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)

  # setup recursive listener on the apps and lib directories from the source script.
  @listener = Listen.to("#{@root}/apps", "#{@root}/lib", "#{@root}") 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 163

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

#apps ⇒ Object 



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# File 'lib/camping/loader.rb', line 167

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 80

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

  load_file
  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

    apps.each do |app|
      @callback.call(app) if @callback
      app.create if app.respond_to?(:create)
    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 124

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 70

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 67

def pause;@listener.pause end

#processing_events? ⇒ Boolean

pass through methods to the Listener. for testing purposes.

Returns:

  • (Boolean) 


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# File 'lib/camping/loader.rb', line 65

def processing_events?;@listener.processing? end

#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 151

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 157

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 135

def remove_constants
	@requires.each do |(path, full)|
 		$LOADED_FEATURES.delete(path)
 	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 68

def start;@listener.start end

#stop ⇒ Object 



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# File 'lib/camping/loader.rb', line 66

def stop;@listener.stop end