使用带迭代的 xf:setvalue 函数时如何引用位置 [英] How to refer to position when using xf:setvalue function with iterate

问题描述

考虑到这一点 代码 示例和这篇文章

Considering this code example and this post

...
<xf:action>
<xf:setvalue
            iterate="instance('fr-send-submission-params')/@*"
            ref="."
            value="event(name(context()))"/>
</xf:action>
...

如何引用当前的迭代位置?喜欢 value="position()"

How can refer to current iterated position? Like value="position()"

我可以将此位置用作 xpath 表达式的变量吗?喜欢 ref="/AnotherElement[position()]"

Can i use this position as variable to xpath expressions? Like ref="/AnotherElement[position()]"

推荐答案

以下作品:

<xf:action iterate="instance('fr-send-submission-params')/@*">
    <xf:var name="p" value="position()"/>
    <xf:setvalue ref="." value="$p"/>
</xf:action>

我认为你不能只使用 xf:setvalue，因为 ref 将表达式的计算上下文更改为单个项目，这意味着 position() 在 value 内返回 1.

I don't think you can get away just with xf:setvalue, because ref changes the evaluation context of the expression to a single item which means that position() returns 1 within value.

我看到您对属性进行迭代的警告:我认为不能保证属性位置是一致的.

A warning as I see that you iterate on attributes: I don't think that attribute position is guaranteed to be consistent.

更新:

如果您有元素，则以下内容有效，但是您需要了解 xf:setvalue 中迭代的项目:

The following works if you have elements, but then you need to have knowledge of the items iterated within the xf:setvalue:

<xf:setvalue
    event="DOMActivate"
    iterate="value"
    ref="."
    value="count(preceding-sibling::value) + 1"/>

所以我认为带有封闭操作的选项要清晰得多.

So I think that the option with an enclosing action is much clearer.

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