the editing interface.

• min_num – Minimum number of sub-blocks that the list must have.

• max_num – Maximum number of sub-blocks that the list may have.

• search_index – If false (default true), the content of this block will not be indexed for searching.

• collapsed – When true, all sub-blocks are initially collapsed.

class wagtail.blocks.StreamBlock(*args, **kwargs)¶

Bases: BaseStreamBlock

A block consisting of a sequence of sub-blocks of different types, which can be mixed and reordered at will. Used as the overall mechanism of the StreamField itself, but can also be nested or used within other structural block types. Takes a list of (name, block_definition) tuples as its first argument:

body = StreamField([
    # ...
    ('carousel', blocks.StreamBlock(
        [
            ('image', ImageBlock()),
            ('quotation', blocks.StructBlock([
                ('text', blocks.TextBlock()),
                ('author', blocks.CharBlock()),
            ])),
            ('video', EmbedBlock()),
        ],
        icon='cogs'
    )),
])

As with StructBlock, the list of sub-blocks can also be provided as a subclass of StreamBlock:

class CarouselBlock(blocks.StreamBlock):
    image = ImageBlock()
    quotation = blocks.StructBlock([
        ('text', blocks.TextBlock()),
        ('author', blocks.CharBlock()),
    ])
    video = EmbedBlock()

    class Meta:
        icon='cogs'

Since StreamField accepts an instance of StreamBlock as a parameter, in place of a list of block types, this makes it possible to re-use a common set of block types without repeating definitions:

class HomePage(Page):
    carousel = StreamField(
        CarouselBlock(max_num=10, block_counts={'video': {'max_num': 2}}),
    )

StreamBlock accepts the following additional options as either keyword arguments or Meta properties:

Parameters:

• required – If true (the default), at least one sub-block must be supplied. This is ignored when using the StreamBlock as the top-level block of a StreamField; in this case, the StreamField’s blank property is respected instead.

• min_num – Minimum number of sub-blocks that the stream must have.

• max_num – Maximum number of sub-blocks that the stream may have.

• search_index – If false (default true), the content of this block will not be indexed for searching.

• block_counts – Specifies the minimum and maximum number of each block type, as a dictionary mapping block names to dicts with (optional) min_num and max_num fields.

• collapsed – When true, all sub-blocks are initially collapsed.

• form_classname – An HTML class attribute to set on the root element of this block as displayed in the editing interface.

• form_attrs – A dictionary of additional attributes to set on the root element of this block as displayed in the editing interface.

body = StreamField([
    # ...
    ('event_promotions', blocks.StreamBlock([
        ('hashtag', blocks.CharBlock()),
        ('post_date', blocks.DateBlock()),
    ], form_classname='event-promotions')),
])

class EventPromotionsBlock(blocks.StreamBlock):
    hashtag = blocks.CharBlock()
    post_date = blocks.DateBlock()

    class Meta:
        form_classname = 'event-promotions'

Supporting components¶