Supported PDF Form Fields
Nutrient supports most form types defined by the PDF specification. We have to differentiate between field objects and annotation objects.
Type | Field object | Annotation object |
---|---|---|
Checkboxes | CheckBoxFormField |
WidgetAnnotation |
Radio buttons | RadioButtonFormField |
WidgetAnnotation |
Push buttons | ButtonFormField |
WidgetAnnotation |
List boxes | ListBoxFormField |
WidgetAnnotation |
Combo boxes | ComboBoxFormField |
WidgetAnnotation |
Text | TextFormField |
WidgetAnnotation |
Signatures | SignatureFormField |
WidgetAnnotation |
Field objects have no visual representation of their own and are represented by FormField
, while annotation objects are visual representations of a single control inside a form field and are represented by WidgetAnnotation
.
To render a WidgetAnnotation
, the associated FormField
will be accessed via the WidgetAnnotation#formFieldName
property. Based on the type of this FormField
, different form controls are rendered.
We currently render generic elements for every form field type. Rendering the custom appearance stream for form fields is planned for a future release.
We also allow creating a FormField
and a WidgetAnnotation
directly from a loaded instance, and this is described in the form creation guide. You can also modify the values of these form fields using the UI or a programmable form-filling API.
Digital Signatures are a special case: A digitally signed SignatureFormField
can’t be directly created by instantiating it. Please refer to the Digital Signatures on PSPDFKit for Web guide for more information.
Signature form fields and signature form elements require that your license includes either Electronic Signatures or Digital Signatures, or that your license was originally obtained in April 2021 or earlier. If none of these requirements are met, then other form elements will be shown, while signature elements will be omitted.