grails - 缺少 r :layoutResources tag 的异常

Question

我正在使用 grails 2.3.4

但是当我启动我的应用程序时，我得到:

|Server running. Browse to http://localhost:8080/testApplication
....[/testApplication].[gsp] Servlet.service() for servlet [gsp] in context w
ith path [/testApplication] threw exception
java.lang.RuntimeException: It looks like you are missing some calls to the r:la
youtResources tag. After rendering your page the following have not been rendere
d: [defer]
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

        at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstruct
orAccessorImpl.java:57)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingC
onstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
        at org.springsource.loaded.ri.ReflectiveInterceptor.jlrConstructorNewIns
tance(ReflectiveInterceptor.java:986)
        at org.codehaus.groovy.reflection.CachedConstructor.invoke(CachedConstru
ctor.java:77)
        at org.codehaus.groovy.runtime.callsite.ConstructorSite$ConstructorSiteN
oUnwrapNoCoerce.callConstructor(ConstructorSite.java:102)
        at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallConstru
ctor(CallSiteArray.java:57)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor
(AbstractCallSite.java:182)
        at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor
(AbstractCallSite.java:190)
        at org.grails.plugin.resource.DevModeSanityFilter.doFilter(DevModeSanity
Filter.groovy:54)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:210)
        at org.codehaus.groovy.grails.web.servlet.mvc.GrailsWebRequestFilter.doF
ilterInternal(GrailsWebRequestFilter.java:69)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerR
equestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:210)
        at org.codehaus.groovy.grails.web.filters.HiddenHttpMethodFilter.doFilte
rInternal(HiddenHttpMethodFilter.java:67)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerR
equestFilter.java:107)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:210)
        at org.springframework.web.filter.CharacterEncodingFilter.doFilterIntern
al(CharacterEncodingFilter.java:88)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerR
equestFilter.java:107)
        at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(D
elegatingFilterProxy.java:343)
        at org.springframework.web.filter.DelegatingFilterProxy.doFilter(Delegat
ingFilterProxy.java:260)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:243)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:210)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperV
alve.java:222)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextV
alve.java:123)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.j
ava:171)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.j
ava:100)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineVal
ve.java:118)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.jav
a:408)
        at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp
11Processor.java:1041)
        at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(
AbstractProtocol.java:603)
        at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoin
t.java:310)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.
java:1110)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor
.java:603)
        at java.lang.Thread.run(Thread.java:722)

我的 index.gsp 文件如下所示:

<html ng-app>
<head>
<meta name="layout" content="main" />
<title>Title Page</title>

<!-- here we are loading angularjs -->

    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.8/angular.min.js"></script>

    <!-- other way: <script src="" $ {resource(dir: 'js/lib', file: 'file.js')}"></script>  -->
<!-- <r:require module="angular" />
<r:layoutResources />
 -->
</head>
<body>
    <div>
        <div>
          <label>Name:</label>
          <input type="text" ng-model="yourName" placeholder="Enter a name here">
          <hr>
          <h1>Hello {{yourName}}!</h1>
        </div>
    </div>
</body>
</html>

如您所见，标签已被注释掉。那么为什么我会得到这个以及如何解决这个长期的异常呢？

非常感谢您的回答!

Answer 1

<r:layoutResources/>应该在您的页面中出现两次(或更常见的是在您的布局 GSP 中)- 一次在 </head> 之前在 </body> 之前以“head”配置和再次渲染资源呈现“延迟”的。这是错误消息所提示的缺少的第二次出现，第一次并没有真正“注释掉”(它在 HTML 注释内，因此仍会呈现，但其输出将在生成的 HTML 中被注释掉)。

因此，您需要“取消注释”第一个匹配项并添加第二个匹配项，或者确保您的页面使用的布局包含 <r:layoutResources/>标记在正确的位置。