User Manual
Data Processing
Loops and Conditions

Loops and Conditions

XTS has two programming levels: the layout language (XML commands like <Loop> and <Switch>) and XPath (expressions inside select and test attributes). This page covers the layout language constructs.

ForAll – iterating over data

<ForAll> runs the same commands for every matching element:

<ForAll select="article">
    <Tr>
        <Td><Paragraph><Value select="@name"/></Paragraph></Td>
        <Td><Paragraph><Value select="@price"/></Paragraph></Td>
    </Tr>
</ForAll>

Inside <ForAll>, the context switches to each matched element, so @name refers to the current article’s name attribute.

ProcessNode – dispatching to records

<ProcessNode> sends each child element to its matching <Record>:

<Record match="catalog">
    <ProcessNode select="*"/>
</Record>

<Record match="article">
    <!-- handle each article -->
</Record>

Use <ProcessNode> when different elements need different treatment. Use <ForAll> when they all get the same treatment.

Loop – counting

<Loop> runs a fixed number of times:

<Loop select="10">
    <!-- runs 10 times -->
    <!-- $loopcounter is 1, 2, ..., 10 -->
</Loop>

The loop counter is stored in $_loopcounter by default, or you can name it: <Loop select="10" variable="i">.

While and Until – conditional loops 

<SetVariable variable="i" select="1"/>
<While test="$i &lt;= 4">
    <PlaceObject>
        <TextBlock>
            <Paragraph><Value select="$i"/></Paragraph>
        </TextBlock>
    </PlaceObject>
    <SetVariable variable="i" select="$i + 1"/>
</While>

This outputs 1, 2, 3, 4. Don’t forget to increment the variable, or you’ll get an infinite loop.

ℹ️
In XML, < must be written as &lt; inside attribute values. So $i <= 4 becomes $i &lt;= 4.

<Until> is the inverse – it runs until the condition becomes true:

<SetVariable variable="i" select="1"/>
<Until test="$i &gt; 4">
    <!-- runs while i <= 4 -->
    <SetVariable variable="i" select="$i + 1"/>
</Until>

Switch/Case – conditional logic

This works like switch/case in most programming languages:

<Switch>
    <Case test="$i = 1">
        <!-- when i is 1 -->
    </Case>
    <Case test="$i = 2">
        <!-- when i is 2 -->
    </Case>
    <Otherwise>
        <!-- when nothing else matches -->
    </Otherwise>
</Switch>

The test attribute expects an XPath expression that evaluates to true() or false(). Only the first matching <Case> is executed. <Otherwise> is optional and runs when no case matches.

Practical example

A data-driven table with conditional styling:

<Record match="inventory">
    <PlaceObject>
        <Table stretch="max">
            <TableHead>
                <Tr>
                    <Td><Paragraph><Value>Product</Value></Paragraph></Td>
                    <Td><Paragraph><Value>Stock</Value></Paragraph></Td>
                </Tr>
            </TableHead>
            <ForAll select="item">
                <Tr>
                    <Td><Paragraph><Value select="@name"/></Paragraph></Td>
                    <Td>
                        <Switch>
                            <Case test="@qty &lt; 10">
                                <Paragraph style="color: red; font-weight: bold;">
                                    <Value select="@qty"/>
                                </Paragraph>
                            </Case>
                            <Otherwise>
                                <Paragraph><Value select="@qty"/></Paragraph>
                            </Otherwise>
                        </Switch>
                    </Td>
                </Tr>
            </ForAll>
        </Table>
    </PlaceObject>
</Record>
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