Q: Create a Chart with XML based on XML

I would like to create a Chart based on this XML:

<?xml version="1.0" encoding="UTF-8"?>
<DOCUMENT>
    <DATE>10/08/2014</DATE>
    <USER_NAME>ADMIN</USER_NAME>
    <APP_ID>102</APP_ID>
    <APP_NAME>Oracle APEX AppBuilder</APP_NAME>
    <TITLE>dba_report_chart</TITLE>
    <REGION ID="0">
        <ROWSET>
            <ROW>
                <Description></Description>
                <Value></Value>
                <Date></Date>
            </ROW>
        </ROWSET>
    </REGION>
</DOCUMENT>

Dataset behind this looks like this:

Date         Description    Value
----         -----          -----
01.01.2014      A            1.2
02.01.2014      A            1.3
03.01.2014      A            0.5
01.01.2014      B            0.3
02.01.2014      B            4.5
03.01.2014      B            4.8

Charttype should be a Line-Chart having one line for each Description-type with the Date on the x-axis. Now here is my try to work out the XML for the Chart.

<Graph depthAngle="50" depthRadius="8" seriesEffect="SE_AUTO_GRADIENT" graphType= "LINE_VERT_ABS">
    <LegendArea visible="true"/>
    <LocalGridData colCount="{count(xdoxslt:group(.//ROW,  'Date'))}" rowCount="{count(xdoxslt:group(.//ROW,  'Description'))}">
        <RowLabels>
            <xsl:for-each-group select=".//ROW" group-by="Description">
                <Label>
                    <xsl:value-of select="current-group()/Description"/>
                </Label>
            </xsl:for-each-group>
        </RowLabels>
        <ColLabels>
            <xsl:for-each select=".//ROW">
                <Label>
                    <xsl:value-of select="Date"/>
                </Label>
            </xsl:for-each>
        </ColLabels>
        <DataValues>
            <RowData>
                <xsl:for-each select=".//ROW" >
                    <Cell>
                        <xsl:value-of select="Value"/>
                    </Cell>
                </xsl:for-each>
            </RowData>
        </DataValues>
    </LocalGridData>
</Graph>

Currently it doesn't work at all meaning it's not displaying any Line. I am a new to XML and I don't really know what I am doing or if it's possible to do this grouping with XML/XSL. I just fooled around a lot with the XML created (by the Word BI Publisher Template Builder plugin).

Hope someone can help me, Thanks Thomas.