Evaluate Expression Example
This example will demonstrate how to use the Evaluate expression step to evaluate C# expressions and assign the result of the expression to a
variable. First, let’s give the definition name as “Evaluate Expression Example” and click the “Create Definition” button to create the definition.
Once the definition is created, select the definition from the list and click the “Edit Definition” button to view the workflow designer.
Let’s define 3 variables at the “Start” step. Define variables dataA, dataB and dataC as numeric data type variables. Click the “Save” button to
save the new variables.
Drag and drop 2 update variables steps to the designer, select the top one and enter the following values for the step properties.
Select the 2nd update variable step at the bottom and enter the following values for the step properties.
Connect the “Start” step to the 2 update variable steps. Drag and drop a Synchronize step to the designer. Connect the two update variable
steps to the Synchronize step. Set the update variable step return values to “True”.
Drag and drop an “Evaluate Expression” step to the designer and connect the step to the “Synchronize” step. Select the “Evaluate Expression”
step and enter following values for the step properties.
Click the “Save Definition” at the top toolbar to save the Workflow definition.
Let’s create a Workflow instance for executing the definition. Select the definition “Evaluate Expression Example” from the drop down list and
enter the instance name as “EvaluateExpression Instance”. Click the “Create Instance” button to create the instance.
Select the instance from the table listing and click the “Execute Instance” button to execute the instance.
Click the “Refresh Page” button to refresh the page. Now the instance should have a status of “finish”. Click the “Execution View” to view the
execution of the instance.
Click the “Evaluate Expression” step to view its execution details.
Execution details show that the step evaluated the expression dataC = dataA + dataB and now the Variable dataC has a value of 220.