Fillable JSON Structure

When working with Fillable PDF Templates in DronaHQ, Fillable JSON refers to two key JSON structures that define and populate data into PDF form fields:

Form JSON - Describes the structure and types of fields present in the uploaded fillable PDF.

Generate PDF JSON - Provides actual values for those fields to generate the final PDF.

Together, they allow you to view available fields and programmatically inject values into the PDF.

Form JSON

Auto-generated from your uploaded fillable PDF. It tells you:

• What fields are available.
• What type each field is (e.g., text, radio, dropdown).
• If a field has selectable options.

[
    {
        "name": "FullName",
        "type": "text"
    },
    {
        "name": "Married",
        "type": "checkbox"
    },
    {
        "name": "Gender",
        "type": "radio",
        "options": ["Male", "Female"]
    },
    {
        "name": "City",
        "type": "dropdown",
        "options": ["New York", "London", "Berlin"]
    },
    {
        "name": "Language",
        "type": "optionlist",
        "options": [
            "English",
            "German",
            "French",
            "Italian"
        ]
    }
]

Generate PDF JSON

You use this to populate the form with data. It mirrors the Form JSON structure and adds a value key. The options key is not required here. Just provide the name, type, and value.

[
    {
        "name": "FullName",
        "type": "text",
        "value": "John Doe"
    },
    {
        "name": "Married",
        "type": "checkbox",
        "value": true
    },
    {
        "name": "Gender",
        "type": "radio",
        "value": "Male"
    },
    {
        "name": "City",
        "type": "dropdown",
        "value": "New York"
    },
    {
        "name": "Language",
        "type": "optionlist",
        "value": ["English", "French"]
    }
]

Embedding Images in Fillable Fields

If a field is of type text, you can also use it to draw an image (e.g., for signatures or ID photos). Just set the type in Generate PDF JSON to either of type image/jpeg or image/png.

The value should be either a Base64-encoded image string, or a publicly accessible image URL.

[
    {
        "name": "Signature",
        "type": "image/png",
        "value": "https://example.com/signature.png"
    }
]

[
    {
        "name": "Signature",
        "type": "image/jpeg",
        "value": "data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD//gAfQ29tcHJlc3NlZCBieSBqcGVnLXJlY29t..."
    }
]