Promo Rotator

Rotates through child promo blocks randomly on page load, displaying only one at a time.

Block inserter example

block.json defines an example with one prc-block/card (“Promo Card”) and inner core/paragraph — inserter preview.

Block Namespace

prc-block/promo-rotator

Category

marketing

Supports

Feature	Enabled
Anchor	Yes
HTML	No
Spacing (blockGap)	Yes
Spacing (margin)	Top and bottom only
Spacing (padding)	Yes (default control)
Typography (fontSize)	Yes (default control)
Typography (fontFamily)	Yes (default control)

Attributes

Attribute	Type	Default	Description
allowedBlocks	array	—	Optional override for which block types can be placed inside. Defaults to prc-block/promo and prc-block/card if not set.

Available Styles

No block style variations defined.

Inner Blocks

Allowed inner blocks (default):

• prc-block/promo
• prc-block/card

The allowedBlocks attribute can override this list to allow any block types.

Inner blocks are displayed vertically in the editor, with an appender that switches from a button appender (when empty) to a default block appender (when blocks exist).

Parent/Ancestor Requirements

None.

Usage Instructions

1. Insert a Promo Rotator block.
2. Add multiple Promo or Card blocks inside it. Each child block represents one possible display option.
3. All child blocks are visible in the editor for content management.
4. On the frontend, only one randomly selected child block is rendered per page load.
5. Customize spacing and typography via block supports.

Block Markup Example

In the editor, all children are visible:

<!-- wp:prc-block/promo-rotator -->
<!-- wp:prc-block/promo {"heading":"Promo A"} /-->
<!-- wp:prc-block/promo {"heading":"Promo B"} /-->
<!-- wp:prc-block/promo {"heading":"Promo C"} /-->
<!-- /wp:prc-block/promo-rotator -->

On the frontend, only one randomly selected promo is rendered.

PHP Rendering

The render_block_callback method outputs the serialized inner block content through wp_kses.

The actual rotation logic is handled by the randomly_select_inner_block method which hooks into render_block:

1. Checks if the block being rendered is prc-block/promo-rotator.
2. Uses array_rand() to randomly select one inner block.
3. Calls render_block() on only the selected inner block.
4. Returns only that single block's rendered HTML.

This means on each page load, a different promo/card is shown at random.

Frontend Interactivity

No frontend JavaScript. The randomization is handled server-side during PHP rendering.

Related Blocks

• prc-block/promo — Primary child block type for promotional content
• prc-block/card — Alternative child block type