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Preview, Patient View & FHIR JSON

The right-hand panel is a live runtime, not a static mock-up. As you edit the questionnaire on the left, it re-renders immediately and runs the real logic — expressions, enableWhen, calculations and validation. You can look at it in three ways, chosen from the mode dropdown at the top of the panel.

The three modes

Switch modes with the preview-mode selector (its label shows the active mode):

  • 👁️ Preview — the form as the author sees it, with design aids switched on. This is the default and the mode you build in.
  • 👤 Patient View — the form as the patient sees it: design aids are gone, items marked hidden are removed, and display/collapsible behaviour matches what a real client would show.
  • {} FHIR JSON — the live Questionnaire resource as formatted, syntax-highlighted JSON. It updates as you edit, so you can watch the FHIR being produced. The search box highlights matches inside the JSON.

Design aids in Preview

👁️ Preview shows extra information that helps while authoring but is not part of the patient's form. A View options menu toggles each one:

  • Show id — the linkId of each item.
  • Show prefix — the item's prefix (e.g. 1., Q3).
  • Show badges — small indicators on items that carry logic or validation (visibility conditions, calculations, required, etc.).
  • Show hidden — reveal items marked hidden (greyed out) so you can inspect them; in Patient View these are always removed.

These toggles only affect the Preview display — they never change the underlying questionnaire.

Jumping between builder and preview

Each preview row has a small ↗ icon that scrolls to and briefly highlights the matching node in the builder tree on the left — handy on a long form where scrolling to find an item by hand is slow. It works the other way too: clicking an item's title in the builder tree scrolls to and highlights that item's row in the preview.

Testing with patient data

Logic like calculations and enableWhen often depends on facts about the patient (age, sex, BMI …). The 👤 Patient preset selector lets you feed those in without leaving the builder. Picking a preset populates the questionnaire variables %age, %gender, %bmi, %pregnant, %smoker, %proc and %comorb, and re-evaluates every initialExpression so the form reflects that patient. Choose ✏ Custom… to set the values by hand.

This is meant for testing the form's behaviour against different scenarios — it is not a data-capture feature.

Resuming a filled-in form

You can also load an existing QuestionnaireResponse to continue a partially completed session — the preview restores the saved answers and re-runs all logic on top of them.

Everything stays in sync

There is no "refresh" step. Any change to an item — its type, text, options, logic or validation — is reflected in the preview on the next render, so the form you see always matches the questionnaire you are editing.

Next: Build a questionnaire from scratch.