Re: [xsl] xsl:for-each-group help needed !

["Imsieke, Gerrit, le-tex gerrit.imsieke@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Hi Martin,

Does your code handle this input?

<blocks>
  <block id="i1">content</block>
  <block id="i2" width="33">content</block>
  <block id="i3" width="67">content</block>
  <block id="i4" width="50">content</block>
  <block id="i5" width="50">content</block>
  <block id="i6" width="25">content</block>
  <block id="i6a" width="80">content</block>
  <block>content</block>
  <block id="i7" width="55">content</block>
  <block id="i8" width="20">content</block>
  <block id="i9">content</block>
</blocks>

i6 and i6a, taken together, have a width of 105. I guess then i6a needs 
to be on a new line.

I introduced an accumulator that can have two values:

<xsl:accumulator name="width" as="xs:integer+" initial-value="0">
  <xsl:accumulator-rule match="blocks" select="0"/>
  <xsl:accumulator-rule match="block"
    select="let $line-width-so-far := $value[1],
                $current-width := xs:integer((@width, 100)[1]),
                $would-be-line-width := $line-width-so-far
                                        + $current-width
                return (
                  if ($would-be-line-width gt 100)
                    then $current-width
                    else (),
                  $would-be-line-width
                )"/>
</xsl:accumulator>

If the line becomes too long, the width of the current block will be 
prepended to the would-be line length in the accumulator. So then there 
is a sequence of "line length if line wrap happened before current 
block" and "line length if line wrap did not happen before current block".
If, on the other hand, the would-be line length is less than or equal to 
100, only a single value (the would-be line length) will go into the 
accumulator.

I added its accumulator value(s) to each block:

<blocks>
   <block id="i1" width="100" acc="100">content</block>
   <block type="composite">
      <block id="i2" width="33" acc="33 133">content</block>
      <block id="i3" width="67" acc="100">content</block>
   </block>
   <block type="composite">
      <block id="i4" width="50" acc="50 150">content</block>
      <block id="i5" width="50" acc="100">content</block>
   </block>
   <block id="i6" width="25" acc="25 125">content</block>
   <block id="i6a" width="80" acc="80 105">content</block>
   <block width="100" acc="100 180">content</block>
   <block type="composite">
      <block id="i7" width="55" acc="55 155">content</block>
      <block id="i8" width="20" acc="75">content</block>
   </block>
   <block id="i9" width="100" acc="100 175">content</block>
</blocks>

This has been achieved with a single grouping:

<xsl:template match="blocks">
  <xsl:copy>
    <xsl:for-each-group select="block"
      group-starting-with="block[accumulator-before('width')[last()] gt 
100]">
      <xsl:choose>
        <xsl:when test="count(current-group()) eq 1">
          <xsl:apply-templates select="current-group()"/>
        </xsl:when>
        <xsl:otherwise>
          <block type="composite">
            <xsl:apply-templates select="current-group()"/>
          </block>
        </xsl:otherwise>
      </xsl:choose>
    </xsl:for-each-group>
  </xsl:copy>
</xsl:template>

Gerrit


On 17.09.2020 00:16, Martin Honnen martin.honnen@xxxxxx wrote:
> I was wondering what output is wanted for
>
> <blocks>
>  B  <block id="i1">content</block>
>  B  <block id="i2" width="33">content</block>
>  B  <block id="i3" width="67">content</block>
>  B  <block id="i4" width="50">content</block>
>  B  <block id="i5" width="50">content</block>
>  B  <block id="i6" width="25">content</block>
>  B  <block>content</block>
>  B  <block id="i7" width="55">content</block>
>  B  <block id="i8" width="20">content</block>
>  B  <block id="i9">content</block>
> </blocks>
>
> Neither my suggestion nor the above seem to only wrap the adjacent
> block[@width] where the accumulator gives 100.
>
> I complicated or strengthened my attempt as
>
>  B  <xsl:template match="blocks">
>  B B B  <xsl:copy>
>  B B B B B  <xsl:for-each-group select="block" group-adjacent="not(@width)">
>  B B B B B B B  <xsl:choose>
>  B B B B B B B B B  <xsl:when test="current-grouping-key()">
>  B B B B B B B B B B B  <xsl:apply-templates select="current-group()"/>
>  B B B B B B B B B  </xsl:when>
>  B B B B B B B B B  <xsl:otherwise>
>  B B B B B B B B B B B  <xsl:for-each-group select="current-group()"
> group-ending-with="block[accumulator-before('width') eq 100]">
>  B B B B B B B B B B B B B  <xsl:choose>
>  B B B B B B B B B B B B B B B  <xsl:when
> test="current-group()[last()][accumulator-before('width') eq 100]">
>  B B B B B B B B B B B B B B B B B  <block type="composite">
>  B B B B B B B B B B B B B B B B B B B  <xsl:apply-templates select="current-group()"/>
>  B B B B B B B B B B B B B B B B B  </block>
>  B B B B B B B B B B B B B B B  </xsl:when>
>  B B B B B B B B B B B B B B B  <xsl:otherwise>
>  B B B B B B B B B B B B B B B B B  <xsl:apply-templates select="current-group()"/>
>  B B B B B B B B B B B B B B B  </xsl:otherwise>
>  B B B B B B B B B B B B B  </xsl:choose>
>  B B B B B B B B B B B  </xsl:for-each-group>
>  B B B B B B B B B  </xsl:otherwise>
>  B B B B B B B  </xsl:choose>
>  B B B B B  </xsl:for-each-group>
>  B B B  </xsl:copy>
>  B  </xsl:template>

--
Gerrit Imsieke
GeschC$ftsfC<hrer / Managing Director
le-tex publishing services GmbH
Weissenfelser Str. 84, 04229 Leipzig, Germany
Phone +49 341 355356 110, Fax +49 341 355356 510
gerrit.imsieke@xxxxxxxxx, http://www.le-tex.de

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