Expression editor

An interface designed for defining complex expressions (conditions) using conditional controls such as If, Else If, while, and do until. A complex expression is formed by combining simple conditions (rules) with logical operators AND and OR or negating these conditions with logical negation operator NOT.

You can access the expression editor by clicking the Expression icon on the Flow service step. The Expression icon appears only when you select a conditional construct control in the flow service step.

Components of expression editor

Expression editor consists of two sections:

  • Expression view
  • Expression builder

Expression view

The Expression view section displays the conditions that are defined. Also, when you hover the mouse pointer on the operator of the condition, the condition's scope is highlighted for reference.

Expression builder

The Expression builder section helps you to create complex conditions by defining rules. By default, a rule step is displayed to start with the condition definition. A rule step consists of Left Operand, Operator, and Right Operand to define a condition. The operands list the fields available in the pipeline. You can group multiple rules to define sub conditions.

The expression builder contains the following controls that aid you in defining the complex conditions:

  • Group-level controls
  • Operator. Lists the set of logical operators that are used to join the rules.
  • Add Group. Groups are a set of rules to define sub conditions.
  • Add Rule . Displays the fields to define a rule.
  • Remove Group. Deletes a group (sub condition) from the complex condition.
  • Negate Group. Reverses a sub condition's meaning. This control is a toggle button control. When you negate a group, the negate group button is renamed as Remove Negation and allows you to remove the negation for that group.
  • Rule-level Controls
  • Add Rule . Displays the fields for you to define a rule.
  • Negate Rule. Reverses a rule's meaning.
  • Delete Rule . Deletes a rule.

At any time you can either modify or delete a part or whole of the complex condition that uses these controls.

When you hover on the operands, the complete path of the operand appears.