Neptune DXP Documentation
Neptune DXP - Open Edition · 25.0 MTS

Binding syntax reference

A binding reads a value from the process flow’s data into a field, a token, or a condition. This topic lists the binding forms and the mistakes to avoid. For the two kinds of data a binding reads, see How data moves through a process flow.

Binding forms

Binding Reads

{Outputs>/<activity>/<property>}

A value from a specific earlier step’s output, named by its activity identifier.

{InterfaceData>/<property>}

A value from interface data, the global store for the run.

{/approverDecision}

The action a person selected on the previous User Task.

You can drag an input from a node’s Inputs panel into a field, which writes the binding for you.

Expressions

To compare or compute values, use an expression. An expression is wrapped in {= }, and reads a value with ${ }. For example:

{= ${InterfaceData>/candidate/yearsOfExperience} >= 5 }

Expressions are used in condition rules. See Condition operators and operand types.

How a condition evaluates

A condition must evaluate to true or false. If it evaluates to anything else, such as a bare value or a missing field, the path is not taken, and a warning is written to the logs. Write a condition as a comparison of a bound value against an expected value, for example {= ${InterfaceData>/name} === "Nora" }, rather than a bare binding such as {= ${InterfaceData>/name} }.

A comparison is strict on both value and type. A number matches a number, and text matches text. {= ${InterfaceData>/count} === 5 } matches the number 5, while {= ${InterfaceData>/count} === "5" } matches the text "5". The number 5 and the text "5" are not equal, so compare a field that holds a number with a number.

A few more points hold when you write a condition:

  • Single quotes and double quotes both work for text, for example === "Nora" and === 'Nora'.

  • Extra spaces inside the expression do not change the result.

  • If a path is not taken when you expected it to be, check the logs for a condition-evaluation warning. A misspelled binding or a type mismatch is the usual cause.

Valid and invalid bindings

The following interface data is used for the examples:

{ "contacts": [ { "firstname": "Sofia" }, { "firstname": "Neha" } ] }
Binding Result

{InterfaceData>/contacts/0/firstname}

Sofia

{= ${InterfaceData>/contacts/length} === 2}

true

Avoid these common mistakes:

Invalid binding Reason

{/contacts/length}

Reads the previous step’s output, not interface data.

{InterfaceData/contacts/length}

Missing the > that separates the model from the path.

{InterfaceData>contacts/length}

Missing the leading / that starts the path.

{= ${Interface Data>/contacts/length} === 2}

InterfaceData must be written as one word, with no space.

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