Merge pull request #794 from atom/webivew-preload

Add "preload" attribute for <webview>

atom/browser/atom_browser_client.cc

@@ -156,6 +156,10 @@ void AtomBrowserClient::AppendExtraCommandLineSwitches(
           info.node_integration ? "true" : "false");
       if (info.plugins)
         command_line->AppendSwitch(switches::kEnablePlugins);
+      if (!info.preload_script.empty())
+        command_line->AppendSwitchPath(
+            switches::kPreloadScript,
+            info.preload_script);
     }
   }
 

atom/browser/lib/guest-view-manager.coffee

@@ -33,7 +33,8 @@ createGuest = (embedder, params) ->
     guestInstanceId: id
     storagePartitionId: params.storagePartitionId
   guestInstances[id] = {guest, embedder}
-  webViewManager.addGuest id, embedder, guest, params.nodeIntegration, params.plugins
+  preload = params.preload ? ''
+  webViewManager.addGuest id, embedder, guest, params.nodeIntegration, params.plugins, preload
 
   # Destroy guest when the embedder is gone.
   embedder.once 'render-view-deleted', ->

atom/browser/web_view/web_view_manager.cc

@@ -7,12 +7,14 @@
 #include "atom/browser/api/atom_api_web_contents.h"
 #include "atom/browser/atom_browser_context.h"
 #include "atom/browser/web_view/web_view_renderer_state.h"
+#include "atom/common/native_mate_converters/gurl_converter.h"
 #include "base/bind.h"
 #include "base/stl_util.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_process_host.h"
 #include "native_mate/dictionary.h"
 #include "native_mate/object_template_builder.h"
+#include "net/base/filename_util.h"
 
 #include "atom/common/node_includes.h"
 
@@ -44,12 +46,14 @@ void WebViewManager::AddGuest(int guest_instance_id,
                               content::WebContents* embedder,
                               content::WebContents* web_contents,
                               bool node_integration,
-                              bool plugins) {
+                              bool plugins,
+                              const GURL& preload_url) {
   web_contents_map_[guest_instance_id] = { web_contents, embedder };
 
   WebViewRendererState::WebViewInfo web_view_info = {
     guest_instance_id, node_integration, plugins
   };
+  net::FileURLToFilePath(preload_url, &web_view_info.preload_script);
   content::BrowserThread::PostTask(
       content::BrowserThread::IO,
       FROM_HERE,

atom/browser/web_view/web_view_manager.h

@@ -24,7 +24,8 @@ class WebViewManager : public content::BrowserPluginGuestManager {
                 content::WebContents* embedder,
                 content::WebContents* web_contents,
                 bool node_integration,
-                bool plugins);
+                bool plugins,
+                const GURL& preload_url);
   void RemoveGuest(int guest_instance_id);
 
  protected:

atom/browser/web_view/web_view_renderer_state.h

@@ -9,6 +9,7 @@
 #include <string>
 #include <utility>
 
+#include "base/files/file_path.h"
 #include "base/memory/singleton.h"
 
 namespace atom {
@@ -23,6 +24,7 @@ class WebViewRendererState {
     int guest_instance_id;
     bool node_integration;
     bool plugins;
+    base::FilePath preload_script;
   };
 
   static WebViewRendererState* GetInstance();

atom/common/options_switches.cc

@@ -66,6 +66,9 @@ const char kEnablePlugins[] = "enable-plugins";
 // Instancd ID of guest WebContents.
 const char kGuestInstanceID[] = "guest-instance-id";
 
+// Script that will be loaded by guest WebContents before other scripts.
+const char kPreloadScript[] = "preload-script";
+
 // Web runtime features.
 const char kExperimentalFeatures[]       = "experimental-features";
 const char kExperimentalCanvasFeatures[] = "experimental-canvas-features";

atom/common/options_switches.h

@@ -38,6 +38,7 @@ extern const char kDarkTheme[];
 extern const char kDirectWrite[];
 extern const char kEnablePlugins[];
 extern const char kGuestInstanceID[];
+extern const char kPreloadScript[];
 
 extern const char kExperimentalFeatures[];
 extern const char kExperimentalCanvasFeatures[];

atom/renderer/lib/init.coffee

@@ -31,6 +31,8 @@ for arg in process.argv
     require('web-frame').setName 'ATOM_SHELL_GUEST_WEB_VIEW'
   else if arg.indexOf('--node-integration=') == 0
     nodeIntegration = arg.substr arg.indexOf('=') + 1
+  else if arg.indexOf('--preload-script=') == 0
+    preloadScript = arg.substr arg.indexOf('=') + 1
 
