Class: Camping::Loader

Inherits:
Object show all
Defined in:
lib/camping/loader.rb

Overview

The Camping Reloader

Camping apps are generally small and predictable. Many Camping apps are contained within a single file. Larger apps are split into a handful of other Ruby libraries within the same directory.

Since Camping apps (and their dependencies) are loaded with Ruby’s require method, there is a record of them in $LOADED_FEATURES. Which leaves a perfect space for this class to manage auto-reloading an app if any of its immediate dependencies changes.

Wrapping Your Apps

Since bin/camping and the Camping::Server class already use the Reloader, you probably don’t need to hack it on your own. But, if you’re rolling your own situation, here’s how.

Rather than this:

require 'yourapp'

Use this:

require 'camping/reloader'
reloader = Camping::Reloader.new('/path/to/yourapp.rb')
blog = reloader.apps[:Blog]
wiki = reloader.apps[:Wiki]

The blog and wiki objects will behave exactly like your Blog and Wiki, but they will update themselves if yourapp.rb changes.

You can also give Reloader more than one script.

Constant Summary collapse

Loaders = 
[]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(file = nil, &blk) ⇒ Loader

Returns a new instance of Loader.



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# File 'lib/camping/loader.rb', line 41

def initialize(file=nil, &blk)
  @file = file
  @mtime = Time.at(0)
  @requires = []
  @apps = {}
  @callback = blk
  @root = Dir.pwd
  @file = @root + '/camp.rb' if @file == nil
  @zeit = Zeitwerk::Loader.new
  Loaders << @zeit

  # setup Zeit for this reloader
  setup_zeit(@zeit)

  dirs = [@root]
  dirs << "#{@root}/apps" if Dir.exist? "#{@root}/apps"
  dirs << "#{@root}/lib" if Dir.exist? "#{@root}/lib"

  # setup recursive listener on the apps and lib directories from the source script.
  @listener = Listen.to(*dirs) do |modified, added, removed|
    @mtime = Time.now
    reload!
  end
  start
end

Instance Attribute Details

#file ⇒ Object (readonly)

Returns the value of attribute file.



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# File 'lib/camping/loader.rb', line 38

def file
  @file
end

Instance Method Details

#==(other) ⇒ Object

Checks if both scripts watches the same file.



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# File 'lib/camping/loader.rb', line 174

def ==(other)
  @file == other.file
end

#apps ⇒ Object 



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# File 'lib/camping/loader.rb', line 178

def apps
  if @app
    { name => @app }
  else
    @apps
  end
end

#load_everything ⇒ Object

remove_constants called inside this.



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# File 'lib/camping/loader.rb', line 84

def load_everything()
  all_requires = $LOADED_FEATURES.dup
  all_apps = Camping::Apps.dup

  # Zeitwerk will Autoload stuff, which is great. But we don't want Zeitwerk
  # autoloading when we evaluate the camp.rb file because it will try to
  # autoload any controllers and helpers that we've defined in there from
  # the descendant /apps and /lib directory, which then make it break.
  @zeit.unload
  load_file
  @zeit.setup
  reload_directory("#{@root}/apps")
  reload_directory("#{@root}/lib")
  Camping.make_camp
ensure
  @requires = []
  new_apps = Camping::Apps - all_apps

  @apps = new_apps.inject({}) do |hash, app|
    if file = app.options[:__FILE__]
      full = File.expand_path(file)
      @requires << [file, full]
    end

    key = app.name.to_sym
    hash[key] = app

    if !@apps.include?(key)
      @callback.call(app) if @callback
      app.create if app.respond_to?(:create)
      app.kindling if app.respond_to?(:kindling)
    end

    hash
  end

  ($LOADED_FEATURES - all_requires).each do |req|
    full = full_path(req)
    @requires << [req, full] # if dirs.any? { |x| full.index(x) == 0 }
  end

  @mtime = mtime

  self

end

#load_file ⇒ Object

load_file

Rack::Builder is mainly used to parse a config.ru file and to build a rack app with middleware from that.



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# File 'lib/camping/loader.rb', line 135

def load_file
  if @file =~ /\.ru$/
    @app = Rack::Builder.parse_file(@file)
  else
    load(@file)
  end
  @requires << [@file, File.expand_path(@file)]
end

#name ⇒ Object 



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# File 'lib/camping/loader.rb', line 74

def name
  @name ||= begin
    base = @file.dup
    base = File.dirname(base) if base =~ /\bconfig\.ru$/
    base.sub!(/\.[^.]+/, '')
    File.basename(base).to_sym
  end
end

#pause ⇒ Object 



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# File 'lib/camping/loader.rb', line 71

def pause = @listener.pause

#processing_events? ⇒ Boolean

pass through methods to the Listener. for testing purposes.

Returns:

  • (Boolean) 


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# File 'lib/camping/loader.rb', line 69

def processing_events? = @listener.processing?

#reload ⇒ Object

Reloads the file if needed. No harm is done by calling this multiple times, so feel free call just to be sure.



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# File 'lib/camping/loader.rb', line 162

def reload
  return if @mtime >= mtime rescue nil
  reload!
end

#reload! ⇒ Object

Force a reload.



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# File 'lib/camping/loader.rb', line 168

def reload!
  remove_constants
  load_everything
end

#remove_constants ⇒ Object

removes all constants recursively included using this script as a root. so everything in /apps, and /lib in relation from this script.



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# File 'lib/camping/loader.rb', line 146

def remove_constants
	@requires.each do |(path, full)|
 		$LOADED_FEATURES.delete(path) unless path.match? "concurrent-ruby"
 	end

  @apps.each do |name, app|
    Camping::Apps.delete(app)
    Object.send :remove_const, name
  end.dup
ensure
  @apps.clear
  @requires.clear
end

#start ⇒ Object 



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# File 'lib/camping/loader.rb', line 72

def start = @listener.start

#stop ⇒ Object 



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# File 'lib/camping/loader.rb', line 70

def stop = @listener.stop