src/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/common/bindings_policy.h"
  11 #include "content/public/common/url_constants.h"
  12 #include "content/public/renderer/render_thread.h"
  13 #include "content/public/renderer/render_view.h"
  14 #include "content/public/renderer/v8_value_converter.h"
  15 #include "content/renderer/web_ui_extension_data.h"
  16 #include "gin/arguments.h"
  17 #include "gin/function_template.h"
  18 #include "third_party/WebKit/public/web/WebDocument.h"
  19 #include "third_party/WebKit/public/web/WebFrame.h"
  20 #include "third_party/WebKit/public/web/WebKit.h"
  21 #include "third_party/WebKit/public/web/WebView.h"
  22 #include "url/gurl.h"
  23 #include "v8/include/v8.h"
  24
  25 namespace content {
  26
  27 namespace {
  28
  29 bool ShouldRespondToRequest(
  30     blink::WebFrame** frame_ptr,
  31     RenderView** render_view_ptr) {
  32   blink::WebFrame* frame = blink::WebFrame::frameForCurrentContext();
  33   if (!frame || !frame->view())
  34     return false;
  35
  36   RenderView* render_view = RenderView::FromWebView(frame->view());
  37   if (!render_view)
  38     return false;
  39
  40   GURL frame_url = frame->document().url();
  41
  42   bool webui_enabled =
  43       (render_view->GetEnabledBindings() & BINDINGS_POLICY_WEB_UI) &&
  44       (frame_url.SchemeIs(kChromeUIScheme) ||
  45        frame_url.SchemeIs(kDataScheme));
  46
  47   if (!webui_enabled)
  48     return false;
  49
  50   *frame_ptr = frame;
  51   *render_view_ptr = render_view;
  52   return true;
  53 }
  54
  55 }  // namespace
  56
  57 // Exposes two methods:
  58 //  - chrome.send: Used to send messages to the browser. Requires the message
  59 //      name as the first argument and can have an optional second argument that
  60 //      should be an array.
  61 //  - chrome.getVariableValue: Returns value for the input variable name if such
  62 //      a value was set by the browser. Else will return an empty string.
  63 void WebUIExtension::Install(blink::WebFrame* frame) {
  64   v8::Isolate* isolate = blink::mainThreadIsolate();
  65   v8::HandleScope handle_scope(isolate);
  66   v8::Handle<v8::Context> context = frame->mainWorldScriptContext();
  67   if (context.IsEmpty())
  68     return;
  69
  70   v8::Context::Scope context_scope(context);
  71
  72   v8::Handle<v8::Object> global = context->Global();
  73   v8::Handle<v8::Object> chrome =
  74       global->Get(gin::StringToV8(isolate, "chrome"))->ToObject();
  75   if (chrome.IsEmpty()) {
  76     chrome = v8::Object::New(isolate);
  77     global->Set(gin::StringToSymbol(isolate, "chrome"), chrome);
  78   }
  79   chrome->Set(gin::StringToSymbol(isolate, "send"),
  80               gin::CreateFunctionTemplate(
  81                   isolate, base::Bind(&WebUIExtension::Send))->GetFunction());
  82   chrome->Set(gin::StringToSymbol(isolate, "getVariableValue"),
  83               gin::CreateFunctionTemplate(
  84                   isolate, base::Bind(&WebUIExtension::GetVariableValue))
  85                   ->GetFunction());
  86 }
  87
  88 // static
  89 void WebUIExtension::Send(gin::Arguments* args) {
  90   blink::WebFrame* frame;
  91   RenderView* render_view;
  92   if (!ShouldRespondToRequest(&frame, &render_view))
  93     return;
  94
  95   std::string message;
  96   if (!args->GetNext(&message)) {
  97     args->ThrowError();
  98     return;
  99   }
 100
 101   // If they've provided an optional message parameter, convert that into a
 102   // Value to send to the browser process.
 103   scoped_ptr<base::ListValue> content;
 104   if (args->PeekNext().IsEmpty() || args->PeekNext()->IsUndefined()) {
 105     content.reset(new base::ListValue());
 106   } else {
 107     v8::Handle<v8::Object> obj;
 108     if (!args->GetNext(&obj)) {
 109       args->ThrowError();
 110       return;
 111     }
 112
 113     scoped_ptr<V8ValueConverter> converter(V8ValueConverter::create());
 114
 115     base::Value* value =
 116         converter->FromV8Value(obj, frame->mainWorldScriptContext());
 117     base::ListValue* list = NULL;
 118     value->GetAsList(&list);
 119     DCHECK(list);
 120     content.reset(list);
 121   }
 122
 123   // Send the message up to the browser.
 124   render_view->Send(new ViewHostMsg_WebUISend(render_view->GetRoutingID(),
 125                                               frame->document().url(),
 126                                               message,
 127                                               *content));
 128 }
 129
 130 // static
 131 std::string WebUIExtension::GetVariableValue(const std::string& name) {
 132   blink::WebFrame* frame;
 133   RenderView* render_view;
 134   if (!ShouldRespondToRequest(&frame, &render_view))
 135     return std::string();
 136
 137   return WebUIExtensionData::Get(render_view)->GetValue(name);
 138 }
 139
 140 }  // namespace content