The Specification class 包含一个gem的基本信息。一般定义在一个 .gemspec文件或者一个 Rakefile，看起来像下面这样：
Gem::Specification.new do |s| s.name = 'example' s.version = '0.1.0' s.licenses = ['MIT'] s.summary = "This is an example!" s.description = "Much longer explanation of the example!" s.authors = ["Ruby Coder"] s.email = '[email protected]' s.files = ["lib/example.rb"] s.homepage = 'https://rubygems.org/gems/example' end
从rubygems2.0开始，说明中可以包含任意的metadata，一些 metadata for restrictions（限制） on the format and size of metadata items you may add to a specification.
目录：
一、必须的gemspec属性
二、推荐的gemspec属性
三、可选的gemspec属性
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一、必须的gemspec属性
author=(o)
Singular writer for authors
Usage:
spec.author = 'John Jones'
authors=(value)
列出所有作者，必须是一个数组。
Usage:
spec.authors = ['John Jones', 'Mary Smith']
files
Files included in this gem. You cannot append to this accessor, you must assign to it.
Only add files you can require to this list, not directories, etc.
Directories are automatically stripped from this list when building a gem, other non-files cause an error.
Usage:
require 'rake'
spec.files = FileList['lib .rb',
'bin/*',
'[A-Z]*',
'test/ *'].to_a
# or without Rake...
spec.files = Dir['lib/ *.rb'] + Dir['bin/*']
spec.files += Dir['[A-Z]*'] + Dir['test/**/*']
spec.files.reject! { |fn| fn.include? "CVS" }
name
该gem的名字
Usage:
spec.name = 'rake'
platform=(platform)
该gem运行平台
This is usually Gem::Platform::RUBY or Gem::Platform::CURRENT.
Most gems contain pure Ruby code; they should simply leave the default value in place. Some gems contain C (or other) code to be compiled into a Ruby “extension”. The should leave the default value in place unless their code will only compile on a certain type of system. Some gems consist of pre-compiled code (“binary gems”). It's especially important that they set the platform attribute appropriately. A shortcut is to set the platform to Gem::Platform::CURRENT, which will cause the gem builder to set the platform to the appropriate value for the system on which the build is being performed.
If this attribute is set to a non-default value, it will be included in the filename of the gem when it is built such as: nokogiri-1.6.0-x86-mingw32.gem
Usage:
spec.platform = Gem::Platform.local
require_paths=(val)
Paths in the gem to add to $LOAD_PATH when this gem is activated.
See also require_paths
If you have an extension you do not need to add "ext" to the require path, the extension build process will copy the extension files into “lib” for you.
The default value is "lib"
Usage:
# If all library files are in the root directory... spec.require_paths = ['.']
rubygems_version
The version of RubyGems used to create this gem.
Do not set this, it is set automatically when the gem is packaged.
summary
A short summary of this gem's description. Displayed in `gem list -d`.
The description should be more detailed than the summary.
Usage:
spec.summary = "This is a small summary of my gem"
version
This gem's version.
The version string can contain numbers and periods, such as 1.0.0. A gem is a 'prerelease' gem if the version has a letter in it, such as 1.0.0.pre.
Usage:
spec.version = '0.4.1'
二、推荐的gemspec属性
license=(o)
The license for this gem.
The license must be no more than 64 characters.
This should just be the name of your license. The full text of the license should be inside of the gem (at the top level) when you build it.
The simplest way, is to specify the standard SPDX ID spdx.org/licenses/ for the license. Ideally you should pick one that is OSI (Open Source Initiative) opensource.org/licenses/alphabetical approved.
The most commonly used OSI approved licenses are BSD-3-Clause and MIT. GitHub also provides a license picker atchoosealicense.com/.
You should specify a license for your gem so that people know how they are permitted to use it, and any restrictions you're placing on it. Not specifying a license means all rights are reserved; others have no rights to use the code for any purpose.
You can set multiple licenses with licenses=
Usage:
spec.license = 'MIT'
licenses=(licenses)
The license(s) for the library.
Each license must be a short name, no more than 64 characters.
This should just be the name of your license. The full text of the license should be inside of the gem when you build it.
