Variables, loops and formatting

Variables insert values from the supplied input, metadata, layout blocks and available system properties. The authoring help panel lists the functions supported by the running app.

Use Input JSON and the variable picker together to build a repeatable design. Select image to enlarge.

Start with representative Input JSON

{
  "data": {
    "customer": {"name": "Asha Rao"},
    "reference": "INV-1042",
    "issuedOn": "2026-10-24",
    "total": 12500.5,
    "lines": [
      {"description": "Consulting", "quantity": 2, "rate": 6000},
      {"description": "Materials", "quantity": 1, "rate": 500.5}
    ]
  }
}

Reference the same nesting in the body:

Prepared for {{data.customer.name}}
Reference: {{data.reference}}
Date: {{data.issuedOn | date "dd-MMM-yyyy"}}
Total: {{data.total | currency "₹"}}

Type {{ to open suggestions. Tab completes another level of a path; Enter completes a reference. A variable chip's fx menu applies a function. Add a pipeline with |; functions run left to right.

Repeat a list

{{#each data.lines}}
{{this.description}}: {{this.rate | mul this.quantity | number "#,##0.00"}}
{{/each}}

Inside the loop, this is the current item and @index is its index. A table row can also use a repeat path. Use a list of objects for line items rather than manually adding one variable per possible row. Test zero, one and several rows and check page breaks.

Function reference

Function	Use
date "dd-MMM-yyyy"	Format a date
until endDate "years"	Date span; supported units include years/months/days and combined text forms
upper, lower, title, trim	Change text case or whitespace
substr 0 3	Take a substring; a negative start counts from the end
before "@", after "@"	Split around a separator
replace "-" "/"	Replace occurrences
default "—"	Supply a fallback for an empty value
number "#,##0.00"	Format digits, grouping and decimals
currency "₹"	Currency symbol and two decimal places
add, sub, mul, div	Arithmetic using a literal or another variable
min, max, round 2, abs	Bounds, rounding and magnitude
lookup "code" "BASIC" "amount"	Find the first matching object in a list and return its field
map metadata	Look up a value in a mapping object

For dates, uppercase MM is the month and lowercase mm is minutes. Use yyyy, MMM, dd, HH, hh and a as appropriate. In number patterns, 0 is required, # is optional, , groups, . separates decimals and % multiplies by 100.

Avoid unresolved values

The variable path must exist in the data source the template expects. Sample values drive the authoring preview; real generation receives the values entered in Generate or supplied by an integration. Match the selected template's generated Form/JSON structure rather than adding another data wrapper blindly.

Correct unknown functions and unresolved references before saving. A default is useful for optional values, but it does not make a wrong variable path correct.