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