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# PhoenixKitWeb.Dashboard.TabsInitializer (phoenix_kit v1.7.87)

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LiveView on_mount hook for initializing dashboard tabs with context-aware badge values.

This hook should run AFTER `ContextProvider` to ensure context data is available. It automatically initializes dashboard tabs and loads badge values for context-aware badges, eliminating the need for custom on_mount hooks in most applications.

## Usage

Add to your live_session after authentication and context hooks:

    live_session :dashboard,
      on_mount: [
        {PhoenixKitWeb.Users.Auth, :phoenix_kit_ensure_authenticated_scope},
        {PhoenixKitWeb.Dashboard.ContextProvider, :default},
        {PhoenixKitWeb.Dashboard.TabsInitializer, :default}
      ] do
      live "/dashboard", DashboardLive.Index
    end

## Mount Options

- `:default` - Initialize tabs with presence tracking and badge subscriptions
- `:minimal` - Initialize tabs without presence tracking (lower overhead)
- `:badges_only` - Only initialize badge values, no presence tracking

## Assigns Set

This hook sets the following assigns:

- `@dashboard_tabs` - List of Tab structs with badge values loaded
- `@tab_viewer_counts` - Map of tab_id => viewer count (unless `:minimal` or `:badges_only`)
- `@collapsed_dashboard_groups` - MapSet of collapsed group IDs
- `@context_badge_values` - Map of tab_id => badge value for context-aware badges

## How It Works

1. Normalizes `current_contexts_map` for legacy single-selector configurations (builds `%{:default => current_context}` if `current_contexts_map` is not set)
2. Calls `LiveTabs.init_dashboard_tabs/2` which:
   - Loads tabs from the Registry
   - Subscribes to tab update PubSub topics
   - Subscribes to badge update topics (with context placeholder resolution)
   - Loads initial values for context-aware badges via their loaders
   - Merges context values into tab badges

## Legacy Single-Selector Compatibility

For apps using the legacy `:dashboard_context_selector` configuration, this hook automatically builds `current_contexts_map` from `current_context`:

    # Legacy config sets these:
    @current_context = %{id: 1, name: "My Farm"}
    @context_selector_config = %{key: :farm, ...}

    # This hook normalizes to:
    @current_contexts_map = %{farm: %{id: 1, name: "My Farm"}}

This allows context-aware badges with `context_key: :farm` to work correctly.

## Manual Alternative

If you need custom initialization logic, skip this hook and use `PhoenixKitWeb.Components.Dashboard.LiveTabs.init_dashboard_tabs/2` in your mount:

    def mount(_params, _session, socket) do
      socket = init_dashboard_tabs(socket)
      {:ok, socket}
    end

## Example with Context-Aware Badges

    # config.exs
    config :phoenix_kit, :user_dashboard_tabs, [
      %{
        id: :alerts,
        label: "Alerts",
        path: "/dashboard/alerts",
        badge: %{
          type: :count,
          context_key: :farm,  # Must match selector key
          loader: {MyApp.Alerts, :count_for_farm},
          color: :error
        }
      }
    ]

    # router.ex
    live_session :dashboard,
      on_mount: [
        {PhoenixKitWeb.Users.Auth, :phoenix_kit_ensure_authenticated_scope},
        {PhoenixKitWeb.Dashboard.ContextProvider, :default},
        {PhoenixKitWeb.Dashboard.TabsInitializer, :default}
      ] do
      live "/dashboard", DashboardLive.Index
    end

    # The badge will automatically show the correct count for the selected farm

## Summary

### Functions

on_mount(atom, params, session, socket)

On mount hook that initializes dashboard tabs with badge values.

## Functions

# on_mount(atom, params, session, socket)

On mount hook that initializes dashboard tabs with badge values.

## Options

- `:default` - Full initialization with presence tracking
- `:minimal` - Skip presence tracking for lower overhead
- `:badges_only` - Only initialize badge values