Fix issue #195 (#196)

* Create ci.yml

* removed travis build file

* changed docker image

* Update readme to include CI results

.github/workflows/ci.yml

@@ -0,0 +1,31 @@
+# This is a basic workflow to help you get started with Actions
+
+name: CI
+
+# Controls when the action will run. 
+on:
+  # Triggers the workflow on push or pull request events but only for the master branch
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+# A workflow run is made up of one or more jobs that can run sequentially or in parallel
+jobs:
+  # This workflow contains a single job called "build"
+  build:
+    # The type of runner that the job will run on
+    runs-on: ubuntu-latest
+    container: nimlang/nim
+    # Steps represent a sequence of tasks that will be executed as part of the job
+    steps:
+      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
+      - uses: actions/checkout@v2
+      # Runs a single command using the runners shell
+      - name: Tests
+        run: |
+          nimble develop -y
+          nim c -r tests/tester.nim

.gitignore

@@ -3,3 +3,5 @@ nimcache/
 karax/tools/karun
 *.code-workspace
 *.exe
+app.js
+app.html

.travis.yml

@@ -1,20 +0,0 @@
-sudo: false
-language: c
-os: linux
-install:
-  - git clone https://github.com/nim-lang/nim
-  - cd nim
-  - git clone --depth 1 https://github.com/nim-lang/csources.git
-  - cd csources
-  - sh build.sh
-  - cd ../
-  - bin/nim c koch
-  - ./koch boot -d:release
-  - ./koch tools
-  - cd ..
-before_script:
-  - set -e
-  - export PATH=$(pwd)/nim/bin:$(pwd):$PATH
-script:
-  - nimble develop
-  - nim c -r tests/tester.nim

examples/button.nim

@@ -1,4 +1,3 @@
-
 include karax / prelude
 
 var lines: seq[kstring] = @[]

examples/hellostyle.nim

@@ -0,0 +1,17 @@
+include karax / prelude
+import karax / vstyles
+
+proc createDom(): VNode =
+  result = buildHtml(tdiv):
+    tdiv(style = style(StyleAttr.color, "red".cstring)):
+      text "red"
+    tdiv(style = style(StyleAttr.color, "blue")):
+      text "blue"
+    # explicit `kstring` required for varargs overload
+    tdiv(style = style((fontStyle, "italic".kstring), (color, "orange".kstring))):
+      text "italic orange"
+    # can use a string directly
+    tdiv(style = "font-style: oblique; color: pink".toCss):
+      text "oblique pink"
+
+setRenderer createDom

examples/hellouniverse.nim

@@ -1,10 +1,9 @@
-
 include karax / prelude
 import random
 
 proc createDom(): VNode =
   result = buildHtml(tdiv):
-    if random(100) <= 50:
+    if rand(100) <= 50:
       text "Hello World!"
     else:
       text "Hello Universe"

examples/login.nim

@@ -1,4 +1,3 @@
-
 include karax / prelude
 from sugar import `=>`
 import karax / errors
@@ -18,7 +17,7 @@ const
 proc validateNotEmpty(field: kstring): proc () =
   result = proc () =
     let x = getVNodeById(field)
-    if x.text.isNil or x.text == "":
+    if x.text == "":
       errors.setError(field, field & " must not be empty")
     else:
       errors.setError(field, "")

examples/toychat.nim

@@ -1,4 +1,3 @@
-
 include login
 
 const
@@ -12,7 +11,7 @@ var allMessages: seq[TextMessage] = @[]
 
 proc doSendMessage() =
   let inputField = getVNodeById(message)
-  allMessages.add(TextMessage(name: "you", content: inputField.text))
+  allMessages.add(TextMessage(name: "you", content: inputField.getInputText))
   inputField.setInputText ""
 
 proc main(): VNode =

karax.nimble

@@ -1,14 +1,15 @@
 # Package
 
-version       = "1.1.1"
+version       = "1.2.1"
 author        = "Andreas Rumpf"
 description   = "Karax is a framework for developing single page applications in Nim."
 license       = "MIT"
 
 # Dependencies
 
-requires "nim >= 0.16.1"
-
+requires "nim >= 0.18.0"
+requires "ws"
+requires "dotenv"
 skipDirs = @["examples", "experiments", "tests"]
 
 bin = @["karax/tools/karun"]

karax/compact.nim

@@ -61,7 +61,7 @@ proc newname*(n: NimNode): NimNode =
     n[1] = newname(n[1])
     result = n
   elif n.kind == nnkSym:
-    result = ident($n.symbol)
+    result = ident(n.strVal)
   else:
     result = n
 

karax/karax.nim

@@ -7,9 +7,8 @@ export kdom.Event, kdom.Blob
 when defined(nimNoNil):
   {.experimental: "notnil".}
 
-proc kout*[T](x: T) {.importc: "console.log", varargs, deprecated.}
-  ## the preferred way of debugging karax applications. Now deprecated,
-  ## you can now use ``system.echo`` instead.
+proc kout*[T](x: T) {.importc: "console.log", varargs.}
+  ## The preferred way of debugging karax applications.
 
 type
   PatchKind = enum
@@ -38,6 +37,7 @@ type
     toFocus: Node
     toFocusV: VNode
     renderId: int
+    rendering: bool
     patches: seq[Patch] # we reuse this to save allocations
     patchLen: int
     patchesV: seq[PatchV]
@@ -154,7 +154,9 @@ proc getVNodeById*(id: cstring; kxi: KaraxInstance = kxi): VNode =
 
 proc toDom*(n: VNode; useAttachedNode: bool; kxi: KaraxInstance = nil): Node =
   if useAttachedNode:
-    if n.dom != nil: return n.dom
+    if n.dom != nil:
+      if n.id != nil: kxi.byId[n.id] = n
+      return n.dom
   if n.kind == VNodeKind.text:
     result = document.createTextNode(n.text)
     attach n
@@ -383,6 +385,8 @@ proc addPatchV(kxi: KaraxInstance; parent: VNode; pos: int; newChild: VNode) =
 proc moveDom(dest, src: VNode) =
   dest.dom = src.dom
   src.dom = nil
+  if dest.id != nil:
+    kxi.byId[dest.id] = dest
   assert dest.len == src.len
   for i in 0..<dest.len:
     moveDom(dest[i], src[i])
@@ -626,8 +630,21 @@ proc avoidDomDiffing*(kxi: KaraxInstance = kxi) =
   ## This is an experimental API.
   kxi.currentTree = nil
 
