Fix an issue with incorrect or blank checkbox appearances. (#29)

In a previous commit, iText's `generateAppearance` field was set to true for all fields except checkboxes in order to enable custom checkboxes to show correctly. However, this had unintended consequences for some developers where checkboxes with the default appearance were completely blank.

In order to work correctly with both custom checkboxes (such as square, circle, diamond, or other) and default checkboxes, developers can now set `generate_appearance` themselves to whatever suits their type of PDF file.

.rubocop.yml

@@ -29,6 +29,7 @@ Layout/LineLength:
     - README.md
     - fillable-pdf.gemspec
   Max: 120
+  AllowedPatterns: ['^(\s*#)']
 
 Layout/SpaceInsideHashLiteralBraces:
   Enabled: false

README.md

@@ -23,9 +23,35 @@ FillablePDF is an extremely simple and lightweight utility that bridges iText an
 
 4. Read-only, write-protected or encrypted PDF files are currently not supported.
 
-5. Adobe generated field arrays (i.e. fields with names such as `array.0` or `array.1.0`) are not supported. 
+5. Adobe generated field arrays (i.e. fields with names such as `array.0` or `array.1.0`) are not supported.
 
 
+## Troubleshooting Issues
+
+### Blank Fields
+
+* **Actual Result:**
+
+  ![Blank](images/blank.png)
+
+* **Expected Result:**
+
+  ![Blank](images/checked.png)
+
+If only of the fields are blank, try setting the `generate_appearance` flag to `true` when calling `set_field` or `set_fields`.
+
+### Invalid Checkbox Appearances
+
+* **Actual Result:**
+
+  ![Blank](images/checked.png)
+
+* **Expected Result:**
+
+  ![Blank](images/distinct.png)
+
+If your checkboxes are showing incorrectly, it's likely because iText is overwriting your checkbox appearances. Try setting the `generate_appearance` flag to `false` when calling `set_field` or `set_fields`.
+
 ## Installation
 
 **Prerequisites:** Java SE Development Kit v8, v11
@@ -131,19 +157,21 @@ An instance of `FillablePDF` has the following methods at its disposal:
     pdf.num_fields
     ```
 
-* `field`
+* `field(key)`
     *Retrieves the value of a field given its unique field name.*
 
     ```ruby
     pdf.field(:full_name)
+    pdf.field('full_name')
     # output example: 'Richard'
     ```
 
-* `field_type`
+* `field_type(key)`
     *Retrieves the string type of a field given its unique field name.*
 
     ```ruby
     pdf.field_type(:football)
+    pdf.field_type('football')
     # output example: '/Btn'
 
     # list of all field types
@@ -157,6 +185,7 @@ An instance of `FillablePDF` has the following methods at its disposal:
 
     ```ruby
     pdf.field_type(:football) == Field::BUTTON
+    pdf.field_type('football') == Field::BUTTON
     ```
 
 * `fields`
@@ -167,52 +196,71 @@ An instance of `FillablePDF` has the following methods at its disposal:
     # output example: {first_name: "Richard", last_name: "Rahl"}
     ```
 
-* `set_field`
-    *Sets the value of a field given its unique field name and value.*
+* `set_field(key, value, generate_appearance: nil)`
+    *Sets the value of a field given its unique field name and value, with an optional `generate_appearance` directive.*
 
     ```ruby
     pdf.set_field(:first_name, 'Richard')
+    pdf.set_field('first_name', 'Richard')
     # result: changes the value of 'first_name' to 'Richard'
     ```
 
-* `set_fields`
-    *Sets the values of multiple fields given a set of unique field names and values.*
+  Optionally, you can choose to override iText's `generateAppearance` flag to take better control of your field's appearance, using `generate_appearance`. Passing `true` will force the field to generate its own appearance, while setting it to `false` would leave the appearance generation up to the PDF viewer application. Omitting the parameter would allow iText to decide what should happen.
+
+    ```ruby
+    pdf.set_field(:first_name, 'Richard', generate_appearance: true)
+    pdf.set_field('first_name', 'Richard', generate_appearance: false)
+    ```
+
+* `def set_fields(fields, generate_appearance: nil)`
+    *Sets the values of multiple fields given a set of unique field names and values, with an optional `generate_appearance` directive.*
 
     ```ruby
-    pdf.set_fields(first_name: 'Richard', last_name: 'Rahl')
+    pdf.set_fields({first_name: 'Richard', last_name: 'Rahl'})
     # result: changes the values of 'first_name' and 'last_name'
     ```
 
-* `set_image`
+  Optionally, you can choose to override iText's `generateAppearance` flag to take better control of your fields' appearance, using `generate_appearance`. Passing `true` will force the field to generate its own appearance, while setting it to `false` would leave the appearance generation up to the PDF viewer application. Omitting the parameter would allow iText to decide what should happen.
+
+    ```ruby
+    pdf.set_fields({first_name: 'Richard', last_name: 'Rahl'}, generate_appearance: true)
+    pdf.set_fields({first_name: 'Richard', last_name: 'Rahl'}, generate_appearance: false)
+    ```
+
+* `set_image(key, file_path)`
   *Places an image file within the rectangular bounding box of the given form field.*
 
