Adding a module to abstract using Autoload to load and manage instances

git-svn-id: https://reductivelabs.com/svn/puppet/trunk@2476 980ebf18-57e1-0310-9a29-db15c13687c0

1 files changed, 74 insertions, 0 deletions

diff --git a/lib/puppet/util/instance_loader.rb b/lib/puppet/util/instance_loader.rb
new file mode 100755
index 000000000..3613b4e39
--- /dev/null
+++ b/lib/puppet/util/instance_loader.rb
@@ -0,0 +1,74 @@
+require 'puppet/util/autoload'
+require 'puppet/util'
+
+# A module that can easily autoload things for us.  Uses an instance
+# of Puppet::Util::Autoload
+module Puppet::Util::InstanceLoader
+    include Puppet::Util
+    # Define a new type of autoloading.
+    def autoload(type, path, options = {})
+        @autoloaders ||= {}
+        @instances ||= {}
+        type = symbolize(type)
+        @instances[type] = {}
+        @autoloaders[type] = Puppet::Util::Autoload.new(self, path, options)
+
+        # Now define our new simple methods
+        unless respond_to?(type)
+            meta_def(type) do |name|
+                loaded_instance(type, name)
+            end
+        end
+    end
+
+    # Return a list of the names of all instances
+    def loaded_instances(type)
+        @instances[type].keys
+    end
+
+    # Collect the docs for all of our instances.
+    def instance_docs(type)
+        docs = ""
+
+        # Use this method so they all get loaded
+        loaded_instances(type).sort { |a,b| a.to_s <=> b.to_s }.each do |name|
+            mod = self.loaded_instance(name)
+            docs += "%s\n%s\n" % [name, "-" * name.to_s.length]
+
+            docs += Puppet::Util::Docs.scrub(mod.doc) + "\n\n"
+        end
+
+        docs
+    end
+
+    # Return the instance hash for our type.
+    def instance_hash(type)
+        @instances[symbolize(type)]
+    end
+
+    # Return the Autoload object for a given type.
+    def instance_loader(type)
+        @autoloaders[symbolize(type)]
+    end
+
+    # Retrieve an alread-loaded instance, or attempt to load our instance.
+    def loaded_instance(type, name)
+        name = symbolize(name)
+        instances = instance_hash(type)
+        unless instances.include? name
+            if instance_loader(type).load(name)
+                unless instances.include? name
+                    Puppet.warning(
+                        "Loaded %s file for %s but %s was not defined" % [type, name, type]
+                    )
+                    return nil
+                end
+            else
+                return nil
+            end
+        end
+        instances[name]
+    end
+end
+
+# $Id$