+proc reqFrame(callback: proc()): int {.importc: "window.requestAnimationFrame".}
+when false:
+  proc cancelFrame(id: int) {.importc: "window.cancelAnimationFrame".}
+
 proc dodraw(kxi: KaraxInstance) =
   if kxi.renderer.isNil: return
+  kxi.renderId = 0
+
+  if kxi.rendering:
+    # there is a render already running, delay 1 frame
+    kxi.renderId = reqFrame(proc () = kxi.dodraw)
+    return
+
+  kxi.rendering = true
+
   let rdata = RouterData(hashPart: hashPart)
   let newtree = kxi.renderer(rdata)
   inc kxi.runCount
@@ -658,16 +675,12 @@ proc dodraw(kxi: KaraxInstance) =
   # now that it's part of the DOM, give it the focus:
   if kxi.toFocus != nil:
     kxi.toFocus.focus()
-  kxi.renderId = 0
+  kxi.rendering = false
   when defined(stats):
     kxi.recursion = 0
     var total = 0
     echo "depth ", depth(kxi.currentTree, total), " total ", total
 
-proc reqFrame(callback: proc()): int {.importc: "window.requestAnimationFrame".}
-when false:
-  proc cancelFrame(id: int) {.importc: "window.cancelAnimationFrame".}
-
 proc redraw*(kxi: KaraxInstance = kxi) =
   # we buffer redraw requests:
   when false:
@@ -787,11 +800,10 @@ proc prepend(parent, kid: Element) =
   parent.insertBefore(kid, parent.firstChild)
 
 proc loadScript*(jsfilename: cstring; kxi: KaraxInstance = kxi) =
-  let body = document.getElementById("body")
   let s = document.createElement("script")
   s.setAttr "type", "text/javascript"
   s.setAttr "src", jsfilename
-  body.prepend(s)
+  document.body.prepend(s)
   redraw(kxi)
 
 proc runLater*(action: proc(); later = 400): Timeout {.discardable.} =
@@ -805,11 +817,18 @@ proc setInputText*(n: VNode; s: cstring) =
   n.text = s
   if n.dom != nil: n.dom.value = s
 
+proc getInputText*(n: VNode): cstring =
+  if n.dom != nil:
+    result = n.dom.value
+
 proc toChecked*(checked: bool): cstring =
   (if checked: cstring"checked" else: cstring(nil))
 
 proc toDisabled*(disabled: bool): cstring =
   (if disabled: cstring"disabled" else: cstring(nil))
 
+proc toSelected*(selected: bool): cstring =
+  (if selected: cstring"selected" else: cstring(nil))
+
 proc vnodeToDom*(n: VNode; kxi: KaraxInstance = nil): Node =
   result = toDom(n, useAttachedNode = false, kxi)

karax/tools/karun.nim

@@ -1,21 +1,16 @@
-## Simple tool to quickly run Karax applications. Generates the HTML
-## required to run a Karax app and opens it in a browser.
-
-import os, 
-  strutils, 
-  parseopt, 
-  browsers, 
-  times, 
-  tables
-  
 
+import os, strutils, browsers,times, tables 
+import parseopt
+import threadpool
+import static_server
 
 const
   css = """
   <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/bulma/0.7.4/css/bulma.min.css">
   <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css">
 """
-  html = """
+
+const html = """
 <!DOCTYPE html>
 <html>
 <head>
@@ -23,33 +18,81 @@ const
   <title>$1</title>
   $2
 </head>
-<body id="body">
-<div id="ROOT" />
-<script type="text/javascript" src="$1.js"></script>
+<body id="body" class="site">
+<div id="ROOT"></div>
+<script type="text/javascript" src="/app.js"></script>
+$3
 </body>
 </html>
 """
+const websocket = """
+<script type="text/javascript">
+var ws = new WebSocket("ws://localhost:8080/ws");
+
+ws.onopen = function(evt) { 
+  console.log("Connection open ..."); 
+  ws.send("Hello WebSockets!");
+};
+
+ws.onmessage = function(evt) {
+  console.log( "Received Message: " + evt.data);
+  if(evt.data == "refresh"){
+    window.location.href = window.location.href
+  }
+};
+
+ws.onclose = function(evt) {
+  console.log("Connection closed.");
+};      
+</script>
+"""
 
 proc exec(cmd: string) =
   if os.execShellCmd(cmd) != 0:
     quit "External command failed: " & cmd
 
