Class: Sprockets::Manifest

Inherits:
Object
  • Object
show all
Defined in:
lib/sprockets/manifest.rb

Overview

The Manifest logs the contents of assets compiled to a single directory. It records basic attributes about the asset for fast lookup without having to compile. A pointer from each logical path indicates with fingerprinted asset is the current one.

The JSON is part of the public API and should be considered stable. This should make it easy to read from other programming languages and processes that don't have sprockets loaded. See `#assets` and `#files` for more infomation about the structure.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Manifest

Create new Manifest associated with an `environment`. `path` is a full path to the manifest json file. The file may or may not already exist. The dirname of the `path` will be used to write compiled assets to. Otherwise, if the path is a directory, the filename will default a random “manifest-123.json” file in that directory.

Manifest.new(environment, "./public/assets/manifest.json")

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# File 'lib/sprockets/manifest.rb', line 27

def initialize(*args)
  if args.first.is_a?(Base) || args.first.nil?
    @environment = args.shift
  end

  @dir, @path = args[0], args[1]

  # Expand paths
  @dir  = File.expand_path(@dir) if @dir
  @path = File.expand_path(@path) if @path

  # If path is given as the second arg
  if @dir && File.extname(@dir) != ""
    @dir, @path = nil, @dir
  end

  # Default dir to the directory of the path
  @dir ||= File.dirname(@path) if @path

  # If directory is given w/o path, pick a random manifest.json location
  if @dir && @path.nil?
    # Find the first manifest.json in the directory
    paths = Dir[File.join(@dir, "manifest*.json")]
    if paths.any?
      @path = paths.first
    else
      @path = File.join(@dir, "manifest-#{SecureRandom.hex(16)}.json")
    end
  end

  unless @dir && @path
    raise ArgumentError, "manifest requires output path"
  end

  data = nil

  begin
    if File.exist?(@path)
      data = json_decode(File.read(@path))
    end
  rescue MultiJson::DecodeError => e
    logger.error "#{@path} is invalid: #{e.class} #{e.message}"
  end

  @data = data.is_a?(Hash) ? data : {}
end

Instance Attribute Details

#dirObject (readonly)

Returns the value of attribute dir


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# File 'lib/sprockets/manifest.rb', line 16

def dir
  @dir
end

#environmentObject (readonly)

Returns the value of attribute environment


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# File 'lib/sprockets/manifest.rb', line 16

def environment
  @environment
end

#pathObject (readonly)

Returns the value of attribute path


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# File 'lib/sprockets/manifest.rb', line 16

def path
  @path
end

Instance Method Details

#assetsObject

Returns internal assets mapping. Keys are logical paths which map to the latest fingerprinted filename.

Logical path (String): Fingerprint path (String)

{ "application.js" => "application-2e8e9a7c6b0aafa0c9bdeec90ea30213.js",
  "jquery.js"      => "jquery-ae0908555a245f8266f77df5a8edca2e.js" }

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# File 'lib/sprockets/manifest.rb', line 82

def assets
  @data['assets'] ||= {}
end

#clean(keep = 2) ⇒ Object

Cleanup old assets in the compile directory. By default it will keep the latest version plus 2 backups.


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# File 'lib/sprockets/manifest.rb', line 171

def clean(keep = 2)
  self.assets.keys.each do |logical_path|
    # Get assets sorted by ctime, newest first
    assets = backups_for(logical_path)

    # Keep the last N backups
    assets = assets[keep..-1] || []

    # Remove old assets
    assets.each { |path, _| remove(path) }
  end
end

#clobberObject

Wipe directive


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# File 'lib/sprockets/manifest.rb', line 185

def clobber
  FileUtils.rm_r(@dir) if File.exist?(@dir)
  logger.info "Removed #{@dir}"
  nil
end

#compile(*args) ⇒ Object

Compile and write asset to directory. The asset is written to a fingerprinted filename like `application-2e8e9a7c6b0aafa0c9bdeec90ea30213.js`. An entry is also inserted into the manifest file.

compile("application.js")

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# File 'lib/sprockets/manifest.rb', line 110

def compile(*args)
  unless environment
    raise Error, "manifest requires environment for compilation"
  end

  paths = environment.each_logical_path(*args).to_a +
    args.flatten.select { |fn| Pathname.new(fn).absolute? if fn.is_a?(String)}

  paths.each do |path|
    if asset = find_asset(path)
      files[asset.digest_path] = {
        'logical_path' => asset.logical_path,
        'mtime'        => asset.mtime.iso8601,
        'size'         => asset.bytesize,
        'digest'       => asset.digest
      }
      assets[asset.logical_path] = asset.digest_path

      target = File.join(dir, asset.digest_path)

      if File.exist?(target)
        logger.debug "Skipping #{target}, already exists"
      else
        logger.info "Writing #{target}"
        asset.write_to target
        asset.write_to "#{target}.gz" if asset.is_a?(BundledAsset)
      end

    end
  end
  save
  paths
end

#filesObject

Returns internal file directory listing. Keys are filenames which map to an attributes array.

 Fingerprint path (String):
   logical_path: Logical path (String)
   mtime: ISO8601 mtime (String)
   digest: Base64 hex digest (String)

{ "application-2e8e9a7c6b0aafa0c9bdeec90ea30213.js" =>
    { 'logical_path' => "application.js",
      'mtime' => "2011-12-13T21:47:08-06:00",
      'digest' => "2e8e9a7c6b0aafa0c9bdeec90ea30213" } }

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# File 'lib/sprockets/manifest.rb', line 99

def files
  @data['files'] ||= {}
end

#remove(filename) ⇒ Object

Removes file from directory and from manifest. `filename` must be the name with any directory path.

manifest.remove("application-2e8e9a7c6b0aafa0c9bdeec90ea30213.js")

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# File 'lib/sprockets/manifest.rb', line 149

def remove(filename)
  path = File.join(dir, filename)
  gzip = "#{path}.gz"
  logical_path = files[filename]['logical_path']

  if assets[logical_path] == filename
    assets.delete(logical_path)
  end

  files.delete(filename)
  FileUtils.rm(path) if File.exist?(path)
  FileUtils.rm(gzip) if File.exist?(gzip)

  save

  logger.info "Removed #{filename}"

  nil
end