Fields and Expressions

A field node’s expression is a Liquid expression without the braces: a path into your data, optionally with filters.

{
  "type": "field",
  "attrs": { "expression": "invoice.issued_on | date: \"%B %-d, %Y\"" }
}

• A path has . between its parts: customer.name reads { "customer": { "name": "..." } }, the field customer/name.
• Page designs have the same Liquid filters as HTML templates, such as upcase, currency, delimited and date. sum also reads amounts written as text, such as "$40" (Footer row).
• An expression can’t contain {{, }}, {% or %}.

Fields go in rich text and in the value of a QR code or barcode. Images, tables and repeating sections name a field by its path, without filters.

Lists

A table or repeating section goes through a list in your data (source) and gives each entry a name (as). Inside it, that name reaches the entry’s values: in a table over line_items as line_item, a cell reads line_item.description. The editor names a new loop’s entries with the singular of its list. These names can’t be used: true, false, nil, null, empty, blank, forloop, tablerowloop, and, or and contains.

The fields DocSpring adds

When you save a layout, DocSpring adds a field for each new value it reads, with a type that fits how it’s used:

• A value whose first filter is date or in_time_zone is a date.
• A value formatted as a number (currency, delimited, round, plus and the other number filters), or compared with >, <, >=, <= or a number, is a number.
• A value used on its own as a condition, or compared with true or false, is a true/false value.
• An image’s field is an image.
• A table’s or repeating section’s source is a list, with a field for each value read from its entries: line_items/~/description.
• Anything else is text.

Fields it already has are kept as they are, including fields the layout no longer reads. You can change a field’s type afterwards. If you delete a field while the layout still reads its value, saving the layout doesn’t add it back, and a submission without that value fails with an undefined variable message.