-proc build(name: string, rest: string, selectedCss: string, run: bool) =
+proc build(rest: string, selectedCss: string, run: bool, watch: bool) =
   echo("Building...")
-  exec("nim js --out:" & name & ".js " & rest)
-  let dest = name & ".html"
-  writeFile(dest, html % [name, selectedCss])
-  if run: openDefaultBrowser(dest)
+  let cmd = "nim js --out:" & "app" & ".js " & rest
+  if watch:
+    discard os.execShellCmd(cmd)
+  else:
+    exec cmd
+  let dest = "app" & ".html"
+  let script = if watch: websocket else: ""
+  writeFile(dest, html % ["app", selectedCss, script])
+  if run: openDefaultBrowser("http://localhost:8080")
+
+proc watchBuild(filePath: string, selectedCss: string, rest: string) {.thread.} = 
+  var files: Table[string, Time] = {"path": getLastModificationTime(".")}.toTable
+  while true:
+    sleep(300)
+    for path in walkDirRec("."):
+      if ".git" in path:
+        continue
+      var (_, _, ext) = splitFile(path)
+      if ext in [".scss",".sass",".less",".styl",".pcss",".postcss"]:
+        continue
+      if files.hasKey(path):
+        if files[path] != getLastModificationTime(path):
+          echo("File changed: " & path)
+          build(rest,selectedCss, false, true)
+          files[path] = getLastModificationTime(path)
+      else:
+        if absolutePath(path) in [absolutePath("app" & ".js"),absolutePath("app" & ".html")]:
+          continue
+        files[path] = getLastModificationTime(path)
+
+proc serve(){.thread.} =
+  serveStatic()
 
 proc main =
   var op = initOptParser()
   var rest = op.cmdLineRest
   var file = ""
   var run = false
-  var selectedCss = ""
   var watch = false
-  var files: Table[string, Time] = {"path": getLastModificationTime(".")}.toTable
-
+  var selectedCss = ""
   while true:
     op.next()
     case op.kind
@@ -59,8 +102,11 @@ proc main =
         run = true
         rest = rest.replace("--run ")
       of "css":
+        if op.val != "":
+          selectedCss = readFile(op.val)
+        else:
           selectedCss = css
-        rest = rest.replace("--css ")
+        rest = rest.substr(rest.find(" "))
       else: discard
     of cmdShortOption:
       if op.key == "r":
@@ -73,25 +119,11 @@ proc main =
     of cmdEnd: break
 
   if file.len == 0: quit "filename expected"
-  let name = file.splitFile.name
-  build(name, rest, selectedCss, run)
+  if run:
+    spawn serve()
   if watch:
-    # TODO: launch http server
-    while true:
-      sleep(300)
-      for path in walkDirRec("."):
-        if ".git" in path:
-          continue
-        if files.hasKey(path):
-          if files[path] != getLastModificationTime(path):
-            echo("File changed: " & path)
-            build(name, rest, selectedCss, run)
-            files[path] = getLastModificationTime(path)
-        else:
-          files[path] = getLastModificationTime(path)
+    spawn watchBuild(file, selectedCss, rest)
+  build(rest,selectedCss, run, watch)
+  sync()
 
 main()
-
-
-
-

karax/tools/karun.nims

@@ -0,0 +1 @@
+switch("threads", "on")

karax/tools/static_server.nim

@@ -0,0 +1,141 @@
+import
+  std/[net, os, strutils, uri, mimetypes, asyncnet, asyncdispatch, md5,
+  logging, httpcore, asyncfile, asynchttpserver, tables, times]
+from cgi import decodeUrl
+import ws, dotenv
+
+var logger = newConsoleLogger()
+addHandler(logger)
+
+when defined(release):
+  setLogFilter(lvlError)
+
+type
+  RawHeaders* = seq[tuple[key, val: string]]
+
+proc toStr(headers: RawHeaders): string =
+  $newHttpHeaders(headers)
+
+proc send(request: Request, code: HttpCode, headers: RawHeaders,
+    body: string): Future[void] =
+  return request.respond(code, body, newHttpHeaders(headers))
+
+proc statusContent(request: Request, status: HttpCode, content: string,
+    headers: RawHeaders): Future[void] =
+  try:
+    result = send(request, status, headers, content)
+    debug("  ", status, " ", toStr(headers))
+  except:
+    error("Could not send response: ", osErrorMsg(osLastError()))
+
+proc sendStaticIfExists(req: Request, paths: seq[string]): Future[HttpCode] {.async.} =
+  result = Http200
+  let mimes = newMimetypes()
+  for p in paths:
+    if fileExists(p):
+      if fpOthersRead notin getFilePermissions(p):
+        return Http403
+      let fileSize = getFileSize(p)
+      let extPos = searchExtPos(p)
+      let mimetype = mimes.getMimetype(
+        if extPos >= 0: p.substr(extPos + 1)
+        else: "")
+      if fileSize < 10_000_000: # 10 mb
+        var file = readFile(p)
+        var hashed = getMD5(file)
+        # If the user has a cached version of this file and it matches our
+        # version, let them use it
+        if req.headers.getOrDefault("If-None-Match") == hashed:
+          await req.statusContent(Http304, "", default(RawHeaders))
+        else:
+          await req.statusContent(Http200, file, @{
+            "Content-Type": mimetype,
+            "ETag": hashed
+          })
+      else:
+        let headers = @{
+          "Content-Type": mimetype,
+          "Content-Length": $fileSize
+        }
+        await req.statusContent(Http200, "", headers)
+        var fileStream = newFutureStream[string]("sendStaticIfExists")
+        var file = openAsync(p, fmRead)
+        # Let `readToStream` write file data into fileStream in the
+        # background.
+        asyncCheck file.readToStream(fileStream)
+        # The `writeFromStream` proc will complete once all the data in the
+        # `bodyStream` has been written to the file.
+        while true:
+          let (hasValue, value) = await fileStream.read()
+          if hasValue:
+            await req.client.send(value)
+          else:
+            break
+        file.close()
+      return
+  # If we get to here then no match could be found.
+  return Http404
+
+proc handleFileRequest(req: Request): Future[HttpCode] {.async.} =
+  # Find static file.
+  var reqPath = cgi.decodeUrl(req.url.path)
+  var staticDir = getEnv("staticDir") # it's assumed a relative dir
+  var status = Http400
+  var path = staticDir / reqPath
+  normalizePathEnd(path, false)
+  if dirExists(path):
+    status = await sendStaticIfExists(req, @[path / "index.html", path / "index.htm"])
+  else:
+    status = await sendStaticIfExists(req, @[path])
+  return status
+
+proc handleWs(req: Request) {.async.} =
+  var ws = await newWebSocket(req)
+  await ws.send("Welcome to simple echo server")
+
+  var files: Table[string, Time] = {"path": getLastModificationTime(".")}.toTable
+  let watchedFiles = [absolutePath "app.js", absolutePath "app.html"]
+  for path in watchedFiles:
+    files[path] = getLastModificationTime(path)
+
+  while ws.readyState == Open:
+    await sleepAsync(500)
+    var changed = false
+    for path in watchedFiles:
+      if files[path] != getLastModificationTime(path):
+        changed = true
+        files[path] = getLastModificationTime(path)
+    if changed:
+      await ws.send("refresh")
+      changed = false
+
+proc serveStatic*() =
+  if fileExists("static.env"):
+    var env: DotEnv
+    env = initDotEnv(getCurrentDir(), "static.env")
+    env.overload()
+  else:
+    putEnv("staticDir", "assets/")
+
+  var server = newAsyncHttpServer()
+  proc cb(req: Request) {.gcsafe, async.} =
+    if req.url.path == "/ws":
+      await handleWs(req)
+    if req.url.path == "/":
+      await req.respond(Http200, readFile "app.html")
+    elif req.url.path == "/app.js":
+      let file = absolutePath("app" & ".js")
+      if not file.fileExists:
+        error(file, " does not exist!")
+      if fpUserRead notin os.getFilePermissions(file):
+        error("Could not read ", file, "!")
+      await req.respond(Http200, readFile(file))
+    else:
+      let status = await handleFileRequest(req)
+      if status != Http200:
+        await req.respond(status, "")
+
+  waitFor server.serve(Port(8080), cb)
+
+when isMainModule:
+  serveStatic()

