PDF-FDF is a Ruby library and command line tool (
pdffdf) to help
generate the FDF files necessary to fill out forms present in PDFs.
It's especially useful in conjunction with the pdftk tool.
In the following examples the file
input.pdf is the original PDF
with form fields,
output.pdf will be the generated PDF with form
fields filled out.
Create a YAML file that contains all the form fields:
pdftk input.pdf dump_data_fields | pdffdf -ln > fields.yml
This will generate a YAML file that contains all the form fields. Additionally each field will be given a unique value starting with 0 so that you can visually identify the form fields in a test PDF.
Generate a test PDF so you can figure out which form fields have which names:
pdffdf -g fields.yml > test.fdf pdftk input.pdf fill_form test.fdf output output.pdf flatten
test.pdffile and the
fields.ymlfile. Using the
test.pdffile as a guide give a meaningful name in the
aliasfield for each of the form fields you care about.
Remove the generated form field values:
grep -v ' value:' fields.yml > master.yml
Fill out values for the form fields. You can set the values directly in the
master.ymlfile however I recommend that you create a new YAML file that only contains the fields you are interested in filling out. PDF-FDF can merge an unlimited number of YAML files into a single form field set. For this example we'll say that you created a new file called
myfields.ymlthat is based on the
master.ymlfile. Also note that in your
myfields.ymlfile you only need to specify two keys for each form field:
value. The other values will be found while merging with
Create your filled out PDF:
pdffdf -g master.yml myfields.yml > form.fdf pdftk input.pdf fill_form form.fdf output output.pdf flatten