Class: Sprockets::UnloadedAsset

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

Overview

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(uri, env) ⇒ UnloadedAsset

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.


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# 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

Instance Attribute Details

#compressed_pathObject (readonly)

Returns the value of attribute compressed_path


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# File 'lib/sprockets/unloaded_asset.rb', line 29

def compressed_path
  @compressed_path
end

#uriObject (readonly)

Returns the value of attribute uri


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# File 'lib/sprockets/unloaded_asset.rb', line 29

def uri
  @uri
end

Instance Method Details

#asset_keyObject

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.


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# File 'lib/sprockets/unloaded_asset.rb', line 77

def asset_key
  "asset-uri:#{compressed_path}"
end

#dependency_history_keyObject

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.


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# 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) ⇒ Object

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.


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# File 'lib/sprockets/unloaded_asset.rb', line 117

def digest_key(digest)
  "asset-uri-digest:#{compressed_path}:#{digest}"
end

#file_digest_key(stat) ⇒ Object

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.


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# File 'lib/sprockets/unloaded_asset.rb', line 127

def file_digest_key(stat)
  "file_digest:#{compressed_path}:#{stat}"
end

#filenameObject

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.


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# File 'lib/sprockets/unloaded_asset.rb', line 43

def filename
  unless @filename
    load_file_params
  end
  @filename
end

#paramsObject

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 `”application/javascript“`

Returns a Hash.


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# File 'lib/sprockets/unloaded_asset.rb', line 63

def params
  unless @params
    load_file_params
  end
  @params
end