Notes on software and the ideas behind it

Find the meaning
behind the code.

I’m Fred Yang. I write about software—how it works, why it behaves the way it does, and the ideas that make code easier to reason about.

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Working notes / 2026

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Architecture, reactivity, and the hidden relationships that shape frontend systems.

xslt

Save the transform result in a variable for reuse

<span xmlns=''><p><span style='font-family:Consolas'><span style='color:blue'><</span><span style='color:#2b91af'>xsl:variable</span><span style='color:blue'> </span><span style='color:red'>name</span><span style='color:blue'>=</span>"<span style='color:blue'>orderMarkup</span>"<span style='color:blue'>> </span></span></p><p><span style='font-family:Consolas'><span style='color:blue'>    <</span><span style='color:#2b91af'>xsl:apply-templates</span><span style='color:blue'> </span><span style='color:red'>select</span><span style='color:blue'>=</span>"<span style='color:blue'>/Customer/Order</span>"<span style='color:blue'> /> </span></span></p><p><span style='font-family:Consolas'><span style='color:blue'></</span><span style='color:#2b91af'>xsl:variable</span><span style='color:blue'>> </span></span></p><p>  </p><p>To reuse the markup </p><p><span style='font-family:Consolas'><span...
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xslt

Xslt variable(node set)

<span xmlns=''><p>  </p><p><span style='font-family:Consolas'><span style='color:blue'><</span><span style='color:#2b91af'>xsl:variable</span><span style='color:blue'> </span><span style='color:red'>name</span><span style='color:blue'> =</span>"<span style='color:blue'>persons</span>"<span style='color:blue'> </span><span style='color:red'>select</span><span style='color:blue'>=</span>"<span style='color:blue'>/all/persons/p</span>"<span style='color:blue'> /> </span></span></p><p><span style='font-family:Consolas'><span style='color:blue'><</span><span style='color:#2b91af'>xsl:variable</span><span style='color:blue'> </span><span style='color:red'>name</span><span style='color:blue'> =</span>"<span style='color:blue'>persons1</span>"<span style='color:blue'>> </span></span></p><p><span style='font-family:Consolas'><span style='color:blue'>    <</span><span style='color:#2b91af'>xsl:copy-of</span><span...
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xslt

msxsl:node-set

<div xmlns='http://www.w3.org/1999/xhtml'> <xsl:variable name="stringArray"> <age>1</age> <age>1</age> <age>1</age> </xsl:variable>
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xslt

xslt variable inmutable

Once a variable’s value is set, it cannot be changed. But you can number nodes using theposition() function, count nodes with the count() function, sum their values with the sum() function, averagethem with the...
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xslt

xpath 1.0 lowercase

translate(Series, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', 'abcdefghijklmnopqrstuvwxyz')Powered by ScribeFire.
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