pdf-forms

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# pdf-forms.cr

Fill out PDF forms with [pdftk](https://gitlab.com/pdftk-java/pdftk).

This shard is a port of the [pdf-forms](https://github.com/jkraemer/pdf-forms) Ruby gem.

## Important Information

This shard has been tested and works great with PDFtk 3.0, Ubuntu 20.04 and Crystal 1.1.1 - 1.12.1.

Also it tested against MacOS latest and Crystal 1.1.1 - 1.12.1.

The installation of the PDFtk 3.0 is recommended for normal work.

Shard can work with PDFtk 2.0 if PDFtk has access to the **/tmp** diretcory. 

## Crystal and OS support

See [older releases](https://github.com/unrooty/pdf-forms.cr/releases) for the support of the older Crystal versions and OS.

You can see [test matrix](https://github.com/unrooty/pdf-forms.cr/actions/workflows/test.yml) with OS and Crystal version supports.

## Installation
- Install PDFtk
  - Ubuntu 20.04 / Ununtu 22.04
    ```bash
      sudo apt install pdftk
    ```
  - MacOS latest
    ```bash
      brew install pdftk-java
    ```

- Add the dependency to your `shard.yml`:

   ```yaml
   dependencies:
     pdf-forms.cr:
       github: unrooty/pdf-forms.cr
       version: 1.1.0 # optional
   ```

-  Run 
  ```bash 
    shards install
  ```

## Usage

### FDF/XFdf creation

```ruby
require "pdf_forms"

fdf = PdfForms::Fdf.new("key" => "value", "other_key" => "other value")

# use to_pdf_data if you just want the fdf data, without writing it to a file
puts fdf.to_pdf_data

# write fdf file
fdf.save_to "path/to/file.fdf"
```

To generate XFDF instead of FDF instantiate `PdfForms::XFdf` instead of `PdfForms::Fdf`.

### Query form fields and fill out PDF forms with pdftk

```ruby
require "pdf_forms"

# adjust the pdftk path to suit your pdftk installation
# add "data_format" => "xfdf" option to generate XFDF instead of FDF when
# filling a form (XFDF is supposed to have better support for non-western encodings)
# add "data_format" => "FdfHex" option to generate FDF with values passed in UTF16 hexadecimal format (Hexadecimal format has also proven more reliable for passing latin accented characters to pdftk)
# add :utf8_fields => true in order to get UTF8 encoded field metadata (this will use dump_data_fields_utf8 instead of dump_data_fields in the call to pdftk)
pdftk = PdfForms.new("/usr/local/bin/pdftk")

# find out the field names that are present in form.pdf
pdftk.get_field_names("path/to/form.pdf")

# take form.pdf, set the "foo" field to "bar" and save the document to myform.pdf
pdftk.fill_form("/path/to/form.pdf", "myform.pdf", { "foo" => "bar" })

# optionally, add the "flatten" option to prevent editing of a filled out form.
# Other supported options are "drop_xfa" and "drop_xmp".
pdftk.fill_form("/path/to/form.pdf", "myform.pdf", { "foo" => "bar"}, { "flatten" => true })

# to enable PDF encryption, pass encrypt: true. By default, a random 'owner
# password' will be used, but you can also set one with the :encrypt_pw option.
pdftk.fill_form("/path/to/form.pdf", "myform.pdf", { "foo" => "bar" }, { "encrypt" => true, "encrypt_options" => "allow printing" })

# you can also protect the PDF even from opening by specifying an additional user_pw option:
pdftk.fill_form("/path/to/form.pdf", "myform.pdf", { "foo" => "bar" }, { "encrypt" => true, "encrypt_options" => "user_pw secret" })
```

Any options shown above can also be set when initializing the PdfForms
instance. In this case, options given to `fill_form` will override the global
options.

### Non-ASCII Characters (UTF8 etc) are not displayed in the filled out PDF

First, check if the field value has been stored properly in the output PDF using `pdftk output.pdf dump_data_fields_utf8`.

If it has been stored but did not render, your input PDF lacks the proper font for your kind of characters. Re-create it and embed any necessary fonts.
If value has not been stored, most of the time there is a problem with filling out the form on your side, not with this shard.

## Testing

Currently shard uses [minitest.cr](https://github.com/ysbaddaden/minitest.cr).

To run specs use `crystal run ./spec/*_test.cr` command.

## Contributing

1. Fork it (<https://github.com/unrooty/pdf-forms.cr/fork>).
2. Create your feature branch (`git checkout -b my-new-feature`).
3. Commit your changes (`git commit -am 'Add some feature'`).
4. Push to the branch (`git push origin my-new-feature`).
5. Create a new Pull Request.

## Contributors

- [Vladislav Volkov](https://github.com/unrooty) - creator and maintainer