     ```ruby
     pdf.set_image(:signature, 'signature.png')
+    pdf.set_image('signature', 'signature.png')
     # result: the image 'signature.png' is shown in the foreground of the form field
     ```
 
-* `set_image_base64`
+* `set_image_base64(key, base64_image_data)`
   *Places a base64 encoded image within the rectangular bounding box of the given form field.*
 
     ```ruby
+    pdf.set_image_base64('signature', 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==')
     pdf.set_image_base64(:signature, 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNk+M9QDwADhgGAWjR9awAAAABJRU5ErkJggg==')
     # result: the base64 encoded image is shown in the foreground of the form field
     ```
 
-* `rename_field`
+* `rename_field(old_key, new_key)`
     *Renames a field given its unique field name and the new field name.*
 
     ```ruby
     pdf.rename_field(:last_name, :surname)
+    pdf.rename_field('last_name', 'surname')
     # result: renames field name 'last_name' to 'surname'
     # NOTE: this action does not take effect until the document is saved
     ```
 
-* `remove_field`
+* `remove_field(key)`
     *Removes a field from the document given its unique field name.*
 
     ```ruby
     pdf.remove_field(:last_name)
+    pdf.remove_field('last_name')
     # result: physically removes field 'last_name' from document
     ```
 
@@ -232,7 +280,7 @@ An instance of `FillablePDF` has the following methods at its disposal:
     # output example: ["Rahl", "Richard"]
     ```
 
-* `save`
+* `save(flatten: false)`
     *Overwrites the previously opened PDF document and flattens it if requested.*
 
     ```ruby
@@ -242,7 +290,7 @@ An instance of `FillablePDF` has the following methods at its disposal:
     # result: document is saved with flattening
     ```
 
-* `save_as`
+* `save_as(file_path, flatten: false)`
     *Saves the filled out PDF document in a given path and flattens it if requested.*
 
     ```ruby
@@ -344,8 +392,8 @@ end
 puts
 
 # setting form fields
-pdf.set_fields(first_name: 'Richard', last_name: 'Rahl')
-pdf.set_fields(football: 'Yes', baseball: 'Yes', basketball: 'Yes', nascar: 'Yes', hockey: 'Yes')
+pdf.set_fields({first_name: 'Richard', last_name: 'Rahl'})
+pdf.set_fields({football: 'Yes', baseball: 'Yes', basketball: 'Yes', nascar: 'Yes', hockey: 'Yes', rugby: 'Yes'}, generate_appearance: false)
 pdf.set_field(:date, Time.now.strftime('%B %e, %Y'))
 pdf.set_field(:newsletter, 'Off') # uncheck the checkbox
 pdf.set_field(:language, 'dart') # select a radio button option
@@ -368,7 +416,7 @@ puts "Values: #{pdf.values}"
 puts
 
 # Checking field type
-if pdf.field_type(:football) == Field::BUTTON
+if pdf.field_type(:rugby) == Field::BUTTON
   puts "Field 'football' is of type BUTTON"
 else
   puts "Field 'football' is not of type BUTTON"
@@ -383,8 +431,8 @@ puts "Renamed field 'last_name' to 'surname'"
 puts
 
 # Removing field
-pdf.remove_field :nascar
-puts "Removed field 'nascar'"
+pdf.remove_field :marketing
+puts "Removed field 'marketing'"
 
 # saving the filled out PDF in another file
 pdf.save_as('output.pdf')

example/run.rb

@@ -15,8 +15,11 @@
 puts
 
 # setting form fields
-pdf.set_fields(first_name: 'Richard', last_name: 'Rahl')
-pdf.set_fields(football: 'Yes', baseball: 'Yes', basketball: 'Yes', nascar: 'Yes', hockey: 'Yes', rugby: 'Yes')
+pdf.set_fields({first_name: 'Richard', last_name: 'Rahl'})
+pdf.set_fields(
+  {football: 'Yes', baseball: 'Yes', basketball: 'Yes', nascar: 'Yes', hockey: 'Yes', rugby: 'Yes'},
+  generate_appearance: false
+)
 pdf.set_field(:date, Time.now.strftime('%B %e, %Y'))
 pdf.set_field(:newsletter, 'Off') # uncheck the checkbox
 pdf.set_field(:language, 'dart') # select a radio button option

lib/fillable-pdf.rb

@@ -87,12 +87,14 @@ def fields
   #
   #   @param [String|Symbol] key the field name
   #   @param [String|Symbol] value the field value
+  #   @param [NilClass|TrueClass|FalseClass] generate_appearance true to generate appearance, false to let the PDF viewer application generate form field appearance, nil (default) to let iText decide what's appropriate
   #
-  def set_field(key, value)
-    # we set generate_appearance to false for buttons to ensure that the chosen
-    # appearance for checkboxes (i.e. check, circle, diamond) is not changed
-    generate_appearance = field_type(key) != Field::BUTTON
-    pdf_field(key).setValue(value.to_s, generate_appearance)
+  def set_field(key, value, generate_appearance: nil)
+    if generate_appearance.nil?
+      pdf_field(key).setValue(value.to_s)
+    else
+      pdf_field(key).setValue(value.to_s, generate_appearance)
+    end
   end
 
