Children inside parent items

Relationship between parent and child items

Some board items can contain other items. In this scenario, the containing item is a parent, and any nested items inside it are its children. Placing an item inside another one creates a parent/child relationship between the items. This relationship affects parents and children in the following ways:

• As long as a child item is inside a parent, its x and y positioning reference is relative to the containing parent item.
• Relative positioning enables moving a parent item on the board along with its children, without affecting the visual layout of the children inside the parent.
• If an app attempts to programmatically update a parent item to resize it, the operation may fail if one or more children fall outside the parent item after resizing it.
  This isn't allowed, because it would break the parent/child relationship between the items.

Supported and unsupported parent items

At this time, the Miro Developer Platform doesn't support all board items that can act as parents. We plan to extend support in the future to include also currently unsupported items.

Supported item that can be a parent of nested child items:

• Frame

Unsupported items that can be parents of nested child items:

• Kanban
• Mind Map
• Table
• User Story Mapping (USM)

Retrieval of parent with nested children

Programmatically retrieving a parent with its children returns different data, depending on whether the parent is supported or not.

The Web SDK can programmatically retrieve board items—including parents and children—in the following ways:

• The get() method
• The getSelection() method
• The selection:update event.

Retrieval of supported parent with children

Retrieving a parent frame with nested children returns the complete data tree structure of the frame and its children, with all their supported properties and values.

Besides the already mentioned methods and the event, the Web SDK can programmatically retrieve a parent frame along with its children with the following method:

• getChildren()

Retrieval of unsupported parent with children

Retrieving an unsupported parent item containing supported child items returns complete data objects for the supported children items.
However, since the parent is unsupported, the Web SDK has limited access to the children:

• The returned width and height values of the child items are read-only.
• The returned x and y coordinates of the child items have the -Infinity value, and they are read-only.

🚧

Retrieving a mind map parent item doesn't return its children.
The operation returns only the data object for the unsupported mind map item.

CRUD actions on children of unsupported parent

It's possible to update the properties of supported items that are children of an unsupported parent item. For example: content or style.
However, since the parent is unsupported, it's not possible to:

• Get the actual position of the child items. Their returned x and y coordinates have the -Infinity value, and they are read-only.
• Update their x or y coordinates to change their position on the board.
• Update their width or height to resize them.

See also

• Frame item reference documentation
• Position relative to parent items
• Position and coordinates