content/renderer/web_ui_mojo_context_state.cc

   1 // Copyright 2014 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_mojo_context_state.h"
   6
   7 #include "base/bind.h"
   8 #include "base/stl_util.h"
   9 #include "content/public/renderer/render_frame.h"
  10 #include "content/public/renderer/resource_fetcher.h"
  11 #include "content/renderer/web_ui_runner.h"
  12 #include "gin/converter.h"
  13 #include "gin/modules/module_registry.h"
  14 #include "gin/per_context_data.h"
  15 #include "gin/public/context_holder.h"
  16 #include "gin/try_catch.h"
  17 #include "third_party/WebKit/public/platform/WebURLResponse.h"
  18 #include "third_party/WebKit/public/web/WebFrame.h"
  19 #include "third_party/WebKit/public/web/WebScriptSource.h"
  20
  21 using v8::Context;
  22 using v8::HandleScope;
  23 using v8::Isolate;
  24 using v8::Object;
  25 using v8::ObjectTemplate;
  26 using v8::Script;
  27
  28 namespace content {
  29
  30 namespace {
  31
  32 // All modules have this prefixed to them when downloading.
  33 // TODO(sky): move this into some common place.
  34 const char kModulePrefix[] = "chrome://mojo/";
  35
  36 void RunMain(base::WeakPtr<gin::Runner> runner,
  37              v8::Local<v8::Value> module) {
  38   v8::Isolate* isolate = runner->GetContextHolder()->isolate();
  39   v8::Local<v8::Function> start;
  40   CHECK(gin::ConvertFromV8(isolate, module, &start));
  41   runner->Call(start, runner->global(), 0, NULL);
  42 }
  43
  44 }  // namespace
  45
  46 // WebUIMojo -------------------------------------------------------------------
  47
  48 WebUIMojoContextState::WebUIMojoContextState(blink::WebFrame* frame,
  49                                              v8::Local<v8::Context> context)
  50     : frame_(frame),
  51       module_added_(false) {
  52   gin::PerContextData* context_data = gin::PerContextData::From(context);
  53   gin::ContextHolder* context_holder = context_data->context_holder();
  54   runner_.reset(new WebUIRunner(frame_, context_holder));
  55   gin::Runner::Scope scoper(runner_.get());
  56   gin::ModuleRegistry::From(context)->AddObserver(this);
  57   content::RenderFrame::FromWebFrame(frame)
  58       ->EnsureMojoBuiltinsAreAvailable(context_holder->isolate(), context);
  59   gin::ModuleRegistry::InstallGlobals(context->GetIsolate(), context->Global());
  60   // Warning |frame| may be destroyed.
  61   // TODO(sky): add test for this.
  62 }
  63
  64 WebUIMojoContextState::~WebUIMojoContextState() {
  65   gin::Runner::Scope scoper(runner_.get());
  66   gin::ModuleRegistry::From(
  67       runner_->GetContextHolder()->context())->RemoveObserver(this);
  68 }
  69
  70 void WebUIMojoContextState::Run() {
  71   gin::ContextHolder* context_holder = runner_->GetContextHolder();
  72   gin::ModuleRegistry::From(context_holder->context())->LoadModule(
  73       context_holder->isolate(),
  74       "main",
  75       base::Bind(RunMain, runner_->GetWeakPtr()));
  76 }
  77
  78 void WebUIMojoContextState::FetchModules(const std::vector<std::string>& ids) {
  79   gin::Runner::Scope scoper(runner_.get());
  80   gin::ContextHolder* context_holder = runner_->GetContextHolder();
  81   gin::ModuleRegistry* registry = gin::ModuleRegistry::From(
  82       context_holder->context());
  83   for (size_t i = 0; i < ids.size(); ++i) {
  84     if (fetched_modules_.find(ids[i]) == fetched_modules_.end() &&
  85         registry->available_modules().count(ids[i]) == 0) {
  86       FetchModule(ids[i]);
  87     }
  88   }
  89 }
  90
  91 void WebUIMojoContextState::FetchModule(const std::string& id) {
  92   const GURL url(kModulePrefix + id);
  93   // TODO(sky): better error checks here?
  94   DCHECK(url.is_valid() && !url.is_empty());
  95   DCHECK(fetched_modules_.find(id) == fetched_modules_.end());
  96   fetched_modules_.insert(id);
  97   ResourceFetcher* fetcher = ResourceFetcher::Create(url);
  98   module_fetchers_.push_back(fetcher);
  99   fetcher->Start(frame_,
 100                  blink::WebURLRequest::RequestContextScript,
 101                  blink::WebURLRequest::FrameTypeNone,
 102                  ResourceFetcher::PLATFORM_LOADER,
 103                  base::Bind(&WebUIMojoContextState::OnFetchModuleComplete,
 104                             base::Unretained(this),
 105                             fetcher));
 106 }
 107
 108 void WebUIMojoContextState::OnFetchModuleComplete(
 109     ResourceFetcher* fetcher,
 110     const blink::WebURLResponse& response,
 111     const std::string& data) {
 112   DCHECK_EQ(kModulePrefix,
 113       response.url().string().utf8().substr(0, arraysize(kModulePrefix) - 1));
 114   const std::string module =
 115       response.url().string().utf8().substr(arraysize(kModulePrefix) - 1);
 116   // We can't delete fetch right now as the arguments to this function come from
 117   // it and are used below. Instead use a scope_ptr to cleanup.
 118   scoped_ptr<ResourceFetcher> deleter(fetcher);
 119   module_fetchers_.weak_erase(
 120       std::find(module_fetchers_.begin(), module_fetchers_.end(), fetcher));
 121   if (data.empty()) {
 122     NOTREACHED();
 123     return;  // TODO(sky): log something?
 124   }
 125
 126   runner_->Run(data, module);
 127 }
 128
 129 void WebUIMojoContextState::OnDidAddPendingModule(
 130     const std::string& id,
 131     const std::vector<std::string>& dependencies) {
 132   FetchModules(dependencies);
 133
 134   gin::ContextHolder* context_holder = runner_->GetContextHolder();
 135   gin::ModuleRegistry* registry = gin::ModuleRegistry::From(
 136       context_holder->context());
 137   registry->AttemptToLoadMoreModules(context_holder->isolate());
 138 }
 139
 140 }  // namespace content