Lavash.LiveView.Base (Lavash v0.4.0-rc.4)

Copy Markdown View Source

Layer-1+2+3 entry point: lavash without the optimistic UI layer.

Use this in place of Lavash.LiveView when you want the Spark DSL surface (state, calculate, read, form, actions, mount do, messages do, etc.) but no client-side optimistic machinery — no SyncedVar, no merge walker, no JS rx transpilation, no data-lavash-display wrapping spans, no LavashOptimistic hook injection.

Example

defmodule MyAppWeb.AdminLive do
  use Lavash.LiveView.Base

  state :user, :map, from: :assigns, assigns_key: :current_user
  state :tab, :string, from: :url, default: "overview"

  actions do
    action :switch_tab, [:tab] do
      set :tab, &(&1.params.tab)
    end
  end

  template do
    ~H"""
    <div>
      <h1>{@user.name}</h1>
      <p>Active tab: {@tab}</p>
    </div>
    """
  end
end

Every change is server-authoritative — clicks roundtrip to the server, the server recomputes, the diff comes back, the DOM updates. Same model as vanilla LiveView, with the Spark DSL on top for declarative state + URL sync + Ash reads + reactive calculations.

What you give up

  • optimistic: true on state fields: a compile-time error. Server is the only writer; the client doesn't apply patches locally.
  • animated: on state fields: same.
  • optimistic: true on calculations: same.
  • data-lavash-display auto-wrapping of bare {@field}: not applied. Rendering goes straight through Phoenix's normal interpolation.
  • JS bundle: a layer-2 consumer of lavash only needs state_sync.js (the reconnect cache); the optimistic lavash.js and its concerns aren't loaded.

What you keep

  • The full DSL surface: state, calculate, read, form, actions, messages, async, mount, when_connected, components, slots, on_mount, navigates, push_events, push_patches, redirects.
  • Compile-time validation: action/event references, phx-value-* matching action params, @assign references in HEEx.
  • URL sync via from: :url (server-side push_patch + client history.replaceState).
  • Socket sync via from: :socket (reconnect-survival cache).
  • Reactive calculations (calculate :foo, rx(...)) — recompute on dep change, server-side.
  • Async reads and calculations (async: true).

Layering note

This module exists per docs/ARCHITECTURE.md punchlist item #10. Layer 4 (optimism) is currently pay-for-what-you-use even with use Lavash.LiveView — if you don't mark any field optimistic: true, the optimistic transformers no-op. Base is the explicit opt-out form: it makes "no client-side optimism" a load-bearing contract that the schema enforces rather than a consequence of you not asking for it.

Options

  • :extensions (list of module that adopts Spark.Dsl.Extension) - A list of DSL extensions to add to the Spark.Dsl

  • :otp_app (atom/0) - The otp_app to use for any application configurable options

  • :fragments (list of module/0) - Fragments to include in the Spark.Dsl. See the fragments guide for more.