使用 XSLT 和 XPath 计算元素最大属性值失败 [英] Calculating element max attribute value fails using XSLT and XPath
问题描述
我正在编写 ui.xsl 以将 ui.xml 转换为 ui.html.ui.xml 是:
I am coding a ui.xsl to translate ui.xml into ui.html. The ui.xml is:
<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<layout class="QGridLayout" name="gridLayout_2">
<item row="8" column="1" colspan="12">
</item>
<item row="11" column="1" colspan="2">
</item>
<item row="11" column="3" colspan="2">
</item>
<item row="11" column="5" colspan="2">
</item>
<item row="11" column="7" colspan="3">
</item>
<item row="1" column="6" colspan="3">
</item>
<item row="2" column="1" colspan="3">
</item>
<item row="2" column="0">
</item>
<item row="3" column="1" colspan="3">
</item>
<item row="6" column="1">
</item>
<item row="6" column="2" colspan="4">
</item>
<item row="3" column="9">
</item>
<item row="7" column="0">
</item>
<item row="7" column="1" colspan="12">
</item>
<item row="3" column="12">
</item>
<item row="4" column="0">
</item>
<item row="4" column="6" colspan="3">
</item>
<item row="4" column="9">
</item>
<item row="4" column="10">
</item>
<item row="10" column="1" colspan="12">
</item>
<item row="4" column="11">
</item>
<item row="4" column="12">
</item>
<item row="5" column="0">
</item>
<item row="5" column="1" colspan="3">
</item>
<item row="5" column="6" colspan="2">
</item>
<item row="5" column="9">
</item>
<item row="5" column="11">
</item>
<item row="5" column="12">
</item>
<item row="1" column="0">
</item>
<item row="4" column="1" colspan="3">
</item>
<item row="4" column="4">
</item>
<item row="2" column="12">
</item>
<item row="3" column="0">
</item>
<item row="1" column="1" colspan="3">
</item>
<item row="9" column="1" colspan="12">
</item>
<item row="1" column="9">
</item>
<item row="3" column="6" colspan="3">
</item>
<item row="1" column="11">
</item>
<item row="1" column="12">
</item>
<item row="3" column="11">
</item>
<item row="2" column="11">
</item>
<item row="0" column="8">
</item>
</layout>
</ui>
我的 ui.xsl 是:
My ui.xsl is:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:fn="http://www.w3.org/2005/xpath-functions">
<xsl:output method="html" />
<xsl:variable name="maxRow" select="/ui/layout/item
[
(@row >= preceding-sibling::item/@row) and
(@row >= following-sibling::item/@row)
]/@row" />
<xsl:variable name="maxCol" select="/ui/layout/item
[
(@column >= preceding-sibling::item/@column) and
(@column >= following-sibling::item/@column)
]/@column" />
<xsl:template match="/">
<html>
<head>
<title>
</title>
</head>
<body>
<p>
maxRow = <xsl:value-of select="$maxRow"/>
maxCol = <xsl:value-of select="$maxCol"/>
</p>
</body>
</html>
</xsl:template>
</xsl:stylesheet>
我希望我能看到 ui.html 有maxRow = 11"；和maxCol = 12"；但是，结果如下:
I am hoping that I can see the ui.html has "maxRow = 11" and "maxCol = 12"; However, here is the result:
<html xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:fn="http://www.w3.org/2005/xpath-functions">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title></title>
</head>
<body><p>
maxRow = 11
maxCol = 1</p></body>
</html>
所以我的问题是这里有什么问题?为什么我可以正确获得 maxRow 但不能正确获得 maxCol?代码逻辑一样，只是两个不同的属性.
So my question here is what's wrong here? Why I can get maxRow correctly but not for maxCol? The code logic is the same, just two different attributes.
推荐答案
所以我的问题是这里有什么问题?
So my question here is what's wrong here?
您的测试与您认为的不同:
Your test does not do what you think it does:
@row >= preceding-sibling::item/@row
对于任何 @row 大于或等于至少一个 其前面的兄弟时返回真.这意味着它适用于许多值，而不仅仅是最大的值.
will return true for any @row that is greater than or equal to at least one of its preceding siblings. That means it will be true for many values, not only the largest one/s.
而且由于您显然使用的是 XSLT 1.0 处理器，尽管您的样式表被标记为 version="2.0"，您将获得满足此条件的第一个值，即值来自第二个 item.
And since you're obviously using an XSLT 1.0 processor, despite your stylesheet being tagged with version="2.0", you will get the first value that meets this condition, i.e. the value from the 2nd item.
您获得 @row 的预期结果纯属巧合.
The fact that you are getting the expected result for the @row is pure coincidence.
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