Class: CorpPdf::Actions::UpdateField

Inherits:
Object
  • Object
show all
Includes:
Base
Defined in:
lib/corp_pdf/actions/update_field.rb

Overview

Action to update a field’s value and optionally rename it in a PDF document

Instance Method Summary collapse

Methods included from Base

#acroform_ref, #apply_patch, #find_page_by_number, #get_object_body_with_patch, #next_fresh_object_number, #patches, #resolver

Constructor Details

#initialize(document, name, new_value, new_name: nil) ⇒ UpdateField

Returns a new instance of UpdateField.



9
10
11
12
13
14
 
# File 'lib/corp_pdf/actions/update_field.rb', line 9

def initialize(document, name, new_value, new_name: nil)
  @document = document
  @name = name
  @new_value = new_value
  @new_name = new_name
end

Instance Method Details

#call ⇒ Object 



16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
 
# File 'lib/corp_pdf/actions/update_field.rb', line 16

def call
  # First try to find in list_fields (already written fields)
  fld = @document.list_fields.find { |f| f.name == @name }

  # If not found, check if field was just added (in patches) and create a Field object for it
  unless fld
    patches = @document.instance_variable_get(:@patches)
    field_patch = patches.find do |p|
      next unless p[:body]
      next unless p[:body].include?("/T")

      t_tok = DictScan.value_token_after("/T", p[:body])
      next unless t_tok

      field_name = DictScan.decode_pdf_string(t_tok)
      field_name == @name
    end

    if field_patch && field_patch[:body].include?("/FT")
      ft_tok = DictScan.value_token_after("/FT", field_patch[:body])
      if ft_tok
        # Create a temporary Field object for newly added field
        position = {}
        fld = Field.new(@name, nil, ft_tok, field_patch[:ref], @document, position)
      end
    end
  end

  return false unless fld

  # Check if this is a signature field and if new_value looks like image data
  if fld.signature_field?
    # Check if new_value looks like base64 image data or data URI
    image_data = @new_value
    if image_data && image_data.is_a?(String) && (image_data.start_with?("data:image/") || (image_data.length > 50 && image_data.match?(%r{^[A-Za-z0-9+/]*={0,2}$})))
      # Try adding signature appearance using Signature field class
      result = CorpPdf::Fields::Signature.add_appearance(@document, fld.ref, image_data)
      return result if result
      # If appearance fails, fall through to normal update
    end
  end

  original = get_object_body_with_patch(fld.ref)
  return false unless original

  # Determine if this is a widget annotation or field object
  is_widget = original.include?("/Subtype /Widget")
  field_ref = fld.ref # Default: the ref we found is the field

  # If this is a widget, we need to also update the parent field object (if it exists)
  # Otherwise, this widget IS the field (flat structure)
  if is_widget
    parent_tok = DictScan.value_token_after("/Parent", original)
    if parent_tok && parent_tok =~ /\A(\d+)\s+(\d+)\s+R/
      field_ref = [Integer(::Regexp.last_match(1)), Integer(::Regexp.last_match(2))]
      field_body = get_object_body_with_patch(field_ref)
      if field_body && !field_body.include?("/Subtype /Widget")
        new_field_body = patch_field_value_body(field_body, @new_value)

        # Check if multiline and remove appearance stream from parent field too
        is_multiline = DictScan.is_multiline_field?(field_body) || DictScan.is_multiline_field?(new_field_body)
        if is_multiline
          new_field_body = DictScan.remove_appearance_stream(new_field_body)
        end

        if new_field_body && new_field_body.include?("<<") && new_field_body.include?(">>")
          apply_patch(field_ref, new_field_body, field_body)
        end
      end
    end
  end

  # Update the object we found (widget or field) - always update what we found
  new_body = patch_field_value_body(original, @new_value)

  # Check if this is a multiline field - if so, remove appearance stream
  # macOS Preview needs appearance streams to be regenerated for multiline fields
  is_multiline = check_if_multiline_field(field_ref)
  if is_multiline
    new_body = DictScan.remove_appearance_stream(new_body)
  end

  # Update field name (/T) if requested
  if @new_name && !@new_name.empty?
    new_body = patch_field_name_body(new_body, @new_name)
  end

  # Validate the patched body is valid before adding to patches
  unless new_body && new_body.include?("<<") && new_body.include?(">>")
    warn "Warning: Invalid patched body for #{fld.ref.inspect}, skipping update"
    return false
  end

  apply_patch(fld.ref, new_body, original)

  # If we renamed the field, also update the parent field object and all widgets
  if @new_name && !@new_name.empty?
    # Update parent field object if it exists (separate from widget)
    if field_ref != fld.ref
      field_body = get_object_body_with_patch(field_ref)
      if field_body && !field_body.include?("/Subtype /Widget")
        new_field_body = patch_field_name_body(field_body, @new_name)
        if new_field_body && new_field_body.include?("<<") && new_field_body.include?(">>")
          apply_patch(field_ref, new_field_body, field_body)
        end
      end
    end

    # Update all widget annotations that reference this field
    update_widget_names_for_field(field_ref, @new_name)
  end

  # Also update any widget annotations that reference this field via /Parent
  update_widget_annotations_for_field(field_ref, @new_value)

  # If this is a checkbox without appearance streams, create them
  if fld.button_field?
    # Check if it's a checkbox (not a radio button) by checking field flags
    field_body = get_object_body_with_patch(field_ref)
    is_radio = false
    if field_body
      field_flags_match = field_body.match(%r{/Ff\s+(\d+)})
      if field_flags_match
        field_flags = field_flags_match[1].to_i
        # Radio button flag is bit 15 = 32768
        is_radio = field_flags.anybits?(32_768)
      end
    end

    if is_radio
      # For radio buttons, update all widget appearances (overwrite existing)
      update_radio_button_appearances(field_ref)
    else
      # For checkboxes, create/update appearance
      widget_ref = find_checkbox_widget(fld.ref)
      if widget_ref
        widget_body = get_object_body_with_patch(widget_ref)
        # Create appearances if /AP doesn't exist, or overwrite if it does
        rect = extract_widget_rect(widget_body)
        if rect && rect[:width].positive? && rect[:height].positive?
          add_checkbox_appearance(widget_ref, rect[:width], rect[:height])
        end
      end
    end
  end

  # Best-effort: set NeedAppearances to true so viewers regenerate appearances
  ensure_need_appearances

  true
end