directus-extension-interface-mustache-value

Directus interface extension that computes a typed value from JavaScript and Mustache and writes it into the form model.

Behavior

• New item:

  • does not auto-compute
  • stays blank
  • does not compute on focus while the route is /+

• Existing item with empty value (null, undefined, or ""):

  • auto-computes on open
  • auto-computes again while dependent fields change, until the field has a value

• Existing item with non-empty value:

  • computes only when this field receives focus

• Read-only / non-editable:

  • never computes

• Save:

  • this extension only updates the form value
  • Directus persists it when the user clicks Save

Notes

• code usage is supported by applying this interface to string or text fields.
• binary is intentionally out of scope in this version.
• Mustache output is rendered without HTML escaping in the persistence path, so {{ url }} works as raw text for stored values.
• The transform function return value is always used as the Mustache context.

Examples

URL string field

Mustache Template

{{ url }}

Integer field

Mustache Template

{{ horas }}

JS Transform Function

(fields) => {
  return {
    horas: 12,
  };
};

Current decision rules

In simplified form:

if route ends with /+:
  keep blank

else if current stored value is null / undefined / "":
  auto-compute

else:
  compute only on focus