See license= for more discussion
Usage:
spec.licenses = ['MIT', 'GPL-2']
三、可选的gemspec属性
add_development_dependency(gem, *requirements)
Adds a development dependency named gem with requirements to this gem.
Usage:
spec.add_development_dependency 'example', '~> 1.1', '>= 1.1.4'
Development dependencies aren't installed by default and aren't activated when a gem is required.
add_runtime_dependency(gem, *requirements)
Adds a runtime dependency named gem with requirements to this gem.
Usage:
spec.add_runtime_dependency 'example', '~> 1.1', '>= 1.1.4'
bindir
可执行脚本的路径，通常是 'bin'
Usage:
spec.bindir = 'bin'
cert_chain
The certificate chain used to sign this gem. See Gem::Security for details.
description
该gem的一个详细的描述
The description should be more detailed than the summary but not excessively long. A few paragraphs is a recommended length with no examples or formatting.
Usage:
spec.description = <<-EOF Rake is a Make-like program implemented in Ruby. Tasks and dependencies are specified in standard Ruby syntax. EOF
该gem的联系邮箱
Usage:
spec.email = '[email protected]' spec.email = ['[email protected]', '[email protected]']
executables
Executables included in the gem.
For example, the rake gem has rake as an executable. You don’t specify the full path (as in bin/rake); all application-style files are expected to be found in bindir. These files must be executable Ruby files. Files that use bash or other interpreters will not work.
Executables included may only be ruby scripts, not scripts for other languages or compiled binaries.
Usage:
spec.executables << 'rake'
extensions
Extensions to build when installing the gem, specifically the paths to extconf.rb-style files used to compile extensions.
These files will be run when the gem is installed, causing the C (or whatever) code to be compiled on the user’s machine.
Usage:
spec.extensions << 'ext/rmagic/extconf.rb'
See Gem::Ext::Builder for information about writing extensions for gems.
extra_rdoc_files
Extra files to add to RDoc such as README or doc/examples.txt
When the user elects to generate the RDoc documentation for a gem (typically at install time), all the library files are sent to RDoc for processing. This option allows you to have some non-code files included for a more complete set of documentation.
Usage:
spec.extra_rdoc_files = ['README', 'doc/user-guide.txt']
homepage
The URL of this gem's home page
Usage:
spec.homepage = 'http://rake.rubyforge.org'
metadata
:attr_accessor: metadata
The metadata holds extra data for this gem that may be useful to other consumers and is settable by gem authors without requiring an update to the rubygems software.
Metadata items have the following restrictions:
-
The metadata must be a Hash object
-
All keys and values must be Strings
-
Keys can be a maximum of 128 bytes and values can be a maximum of 1024 bytes
-
All strings must be UTF-8, no binary data is allowed
To add metadata for the location of a issue tracker:
s.metadata = { "issue_tracker" => "https://example/issues" }
post_install_message
A message that gets displayed after the gem is installed.
Usage:
spec.post_install_message = "Thanks for installing!"
rdoc_options
Specifies the rdoc options to be used when generating API documentation.
Usage:
spec.rdoc_options << '--title' << 'Rake -- Ruby Make' << '--main' << 'README' << '--line-numbers'
required_ruby_version
The version of Ruby required by this gem
required_ruby_version=(req)
The version of Ruby required by this gem. The ruby version can be specified to the patch-level:
$ ruby -v -e 'p Gem.ruby_version' ruby 2.0.0p247 (2013-06-27 revision 41674) [x86_64-darwin12.4.0] #<Gem::Version "2.0.0.247">
Usage:
# This gem will work with 1.8.6 or greater... spec.required_ruby_version = '>= 1.8.6' # Only with ruby 2.0.x spec.required_ruby_version = '~> 2.0'
required_rubygems_version
The RubyGems version required by this gem
required_rubygems_version=(req)
The RubyGems version required by this gem
requirements
Lists the external (to RubyGems) requirements that must be met for this gem to work. It's simply information for the user.
Usage:
spec.requirements << 'libmagick, v6.0' spec.requirements << 'A good graphics card'
signing_key
用来签名gem，详述请看 Gem::Security