   ##
@@ -157,9 +159,10 @@ def set_image_base64(key, base64_image_data)
   # Sets the values of multiple fields given a set of unique field names and values.
   #
   #   @param [Hash] fields the set of field names and values
+  #   @param [NilClass|TrueClass|FalseClass] generate_appearance true to generate appearance, false to let the PDF viewer application generate form field appearance,  nil (default) to let iText decide what's appropriate
   #
-  def set_fields(fields)
-    fields.each { |key, value| set_field key, value }
+  def set_fields(fields, generate_appearance: nil)
+    fields.each { |key, value| set_field key, value, generate_appearance: generate_appearance }
   end
 
   ##
@@ -220,7 +223,7 @@ def save(flatten: false)
   # Saves the filled out PDF document in a given path and flattens it if requested.
   #
   #   @param [String] file_path the name of the PDF file or file path
-  #   @param [Hash] flatten: true if PDF should be flattened, false otherwise
+  #   @param [TrueClass|FalseClass] flatten true if PDF should be flattened, false otherwise
   #
   def save_as(file_path, flatten: false)
     if @file_path == file_path
@@ -245,7 +248,7 @@ def close
   ##
   # Writes the contents of the modified fields to the previously opened PDF file.
   #
-  #   @param [Hash] flatten: true if PDF should be flattened, false otherwise
+  #   @param [TrueClass|FalseClass] flatten: true if PDF should be flattened, false otherwise
   #
   def finalize(flatten: false)
     @pdf_form.flattenFields if flatten

test/pdf_test.rb

@@ -19,6 +19,7 @@ def test_that_an_error_is_thrown_for_non_existing_file
     err = assert_raises IOError do
       @pdf = FillablePDF.new 'test.pdf'
     end
+
     assert_match 'is not found', err.message
   end
 
@@ -46,6 +47,7 @@ def test_that_a_field_type_can_be_accessed_by_name
 
   def test_that_a_field_value_can_be_modified
     @pdf.set_field(:first_name, 'Richard')
+
     assert_equal 'Richard', @pdf.field(:first_name)
   end
 
@@ -59,26 +61,32 @@ def test_that_a_base64_can_be_placed_in_photo_field
 
   def test_that_an_asian_font_works
     @pdf.set_field(:first_name, '理查德')
+
     assert_equal '理查德', @pdf.field(:first_name)
   end
 
   def test_that_multiple_field_values_can_be_modified
-    @pdf.set_fields(first_name: 'Richard', last_name: 'Rahl')
+    @pdf.set_fields({first_name: 'Richard', last_name: 'Rahl'})
+
     assert_equal 'Richard', @pdf.field(:first_name)
     assert_equal 'Rahl', @pdf.field(:last_name)
   end
 
   def test_that_a_checkbox_can_be_checked_and_unchecked
     @pdf.set_field(:nascar, 'Yes')
+
     assert_equal 'Yes', @pdf.field(:nascar)
     @pdf.set_field(:newsletter, 'Off')
+
     assert_equal 'Off', @pdf.field(:newsletter)
   end
 
   def test_that_a_radio_button_can_be_checked_and_unchecked
     @pdf.set_field(:language, 'ruby')
+
     3.times { |i| assert_equal 'ruby', @pdf.field("language.#{i}".gsub('.0', '')) }
     @pdf.set_field(:language, 'Off')
+
     3.times { |i| assert_equal 'Off', @pdf.field("language.#{i}".gsub('.0', '')) }
   end
 
@@ -89,6 +97,7 @@ def test_that_a_field_can_be_renamed
     err = assert_raises RuntimeError do
       @pdf.field(:last_name)
     end
+
     assert_match 'unknown key name', err.message
     assert_equal 'Test', @pdf.field(:surname)
   end
@@ -98,6 +107,7 @@ def test_that_a_field_can_be_removed
     err = assert_raises RuntimeError do
       @pdf.field(:first_name)
     end
+
     assert_match 'unknown key name', err.message
   end
 
@@ -111,9 +121,11 @@ def test_that_field_values_can_be_accessed
 
   def test_that_a_file_can_be_saved
     @pdf.save_as(@tmp)
+
     refute_nil FillablePDF.new(@tmp)
     @pdf = FillablePDF.new(@tmp)
     @pdf.save
+
     refute_nil FillablePDF.new(@tmp)
   end