karax/vdom.nim

@@ -35,7 +35,19 @@ type
     mark, ruby, rt, rp, bdi, dbo, span, br, wbr,
     ins, del, img, iframe, embed, `object` = "object",
     param, video, audio, source, track, canvas, map,
-    area, svg, math, path, circle
+    area, math,
+
+    # SVG elements, see: https://www.w3.org/TR/SVG2/eltindex.html
+    animate, animateMotion, animateTransform, circle, clipPath, defs, desc,
+    `discard` = "discard", ellipse, feBlend, feColorMatrix, feComponentTransfer,
+    feComposite, feConvolveMatrix, feDiffuseLighting, feDisplacementMap,
+    feDistantLight, feDropShadow, feFlood, feFuncA, feFuncB, feFuncG, feFuncR,
+    feGaussianBlur, feImage, feMerge, feMergeNode, feMorphology, feOffset,
+    fePointLight, feSpecularLighting, feSpotLight, feTile, feTurbulence,
+    filter, foreignObject, g, image, line, linearGradient, marker, mask,
+    metadata, mpath, path, pattern, polygon, polyline, radialGradient, rect,
+    `set` = "set", stop, svg, switch, symbol, txt = "text", textPath, tspan,
+    unknown, use, view,
 
     table, caption, colgroup, col, tbody, thead,
     tfoot, tr, td, th,
@@ -97,6 +109,13 @@ type
                   ## passed (useful for on-the-fly text completions)
     onload, # img
 
+    ontransitioncancel,
+    ontransitionend,
+    ontransitionrun,
+    ontransitionstart,
+
+    onwheel # fires when the user rotates a wheel button on a pointing device.
+
 macro buildLookupTables(): untyped =
   var a = newTree(nnkBracket)
   for i in low(VNodeKind)..high(VNodeKind):
@@ -298,6 +317,12 @@ proc sameAttrs*(a, b: VNode): bool =
 proc addEventListener*(n: VNode; event: EventKind; handler: EventHandler) =
   n.events.add((event, handler, nil))
 
+when kstring is cstring:
+  proc len(a: kstring): int =
+    # xxx: maybe move where kstring is defined
+    # without this, `n.field.len` fails on js (non web) platform
+    if a == nil: 0 else: a.len
+
 template toStringAttr(field) =
   if n.field.len > 0:
     result.add " " & astToStr(field) & " = " & $n.field

karax/vstyles.nim

@@ -1,5 +1,9 @@
+##[
+see examples/hellostyle.nim
+]##
 
-import macros, kbase
+import std/[macros, strutils]
+import kbase
 
 when defined(js):
   import kdom, jdict
@@ -234,7 +238,10 @@ proc eq*(a, b: VStyle): bool =
     if a[i] != b[i]: return false
   return true
 
-proc setAttr(s: VStyle; a, value: kstring) {.noSideEffect.} =
+proc setAttr*(s: VStyle; a, value: kstring) {.noSideEffect.} =
+  ## inserts (a, value) in sorted order of key `a`
+  # worst case quadratic complexity (if given styles in reverse order), hopefully
+  # not a concern assuming small cardinal
   var i = 0
   while i < s.len:
     if s[i] == a:
@@ -243,8 +250,8 @@ proc setAttr(s: VStyle; a, value: kstring) {.noSideEffect.} =
     elif s[i] > a:
       s.add ""
       s.add ""
-      # insertion point here:
-      for j in countdown(s.len-1, i, 2):
+      # insertion point here, shift all remaining pairs by 2 indexes
+      for j in countdown(s.len-1, i+3, 2):
         s[j] = s[j-2]
         s[j-1] = s[j-3]
       s[i] = a
@@ -289,6 +296,24 @@ proc style*(a: StyleAttr; val: kstring): VStyle {.noSideEffect.} =
     result[] = @[]
   result.setAttr a, val
 
