# HG changeset patch
# User Jaroslav Tulach <jaroslav.tulach@apidesign.org>
# Date 1401260868 -7200
# Node ID 5186733b7e07b8640fa702ef7c2593ee11a05f9b
# Parent  ace1ff1087e771eb8c5620db1c8a394f9b4e2caa
Load scripts asynchronously

diff -r ace1ff1087e7 -r 5186733b7e07 rt/vm/src/main/java/org/apidesign/vm4brwsr/VM.java
--- a/rt/vm/src/main/java/org/apidesign/vm4brwsr/VM.java	Tue May 27 16:36:07 2014 +0200
+++ b/rt/vm/src/main/java/org/apidesign/vm4brwsr/VM.java	Wed May 28 09:07:48 2014 +0200
@@ -487,16 +487,34 @@
                 + "    name = replaceAll(name, '.', '_');\n"
                 + "    return name;\n"
                 + "  };\n"
+                + "  var pending = [];\n"
+                + "  var pendingClasses = [];\n"
+                + "  function extensionLoaded(ev) {\n"
+                + "    var at = pending.indexOf(ev.target);\n"
+                + "    pending.splice(at, 1);\n"
+                + "    if (pending.length === 0) {\n"
+                + "      for (var i = 0; i < pendingClasses.length; i += 2) {\n"
+                + "        var vm = pendingClasses[i];\n"
+                + "        var n = pendingClasses[i + 1];\n"
+                + "        vm.loadClass(n);\n"
+                + "      }\n"
+                + "      pendingClasses = [];\n"
+                + "    }\n"
+                + "  }\n"
+                + "  function extensionError(ev) {\n"
+                + "    console.log('error loading ' + ev.target.src);\n"
+                + "    extensionLoaded(ev);\n"
+                + "  }\n"
                 + "  function loadExtension(url) {\n"
                 + "      if (url.substring(url.length - 4) == '.jar')\n"
                 + "        url = url.substring(0, url.length - 4) + '.js';\n"
-                + "      var xhr = new XMLHttpRequest();\n"
-                + "      xhr.open('GET', url, false);\n"
-                + "      xhr.send();\n"
                 + "      var script = document.createElement('script');\n"
                 + "      script.type = 'text/javascript';\n"
-                + "      script.text = xhr.responseText;\n"
+                + "      script.src = url;\n"
+                + "      script.onload = extensionLoaded;\n"
+                + "      script.onerror = extensionError;\n"
                 + "      document.getElementsByTagName('head')[0].appendChild(script);\n"
+                + "      pending.push(script);\n"
                 + "  }\n"
                 + "  global.bck2brwsr = function() {\n"
                 + "    var args = Array.prototype.slice.apply(arguments);\n"
@@ -570,7 +588,7 @@
                 + "        ['load__Ljava_lang_Object_2Ljava_lang_Object_2Ljava_lang_String_2_3Ljava_lang_Object_2_3B']\n"
                 + "        (vm, name, args, arr);\n"
                 + "    };\n"
-                + "    loader.loadClass = function(name) {\n"
+                + "    var loadClass = function(name) {\n"
                 + "      var attr = mangleClass(name);\n"
                 + "      var fn = vm[attr];\n"
                 + "      if (fn) return fn(false);\n"
@@ -586,10 +604,22 @@
                 + "    if (vm['loadClass']) {\n"
                 + "      throw 'Cannot initialize the bck2brwsr VM twice!';\n"
                 + "    }\n"
-                + "    vm['loadClass'] = loader.loadClass;\n"
+                + "    vm['loadClass'] = loadClass;\n"
                 + "    vm['_reload'] = reload;\n"
                 + "    vm['loadBytes'] = loadBytes;\n"
                 + "    initVM();\n"
+                + "    loader.loadClass = function(name) {\n"
+                + "      if (pending.length === 0) {\n"
+                + "        try {\n"
+                + "          return loadClass(name);\n"
+                + "        } catch (err) {\n"
+                + "          if (pending.length === 0) throw err;\n"
+                + "        }\n"
+                + "      }\n"
+                + "      pendingClasses.push(vm);\n"
+                + "      pendingClasses.push(name);\n"
+                + "      return null;\n"
+                + "    }\n"
                 + "    return loader;\n"
                 + "  };\n");
             append(