6
我一直在閱讀本教程：http://tylermcginnis.com/reactjs-tutorial-a-comprehensive-guide-to-building-apps-with-react/，並且在使用Nashorn在JVM上呈現React時遇到問題。使用JVM Nashorn（Play Framework）渲染React.js時出錯。我得到「null不是函數」
我的App.js文件如下。它在客戶端上運行時正常工作。給出了一個錯誤只是用犀牛/ JVM時：
var App = React.createClass({
getInitialState: function(){
return {
name: 'Tyler McGinnis',
friends: ['Jake Lingwall', 'Murphy Randall', 'Merrick Christensen'],
}
},
addFriend: function(friend){
this.setState({
friends: this.state.friends.concat([friend])
});
},
render: function(){
return (
<div>
<h3> Name: {this.state.name} </h3>
<AddFriend addNew={this.addFriend} />
<ShowList names={this.state.friends} />
</div>
)
}
});
var AddFriend = React.createClass({
getInitialState: function(){
return {
newFriend: ''
}
},
updateNewFriend: function(e){
this.setState({
newFriend: e.target.value
});
},
handleAddNew: function(){
this.props.addNew(this.state.newFriend);
this.setState({
newFriend: ''
});
},
render: function(){
return (
<div>
<input type="text" value={this.state.newFriend} onChange={this.updateNewFriend} />
<button onClick={this.handleAddNew}> Add Friend </button>
</div>
);
}
});
var ShowList = React.createClass({
render: function(){
var listItems = this.props.names.map(function(friend){
return <li> {friend} </li>;
});
return (
<div>
<h3> Friends </h3>
<ul>
{listItems}
</ul>
</div>
)
}
});
我的JVM代碼：
ScriptEngine engine = new ScriptEngineManager(null).getEngineByName("nashorn");
String script = "var global = this;" +
"console = {log: print, warn: print, error: print};";
engine.eval (script);
// Evaluate React and the application code.
engine.eval(new FileReader("target/web/web-modules/main/webjars/lib/react/react-with-addons.js"));
engine.eval(new FileReader("target/web/public/main/javascripts/components/App.js"));
html = engine.eval("React.renderToString(React.createElement(App));").toString();
當我運行這段代碼，我得到的後續堆棧跟蹤錯誤：
Warning: ReactDOMButton(...): No `render` method found on the returned component instance: you may have forgotten to define `render` in your component or you may have accidentally tried to render an element whose type is a function that isn't a React component.
Warning: getInitialState was defined on ReactDOMButton, a plain JavaScript class. This is only supported for classes created using React.createClass. Did you mean to define a state property instead?
javax.script.ScriptException: TypeError: null is not a function in <eval> at line number 7395
at jdk.nashorn.api.scripting.NashornScriptEngine.throwAsScriptException(NashornScriptEngine.java:586)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:570)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:525)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:521)
at jdk.nashorn.api.scripting.NashornScriptEngine.eval(NashornScriptEngine.java:192)
at javax.script.AbstractScriptEngine.eval(AbstractScriptEngine.java:264)
at controllers.Application.index(Application.java:50)
at Routes$$anonfun$routes$1$$anonfun$applyOrElse$1$$anonfun$apply$1.apply(routes_routing.scala:80)
at Routes$$anonfun$routes$1$$anonfun$applyOrElse$1$$anonfun$apply$1.apply(routes_routing.scala:80)
at play.core.Router$HandlerInvokerFactory$$anon$4.resultCall(Router.scala:264)
at play.core.Router$HandlerInvokerFactory$JavaActionInvokerFactory$$anon$15$$anon$1.invocation(Router.scala:255)
at play.core.j.JavaAction$$anon$1.call(JavaAction.scala:55)
at play.core.j.JavaAction$$anonfun$11.apply(JavaAction.scala:82)
at play.core.j.JavaAction$$anonfun$11.apply(JavaAction.scala:82)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
at play.core.j.HttpExecutionContext$$anon$2.run(HttpExecutionContext.scala:40)
at play.api.libs.iteratee.Execution$trampoline$.execute(Execution.scala:46)
at play.core.j.HttpExecutionContext.execute(HttpExecutionContext.scala:32)
at scala.concurrent.impl.Future$.apply(Future.scala:31)
at scala.concurrent.Future$.apply(Future.scala:485)
at play.core.j.JavaAction$class.apply(JavaAction.scala:82)
at play.core.Router$HandlerInvokerFactory$JavaActionInvokerFactory$$anon$15$$anon$1.apply(Router.scala:252)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4$$anonfun$apply$5.apply(Action.scala:130)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4$$anonfun$apply$5.apply(Action.scala:130)
at play.utils.Threads$.withContextClassLoader(Threads.scala:21)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4.apply(Action.scala:129)
at play.api.mvc.Action$$anonfun$apply$1$$anonfun$apply$4.apply(Action.scala:128)
at scala.Option.map(Option.scala:145)
at play.api.mvc.Action$$anonfun$apply$1.apply(Action.scala:128)
at play.api.mvc.Action$$anonfun$apply$1.apply(Action.scala:121)
at play.api.libs.iteratee.Iteratee$$anonfun$mapM$1.apply(Iteratee.scala:483)
at play.api.libs.iteratee.Iteratee$$anonfun$mapM$1.apply(Iteratee.scala:483)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMapM$1.apply(Iteratee.scala:519)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMapM$1.apply(Iteratee.scala:519)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMap$1$$anonfun$apply$14.apply(Iteratee.scala:496)
at play.api.libs.iteratee.Iteratee$$anonfun$flatMap$1$$anonfun$apply$14.apply(Iteratee.scala:496)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.liftedTree1$1(Future.scala:24)
at scala.concurrent.impl.Future$PromiseCompletingRunnable.run(Future.scala:24)
at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:41)
at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: <eval>:7395 TypeError: null is not a function
