Class: Acrofill::Form

Inherits:
Object
  • Object
show all
Defined in:
lib/acrofill/form.rb

Overview

The interactive form of a document: field lookup by fully-qualified name, value filling with appearance regeneration, and flattening.

Defined Under Namespace

Classes: Field

Constant Summary collapse

MULTILINE_FLAG = 
1 << 12
PUSHBUTTON_FLAG = 
1 << 16
COMB_FLAG = 
1 << 24
OFF_VALUES =

Values that uncheck a button, compared case-insensitively: "Off" unchecking while "off" ticked the box was a silent data error. A state the template actually names is matched first, so a checkbox whose on state is literally called "no" stays checkable.

['', 'off', 'false', 'no', '0'].freeze

Instance Method Summary collapse

Constructor Details

#initialize(doc) ⇒ Form

Returns a new instance of Form.

Raises:



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# File 'lib/acrofill/form.rb', line 18

def initialize(doc)
  @doc = doc
  @acroform = doc.deref(doc.root[:AcroForm])
  raise Error, 'document has no AcroForm' unless @acroform.is_a?(Hash)

  @appearance = Appearance.new(doc, @acroform)
  # name => array of { node:, widgets: } groups. Several field dicts may
  # share one fully-qualified name (PDF 32000 §12.7.3.2 treats them as a
  # single logical field, e.g. "SSN" repeated on every page) — filling
  # must update all of them.
  @fields = Hash.new { |h, k| h[k] = [] }
  roots = doc.deref(@acroform[:Fields])
  collect_fields(roots.is_a?(Array) ? roots : [])
end

Instance Method Details

#fields ⇒ Object

Metadata for every logical field, in document order.



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# File 'lib/acrofill/form.rb', line 34

def fields
  @fields.map do |name, groups|
    type = field_type(groups.first[:node])
    Field.new(
      name: name,
      type: type,
      value: decode_text_string(@doc.deref(groups.first[:node][:V])),
      states: type == :Btn ? on_states(all_widgets(groups)) : nil
    )
  end
end

#fill(name, value) ⇒ Object

Sets the field value and rebuilds widget appearances. Unknown names are ignored (returns false), matching pdftk's fill_form behaviour.



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# File 'lib/acrofill/form.rb', line 48

def fill(name, value)
  groups = @fields.fetch(name, [])
  return false if groups.empty?

  # Several field dicts may share one name without sharing one /FT.
  # Dispatching on the first one's type would push a checkbox through
  # the text path, overwriting its /AP state dictionary with a text
  # appearance, so each type is handled with its own groups.
  groups.group_by { |group| field_type(group[:node]) }.map do |type, typed|
    case type
    when :Btn then fill_button(typed, value)
    when :Tx, :Ch, nil then fill_text_groups(typed, value)
    else false # signatures and unknown types are left untouched
    end
  end.any?
end

#flatten! ⇒ Object

Stamps every visible widget appearance into its page's content and removes the interactive layer, like pdftk's output ... flatten.



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# File 'lib/acrofill/form.rb', line 67

def flatten!
  Flattener.new(@doc).flatten!
end