crystal-bplist

Apple's binary property list format implementation in Crystal.

bplist module provides an interface for reading and writing the “property list” files used by Apple, primarily on macOS and iOS. This module supports only binary plist files.

Values can be strings, integers, floats, booleans, arrays, hashes (but only with string keys), Bytes, or Time objects.

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     bplist:
       github: mamantoha/crystal-bplist

2. Run shards install

Usage

Bplist::Writer

Transform a Crystal hash into bplist format:

require "bplist"

hash = {
  "ExampleDictionary" => {
    "ExampleDate" => Time.parse("2023-04-01 12:00:00 +00:00", "%Y-%m-%d %H:%M:%S %z", Time::Location::UTC),
    "ExampleArray" => [
      "Item 1",
      "Item 2",
      "Item 3",
    ],
  },
  "ExampleString" => "Hello, world!",
  "ExampleInteger" => 42,
  "ExampleBoolean" => true,
}

writer = Bplist::Writer.new(hash)
writer.write_to_file("#{__DIR__}/../assets/example_mod.plist")

crystal ./samples/write.cr

Rewrite the property list file in XML format:

plutil -convert xml1 assets/example_mod.plist -o assets/example_mod.xml
cat assets/example_mod.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>ExampleBoolean</key>
  <true/>
  <key>ExampleDictionary</key>
  <dict>
    <key>ExampleArray</key>
    <array>
      <string>Item 1</string>
      <string>Item 2</string>
      <string>Item 3</string>
    </array>
    <key>ExampleDate</key>
    <date>2023-04-01T12:00:00Z</date>
  </dict>
  <key>ExampleInteger</key>
  <integer>42</integer>
  <key>ExampleString</key>
  <string>Hello, world!</string>
</dict>
</plist>

Bplist::Parser

Parse a binary plist file and retrieve a Bplist::Any object:

require "bplist"

bplist = Bplist::Parser.new("#{__DIR__}/../assets/example.plist")

result = bplist.parse
pp result

{"ExampleDictionary" =>
  {"ExampleDate" => 2023-04-01 12:00:00.0 UTC,
   "ExampleArray" => ["Item 1", "Item 2", "Item 3"]},
 "ExampleString" => "Hello, world!",
 "ExampleInteger" => 42,
 "ExampleBoolean" => true}

Useful links

• https://medium.com/@karaiskc/understanding-apples-binary-property-list-format-281e6da00dbd
• https://github.com/opensource-apple/CF/blob/master/CFBinaryPList.c
• https://docs.python.org/3/library/plistlib.html
• https://github.com/python/cpython/blob/main/Lib/plistlib.py
• http://fileformats.archiveteam.org/wiki/Property_List/Binary

Contributing

1. Fork it (https://github.com/mamantoha/crystal-bplist/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

• Anton Maminov - creator and maintainer