XPath 检查节点为空 [英] XPath Check Node is Blank
问题描述
使用XPath，如何检查节点或标签值是否为空?
给定示例 XML:
问题(以下需要 XPath 表达式):
1. 我将如何检查 ExceptionMessage1 是否为空.
2. 我将如何检查 ExceptionMessage2 @nil == true?
3.如果有ExceptionMessage3怎么办，可以是:
一种.包含异常消息
湾没有消息，@nil="true"(组合 ExceptionMessage1 和 ExceptionMessage2 行为)
<身体><SellResponse><SellResult><ExceptionMessage1>JourneyManager.SellJourney(segment):Segment 已经在不同的服务等级下预订</ExceptionMessage1><ExceptionMessage2 nil="true"/><NSProcessTime>0</NSProcessTime><ProcessTime>0</ProcessTime><预订 nil="true"/><成功 nil="true"/><警告 nil="true"/><错误 nil="true"/><OtherServiceInformations nil="true"/></SellResult></SellResponse></身体></信封> TIA
检查 ExceptionMessage1 是否为空"
如果 ExceptionMessage1 有子节点(非空)，下面应该返回 true 否则返回 false :
not(//ExceptionMessage1/node())<块引用>
检查 ExceptionMessage2 @nil == true 是否为真"
这很简单，我认为:
boolean(//ExceptionMessage2/@nil = 'true')<块引用>
使用 ExceptionMessage3，我想检查它是否不为空或 nil=true"
以下 XPath 返回 true，如果有 ExceptionMessage3 不是空白或属性 nil 等于 'true' :
boolean(//ExceptionMessage3[node() or @nil='true'])如果上下文明确需要布尔值，您可以省略 boolean() 调用.在这种情况下，转换将自动进行.
Using XPath, how to check if the node or tag value is blank?
Given the Sample XML:
Questions (Need XPath expression for the following):
1. how will I check if ExceptionMessage1 is blank.
2. how will I check if ExceptionMessage2 @nil == true?
3. how about if there will be ExceptionMessage3, it can either be:
a. Contains exception message
b. No message, with @nil="true" (Combined ExceptionMessage1 & ExceptionMessage2 behaviors)
<Envelope>
<Body>
<SellResponse>
<SellResult>
<ExceptionMessage1>JourneyManager.SellJourney(segment): Segment already booked under different class of service</ExceptionMessage1>
<ExceptionMessage2 nil="true"/>
<NSProcessTime>0</NSProcessTime>
<ProcessTime>0</ProcessTime>
<Booking nil="true"/>
<Success nil="true"/>
<Warning nil="true"/>
<Error nil="true"/>
<OtherServiceInformations nil="true"/>
</SellResult>
</SellResponse>
</Body>
</Envelope>
TIA
"check if ExceptionMessage1 is blank"
The following should return true if ExceptionMessage1 has child node (not blank) and return false otherwise :
not(//ExceptionMessage1/node())
"check if ExceptionMessage2 @nil == true"
This is straightforward, I think :
boolean(//ExceptionMessage2/@nil = 'true')
"With ExceptionMessage3, I want to check if it is not blank or nil=true"
The following XPath returns true, if there is ExceptionMessage3 that is not blank or has attribute nil equals 'true' :
boolean(//ExceptionMessage3[node() or @nil='true'])
You might be able to omit boolean() call if the context explicitly expects a boolean value. The conversion will be automatic in that case.
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