+proc toCss*(a: string): VStyle =
+  ##[
+  See example in hellostyle.nim
+  Allows passing a css string directly, eg:
+  tdiv(style = style((fontStyle, "italic".kstring), (color, "orange".kstring))): discard
+  tdiv(style = "font-style: oblique; color: pink".toCss): discard
+  ]##
+  when defined(js):
+    result = newJSeq[cstring]()
+  else:
+    new(result)
+    result[] = @[]
+  for ai in a.split(";"):
+    var ai = ai.strip
+    if ai.len == 0: continue
+    let aj = ai.strip.split(":", maxsplit=1)
+    result.setAttr(aj[0], aj[1])
+
 when defined(js):
   proc setStyle(d: Style; key, val: cstring) {.importcpp: "#[#] = #", noSideEffect.}
 

readme.md

@@ -0,0 +1,394 @@
+![karax](https://user-images.githubusercontent.com/22755228/117183486-482b2a00-ade0-11eb-88e6-d8eeb28951ca.png)
+
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+ 
+# Karax
+Karax is a framework for developing single page applications in Nim.
+
+## Install
+
+To use Karax you must have nim installed. You can follow the instructions [here](https://nim-lang.org/install.html).
+
+Then you can install karax through nimble:
+``nimble install karax``
+
+## Try Karax
+To try it out, run:
+
+``cd ~/projects # Insert your favourite directory for projects``
+
+``nimble develop karax # This will clone Karax and create a link to it in ~/.nimble``
+
+``cd karax``
+
+``cd examples/todoapp``
+
+``nim js todoapp.nim``
+
+``open todoapp.html``
+
+``cd ../..``
+
+``cd examples/mediaplayer``
+
+``nim js playerapp.nim``
+
+``open playerapp.html``
+
+It uses a virtual DOM like React, but is much smaller than the existing
+frameworks plus of course it's written in Nim for Nim. No external
+dependencies! And thanks to Nim's whole program optimization only what
+is used ends up in the generated JavaScript code.
+
+
+## Goals
+
+
+- Leverage Nim's macro system to produce a framework that allows
+  for the development of applications that are boilerplate free.
+- Keep it small, keep it fast, keep it flexible.
+
+
+
+## Hello World
+
+
+The simplest Karax program looks like this:
+
+```nim
+
+include karax / prelude
+
+proc createDom(): VNode =
+  result = buildHtml(tdiv):
+    text "Hello World!"
+
+setRenderer createDom
+```
+
+Since ``div`` is a keyword in Nim, karax choose to use ``tdiv`` instead
+here. ``tdiv`` produces a ``<div>`` virtual DOM node.
+
+As you can see, karax comes with its own ``buildHtml`` DSL for convenient
+construction of (virtual) DOM trees (of type ``VNode``). Karax provides
+a tiny build tool called ``karun`` that generates the HTML boilerplate code that
+embeds and invokes the generated JavaScript code::
+
+``nim c karax/tools/karun``
+``karax/tools/karun -r helloworld.nim``
+
+Via ``-d:debugKaraxDsl`` we can have a look at the produced Nim code by
+``buildHtml``:
+
+```nim
+
+let tmp1 = tree(VNodeKind.tdiv)
+add(tmp1, text "Hello World!")
+tmp1
+```
+(I shortened the IDs for better readability.)
+
+Ok, so ``buildHtml`` introduces temporaries and calls ``add`` for the tree
+construction so that it composes with all of Nim's control flow constructs:
+
+
+```nim
+
+include karax / prelude
+import random
+
+proc createDom(): VNode =
+  result = buildHtml(tdiv):
+    if rand(100) <= 50:
+      text "Hello World!"
+    else:
+      text "Hello Universe"
+
+randomize()
+setRenderer createDom
+
+```
+Produces:
+
+```nim
+
+let tmp1 = tree(VNodeKind.tdiv)
+if rand(100) <= 50:
+  add(tmp1, text "Hello World!")
+else:
+  add(tmp1, text "Hello Universe")
+tmp1
+```
+
+## Event model
+
+Karax does not change the DOM's event model much, here is a program
+that writes "Hello simulated universe" on a button click:
+
+```nim
+
+include karax / prelude
+# alternatively: import karax / [kbase, vdom, kdom, vstyles, karax, karaxdsl, jdict, jstrutils, jjson]
+
+var lines: seq[kstring] = @[]
+
+proc createDom(): VNode =
+  result = buildHtml(tdiv):
+    button:
+      text "Say hello!"
+      proc onclick(ev: Event; n: VNode) =
+        lines.add "Hello simulated universe"
+    for x in lines:
+      tdiv:
+        text x
+
+setRenderer createDom
+```
+
+``kstring`` is Karax's alias for ``cstring`` (which stands for "compatible
+string"; for the JS target that is an immutable JavaScript string) which
+is preferred for efficiency on the JS target. However, on the native targets
+``kstring`` is mapped  to ``string`` for efficiency. The DSL for HTML
+construction is also avaible for the native targets (!) and the ``kstring``
+abstraction helps to deal with these conflicting requirements.
+
+Karax's DSL is quite flexible when it comes to event handlers, so the
+following syntax is also supported:
+
+```nim
+
+include karax / prelude
+from sugar import `=>`
+
+var lines: seq[kstring] = @[]
+
+proc createDom(): VNode =
+  result = buildHtml(tdiv):
+    button(onclick = () => lines.add "Hello simulated universe"):
+      text "Say hello!"
+    for x in lines:
+      tdiv:
+        text x
+
+setRenderer createDom
+```
+
+The ``buildHtml`` macro produces this code for us:
+
+```nim
+
+let tmp2 = tree(VNodeKind.tdiv)
+let tmp3 = tree(VNodeKind.button)
+addEventHandler(tmp3, EventKind.onclick,
+                () => lines.add "Hello simulated universe", kxi)
+add(tmp3, text "Say hello!")
+add(tmp2, tmp3)
+for x in lines:
+  let tmp4 = tree(VNodeKind.tdiv)
+  add(tmp4, text x)
+  add(tmp2, tmp4)
+tmp2
+```
+As the examples grow larger it becomes more and more visible of what
+a DSL that composes with the builtin Nim control flow constructs buys us.
+Once you have tasted this power there is no going back and languages
+without AST based macro system simply don't cut it anymore.
+
+
+## Attaching data to an event handler
+
+
+Since the type of an event handler is ``(ev: Event; n: VNode)`` or ``()`` any
+additional data that should be passed to the event handler needs to be
+done via Nim's closures. In general this means a pattern like this:
+
+```nim
+
+proc menuAction(menuEntry: kstring): proc() =
