Allow plugins to specify a minimum `requires version`

lib/discourse.rb

@@ -1,6 +1,7 @@
 require 'cache'
 require_dependency 'plugin/instance'
 require_dependency 'auth/default_current_user_provider'
+require_dependency 'version'
 
 module Discourse
 
@@ -78,8 +79,18 @@ module Discourse
   end
 
   def self.activate_plugins!
-    @plugins = Plugin::Instance.find_all("#{Rails.root}/plugins")
-    @plugins.each { |plugin| plugin.activate! }
+    all_plugins = Plugin::Instance.find_all("#{Rails.root}/plugins")
+
+    @plugins = []
+    all_plugins.each do |p|
+      v = p.metadata.required_version || Discourse::VERSION::STRING
+      if Discourse.has_needed_version?(Discourse::VERSION::STRING, v)
+        p.activate!
+        @plugins << p
+      else
+        STDERR.puts "Could not activate #{p.metadata.name}, discourse does not meet required version (#{v})"
+      end
+    end
   end
 
   def self.disabled_plugin_names

lib/plugin/instance.rb

@@ -31,13 +31,6 @@ class Plugin::Instance
   def initialize(metadata=nil, path=nil)
     @metadata = metadata
     @path = path
-
-    if @path
-      # Automatically include all ES6 JS and hbs files
-      root_path = "#{File.dirname(@path)}/assets/javascripts"
-      DiscoursePluginRegistry.register_glob(root_path, 'js.es6')
-      DiscoursePluginRegistry.register_glob(root_path, 'hbs')
-    end
   end
 
   def add_admin_route(label, location)
@@ -216,6 +209,14 @@ class Plugin::Instance
   # this allows us to present information about a plugin in the UI
   # prior to activations
   def activate!
+
+    if @path
+      # Automatically include all ES6 JS and hbs files
+      root_path = "#{File.dirname(@path)}/assets/javascripts"
+      DiscoursePluginRegistry.register_glob(root_path, 'js.es6')
+      DiscoursePluginRegistry.register_glob(root_path, 'hbs')
+    end
+
     self.instance_eval File.read(path), path
     if auto_assets = generate_automatic_assets!
       assets.concat auto_assets.map{|a| [a]}

lib/plugin/metadata.rb

@@ -2,7 +2,7 @@
 module Plugin; end
 
 class Plugin::Metadata
-  FIELDS ||= [:name, :about, :version, :authors, :url]
+  FIELDS ||= [:name, :about, :version, :authors, :url, :required_version]
   attr_accessor *FIELDS
 
   def self.parse(text)
@@ -21,7 +21,7 @@ class Plugin::Metadata
       attribute, *description = line[1..-1].split(":")
 
       description = description.join(":")
-      attribute = attribute.strip.to_sym
+      attribute = attribute.strip.gsub(/ /, '_').to_sym
 
       if FIELDS.include?(attribute)
         self.send("#{attribute}=", description.strip)

lib/version.rb

@@ -10,4 +10,24 @@ module Discourse
       STRING = [MAJOR, MINOR, TINY, PRE].compact.join('.')
     end
   end
+
+  def self.has_needed_version?(current, needed)
+    current_split = current.split('.')
+    needed_split = needed.split('.')
+
+    (0..[current_split.size, needed_split.size].max).each do |idx|
+      current_str = current_split[idx] || ''
+
+      c0 = (needed_split[idx] || '').sub('beta', '').to_i
+      c1 = (current_str || '').sub('beta', '').to_i
+
+      # beta is less than stable
+      return false if current_str.include?('beta') && (c0 == 0) && (c1 > 0)
+
+      return true if c1 > c0
+      return false if c0 > c1
+    end
+
+    true
+  end
 end

spec/components/plugin/metadata_spec.rb

@@ -10,6 +10,7 @@ describe Plugin::Metadata do
 # version: 0.1
 # authors: Frank Zappa
 # url: http://discourse.org
+# required version: 1.3.0beta6+48
 
 some_ruby
 TEXT
@@ -19,6 +20,7 @@ TEXT
       expect(metadata.version).to eq("0.1")
       expect(metadata.authors).to eq("Frank Zappa")
       expect(metadata.url).to eq("http://discourse.org")
+      expect(metadata.required_version).to eq("1.3.0beta6+48")
     end
   end
 

spec/components/version_spec.rb

@@ -0,0 +1,40 @@
+require 'spec_helper'
+require 'version'
+
+describe Discourse::VERSION do
+
+  context "has_needed_version?" do
+
+    it "works for major comparisons" do
+      expect(Discourse.has_needed_version?('1.0.0', '1.0.0')).to eq(true)
+      expect(Discourse.has_needed_version?('2.0.0', '1.0.0')).to eq(true)
+      expect(Discourse.has_needed_version?('0.0.1', '1.0.0')).to eq(false)
+    end
+
+    it "works for minor comparisons" do
+      expect(Discourse.has_needed_version?('1.1.0', '1.1.0')).to eq(true)
+      expect(Discourse.has_needed_version?('1.2.0', '1.1.0')).to eq(true)
+      expect(Discourse.has_needed_version?('2.0.0', '1.1.0')).to eq(true)
+      expect(Discourse.has_needed_version?('0.1.0', '0.1.0')).to eq(true)
+
+      expect(Discourse.has_needed_version?('1.0.0', '1.1.0')).to eq(false)
+      expect(Discourse.has_needed_version?('0.0.1', '0.1.0')).to eq(false)
+    end
+
+    it "works for tiny comparisons" do
+      expect(Discourse.has_needed_version?('2.0.0', '2.0.0')).to eq(true)
+      expect(Discourse.has_needed_version?('2.0.1', '2.0.0')).to eq(true)
+      expect(Discourse.has_needed_version?('1.12.0', '2.0.0')).to eq(false)
+      expect(Discourse.has_needed_version?('1.12.0', '2.12.5')).to eq(false)
+    end
+
+    it "works for beta comparisons" do
+      expect(Discourse.has_needed_version?('1.3.0.beta3', '1.2.9')).to eq(true)
+      expect(Discourse.has_needed_version?('1.3.0.beta3', '1.3.0.beta1')).to eq(true)
+      expect(Discourse.has_needed_version?('1.3.0.beta3', '1.3.0.beta4')).to eq(false)
+      expect(Discourse.has_needed_version?('1.3.0.beta3', '1.3.0')).to eq(false)
+    end
+
+  end
+end
+