A general-purpose LiveComponent for selecting, ordering, previewing and removing a set of images.

Generalizes the gallery + picker pattern so any PhoenixKit consumer can embed it instead of re-implementing the plumbing. The component manages an ordered list of file UUIDs and reports changes to the parent LiveView.

Usage

<.live_component
  module={PhoenixKitWeb.Components.MediaGallery}
  id="my-gallery"
  selected={@image_uuids}
  phoenix_kit_current_user={@current_user}
/>

# Receive changes in parent LiveView
def handle_info({PhoenixKitWeb.Components.MediaGallery, "my-gallery", {:changed, uuids}}, socket) do
  {:noreply, assign(socket, :image_uuids, uuids)}
end

Attrs

• id — required; used for element IDs and change notifications
• title — optional heading above the gallery
• selected — ordered list of file UUIDs (current selection); default []
• mode — :single or :multiple (default :multiple)
• cols — grid columns for the thumbnail layout (default 4). Either an integer 1..6, or a string of Tailwind grid-column classes for a responsive grid (e.g. "grid-cols-4 lg:grid-cols-6 2xl:grid-cols-8"). Plumbed straight through to <.draggable_list>.
• featured_first — when true, the first item in :selected renders a "Featured" badge in the top-left corner. Matches the phoenix_kit_posts post-creation convention where the first image is the featured one and drag-reordering changes the feature. Default false so existing consumers aren't surprised.
• scope_folder_id — folder scope passed to the picker
• phoenix_kit_current_user — required for upload in the picker
• readonly — when true, hides the pick button, remove buttons, and DnD; preview (lightbox) still works; default false
• max_count — integer upper bound on the number of selected images for :multiple mode; nil means unlimited. For :single mode the limit is always 1 (implied by mode). When the limit is reached, the "Add" tile is hidden entirely (not just disabled) and apply_selection refuses to exceed it.

Change notifications — required host wiring (silent failure otherwise)

This is a LiveComponent, so it has no handle_info of its own: after any change (pick / remove / reorder) it sends a process message to the host LiveView via send/2:

{PhoenixKitWeb.Components.MediaGallery, id, {:changed, ordered_uuids}}

The host MUST handle this (see the Usage example above) and persist ordered_uuids — it is a controlled component: it renders whatever the host passes back as :selected. Forget the handler and the user's picks/reorders are silently dropped (no crash, no warning). Each host stores the selection differently (its own field/assoc), so there is intentionally no use ...Embed macro — the handling is yours to write.

Reorder event contract

The thumbnail grid uses the canonical <.draggable_list> primitive (PhoenixKitWeb.Components.Core.DraggableList), which fires the "reorder_images" event with payload %{"ordered_ids" => uuids}.

Because MediaGallery is a LiveComponent, the grid is rendered with target={"##{@id}"} so the SortableGrid hook routes the event via pushEventTo to this component's own handle_event/3 — not the host LiveView. Each gallery's id is unique, so multiple galleries on the same page never cross-deliver reorder events.