at jdk.nashorn.internal.runtime.ECMAErrors.error(ECMAErrors.java:58)
at jdk.nashorn.internal.runtime.ECMAErrors.typeError(ECMAErrors.java:214)
at jdk.nashorn.internal.runtime.ECMAErrors.typeError(ECMAErrors.java:186)
at jdk.nashorn.internal.runtime.ECMAErrors.typeError(ECMAErrors.java:173)
at jdk.nashorn.internal.runtime.linker.NashornBottomLinker.linkNull(NashornBottomLinker.java:176)
at jdk.nashorn.internal.runtime.linker.NashornBottomLinker.getGuardedInvocation(NashornBottomLinker.java:66)
at jdk.internal.dynalink.support.CompositeGuardingDynamicLinker.getGuardedInvocation(CompositeGuardingDynamicLinker.java:124)
at jdk.internal.dynalink.support.LinkerServicesImpl.getGuardedInvocation(LinkerServicesImpl.java:144)
at jdk.internal.dynalink.DynamicLinker.relink(DynamicLinker.java:232)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:7393(<eval>:7395)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:7412(<eval>:7421)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:535)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.apply(NativeFunction.java:130)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:13839$L:13899$L:13902(<eval>:13909)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:6750(<eval>:6855)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:541)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.apply(NativeFunction.java:130)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:13839$L:13899$L:13902(<eval>:13909)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:14682$L:14719(<eval>:14720)
at jdk.nashorn.internal.scripts.Script$\^eval\_$14.L:4-1$L:13161$L:13341(<eval>:13353)
at jdk.nashorn.internal.scripts.Script$\^eval\_$9.L:4-1$L:7866$L:8127(<eval>:8153)
at jdk.nashorn.internal.scripts.Script$\^eval\_$9.L:4-1$L:7866$L:8057(<eval>:8063)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:14682$L:14719(<eval>:14720)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:6750(<eval>:6869)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:541)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.apply(NativeFunction.java:130)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:13839$L:13899$L:13902(<eval>:13909)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:14682$L:14719(<eval>:14720)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:6750(<eval>:6869)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:541)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.apply(NativeFunction.java:130)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:13839$L:13899$L:13902(<eval>:13909)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:14682$L:14719(<eval>:14720)
at jdk.nashorn.internal.scripts.Script$\^eval\_$14.L:4-1$L:13161$L:13341(<eval>:13353)
at jdk.nashorn.internal.scripts.Script$\^eval\_$9.L:4-1$L:7866$L:8127(<eval>:8153)
at jdk.nashorn.internal.scripts.Script$\^eval\_$9.L:4-1$L:7866$L:8057(<eval>:8063)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:14682$L:14719(<eval>:14720)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:6750(<eval>:6869)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:541)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.apply(NativeFunction.java:130)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:13839$L:13899$L:13902(<eval>:13909)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:14682$L:14719(<eval>:14720)
at jdk.nashorn.internal.scripts.Script$\^eval\_$8.L:4-1$L:6628$L:6750(<eval>:6869)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:541)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.apply(NativeFunction.java:130)
at jdk.nashorn.internal.scripts.Script$\^eval\_$15.L:4-1$L:13839$L:13899$L:13902(<eval>:13909)
at jdk.nashorn.internal.scripts.Script$\^eval\_$16.L:4-1$L:14906$renderToString$L:14945(<eval>:14948)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:535)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.internal.objects.NativeFunction.call(NativeFunction.java:162)
at jdk.nashorn.internal.scripts.Script$\^eval\_$19.L:4-1$L:18201$L:18319(<eval>:18335)
at jdk.nashorn.internal.scripts.Script$\^eval\_$16.L:4-1$L:14906$renderToString(<eval>:14945)
at jdk.nashorn.internal.scripts.Script$\^eval\_.runScript(<eval>:1)
at jdk.nashorn.internal.runtime.ScriptFunctionData.invoke(ScriptFunctionData.java:535)
at jdk.nashorn.internal.runtime.ScriptFunction.invoke(ScriptFunction.java:209)
at jdk.nashorn.internal.runtime.ScriptRuntime.apply(ScriptRuntime.java:378)
at jdk.nashorn.api.scripting.NashornScriptEngine.evalImpl(NashornScriptEngine.java:568)
... 43 more
如果我刪除此行：
<button onClick={this.handleAddNew}> Add Friend </button>
fr在AddFriend渲染函數中，錯誤消失。
編輯
如果我嘗試打印按鈕元素的上述結果，通過執行以下操作：
function makeString(button){
var objStr = '';
for (var member in button) {
objStr += (objStr ? ',\n': '')+
member + ':' + button[member] + '';
}
return objStr;
}
var button = React.createElement("button", {onClick: this.handleAddNew}, " Add Friend ")
var bs = makeString(button);
bs += '\n\n*****_owner:\n\n';
bs += makeString(button['_owner']);
bs += '\n\n*****_context:\n\n';
bs += makeString(button['_context']);
bs += '\n\n*****_store:\n\n';
bs += makeString(button['_store']);
bs += '\n\n*****props:\n\n';
bs += makeString(button['props']);
console.log(bs);
我得到以下打印出來：從http://pastebin.com/raw.php?i=hEMkN8UP
下面是一個人使用犀牛渲染反應的博客文章：。HTTP：// winterbe。 com/posts/2015/02/16/isomorphic-react-webapps-on-the-jvm /你似乎有一個錯誤「ReactDOMButton（...）：沒有找到'render'方法」，你確定React你在拉扯的是「猶太教」？當你刪除
我確信我拉的猶太教是潔淨的，它與瀏覽器中使用的確切反應相同，並且工作正常。