Add Semi-automatic updates feature

Signed-off-by: Igor Shishkin <me@teran.ru>

Makefile

@@ -14,6 +14,7 @@ build:
 	$(LUAC) -s -o temp/deduplicator.lrplugin/Info.lua temp/deduplicator.lrplugin/Info.lua
 	$(LUAC) -s -o temp/deduplicator.lrplugin/FindDuplicates.lua temp/deduplicator.lrplugin/FindDuplicates.lua
 	$(LUAC) -s -o temp/deduplicator.lrplugin/JSON.lua temp/deduplicator.lrplugin/JSON.lua
+	$(LUAC) -s -o temp/deduplicator.lrplugin/GithubCheckUpdates.lua temp/deduplicator.lrplugin/GithubCheckUpdates.lua
 	cp -rv temp/deduplicator.lrplugin build/
 	cd build && zip -r deduplicator.lrplugin.zip deduplicator.lrplugin
 

README.md

@@ -12,6 +12,8 @@ Usually for plugins is used `~/Library/Application\ Support/Adobe/Lightroom/Plug
 
 # Usage
 
+### Checking for duplicates
+
 > Library -> Plug-in Extras -> Find duplicates
 
 The plugin will start to check all the *available* images in your catalog this could take a while.
@@ -22,6 +24,12 @@ After the process would be completed the Deduplicator will put all the supposed
 
 *NOTE:* the plugin takes selection or all photos if <= 1 photo is selected.
 
+### Semi-automatic updates
+
+> Help -> Plug-in Extras -> Check for updates
+
+This will check GitHub if there's a new release and suggest you to check it out.
+
 # How it works inside
 
 Deduplicator plug-in relies on [imgsum](https://github.com/teran/imgsum) to calculate

deduplicator.lrdevplugin/GithubCheckUpdates.lua

@@ -0,0 +1,27 @@
+local LrHttp = import 'LrHttp'
+local LrDialogs = import 'LrDialogs'
+local LrTasks = import 'LrTasks'
+
+local json = require 'JSON'
+json.strictTypes = true
+
+require 'Info'
+
+function checkForUpdates()
+  local responseBody, headers = LrHttp.get(latestReleaseJsonUrl)
+  r = json:decode(responseBody)
+  if r['tag_name'] ~= plugin_version then
+    local referToNewRelease = LrDialogs.confirm(
+      'Update is available!',
+      'Release ' .. r['tag_name'] .. ' is present, wanna visit release page?',
+      'Yes, I want to download an update!',
+      'No, thanks.'
+    )
+
+    if referToNewRelease == 'ok' then
+      LrHttp.openUrlInBrowser(r['html_url'])
+    end
+  end
+end
+
+LrTasks.startAsyncTask(checkForUpdates)

deduplicator.lrdevplugin/Info.lua

@@ -6,6 +6,7 @@ plugin_build = 100002
 plugin_version = plugin_major .. '.' .. plugin_minor .. '.' .. plugin_revision .. '.' .. plugin_build
 plugin_id = 'me.teran.lightroom.deduplicator'
 plugin_home_url = "https://github.com/teran/deduplicator"
+latestReleaseJsonUrl = 'https://api.github.com/repos/teran/deduplicator/releases/latest'
 
 return {
   LrSdkVersion = 6.0,
@@ -17,5 +18,9 @@ return {
     file = 'FindDuplicates.lua',
     enabledWhen = 'photosAvailable',
   },
+  LrHelpMenuItems = {
+    title = 'Check for updates',
+    file = 'GithubCheckUpdates.lua',
+  },
   VERSION = { major=plugin_major, minor=plugin_minor, revision=plugin_revision, build=plugin_build, },
 }