From 5e43c01e7b5b1d867149a8fae8973ad5004aef93 Mon Sep 17 00:00:00 2001
From: Darren Hardy <drh@stanford.edu>
Date: Mon, 15 Aug 2016 14:27:51 -0700
Subject: [PATCH] Adds publish_notify_on_success to touch change files in the
 PURL filesystem

---
 lib/dor/models/publishable.rb | 12 ++++++++++++
 spec/dor/publishable_spec.rb  | 23 +++++++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/lib/dor/models/publishable.rb b/lib/dor/models/publishable.rb
index 4aba4f20..2bb624a1 100644
--- a/lib/dor/models/publishable.rb
+++ b/lib/dor/models/publishable.rb
@@ -1,4 +1,5 @@
 require 'dor/datastreams/content_metadata_ds'
+require 'fileutils'
 
 module Dor
   module Publishable
@@ -61,6 +62,7 @@ def publish_metadata
         end
         DigitalStacksService.transfer_to_document_store(pid, public_xml, 'public')
         DigitalStacksService.transfer_to_document_store(pid, generate_public_desc_md, 'mods') if metadata_format == 'mods'
+        publish_notify_on_success
       else
         # Clear out the document cache for this item
         DigitalStacksService.prune_purl_dir pid
@@ -74,5 +76,15 @@ def publish_metadata_remotely
       endpoint.post ''
       endpoint.url
     end
+
+    ##
+    # When publishing a PURL, we drop a `aa11bb2222` file into the `local_recent_changes` folder
+    # to notify other applications watching the filesystem (i.e., purl-fetcher).
+    # @param [String] `local_recent_changes` usually `/purl/recent_changes`
+    def publish_notify_on_success(local_recent_changes = Config.stacks.local_recent_changes)
+      raise ArgumentError, "Missing local_recent_changes directory: #{local_recent_changes}" unless File.directory?(local_recent_changes)
+      id = pid.gsub(/^druid:/, '')
+      FileUtils.touch(File.join(local_recent_changes, id))
+    end
   end
 end
diff --git a/spec/dor/publishable_spec.rb b/spec/dor/publishable_spec.rb
index 480621c6..cdc939f9 100644
--- a/spec/dor/publishable_spec.rb
+++ b/spec/dor/publishable_spec.rb
@@ -327,6 +327,7 @@ class ItemizableItem < ActiveFedora::Base
           expect(Dor::DigitalStacksService).to receive(:transfer_to_document_store).with('druid:ab123cd4567', /<oai_dc:dc/, 'dc')
           expect(Dor::DigitalStacksService).to receive(:transfer_to_document_store).with('druid:ab123cd4567', /<publicObject/, 'public')
           expect(Dor::DigitalStacksService).to receive(:transfer_to_document_store).with('druid:ab123cd4567', /<mods:mods/, 'mods')
+          expect(@item).to receive(:publish_notify_on_success).with(no_args)
         end
         it 'identityMetadta, contentMetadata, rightsMetadata, generated dublin core, and public xml' do
           @item.rightsMetadata.content = "<rightsMetadata><access type='discover'><machine><world/></machine></access></rightsMetadata>"
@@ -340,6 +341,28 @@ class ItemizableItem < ActiveFedora::Base
       end
     end
 
+    context 'publish_notify_on_success' do
+      let(:dir) { '/my/dir' }
+      it 'writes empty file' do
+        Dor::Config.push! {|config| config.stacks.local_recent_changes dir}
+        expect(File).to receive(:directory?).with(dir).and_return(true)
+        expect(FileUtils).to receive(:touch).with(dir + '/ab123cd4567')
+        @item.publish_notify_on_success
+      end
+      it 'writes empty file even when given only the base id' do
+        Dor::Config.push! {|config| config.stacks.local_recent_changes dir}
+        expect(File).to receive(:directory?).with(dir).and_return(true)
+        expect(@item).to receive(:pid).and_return('aa111bb2222')
+        expect(FileUtils).to receive(:touch).with(dir + '/aa111bb2222')
+        @item.publish_notify_on_success
+      end
+      it 'raises error if not configured' do
+        expect(File).to receive(:directory?).with(nil).and_return(false)
+        expect(FileUtils).not_to receive(:touch)
+        expect { @item.publish_notify_on_success }.to raise_error(ArgumentError, /Missing local_recent_changes directory/)
+      end
+    end
+
     context 'error handling' do
       it 'throws an exception if any of the required datastreams are missing' do
         skip 'write an error handling test'