Eclipse Facelet HTML Validator：无法将表达式运算符应用于方法绑定
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Eclipse Facelet HTML Validator: Cannot apply expression operators to method bindings
提问by Candice
The Eclipse Facelet HTML Validator reports an error "Cannot apply expression operators to method bindings" for the following line:
Eclipse Facelet HTML 验证器针对以下行报告错误“无法将表达式运算符应用于方法绑定”：
<ui:fragment rendered="#{!empty managedBean.getSomething('ENUM_VALUE', someInt)}">
I found this in the Juno help(I'm using Kepler):
我在Juno 帮助中找到了这个（我正在使用开普勒）：
Applying operator to method binding
#{bean.action * 5}
If bean.action indicates a method "action()" on bean, then it is not legal EL to treat its result as a value. In the example, multiplying action by 5 attempts treat it is as a value.
I'm having trouble understanding why it's not legal to treat its result as a value? What's the correct way to write the EL then? Thanks!
我无法理解为什么将其结果视为值是不合法的？那么编写 EL 的正确方法是什么？谢谢！
回答by pasql
If you like you can hide the error message by setting
如果您愿意，可以通过设置隐藏错误消息
Window-> Preferences-> Web-> JavaServer Faces Tool-> Validation -> General Problems
Window-> Preferences-> Web-> JavaServer Faces Tool->Validation -> General Problems
the value Applying method operator to bindingto Ignore.
值Applying method operator to binding到Ignore。
回答by Rash
Have you tried putting paranthesis around your method. Like this:
你有没有试过在你的方法周围加上括号。像这样：
#{!empty (managedBean.getSomething('ENUM_VALUE', someInt))}
This way JSF evaluates the method and then checks for null or empty.
通过这种方式，JSF 会评估该方法，然后检查是否为 null 或为空。
I am no expert in JSF, but I had the same problem in one of the similar expression:
我不是 JSF 方面的专家，但我在一个类似的表达式中遇到了同样的问题：
#{some_method() == 0 and some_other_method() eq 'some value'}
I saw the same issue shown by Eclipse but the page was running correctly. After I put paranthesis around both of my expressions, Eclipse did not show that error.
我看到了 Eclipse 显示的相同问题，但页面运行正常。在我的两个表达式周围加上括号后，Eclipse 没有显示该错误。
