ActiveSupport::FileUpdateChecker (original) (raw)

File Update Checker

FileUpdateChecker specifies the API used by Rails to watch files and control reloading. The API depends on four methods:

• initialize which expects two parameters and one block as described below.
• updated? which returns a boolean if there were updates in the filesystem or not.
• execute which executes the given block on initialization and updates the latest watched files and timestamp.
• execute_if_updated which just executes the block if it was updated.

After initialization, a call to execute_if_updated must execute the block only if there was really a change in the filesystem.

This class is used by Rails to reload the I18n framework whenever they are changed upon a new request.

i18n_reloader = ActiveSupport::FileUpdateChecker.new(paths) do
  I18n.reload!
end

ActiveSupport::Reloader.to_prepare do
  i18n_reloader.execute_if_updated
end

Methods

E

• execute,
• execute_if_updated

N

• new

U

• updated?

Class Public methods

new(files, dirs = {}, &block)Link

It accepts two parameters on initialization. The first is an array of files and the second is an optional hash of directories. The hash must have directories as keys and the value is an array of extensions to be watched under that directory.

This method must also receive a block that will be called once a path changes. The array of files and list of directories cannot be changed after FileUpdateChecker has been initialized.

Source: show | on GitHub

def initialize(files, dirs = {}, &block) unless block raise ArgumentError, "A block is required to initialize a FileUpdateChecker" end

@files = files.freeze @glob = compile_glob(dirs) @block = block

@watched = nil @updated_at = nil

@last_watched = watched @last_update_at = updated_at(@last_watched) end

Instance Public methods

execute()Link

Executes the given block and updates the latest watched files and timestamp.

Source: show | on GitHub

def execute @last_watched = watched @last_update_at = updated_at(@last_watched) @block.call ensure @watched = nil @updated_at = nil end

execute_if_updated()Link

Execute the block given if updated.

Source: show | on GitHub

def execute_if_updated if updated? yield if block_given? execute true else false end end

updated?()Link

Check if any of the entries were updated. If so, the watched and/or updated_at values are cached until the block is executed via execute or execute_if_updated.

Source: show | on GitHub

def updated? current_watched = watched if @last_watched.size != current_watched.size @watched = current_watched true else current_updated_at = updated_at(current_watched) if @last_update_at < current_updated_at @watched = current_watched @updated_at = current_updated_at true else false end end end