What’s an Expression

An expression is essentially a javascript syntax enclosed in {{ and }} or {% and %}. The expression is any valid set of variables, operators, and expressions that evaluates to a single value. The value may be a number, a string, an array or a logical value.

You may also use any of the standard built-in objects such as Math, String, Array or methods in the expressions.

Example 1 - Addition of 2 numeric values

{{ 1+1 }}

Example 2 - Display “hello”. You can use either {{ and }} or alternatively {% and %}. They are interchangable.

{% "hello" %}

Example 3 - Display the JSON field “title”

{{ data.title }}

Example 4 - Conditional (ternary) operator

{{ data.status == 2 ? "Pending" : "Unknown" }}

Example 5 - Mapping of statuses - The values of the field status are 1, 2 or 3. The status field can be either string type or numeric type

{% ifNull( {"0":"Unknown",  "1": "Pending",  "2": "Done"}[data.status] , "N/A") %}