content/renderer/web_ui_extension.cc

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/renderer/web_ui_extension.h"
   6
   7 #include "base/memory/scoped_ptr.h"
   8 #include "base/values.h"
   9 #include "content/common/view_messages.h"
  10 #include "content/public/child/v8_value_converter.h"
  11 #include "content/public/common/bindings_policy.h"
  12 #include "content/public/common/url_constants.h"
  13 #include "content/public/renderer/render_thread.h"
  14 #include "content/public/renderer/render_view.h"
  15 #include "content/renderer/chrome_object_extensions_utils.h"
  16 #include "content/renderer/web_ui_extension_data.h"
  17 #include "gin/arguments.h"
  18 #include "gin/function_template.h"
  19 #include "third_party/WebKit/public/web/WebDocument.h"
  20 #include "third_party/WebKit/public/web/WebKit.h"
  21 #include "third_party/WebKit/public/web/WebLocalFrame.h"
  22 #include "third_party/WebKit/public/web/WebView.h"
  23 #include "url/gurl.h"
  24 #include "v8/include/v8.h"
  25
  26 namespace content {
  27
  28 namespace {
  29
  30 bool ShouldRespondToRequest(
  31     blink::WebFrame** frame_ptr,
  32     RenderView** render_view_ptr) {
  33   blink::WebFrame* frame = blink::WebLocalFrame::frameForCurrentContext();
  34   if (!frame || !frame->view())
  35     return false;
  36
  37   RenderView* render_view = RenderView::FromWebView(frame->view());
  38   if (!render_view)
  39     return false;
  40
  41   GURL frame_url = frame->document().url();
  42
  43   bool webui_enabled =
  44       (render_view->GetEnabledBindings() & BINDINGS_POLICY_WEB_UI) &&
  45       (frame_url.SchemeIs(kChromeUIScheme) ||
  46        frame_url.SchemeIs(url::kDataScheme));
  47
  48   if (!webui_enabled)
  49     return false;
  50
  51   *frame_ptr = frame;
  52   *render_view_ptr = render_view;
  53   return true;
  54 }
  55
  56 }  // namespace
  57
  58 // Exposes two methods:
  59 //  - chrome.send: Used to send messages to the browser. Requires the message
  60 //      name as the first argument and can have an optional second argument that
  61 //      should be an array.
  62 //  - chrome.getVariableValue: Returns value for the input variable name if such
  63 //      a value was set by the browser. Else will return an empty string.
  64 void WebUIExtension::Install(blink::WebFrame* frame) {
  65   v8::Isolate* isolate = blink::mainThreadIsolate();
  66   v8::HandleScope handle_scope(isolate);
  67   v8::Local<v8::Context> context = frame->mainWorldScriptContext();
  68   if (context.IsEmpty())
  69     return;
  70
  71   v8::Context::Scope context_scope(context);
  72
  73   v8::Local<v8::Object> chrome = GetOrCreateChromeObject(isolate,
  74                                                           context->Global());
  75   chrome->Set(gin::StringToSymbol(isolate, "send"),
  76               gin::CreateFunctionTemplate(
  77                   isolate, base::Bind(&WebUIExtension::Send))->GetFunction());
  78   chrome->Set(gin::StringToSymbol(isolate, "getVariableValue"),
  79               gin::CreateFunctionTemplate(
  80                   isolate, base::Bind(&WebUIExtension::GetVariableValue))
  81                   ->GetFunction());
  82 }
  83
  84 // static
  85 void WebUIExtension::Send(gin::Arguments* args) {
  86   blink::WebFrame* frame;
  87   RenderView* render_view;
  88   if (!ShouldRespondToRequest(&frame, &render_view))
  89     return;
  90
  91   std::string message;
  92   if (!args->GetNext(&message)) {
  93     args->ThrowError();
  94     return;
  95   }
  96
  97   // If they've provided an optional message parameter, convert that into a
  98   // Value to send to the browser process.
  99   scoped_ptr<base::ListValue> content;
 100   if (args->PeekNext().IsEmpty() || args->PeekNext()->IsUndefined()) {
 101     content.reset(new base::ListValue());
 102   } else {
 103     v8::Local<v8::Object> obj;
 104     if (!args->GetNext(&obj)) {
 105       args->ThrowError();
 106       return;
 107     }
 108
 109     scoped_ptr<V8ValueConverter> converter(V8ValueConverter::create());
 110
 111     base::Value* value =
 112         converter->FromV8Value(obj, frame->mainWorldScriptContext());
 113     base::ListValue* list = NULL;
 114     value->GetAsList(&list);
 115     DCHECK(list);
 116     content.reset(list);
 117   }
 118
 119   // Send the message up to the browser.
 120   render_view->Send(new ViewHostMsg_WebUISend(render_view->GetRoutingID(),
 121                                               frame->document().url(),
 122                                               message,
 123                                               *content));
 124 }
 125
 126 // static
 127 std::string WebUIExtension::GetVariableValue(const std::string& name) {
 128   blink::WebFrame* frame;
 129   RenderView* render_view;
 130   if (!ShouldRespondToRequest(&frame, &render_view))
 131     return std::string();
 132
 133   return WebUIExtensionData::Get(render_view)->GetValue(name);
 134 }
 135
 136 }  // namespace content