fomkin / korolev Goto Github PK

Allow to add static js and css urls when defining Korolev.

Proposal

FormData allows to send HTML forms asynchronously. Idea is to send forms via HTTP[S] and notify about progress via WebSocket.

Algorithm

1. User presses "Submit" button.
2. Event received by korolev-server
3. Server initiates FromData uploading using XMLHttpRequest.send
4. Client invoke progress callback for every progress event

API

val myForm = elementId

'form(

  myForm,

  eventWithAccess('submit) { access => 
    access
      .downloadFormData(myForm)
      .onProgress { (loaded, total) =>
        // transition …
      }
      .start
      .map { formData =>
        val picture = data.file("picture") // Array[Byte]
        val title = data.text("title") // String
        // transition ...
      }
  },
        
  'input('name = "title", 'type /= "text"),
  'input('name = "picture", 'type /= "file"),
  'input('type /= "button", "Submit")
)

Tasks

1. multipart/form-data codec
2. Allow Korolev to receive FormData
3. Progress events
4. Example

Depend on #37 #25

Now we have no way to identify user inside render, but we should have it.

Downloaded https://repo1.maven.org/maven2/com/lihaoyi/utest_2.11/0.4.4/utest_2.11-0.4.4.jar
[info] Compiling 1 Scala source to C:\home\projects\git\korolev\async.jvm\target\scala-2.11\classes...
[info] Compiling 2 Scala sources to C:\home\projects\git\korolev\vdom.jvm\target\scala-2.11\classes...
[info] Compiling 5 Scala sources to C:\home\projects\git\korolev\bridge.jvm\target\scala-2.11\classes...
[info] Compiling 8 Scala sources to C:\home\projects\git\korolev\korolev.jvm\target\scala-2.11\classes...
[info] Compiling 8 Scala sources to C:\home\projects\git\korolev\server\target\scala-2.11\classes...
[info] Compiling 6 Scala sources to C:\home\projects\git\korolev\server-blaze\target\scala-2.11\classes...
java.lang.RuntimeException: No main class detected.
at scala.sys.package$.error(package.scala:27)
[trace] Stack trace suppressed: run last simpleExample/compile:run for the full output.
[error] (simpleExample/compile:run) No main class detected.
[error] Total time: 28 s, completed Feb 18, 2017 10:53:34 AM

C:\home\projects\git\korolev>sbt simpleExample/run

It would be cool to support Java EE application containers.

Looks like we need to have session management.

1. State for every session should be stored in abstract KV storage (simple concurrent mutable map by default).
2. When user enter the server first time server sets cookie with unique session key.
3. When user enter next time state should be restored.

If DOM was updated, events tail of events should be dropped.

Currently we bound on http4s. It should become a module named http4s with Task as IO monad. KorlevServerHttp4s should generate rout, not runnable.

val application = Korolev(TheState.empty)
  .bindHttp(port, host)
  .render(renderPartialFunction)
  .stateStorage(stateStorageInstance)

1. Every browser should have deviceId. If it absent we have to set it using cookie.
2. Add deviceId to State resolver. It is state generator for new sessions.
3. Initial state should be finally dropped.

Now access objects make render functions impure. This disallow to enable memorization for render functions.

• 1. Introduction
• 1.1. Principles
• 2. Understanding Korolev
• 2.1. Device and Session
• 2.2. State
• 2.3. Render
• 2.4. Transitions
• 2.5. Events
• 2.6. EventResult
• 2.7. FormData
• 2.8. Delays
• 2.9. External Binding
• 2.10. Routing
• 3.3. Web Components
• 4. Integrations
• 4.1. JCache

Allow to plug metric trackers. What should be tracked:

1. State loading (for new sessions, existing sessions)
2. Static pages rendering
3. Diffs
4. Routing

It may be useful when we want to play some basic animation or hide something after timeout.

