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

Hello all !

A slide is divided as blocks. Usually, there is one bloc per line, but
sometimes, two or more blocks can be on one line, if their width sum is
100.

My input has non-grouped blocks, and I want my input group blocks per line.

Here is a sample input :

<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 id="i7" width="55">content</block>
 B  <block id="i8" width="20">content</block>
 B  <block id="i9">content</block>
</blocks>

Here is the expected output :

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

I have no idea of which form of for-each-group I have to use...

Is a solution with two-pass where I first calculate cumulated width with
an accumulator, followed a group-end-with="@cumulative-width eq 100"
could be a correct solution ?

You can use that accumulator in your group-ending-with, without two
passes I think, but I only could get it to work by wrapping it into an
outer group-adjacent="not(@width)"

  <xsl:accumulator name="width" as="xs:integer" initial-value="0">
    <xsl:accumulator-rule match="blocks" select="0"/>
    <xsl:accumulator-rule match="block[not(@width)]" select="0"/>
    <xsl:accumulator-rule match="block[@width]" select="if ($value eq
100) then xs:integer(@width) else + $value + xs:integer(@width)"/>
  </xsl:accumulator>

  <xsl:template match="blocks">
    <xsl:copy>
      <xsl:for-each-group select="block" group-adjacent="not(@width)">
        <xsl:choose>
          <xsl:when test="current-grouping-key()">
            <xsl:apply-templates select="current-group()"/>
          </xsl:when>
          <xsl:otherwise>
            <xsl:for-each-group select="current-group()"
group-ending-with="block[accumulator-before('width') eq 100]">
              <block>
                <xsl:apply-templates select="current-group()"/>
              </block>
            </xsl:for-each-group>
          </xsl:otherwise>
        </xsl:choose>
      </xsl:for-each-group>
    </xsl:copy>
  </xsl:template>