#-- copyright # OpenProject is an open source project management software. # Copyright (C) 2012-2020 the OpenProject GmbH # # This program is free software; you can redistribute it and/or # modify it under the terms of the GNU General Public License version 3. # # OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows: # Copyright (C) 2006-2017 Jean-Philippe Lang # Copyright (C) 2010-2013 the ChiliProject Team # # This program is free software; you can redistribute it and/or # modify it under the terms of the GNU General Public License # as published by the Free Software Foundation; either version 2 # of the License, or (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write to the Free Software # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. # # See docs/COPYRIGHT.rdoc for more details. #++ require 'digest/sha1' module ::Widget class Base < Widget::ReportingWidget attr_reader :engine, :output attr_accessor :request ## # Deactivate caching for certain widgets. If called on Widget::Base, # caching is deactivated globally def self.dont_cache! @dont_cache = true end ## # Query whether this widget class should be cached. def self.dont_cache? @dont_cache or self != Widget::Base && Widget::Base.dont_cache? end def initialize(query) @subject = query @engine = query.class @options = {} end ## # Write a string to the canvas. The string is marked as html_safe. # This will write twice, if @cache_output is set. def write(str) str ||= '' @output ||= ''.html_safe @output = @output + '' if @output.frozen? # Rails 2 freezes tag strings @output.concat str.html_safe @cache_output.concat(str.html_safe) if @cache_output str.html_safe end ## # Render this widget. Abstract method. Needs to call #write at least once def render raise NotImplementedError, "#render is missing in my subclass #{self.class}" end ## # Render this widget, passing options. # Available options: # :to => canvas - The canvas (streaming or otherwise) to render to. Has to respond to #write def render_with_options(options = {}, &block) set_canvas(options.delete(:to)) if options.has_key? :to @options = options render_with_cache(options, &block) @output end def cache_key @cache_key ||= Digest::SHA1::hexdigest begin if subject.respond_to? :cache_key "#{I18n.locale}/#{self.class.name.demodulize}/#{subject.cache_key}/#{@options.sort_by(&:to_s)}" else subject.inspect end end end def cached? cache? && Rails.cache.exist?(cache_key) end private def cache? !self.class.dont_cache? end ## # Render this widget or serve it from cache def render_with_cache(_options = {}, &block) if cached? write Rails.cache.fetch(cache_key) else render(&block) Rails.cache.write(cache_key, @cache_output || @output) if cache? end end ## # Set the canvas. If the canvas object isn't a string (e.g. cannot be cached easily), # a @cache_output String is created, that will mirror what is being written to the canvas. def set_canvas(canvas) @cache_output = ''.html_safe @output = canvas end end end