Re: [xsl] Group by Element based on Attribute inside container using 1.0

[Michael Ludwig <mlu@xxxxxxxxxxxxx>]

Friend, Darris E schrieb:
> Outstanding! I did a little research on the Sort. Your method did sort
> by year, but not exactly the way I wanted. Partly because I did not
> mention the most recent year first.

And partly, and probably more significantly, because one of my substring
expressions was wrong. I wrote substring( $date, 6, 4) to select the
year part of the string "DD/MM/YYYY", but that selects "/YYY" whereas it
should be "YYYY", which requires substring( $date, 7, 4). As I wrote,
substring() in XPath is 1-based, not 0-based.

So the last digit of the year wasn't taken into account, which provided
a wrong result.

> I altered your statement removing the concat and two substrings (also
> note the third argument for substring is dropped) and produced the
> following:
>
> <xsl:sort select="substring( ObjectClassField[ @name = 'Date
> Inspected'], 6)" order="descending"/>

This sorts on "/YYYY", and it accidentally works here, as in your data
sample there don't seem to be two inspections in one year. It would be
more robust, however, to use either YYYYMMDD:

<xsl:sort select="concat(
  substring( ObjectClassField[ @name = $inspected], 7, 4),
  substring( ObjectClassField[ @name = $inspected], 1, 2),
  substring( ObjectClassField[ @name = $inspected], 4, 2))"/>

Or YYYY, then MM, then DD:

<xsl:sort select="substring(ObjectClassField[@name = $inspected], 7, 4)"/>
<xsl:sort select="substring(ObjectClassField[@name = $inspected], 1, 2)"/>
<xsl:sort select="substring(ObjectClassField[@name = $inspected], 4, 2)"/>

With a variable $inspected defined outside the xsl:apply-templates or
xsl:for-each that is sorted:

<xsl:variable name="inspected" select="'Date Inspected'"/>

And of course sorting years as strings only works when they all have the
same number of digits, so in order to sort years like -44 (44 BC), 0,
800, or 10123, you want:

<xsl:sort select="Year" data-type="number"/>

But then, you'd also need some more intelligent substring work to parse
the dates.

> Thank you for your help and patience.
> darris

You're very welcome, thanks for reporting back.

Michael Ludwig