简体繁体 English

之间的区别？

[英]Difference between //, .//, and ..// in XPath?

原文 2020-09-22 13:52:53 7 1 xml/ xpath/ xml-parsing/ robotframework

Can anyone please help with the difference between the below XPaths and help me understand which of these to use when.任何人都可以帮助解决以下 XPath 之间的区别，并帮助我了解何时使用其中的哪些。 I have found all three of them to work but not sure when to use them.我发现它们三个都可以工作，但不确定何时使用它们。

Get Element Text ${output} //priority
Get Element Text ${output} .//vrrp-group/name
Get Element Text ${output} ..//track/priority-hold-time

1 个解决方案

In general一般来说

// selects among descendant or self nodes (along the descendant-or-self axis ). //在后代节点或自身节点之间进行选择（沿descendant-or-self节点descendant-or-self轴）。 It is short for /descendant-or-self::node()/ .它是/descendant-or-self::node()/缩写。

// starts from the root node, thus covering the entire document. //从根节点开始，从而覆盖整个文档。
.// starts from the context node . .//从上下文节点开始。
..// starts from the parent of the context node. ..//从上下文节点的父节点开始。

In your particular case在您的特定情况下

//priority selects all priority elements in the document. //priority选择文档中的所有priority元素。
.//vrrp-group/name selects, beneath the context node, all name elements with a vrrp-group parent. .//vrrp-group/name在上下文节点下选择所有具有vrrp-group父级的name元素。
..//track/priority-hold-time selects, beneath the parent of the context node, all priority-hold-time elements with a track parent. ..//track/priority-hold-time在上下文节点的父节点下选择所有具有track父节点的priority-hold-time元素。

Robotframework note: Robotframework注意事项：

In the context of the Get Element Text Robotframework XML library command, the XPath must be relative to the source node ( ${output} in your case).在Get Element Text Robotframework XML 库命令的上下文中，XPath 必须相对于源节点（在您的情况下${output} ）。 Absolute XPaths such as //priority are not allowed there.那里不允许使用绝对 XPath，例如//priority 。