avielg / picasso

(currently using Xcode Cloud)

Picasso

JSON → Native SwiftUI 🎉

Eventually also:

1. Swift on the server → Native SwiftUI
2. JSON or Swift on the server → Jetpack Compose

---

Usage

1. Clone or download the repo.
2. Run ./build_framework.sh
3. Grab the framework from _build_framework/PicassoKit.xcframework and drag into your Xcode project.
4. Add AnyCodable as a dependency to your target.

Getting Started

1. import PicassoKit

2. Provide an encoder and decoder: Parser.shared = Parser(encoder: ..., decoder: ...). Picasso is tested on 3 options:

   1. ZippyJSON for decoding (pair with Apple's JSONEncoder).
   2. Apple's JSONDecoder and JSONEncoder.
   3. MessagePacker for MessagePack support.

3. Create a PicassoView anywhere in your SwiftUI code:

   struct MyCoolView: View {
       var body: some View {
         VStack {
           Text("Hello!")
           PicassoView(URL("my.server.com/picasso/coolcontent")!) // <--
         }
       }
   }

Building Payload

Instead of typing the view hierarchy in JSON yourself (or if you want to use MessagePack), construct your UI from various PC views (PCStack, PCText etc.) and encode the main view:

func someView() -> PCStackView {
  PCStackView(...)
}

let view = someView()
let data = try someEncoder.encode(view)
let json = String(data: data, encoding: .utf8)
// upload the result json to your backend etc.

JSON Syntax

While not a comprehensive guide, this should provide an idea of how the JSON syntax looks like:

{
  "VStack": [
    {
      "text": "Hello!",
      "modifiers": {
        "font": { "weight": "bold", "style": "title" },
        "padding": { "top": 30, "leading": 100 }
      }
    },
    {
      "HStack": [...other views...],
      "alignment": "bottomTrailing",
      "modifiers": {
        "overlay": {
          "alignment": "bottom",
          "content": {...some view...}
        }
      }
    },
    {
      "optional": {
        "content": { "text": "Hi there! :)" },
        "presentationFlag": "show-text" }
    },
    {
      "button": "Toggle Hidden Text",
      "toggleFlag": "show-text",
    },
    {
      "image": "https://picsum.photos/200/400",
      "scale": 2
    }
  ]
}

---

ToDo/Reminders

(beyond the obvious missing stuff...)

• Eventually split Parser/modifiers(from:) to categories: text, etc.
• Remove the SwiftUI.View conformance from the types, make it separate (to later compile on Linux)
• Find a way to type erase the modifiers like AnyPCView?
• Somehow single pass on the JSON?
• Fix the .indices in containers body (stack and scrollview)
• Add MessagePack with perf tests against JSON
• Figure out the crash in msgpack-swift when trying to parse modifiers (bug in the library)