+  result = proc() =
+    echo "clicked ", menuEntry
+
+proc buildMenu(menu: seq[kstring]): VNode =
+  result = buildHtml(tdiv):
+    for m in menu:
+      nav(class="navbar is-primary"):
+        tdiv(class="navbar-brand"):
+          a(class="navbar-item", onclick = menuAction(m)):
+```
+
+## DOM diffing
+
+Ok, so now we have seen DOM creation and event handlers. But how does
+Karax actually keep the DOM up to date? The trick is that every event
+handler is wrapped in a helper proc that triggers a *redraw* operation
+that calls the *renderer* that you initially passed to ``setRenderer``.
+So a new virtual DOM is created and compared against the previous
+virtual DOM. This comparison produces a patch set that is then applied
+to the real DOM the browser uses internally. This process is called
+"virtual DOM diffing" and other frameworks, most notably Facebook's
+*React*, do quite similar things. The virtual DOM is faster to create
+and manipulate than the real DOM so this approach is quite efficient.
+
+
+## Form validation
+Most applications these days have some "login"
+mechanism consisting of ``username`` and ``password`` and
+a ``login`` button. The login button should only be clickable
+if ``username`` and ``password`` are not empty. An error
+message should be shown as long as one input field is empty.
+
+To create new UI elements we write a ``loginField`` proc that
+returns a ``VNode``:
+
+```nim
+
+proc loginField(desc, field, class: kstring;
+                validator: proc (field: kstring): proc ()): VNode =
+  result = buildHtml(tdiv):
+    label(`for` = field):
+      text desc
+    input(class = class, id = field, onchange = validator(field))
+```
+
+We use the ``karax / errors`` module to help with this error
+logic. The ``errors`` module is mostly a mapping from strings to
+strings but it turned out that the logic is tricky enough to warrant
+a library solution. ``validateNotEmpty`` returns a closure that
+captures the ``field`` parameter:
+
+```nim
+
+proc validateNotEmpty(field: kstring): proc () =
+  result = proc () =
+    let x = getVNodeById(field).getInputText
+    if x.isNil or x == "":
+      errors.setError(field, field & " must not be empty")
+    else:
+      errors.setError(field, "")
+```
+
+This indirection is required because
+event handlers in Karax need to have the type ``proc ()``
+or ``proc (ev: Event; n: VNode)``. The errors module also
+gives us a handy ``disableOnError`` helper. It returns
+``"disabled"`` if there are errors. Now we have all the
+pieces together to write our login dialog:
+
+
+```nim
+
+# some consts in order to prevent typos:
+const
+  username = kstring"username"
+  password = kstring"password"
+
+var loggedIn: bool
+
+proc loginDialog(): VNode =
+  result = buildHtml(tdiv):
+    if not loggedIn:
+      loginField("Name :", username, "input", validateNotEmpty)
+      loginField("Password: ", password, "password", validateNotEmpty)
+      button(onclick = () => (loggedIn = true), disabled = errors.disableOnError()):
+        text "Login"
+      p:
+        text errors.getError(username)
+      p:
+        text errors.getError(password)
+    else:
+      p:
+        text "You are now logged in."
+
+setRenderer loginDialog
+```
+
+(Full example [here](https://github.com/karaxnim/karax/blob/master/examples/login.nim).)
+
+This code still has a bug though, when you run it, the ``login`` button is not
+disabled until some input fields are validated! This is easily fixed,
+at initialization we have to do:
+
+```nim
+
+setError username, username & " must not be empty"
+setError password, password & " must not be empty"
+```
+There are likely more elegant solutions to this problem.
+
+## Routing
+
+
+For routing ``setRenderer`` can be called with a callback that takes a parameter of
+type ``RouterData``. Here is the relevant excerpt from the famous "Todo App" example:
+
+```nim
+
+proc createDom(data: RouterData): VNode =
+  if data.hashPart == "#/": filter = all
+  elif data.hashPart == "#/completed": filter = completed
+  elif data.hashPart == "#/active": filter = active
+  result = buildHtml(tdiv(class="todomvc-wrapper")):
+    section(class = "todoapp"):
+        ...
+
+setRenderer createDom
+```
+(Full example [here](https://github.com/karaxnim/karax/blob/master/examples/todoapp/todoapp.nim).)
+
+## Server Side HTML Rendering
+
+Karax can also be used to render HTML on the server.  Only a subset of
+modules can be used since there is no JS interpreter.
+
+```nim
+
+import karax / [karaxdsl, vdom]
+
+const places = @["boston", "cleveland", "los angeles", "new orleans"]
+
+proc render*(): string =
+  let vnode = buildHtml(tdiv(class = "mt-3")):
+    h1: text "My Web Page"
+    p: text "Hello world"
+    ul:
+      for place in places:
+        li: text place
+    dl:
+      dt: text "Can I use Karax for client side single page apps?"
+      dd: text "Yes"
+
+      dt: text "Can I use Karax for server side HTML rendering?"
+      dd: text "Yes"
+  result = $vnode
+
+echo render()
+```
+## Generate HTML with event handlers
+
+If you are writing a static site generator or do server-side HTML rendering
+via ``nim c``, you may want to override ``addEventHandler`` when using event
+handlers to avoid compiler complaints.
+
+Here's an example of auto submit a dropdown when a value is selected:
+
+```nim
+
+template kxi(): int = 0
+template addEventHandler(n: VNode; k: EventKind; action: string; kxi: int) =
+  n.setAttr($k, action)
+
+let
+  names = @["nim", "c", "python"]
+  selected_name = request.params.getOrDefault("name")
+  hello = buildHtml(html):
+    form(`method` = "get"):
+      select(name="name", onchange="this.form.submit()"):
+        for name in names:
+          if name == selected_name:
+            option(selected = ""): text name
+          else:
+            option: text name
+```
+
+## License
+MIT License. See [here](https://github.com/karaxnim/karax/blob/master/LICENSE.txt).