 if location.protocol is 'chrome-devtools:'
   # Override some inspector APIs.
@@ -86,3 +88,6 @@ else
     delete global.process
     delete global.setImmediate
     delete global.clearImmediate
+
+# Load the script specfied by the "preload" attribute.
+require preloadScript if preloadScript

atom/renderer/lib/web-view.coffee

@@ -21,6 +21,7 @@ WEB_VIEW_ATTRIBUTE_MINWIDTH = 'minwidth'
 WEB_VIEW_ATTRIBUTE_PARTITION = 'partition'
 WEB_VIEW_ATTRIBUTE_NODEINTEGRATION = 'nodeintegration'
 WEB_VIEW_ATTRIBUTE_PLUGINS = 'plugins'
+WEB_VIEW_ATTRIBUTE_PRELOAD = 'preload'
 AUTO_SIZE_ATTRIBUTES = [
   WEB_VIEW_ATTRIBUTE_AUTOSIZE,
   WEB_VIEW_ATTRIBUTE_MAXHEIGHT,
@@ -38,6 +39,8 @@ ERROR_MSG_CONTENTWINDOW_NOT_AVAILABLE = '<webview>: ' +
     'contentWindow is not available at this time. It will become available ' +
     'when the page has finished loading.'
 ERROR_MSG_INVALID_PARTITION_ATTRIBUTE = 'Invalid partition attribute.'
+ERROR_MSG_INVALID_PRELOAD_ATTRIBUTE =
+    'Only "file:" or "asar:" protocol is supported in "preload" attribute.'
 
 # Represents the state of the storage partition.
 class Partition
@@ -379,6 +382,17 @@ class WebView
       storagePartitionId: storagePartitionId
       nodeIntegration: @webviewNode.hasAttribute WEB_VIEW_ATTRIBUTE_NODEINTEGRATION
       plugins: @webviewNode.hasAttribute WEB_VIEW_ATTRIBUTE_PLUGINS
+    if @webviewNode.hasAttribute WEB_VIEW_ATTRIBUTE_PRELOAD
+      preload = @webviewNode.getAttribute WEB_VIEW_ATTRIBUTE_PRELOAD
+      # Get the full path.
+      a = document.createElement 'a'
+      a.href = preload
+      params.preload = a.href
+      # Only support file: or asar: protocol.
+      protocol = params.preload.substr 0, 5
+      unless protocol in ['file:', 'asar:']
+        delete params.preload
+        console.error ERROR_MSG_INVALID_PRELOAD_ATTRIBUTE
     guestViewInternal.createGuest 'webview', params, (guestInstanceId) =>
       @pendingGuestCreation = false
       unless @elementAttached

docs/api/web-view-tag.md

@@ -90,6 +90,20 @@ APIs like `require` and `process` to access low level system resources.
 
 If "on", the guest page in `webview` will be able to use browser plugins.
 
+### preload
+
+```html
+<webview src="https://www.github.com/" preload="./test.js"></webview>
+```
+
+Specifies a script that will be loaded before other scripts run in the guest
+page. The protocol of script's URL must be either `file:` or `asar:`, because it
+will be loaded by `require` in guest page under the hood.
+
+When the guest page doesn't have node integration this script will still have
+access to all Node APIs, but global objects injected by Node will be deleted
+after this script has done execution.
+
 ## Methods
 
 ### `<webview>`.getUrl()

spec/fixtures/module/preload.js

@@ -0,0 +1 @@
+console.log([typeof require, typeof module, typeof process].join(' '));

spec/fixtures/pages/e.html

@@ -0,0 +1,7 @@
+<html>
+<body>
+<script type="text/javascript" charset="utf-8">
+  console.log('Window script is loaded before preload script');
+</script>
+</body>
+</html>

spec/webview-spec.coffee

@@ -47,6 +47,17 @@ describe '<webview> tag', ->
       webview.src = "file://#{fixtures}/pages/d.html"
       document.body.appendChild webview
 
+  describe 'preload attribute', ->
+    it 'loads the script before other scripts in window', (done) ->
+      listener = (e) ->
+        assert.equal e.message, 'function object object'
+        webview.removeEventListener 'console-message', listener
+        done()
+      webview.addEventListener 'console-message', listener
+      webview.setAttribute 'preload', "#{fixtures}/module/preload.js"
+      webview.src = "file://#{fixtures}/pages/e.html"
+      document.body.appendChild webview
+
   describe 'new-window event', ->
     it 'emits when window.open is called', (done) ->
       webview.addEventListener 'new-window', (e) ->