List Form Fields

This guide will show you how to get all the form fields in a PDF document.

Sample input #

Before you begin #

You should get your API key from your UniCloud account.

If you are using the UniPDF SDK for the first time, follow this guide to set up a local development environment.

Clone the project repository #

In your terminal, clone the examples repository. It contains the Go code we will be using for this guide.

git clone https://github.com/unidoc/unipdf-examples.git

Navigate to the forms folder in the unipdf-examples directory.

cd unipdf-examples/forms

How it works #

Lines 9-17 import the UniPDF packages and other required dependencies.

The init function in lines 19-26 authenticates your request with your UNIDOC_LICENSE_API_KEY.

The main function in lines 28-40 validates your input and passes it as an argument to the listFormFields function.

Lines 42-212 define the listFormFields function, which accepts inputPath as a parameter. The function reads the PDF from the inputPath with the pdfReader() method and returns a list of form fields(widget annotations) on each page in the input PDF.

Run the code #

Run this command to get all the form fields in a PDF. This will also install the required dependencies to run the program.

Sample output #

You will get all the form fields for each page in the PDF on the terminal.

AcroForm (0xc0000de000)
 NeedAppearances: <nil>
 SigFlags: <nil>
 CO: []
 DR: &{<nil> <nil> <nil> <nil> <nil> Dict("ZaDb": IObject:42, ) <nil> <nil> 0xc0004b4300 <nil>}
 DA: <nil>
 Q: <nil>
 XFA: <nil>
 #Fields: 9
 =====
=====
Field 1
Name: full_name
 Flags: Clear (0)
 Text
 - DA: <nil>
 - '<nil>'
 Annotations: 1
 - Annotation 1 
 - Page number: 1
 - Rect: [123.970000, 619.020000, 343.990000, 633.600000]
 - wa.AS: <nil>
 - wa.AP: <nil>
 - wa.F:  4
   - Appearance dict not present: <nil>

...

=====
Field 9
Name: fav_color
 Flags: Combo (131072)
 Choice
 - '<nil>'
 Annotations: 1
 - Annotation 1 
 - Page number: 1
 - Rect: [144.520000, 461.610000, 243.920000, 476.190000]
 - wa.AS: <nil>
 - wa.AP: <nil>
 - wa.F:  4
   - Appearance dict not present: <nil>