Computed Text

How to add and configure a Computed Text field in the Notebook Editor.

What This Field Does

A Computed Text derives text from an expression over other fields in the same form — for example, joining a site code and plot number, or classifying a measurement into ‘Low’ / ‘Medium’ / ‘High’. The generated value is read-only for data collectors; they see the result but cannot edit it, and it updates automatically as the fields it references change.

The field stays blank until every field its expression references has a usable value, so a partially filled form shows no result rather than a misleading one.

Adding the Field

To add this field, open the ADD A FIELD dialog, navigate to the TEXT tab, and click the Computed Text card. Then click the ADD FIELD button in the lower right.

Adding a Computed Text — the TEXT tab in the ADD A FIELD dialog

Configuring the Field

Click the field’s grey header bar to expand it and see its settings. For an overview of the settings shared by all fields — including Label, Helper Text, Field ID, and the field toolbar — see Field Identity and Field Toolbar.

Give the field a meaningful Label, review the auto-populated Field ID, and add any desired Helper Text.

Computed Text configuration in the {{Notebook}} Editor

Computed Text-Specific Settings

The Computed Text’s key feature is the Expression text area, which defines the generated text. Each referenced field is written by wrapping its Field ID in braces, and text is joined with the & operator, e.g. {Site-Code} & '-' & {Plot}. Below the expression, a searchable field picker lists the referenceable fields in the form; selecting one inserts that field’s reference, which avoids typing the Field ID by hand.

Setting

What It Does

Expression

A text area where you define the generated text using literals, operators, and field references in single-brace syntax (e.g., {Site-Code} & '-' & {Plot}).

Insert field

A searchable picker of the referenceable fields in the form. Selecting one inserts its braced reference into the expression.

The expression is typed and checked when the notebook is designed — mixing types is reported as an error in the Editor. The overall expression must produce text. The operators are:

  • Concatenation (&) — joins text, e.g. {Site-Code} & '-A'.

  • Arithmetic (+ - * / %) — numbers only (useful inside conditions).

  • Comparisons (< > <= >=) — two numbers or two texts, producing true/false; equality (==, !=) requires matching types.

  • Logic (&&, ||, !) — true/false values only.

  • Conditionals — a ternary condition ? ifTrue : ifFalse, with a true/false condition and same-typed branches. Ternaries can be nested to classify values, e.g. {vegType} == 'hedge' ? ({vegHeight} < 3 ? 'Low' : 'High') : 'Medium'.

Number and checkbox fields can be referenced anywhere in the expression — only the final result must be text.

All referenced fields must be in the same form as the Computed Text. A Computed Text cannot reference another computed field or a Templated String. For record identifiers (HRIDs), use a Templated String instead.

Shared Field Options

Configure any of the shared field options as needed.

For settings shared across all field types — including Annotation, Uncertainty, Conditions, Copy value to new records, and Display in child records — see Field Options.

Tips

  • Use the field picker to build expressions rather than typing Field IDs by hand. Selecting a field inserts the exact braced reference, so you avoid typos and do not need to remember a field’s ID.

  • Nest ternaries for classifications — thresholds like Low/Medium/High are a natural fit, as in the example above.

  • The result stays blank until all referenced fields have values. This is intentional — a partially complete record shows no value rather than a misleading partial calculation.

  • Computed Texts are read-only for data collectors. They see the generated text but cannot edit it, keeping the value consistent with its inputs.

  • String comparisons are exact, including case. {vegType} == 'hedge' will not match a value of Hedge — the expression takes the other branch with no error. When comparing against fixed values, prefer a Choice field for the input so the values are exact by construction.