readme.rst

@@ -1,355 +0,0 @@
-Karax – Single page applications in Nim |travis|
-================================================
-
-Karax is a framework for developing single page applications in Nim.
-
-To try it out, run::
-
-  cd ~/projects # Insert your favourite directory for projects
-
-  nimble develop karax # This will clone Karax and create a link to it in ~/.nimble
-
-  cd karax
-
-  cd examples/todoapp
-  nim js todoapp.nim
-  open todoapp.html
-  cd ../..
-
-  cd examples/mediaplayer
-  nim js playerapp.nim
-  open playerapp.html
-
-It uses a virtual DOM like React, but is much smaller than the existing
-frameworks plus of course it's written in Nim for Nim. No external
-dependencies! And thanks to Nim's whole program optimization only what
-is used ends up in the generated JavaScript code.
-
-
-Goals
-=====
-
-- Leverage Nim's macro system to produce a framework that allows
-  for the development of applications that are boilerplate free.
-- Keep it small, keep it fast, keep it flexible.
-
-.. |travis| image:: https://travis-ci.org/pragmagic/karax.svg?branch=master
-    :target: https://travis-ci.org/pragmagic/karax
-
-
-Hello World
-===========
-
-The simplest Karax program looks like this:
-
-.. code-block:: nim
-
-  include karax / prelude
-
-  proc createDom(): VNode =
-    result = buildHtml(tdiv):
-      text "Hello World!"
-
-  setRenderer createDom
-
-
-Since ``div`` is a keyword in Nim, karax choose to use ``tdiv`` instead
-here. ``tdiv`` produces a ``<div>`` virtual DOM node.
-
-As you can see, karax comes with its own ``buildHtml`` DSL for convenient
-construction of (virtual) DOM trees (of type ``VNode``). Karax provides
-a tiny build tool called ``karun`` that generates the HTML boilerplate code that
-embeds and invokes the generated JavaScript code::
-
-  nim c karax/tools/karun
-  karax/tools/karun -r helloworld.nim
-
-Via ``-d:debugKaraxDsl`` we can have a look at the produced Nim code by
-``buildHtml``:
-
-.. code-block:: nim
-
-  let tmp1 = tree(VNodeKind.tdiv)
-  add(tmp1, text "Hello World!")
-  tmp1
-
-(I shortened the IDs for better readability.)
-
-Ok, so ``buildHtml`` introduces temporaries and calls ``add`` for the tree
-construction so that it composes with all of Nim's control flow constructs:
-
-
-.. code-block:: nim
-
-  include karax / prelude
-  import random
-
-  proc createDom(): VNode =
-    result = buildHtml(tdiv):
-      if random(100) <= 50:
-        text "Hello World!"
-      else:
-        text "Hello Universe"
-
-  randomize()
-  setRenderer createDom
-
-
-Produces:
-
-.. code-block:: nim
-
-  let tmp1 = tree(VNodeKind.tdiv)
-  if random(100) <= 50:
-    add(tmp1, text "Hello World!")
-  else:
-    add(tmp1, text "Hello Universe")
-  tmp1
-
-
-Event model
-===========
-
-Karax does not change the DOM's event model much, here is a program
-that writes "Hello simulated universe" on a button click:
-
-.. code-block:: nim
-
-  include karax / prelude
-  # alternatively: import karax / [kbase, vdom, kdom, vstyles, karax, karaxdsl, jdict, jstrutils, jjson]
-
-  var lines: seq[kstring] = @[]
-
-  proc createDom(): VNode =
-    result = buildHtml(tdiv):
-      button:
-        text "Say hello!"
-        proc onclick(ev: Event; n: VNode) =
-          lines.add "Hello simulated universe"
-      for x in lines:
-        tdiv:
-          text x
-
-  setRenderer createDom
-
-
-``kstring`` is Karax's alias for ``cstring`` (which stands for "compatible
-string"; for the JS target that is an immutable JavaScript string) which
-is preferred for efficiency on the JS target. However, on the native targets
-``kstring`` is mapped  to ``string`` for efficiency. The DSL for HTML
-construction is also avaible for the native targets (!) and the ``kstring``
-abstraction helps to deal with these conflicting requirements.
-
-Karax's DSL is quite flexible when it comes to event handlers, so the
-following syntax is also supported:
-
-.. code-block:: nim
-
-  include karax / prelude
-  from sugar import `=>`
-
-  var lines: seq[kstring] = @[]
-
-  proc createDom(): VNode =
-    result = buildHtml(tdiv):
-      button(onclick = () => lines.add "Hello simulated universe"):
-        text "Say hello!"
-      for x in lines:
-        tdiv:
-          text x
-
-  setRenderer createDom
-
-
-The ``buildHtml`` macro produces this code for us:
-
-.. code-block:: nim
-
-  let tmp2 = tree(VNodeKind.tdiv)
-  let tmp3 = tree(VNodeKind.button)
-  addEventHandler(tmp3, EventKind.onclick,
-                  () => lines.add "Hello simulated universe", kxi)
-  add(tmp3, text "Say hello!")
-  add(tmp2, tmp3)
-  for x in lines:
-    let tmp4 = tree(VNodeKind.tdiv)
-    add(tmp4, text x)
-    add(tmp2, tmp4)
-  tmp2
-
-As the examples grow larger it becomes more and more visible of what
-a DSL that composes with the builtin Nim control flow constructs buys us.
-Once you have tasted this power there is no going back and languages
-without AST based macro system simply don't cut it anymore.
-
-
-Attaching data to an event handler
-==================================
-
-Since the type of an event handler is ``(ev: Event; n: VNode)`` or ``()`` any
-additional data that should be passed to the event handler needs to be
-done via Nim's closures. In general this means a pattern like this:
-
-.. code-block:: nim
-