Global timer (session context)

KorolevServer[Boolean](
  ...
  timers = {
    case true => 
      delay(2 seconds) {
         case _ => false
      }
  }
)

Inside view

render = {
  case state =>
    'div(
      h1("Title"),
      if (!state) <> 
      else 'div(
        "Something we want to hide",
        delay(2 seconds) {
          case _ => false
        }
      )
    )
}

We are using Artillery framework for load testing. I launched basic quick load test for routingExample artillery quick --duration 20 --rate 5 -n 5 http://localhost:8181 ,

I got that big stack trace (I recduced it a little) :

[ForkJoinPool-1-worker-1] ERROR org.http4s.blaze.pipeline.Stage - Error during 'handleRequest' of HttpServerStage
scala.MatchError: [Ljava.lang.String;@623a6f (of class [Ljava.lang.String;)
[ForkJoinPool-1-worker-1] INFO org.http4s.blaze.pipeline.Stage - Shutting down HttpPipeline at Tue Jan 31 10:48:06 EET 2017
[ForkJoinPool-1-worker-1] ERROR org.http4s.blaze.pipeline.Stage - NIO2 channel closed with an unexpected error
scala.MatchError: [Ljava.lang.String;@623a6f (of class [Ljava.lang.String;)

It seems like there are some problems in cookies handling.

After KorolevAccess removal access to Dux was disallowed. We need turn them back.

Do some JavaScript when DOM element added/removed from from virtual DOM

What we have

import korolev.Korolev.Render
import korolev.EventResult

What we need

import korolev._

Idea is to serve some resource files like css or png directly from class path.

Korolev requires cookie to work. EU Cookie Law requires warn user about that. It can be done by programmer (just add closable panel to top of page) or Korolev, before the deviceId will be set.

A lot of people say that unsecure Korolev pages don't works because corporative secure policy forbid WebSockets (or proxy doesn't support them). We need to have SSL support.

The diff algorithm works fine when appending:

val a = 'div (
  'h2 /= "", 'h1 /= "", 'h2 /= "", 'h1 /= "", 'h2 /= "", 'h1 /= "", 'h2 /= "")

val b = 'div (
  'h2 /= "", 'h1 /= "", 'h2 /= "", 'h1 /= "", 'h2 /= "", 'h1 /= "", 'h2 /= "",
  'h1 /= "new")
  
VDom.changes(a, b) == List(SetAttr(0,"h1","new",false))

But seams to preform poorly when prepending:

val a = 'div (
  'h2 /= "", 'h1 /= "", 'h2 /= "", 'h1 /= "", 'h2 /= "", 'h1 /= "", 'h2 /= "")

val b = 'div (
  'h1 /= "new",
  'h2 /= "", 'h1 /= "", 'h2 /= "", 'h1 /= "", 'h2 /= "", 'h1 /= "", 'h2 /= "")

VDom.changes(a, b) == List(
  SetAttr(0,"h2","",false),
  RemoveAttr(0,"h2",""false),
  SetAttr(0,"h1","",false),
  RemoveAttr(0,"h1",""false),
  SetAttr(0,"h2","",false),
  RemoveAttr(0,"h2",""false),
  SetAttr(0,"h1","",false),
  RemoveAttr(0,"h1",""false),
  SetAttr(0,"h2","",false),
  RemoveAttr(0,"h2",""false),
  SetAttr(0,"h1","",false),
  RemoveAttr(0,"h1",""false),
  SetAttr(0,"h2","",false),
  RemoveAttr(0,"h2",""false),
  SetAttr(0,"h1","new",false)
)

FWIW the kivi implementation seams to hande these cases while remaining reasonably simple

No we able listen only mousedown, mouseup, click and submit. We need to be able to listen any event.

1. Remove promises #78
2. Remove maps #95
3. Fallback to long polling #68
4. Remove usage of event constructors #79

1. korolev-server-blaze-fs2-scalaz
2. korolev-server-blaze-fs2-cats
3. korolev-server-blaze

When a http request comes in it goes through korolev/server/package.scala:

def renderStatic(request: Request): F[Response] = {

If the file is a javascript static resource then it returns

<!DOCTYPE html><html ><head ><script > then the javascript code -

resulting in a error

What is Router?

case class Router[F[_]: Async, S](
  from: S => Path,
  to: (DeviceId, Path) => F[S]
)

Router should:

1. Map State to the Path. For example we have state case class State(blogId: String @@ Blog, articleId: String @@ Article, text: String). So path is /blogs/${state.blogId}/articles/${state.articleId}.
2. Map Path to the State. We should remember that state state generation can produce side effects like DB access.

When people want to use Scalaz or Cats they are don't want to use Future from standard library. I think we have to write our own monad like type class. Good namings: Async, Deferred

Session has no information about static router input.