Generates binary protocol specifications from plugin schemas.

This module auto-generates field mappings and encoders for plugin-defined properties, preventing protocol chaos through systematic field numbering.

Field Numbering

Each property in a component gets a unique field number:

prop "volume", :f32
# → FIELD_VOLUME = 0x07
# → [f32]

Field numbers are assigned sequentially starting from 0x01 for each component, ensuring no collisions within a plugin.

Binary Format

The protocol uses a compact binary format:

+--------+--------+--------+--------+
| opcode |  id    | field  | value  |
+--------+--------+--------+--------+
  1 byte  8 bytes  1 byte  N bytes

Where:

• opcode: CREATE_NODE, UPDATE_PROP, etc.
• id: 64-bit node identifier
• field: field number (0x01-0xFF)
• value: type-encoded value

Type Encoding

Capability Negotiation & Lifecycle Events

The protocol also encodes capability negotiation and lifecycle events:

# Capability negotiation
encode_capability_negotiation([:gestures, :animation], [:gestures, :accessibility, :animation])
# → binary with requested + provided capabilities

# Lifecycle events
encode_lifecycle_event(:init, %{opts: []})
encode_lifecycle_event(:activate, %{})
encode_lifecycle_event(:cleanup, %{})

Example

defmodule MyApp.VideoPlugin do
  use Dala.Plugin

  component "video" do
    prop "source", :string
    prop "volume", :f32
    prop "autoplay", :bool
  end
end

Generates:

FIELD_SOURCE = 0x01
FIELD_VOLUME = 0x02
FIELD_AUTOPLAY = 0x03

# Encoding {"video.mp4", 0.8, true}:
# 01 00 00 00 00 00 00 00 00  # id (8 bytes)
# 01 0B 76 69 64 65 6F 2E 6D  # field 01, string "video.mp4"
# 70 02 00 00 00 00 02 03 10  # field 02, f32 0.8
# 03 01                       # field 03, bool true