-  proc menuAction(menuEntry: kstring): proc() =
-    result = proc() =
-      echo "clicked ", menuEntry
-
-  proc buildMenu(menu: seq[kstring]): VNode =
-    result = buildHtml(tdiv):
-      for m in menu:
-        nav(class="navbar is-primary"):
-          tdiv(class="navbar-brand"):
-            a(class="navbar-item", onclick = menuAction(m)):
-
-
-DOM diffing
-===========
-
-Ok, so now we have seen DOM creation and event handlers. But how does
-Karax actually keep the DOM up to date? The trick is that every event
-handler is wrapped in a helper proc that triggers a *redraw* operation
-that calls the *renderer* that you initially passed to ``setRenderer``.
-So a new virtual DOM is created and compared against the previous
-virtual DOM. This comparison produces a patch set that is then applied
-to the real DOM the browser uses internally. This process is called
-"virtual DOM diffing" and other frameworks, most notably Facebook's
-*React*, do quite similar things. The virtual DOM is faster to create
-and manipulate than the real DOM so this approach is quite efficient.
-
-
-Form validation
-===============
-
-Most applications these days have some "login"
-mechanism consisting of ``username`` and ``password`` and
-a ``login`` button. The login button should only be clickable
-if ``username`` and ``password`` are not empty. An error
-message should be shown as long as one input field is empty.
-
-To create new UI elements we write a ``loginField`` proc that
-returns a ``VNode``:
-
-.. code-block:: nim
-
-  proc loginField(desc, field, class: kstring;
-                  validator: proc (field: kstring): proc ()): VNode =
-    result = buildHtml(tdiv):
-      label(`for` = field):
-        text desc
-      input(class = class, id = field, onchange = validator(field))
-
-We use the ``karax / errors`` module to help with this error
-logic. The ``errors`` module is mostly a mapping from strings to
-strings but it turned out that the logic is tricky enough to warrant
-a library solution. ``validateNotEmpty`` returns a closure that
-captures the ``field`` parameter:
-
-.. code-block:: nim
-
-  proc validateNotEmpty(field: kstring): proc () =
-    result = proc () =
-      let x = getVNodeById(field)
-      if x.text.isNil or x.text == "":
-        errors.setError(field, field & " must not be empty")
-      else:
-        errors.setError(field, "")
-
-This indirection is required because
-event handlers in Karax need to have the type ``proc ()``
-or ``proc (ev: Event; n: VNode)``. The errors module also
-gives us a handy ``disableOnError`` helper. It returns
-``"disabled"`` if there are errors. Now we have all the
-pieces together to write our login dialog:
-
-
-.. code-block:: nim
-
-  # some consts in order to prevent typos:
-  const
-    username = kstring"username"
-    password = kstring"password"
-
-  var loggedIn: bool
-
-  proc loginDialog(): VNode =
-    result = buildHtml(tdiv):
-      if not loggedIn:
-        loginField("Name :", username, "input", validateNotEmpty)
-        loginField("Password: ", password, "password", validateNotEmpty)
-        button(onclick = () => (loggedIn = true), disabled = errors.disableOnError()):
-          text "Login"
-        p:
-          text errors.getError(username)
-        p:
-          text errors.getError(password)
-      else:
-        p:
-          text "You are now logged in."
-
-  setRenderer loginDialog
-
-(Full example `here <https://github.com/pragmagic/karax/blob/master/examples/login.nim>`_.)
-
-This code still has a bug though, when you run it, the ``login`` button is not
-disabled until some input fields are validated! This is easily fixed,
-at initialization we have to do:
-
-.. code-block:: nim
-
-  setError username, username & " must not be empty"
-  setError password, password & " must not be empty"
-
-There are likely more elegant solutions to this problem.
-
-
-Routing
-=======
-
-For routing ``setRenderer`` can be called with a callback that takes a parameter of
-type ``RouterData``. Here is the relevant excerpt from the famous "Todo App" example:
-
-.. code-block:: nim
-
-  proc createDom(data: RouterData): VNode =
-    if data.hashPart == "#/": filter = all
-    elif data.hashPart == "#/completed": filter = completed
-    elif data.hashPart == "#/active": filter = active
-    result = buildHtml(tdiv(class="todomvc-wrapper")):
-      section(class = "todoapp"):
-        ...
-
-  setRenderer createDom
-
-(Full example `here <https://github.com/pragmagic/karax/blob/master/examples/todoapp/todoapp.nim>`_.)
-
-
-Server Side HTML Rendering
-==========================
-
-Karax can also be used to render HTML on the server.  Only a subset of
-modules can be used since there is no JS interpreter.
-
-.. code-block:: nim
-
-  import karax / [karaxdsl, vdom]
-
-  const places = @["boston", "cleveland", "los angeles", "new orleans"]
-
-  proc render*(): string =
-    let vnode = buildHtml(tdiv(class = "mt-3")):
-      h1: text "My Web Page"
-      p: text "Hello world"
-      ul:
-        for place in places:
-          li: text place
-      dl:
-        dt: text "Can I use Karax for client side single page apps?"
-        dd: text "Yes"
-
-        dt: text "Can I use Karax for server side HTML rendering?"
-        dd: text "Yes"
-    result = $vnode
-
-  echo render()