Merge pull request #844 from atom/custom-resource-loader

Add custom resource loader, fixes #197

docs/creating-a-package.md

@@ -214,6 +214,19 @@ your grammar supports:
 ]
 ```
 
+## Bundle External Resources
+
+It's common to ship external resources like images and fonts in the package, to
+make it easy to reference the resources in HTML or CSS, you can use the `atom`
+protocol URLs to load resources in the package.
+
+The URLs should be in the format of
+`atom://package-name/relative-path-to-package-of-resource`, for example, the
+`atom://image-view/images/transparent-background.gif` would be equivablent to
+`~/.atom/packages/image-view/images/transparent-background.gif`.
+
+You can also use the `atom` protocol URLs in themes.
+
 ## Writing Tests
 
 Your package **should** have tests, and if they're placed in the _spec_ directory,

package.json

@@ -9,7 +9,7 @@
   "bugs": {
     "url": "https://github.com/atom/atom/issues"
   },
-  "atomShellVersion": "0.4.5",
+  "atomShellVersion": "0.4.7",
   "dependencies": {
     "async": "0.2.6",
     "coffee-script": "1.6.2",

spec/atom-protocol-handler-spec.coffee

@@ -0,0 +1,15 @@
+$ = require 'jquery'
+
+describe '"atom" protocol URL', ->
+  it 'sends the file relative in the package as response', ->
+    called = false
+    callback = -> called = true
+    $.ajax
+      url: 'atom://async/package.json'
+      success: callback
+      # In old versions of jQuery, ajax calls to custom protocol would always
+      # be treated as error eventhough the browser thinks it's a success
+      # request.
+      error: callback
+
+    waitsFor 'request to be done', -> called is true

src/atom-application.coffee

@@ -1,5 +1,6 @@
 AtomWindow = require 'atom-window'
 ApplicationMenu = require 'application-menu'
+AtomProtocolHandler = require 'atom-protocol-handler'
 BrowserWindow = require 'browser-window'
 Menu = require 'menu'
 autoUpdater = require 'auto-updater'
@@ -45,6 +46,7 @@ class AtomApplication
 
   windows: null
   applicationMenu: null
+  atomProtocolHandler: null
   resourcePath: null
   version: null
 
@@ -56,6 +58,7 @@ class AtomApplication
     @windows = []
 
     @applicationMenu = new ApplicationMenu(@version, devMode)
+    @atomProtocolHandler = new AtomProtocolHandler(@resourcePath)
 
     @listenForArgumentsFromNewProcess()
     @setupJavaScriptArguments()

src/atom-protocol-handler.coffee

@@ -0,0 +1,27 @@
+app = require 'app'
+fs = require 'fs'
+path = require 'path'
+protocol = require 'protocol'
+
+# Private: Handles requests with 'atom' protocol.
+#
+# It's created by {AtomApplication} upon instantiation, and is used to create a
+# custom resource loader by adding the 'atom' custom protocol.
+module.exports =
+class AtomProtocolHandler
+  constructor: (@resourcePath) ->
+    @loadPaths = [
+      path.join(@resourcePath, 'node_modules')
+      path.join(app.getHomeDir(), '.atom', 'packages')
+    ]
+
+    @registerAtomProtocol()
+
+  # Private: Creates the 'atom' custom protocol handler.
+  registerAtomProtocol: ->
+    protocol.registerProtocol 'atom', (request) =>
+      relativePath = path.normalize(request.url.substr(7))
+      for loadPath in @loadPaths
+        filePath = path.join(loadPath, relativePath)
+        break if fs.statSyncNoException(filePath)?
+      return new protocol.RequestFileJob(filePath)