Element <while>

Purpose: Repeat child statements while a condition is true, subject to an iteration limit.

Why: Use it for a bounded per-row loop only when repeated child execution cannot be expressed directly.

Example

<while condition="should_continue"/>

Decision guide

Business value: Expresses bounded repeated child execution when the stopping condition is data-dependent.

• Use when

  • A row-level workflow must repeat until an explicit condition or bound is reached.

• Choose another approach when

  • A fixed count, collection, or direct expression can represent the repetition.

• Prerequisites

  • Provide a terminating condition and a safe maximum iteration bound.

• Alternatives

  • Use generate for fixed or source-derived record counts. (See: <generate>)
  • Use list for a bounded collection assembled without a loop. (See: <list>)

Complete examples

Repeat a row-local operation under an explicit stop condition

Use while only for bounded iterative logic that cannot be expressed as direct field dependencies; echo is useful while diagnosing that loop, not as an exporter.

<setup>
    <generate name="loop_result" count="1" target="LogExporter">
        <key name="n" script="0"/>
        <while condition="3 > n">
            <echo>looping, n is {n}</echo>
            <key name="n" script="n + 1"/>
        </while>
        <key name="final_value" script="n"/>
    </generate>
</setup>

Rules and invalid combinations

No additional element-specific rules. Required attributes, types, and supported values are shown below.

Allowed parents / Allowed children

Allowed parents: else, else-if, generate, if, iterate, nestedKey, while

Allowed children:

All registered DSL elements.

Attributes

Show all 2 attributes

condition

Condition to evaluate before each loop iteration.

required; string.

maxIterations

Maximum number of iterations before raising an error (default 10000).

optional; integer; Default: null.