Flex layout

system:flex

Organizes child nodes horizontally or vertically, and can iterate over a collection and paginate it.

Nodes are written into the body or children of a resource pack card template. Besides their own fields, all nodes share id, style, when, unless and repeat; see Common node fields.

JSON fields

Field	Type	Required	Default	Description
type	Resource ID	yes	—	system:flex
direction	String	no	"row"	Layout direction, row or column.
wrap	Boolean	no	true	Whether wrapping is allowed.
source	String	no	""	Input collection, resource path or context parameter; see this page for how it is used.
filter	String	no	""	State key read by index, used to filter the collection.
page_size	Integer	no	0	Page capacity; 0 does not paginate on its own.
children	Card node array	yes	—	Child node array.
text_separator	String	no	omitted	Separator used when extracting plain text; does not change the visual layout.

JSON example

{
  "type": "system:flex",
  "children": [
    {
      "type": "system:text",
      "text": "Host"
    },
    {
      "type": "system:text",
      "text": "{{player_name}}"
    }
  ],
  "direction": "row"
}

Placed in the body of a card template or the children of a container. Placeholders come from server snapshots and client build events; changing only the JSON does not produce the missing data or business handlers.

Java entry point

com.iafenvoy.system.screen.card.node.layout.FlexNode. This page is based on the Codec in the current 26.1.2 source.