Behaviour a Component implements to describe itself to assistive technology.

Parallels Raxol.MCP.ToolProvider: the callback receives the Component's declaration Element (the same map mcp_tools/1 receives) and returns an accessibility node. Raxol.Core.Accessibility.Projection walks the Element tree and calls this callback for Components that implement it, falling back to a default role/label extraction otherwise.

A Component knows where its own fields live (field locations are heterogeneous across the codebase), so co-locating the extractor here keeps each Component authoritative about its own shape.

Returning children

Omit :children for leaf Components (Button, TextInput, Checkbox) -- the projection recurses the Element's own children. Set :children only when the Component synthesizes semantic children not present as Element children (e.g. SelectList options built from an :options attr, Tabs, Table rows).

Example

@impl Raxol.Core.Accessibility.Provider
def a11y_node(node) do
  %{role: :checkbox, label: node[:label], id: node[:id],
    state: %{checked?: node[:checked] || false}}
end