<if> - Business Process and Data Transformation Language Reference

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Business Process and Data Transformation Language Reference

<if>

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Ensemble Reference Material > Business Process and Data Transformation Language Reference > BPL Elements > <if>

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Evaluate a condition and perform one action if true, another if false.

Synopsis

<if condition="1">   <true>     ...   </true>   <false>     ...   </false> </if>

Details

Attribute or Element	Description	Value
condition attribute	Required. An expression that, if true, causes the contents of the <true> element to execute. If false, the contents of the <false> element are executed.	An expression that evaluates to the integer value 1 (if true) or 0 (if false). This expression must use the scripting language specified by the containing <process> element.
name, disabled, xpos, ypos, xend, yend attributes	See “Common Attributes and Elements.”
<annotation> element	See “Common Attributes and Elements.”
<true> element	Optional. If the condition is true, activities inside the <true> element are executed.
<false> element	Optional. If the condition is false, activities inside the <false> element are executed.

Description

The <if> element evaluates an expression and, depending on its value, executes one of two sets of activities (one if the expression evaluates to a true value, the other if it evaluates to a false value).

The <if> element may contain a <true> element and a <false> element which define the actions to execute if the expression evaluates to true or false, respectively.

If both <true> and <false> elements are provided, they may appear within the <if> element in any order.

If the condition is true and there is no <true> element, or if the condition is false and there is no <false> element, no activity results from the <if> element.

The following example shows an <if> element used to coordinate the results of a combination of <call> and <sync> elements used together.

<sequence name="thread1">
  <call name="A" />
  <call name="B"  />
  <sync calls="A,B" type="all" timeout="10" />
  // Did the synchronization time out before it finished?
  <if condition='synctimedout="1"'>
    <true>
      <trace value="thread1 timeout: Call A or B did not return." />
    </true>
    // If not, then the calls came back, so assign the results.
      <false>
        <assign property="context.TheResultsFromEast"
                value='syncresponses.GetAt("A")'
                action="append"/>
        <assign property="context.TheResultsFromWest"
                value='syncresponses.GetAt("B")'
                action="append"/>
      </false>
    </if>
  </sequence>

The <if> activity in this example has a condition that tests the execution context variable synctimedout against the integer value 1. synctimedout can have the value 0, 1, or 2 as described in the documentation for <call>. If the two values are equal, this <if> condition receives the integer value 1 and statements inside the <true> element are executed. Otherwise, statements inside the <false> element are executed.

Note:

There is more information about the business process execution context in documentation of the <assign> element.

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