Question

在自定义控件中，有一个重复控件引用文件夹（而不是视图）中的列。文件夹的默认设计可以与自定义控件一起及时更改。因此，可能会发生自定义控件的代码比文件夹的设计更新，因此设计不匹配并且XPage错误输出。

我特别想要的是自定义控件处理与缺少视图/文件夹列或类似设计错误相关的错误。该错误将在某处报告，通知用户他/她可以激活可以修复该情况的内容。

我知道如何捕获JavaScript错误，遗憾的是所有列值都在表达式语言中。当然，我可以重新编码，但我想知道是否有更好的方法。

简而言之：我怎样才能捕获表达式语言错误？

Answer 1

您可以通过添加自己的EL和自己的VariableResolver来捕获PropertyResolver语言错误。为此，您必须创建两个Java类：

变量解析器

package ch.hasselba.xpages.demo;

import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;
import javax.faces.el.EvaluationException;
import javax.faces.el.VariableResolver;

public class ELErrVariableResolver extends VariableResolver {

  private final VariableResolver delegate;

  public ELErrVariableResolver(VariableResolver resolver) {
    delegate = resolver;
  }

  @Override
  public Object resolveVariable(FacesContext context, String name) throws EvaluationException {
      Object variable = null;
      try{
          variable = delegate.resolveVariable(context, name);
      }catch( EvaluationException ee ){
          addResolveErrMessage( context, name );
      }

     return variable;
  }

  public void addResolveErrMessage( FacesContext context , String name ){
      FacesMessage msg = new FacesMessage();
      msg.setSummary( "BAD EL! Variable '" + name + "' not found." );
      msg.setSeverity( FacesMessage.SEVERITY_FATAL );
      context.addMessage("BAD EL!", msg);
  }
}

属性解析器

package ch.hasselba.xpages.demo;

import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;
import javax.faces.el.EvaluationException;
import javax.faces.el.PropertyNotFoundException;
import javax.faces.el.PropertyResolver;

public class ELErrPropertyResolver extends PropertyResolver{

    private final PropertyResolver delegate;

      public ELErrPropertyResolver(PropertyResolver resolver) {
        delegate = resolver;
      }


    @Override
    public Class getType(Object paramObject1, Object paramObject2)
            throws EvaluationException, PropertyNotFoundException {
        Class c = null;
        try{
            c = delegate.getType(paramObject1, paramObject2);
        }catch(Exception e){
            addResolveErrMessage( FacesContext.getCurrentInstance(), paramObject1.toString() + "." + paramObject2.toString() );
        }
        return c;
    }

    @Override
    public Class getType(Object paramObject, int paramInt)
            throws EvaluationException, PropertyNotFoundException {
        Class c = null;
        try{
            c = delegate.getType(paramObject, paramInt);
        }catch(Exception e){
            addResolveErrMessage( FacesContext.getCurrentInstance(), paramObject.toString() + "." + paramInt );
        }
        return c;
    }

    @Override
    public Object getValue(Object paramObject1, Object paramObject2)
            throws EvaluationException, PropertyNotFoundException {
        Object c = null;

        try{
            c = delegate.getValue(paramObject1, paramObject2);
        }catch(Exception e){
            addResolveErrMessage( FacesContext.getCurrentInstance(), paramObject1.toString() + "."  + paramObject2.toString() );
        }
        return c;
    }

    @Override
    public Object getValue(Object paramObject, int paramInt)
            throws EvaluationException, PropertyNotFoundException {
        Object c = null;
        try{
            c = delegate.getValue(paramObject, paramInt);
        }catch(Exception e){
            addResolveErrMessage( FacesContext.getCurrentInstance(), paramObject.toString() + "." + paramInt );
        }
        return c;
    }

    @Override
    public boolean isReadOnly(Object paramObject1, Object paramObject2)
            throws EvaluationException, PropertyNotFoundException {
        boolean c = false;
        try{
            c = delegate.isReadOnly(paramObject1, paramObject2);
        }catch(Exception e){
            addResolveErrMessage( FacesContext.getCurrentInstance(), paramObject1.toString() + "." + paramObject2.toString() );
        }
        return c;
    }

    @Override
    public boolean isReadOnly(Object paramObject, int paramInt)
            throws EvaluationException, PropertyNotFoundException {
        boolean c = false;
        try{
            c = delegate.isReadOnly(paramObject, paramInt);
        }catch(Exception e){
            addResolveErrMessage( FacesContext.getCurrentInstance(), paramObject.toString() + "." + paramInt );
        }
        return c;
    }

    @Override
    public void setValue(Object paramObject1, Object paramObject2,
            Object paramObject3) throws EvaluationException,
            PropertyNotFoundException {
        try{
            delegate.setValue(paramObject1, paramObject2, paramObject3);
        }catch(Exception e){
            addResolveErrMessage( FacesContext.getCurrentInstance(), paramObject1.toString() + "." + paramObject2.toString() );
        }

    }

    @Override
    public void setValue(Object paramObject1, int paramInt, Object paramObject2)
            throws EvaluationException, PropertyNotFoundException {

        try{
            delegate.setValue(paramObject1, paramInt, paramObject2);
        }catch(Exception e){
            addResolveErrMessage( FacesContext.getCurrentInstance(), paramObject1.toString() + "." + paramInt );
        }

    }

    public void addResolveErrMessage( FacesContext context , String name ){
          FacesMessage msg = new FacesMessage();
          msg.setSummary( "BAD EL! Property '" + name + "' not found." );
          msg.setSeverity( FacesMessage.SEVERITY_FATAL );
          context.addMessage("BAD EL!", msg);
      }
}

将新的解析器添加到faces-config.xml：

<?xml version="1.0" encoding="UTF-8"?>
<faces-config>
   <application>
        <variable-resolver>ch.hasselba.xpages.demo.ELErrVariableResolver
        </variable-resolver>
        <property-resolver>ch.hasselba.xpages.demo.ELErrPropertyResolver
        </property-resolver>
    </application>
</faces-config>

在您的CC上添加xp:messages组件以显示您的消息（或更改类中的错误例程以添加您想要的任何内容。

Answer 2

在自定义控件中，您可以检查要使用的文件夹/视图是否正确。 Aka有正确的设计。这可以在beforepageload事件中完成。当设计检查报告错误时，应将其写入日志文件，并向用户显示“nice”消息。

可以使用openntf上的各种日志记录项目来完成错误记录，例如xlogger 当您的代码报告错误时，您可以将名为“displayRepeat”的范围值设置为false。应根据此displayRepeat值呈现重复控件（和其他控件）。

向用户显示不错的错误消息。将错误控件放在控件的顶部并添加以下代码：

facesContext.addMessage( null, 
new javax.faces.application.FacesMessage( "your error message" ) );

如何在XPage中的自定义控件中处理设计错误？

2 个答案: