class Sprockets::UnloadedAsset

Internal: Used to parse and store the URI to an unloaded asset Generates keys used to store and retrieve items from cache

Attributes

compressed_path[R]
uri[R]

Public Class Methods

new(uri, env) click to toggle source

Internal: Initialize object for generating cache keys

uri - A String containing complete URI to a file including scheme

and full path such as
"file:///Path/app/assets/js/app.js?type=application/javascript"

env - The current “environment” that assets are being loaded into.

We need it so we know where the +root+ (directory where Sprockets
is being invoked). We also need it for the `file_digest` method,
since, for some strange reason, memoization is provided by
overriding methods such as `stat` in the `PathUtils` module.

Returns UnloadedAsset.

# File lib/sprockets/unloaded_asset.rb, line 22
def initialize(uri, env)
  @uri               = uri.to_s
  @env               = env
  @compressed_path   = URITar.new(uri, env).compressed_path
  @params            = nil # lazy loaded
  @filename          = nil # lazy loaded
end

Public Instance Methods

asset_key() click to toggle source

Internal: Key of asset

Used to retrieve an asset from the cache based on “compressed” path to asset. A “compressed” path can either be relative to the root of the project or an absolute path.

Returns a String.

# File lib/sprockets/unloaded_asset.rb, line 77
def asset_key
  "asset-uri:#{compressed_path}"
end
dependency_history_key() click to toggle source

Public: Dependency History key

Used to retrieve an array of “histories” each of which contains a set of stored dependencies for a given asset path and filename digest.

A dependency can refer to either an asset e.g. index.js may rely on jquery.js (so jquery.js is a dependency), or other factors that may affect compilation, such as the VERSION of Sprockets (i.e. the environment) and what “processors” are used.

For example a history array with one Set of dependencies may look like:

[[“environment-version”, “environment-paths”, “processors:type=text/css&file_type=text/css”,

"file-digest:///Full/path/app/assets/stylesheets/application.css",
"processors:type=text/css&file_type=text/css&pipeline=self",
"file-digest:///Full/path/app/assets/stylesheets"]]

This method of asset lookup is used to ensure that none of the dependencies have been modified since last lookup. If one of them has, the key will be different and a new entry must be stored.

URI dependencies are later converted to “compressed” paths

Returns a String.

# File lib/sprockets/unloaded_asset.rb, line 104
def dependency_history_key
  "asset-uri-cache-dependencies:#{compressed_path}:#{ @env.file_digest(filename) }"
end
digest_key(digest) click to toggle source

Internal: Digest key

Used to retrieve a string containing the “compressed” path to an asset based on a digest. The digest is generated from dependencies stored via information stored in the ‘dependency_history_key` after each of the “dependencies” is “resolved”. For example “environment-version” may be resolved to “environment-1.0-3.2.0” for version “3.2.0” of Sprockets

Returns a String.

# File lib/sprockets/unloaded_asset.rb, line 117
def digest_key(digest)
  "asset-uri-digest:#{compressed_path}:#{digest}"
end
file_digest_key(stat) click to toggle source

Internal: File digest key

The digest for a given file won’t change if the path and the stat time hasn’t changed We can save time by not re-computing this information and storing it in the cache

Returns a String.

# File lib/sprockets/unloaded_asset.rb, line 127
def file_digest_key(stat)
  "file_digest:#{compressed_path}:#{stat}"
end
filename() click to toggle source

Internal: Full file path without schema

This returns a string containing the full path to the asset without the schema. Information is loaded lazily since we want ‘UnloadedAsset.new(dep, self).relative_path` to be fast. Calling this method the first time allocates an array and a hash.

Example

If the URI is ‘file:///Full/path/app/assets/javascripts/application.js“` then the filename would be `”/Full/path/app/assets/javascripts/application.js“`

Returns a String.

# File lib/sprockets/unloaded_asset.rb, line 43
def filename
  unless @filename
    load_file_params
  end
  @filename
end
params() click to toggle source

Internal: Hash of param values

This information is generated and used internally by Sprockets. Known keys include ‘:type` which stores the asset’s mime-type, ‘:id` which is a fully resolved digest for the asset (includes dependency digest as opposed to a digest of only file contents) and `:pipeline`. Hash may be empty.

Example

If the URI is ‘file:///Full/path/app/assets/javascripts/application.js“type=application/javascript` Then the params would be `{type: ”application/javascript“}`

Returns a Hash.

# File lib/sprockets/unloaded_asset.rb, line 63
def params
  unless @params
    load_file_params
  end
  @params
end

Private Instance Methods

load_file_params() click to toggle source

Internal: Parses uri into filename and params hash

Returns Array with filename and params hash

# File lib/sprockets/unloaded_asset.rb, line 135
def load_file_params
  @filename, @params = URIUtils.parse_asset_uri(uri)
end