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              mojo::ScopedMessagePipeHandle* handle,
  40              v8::Handle<v8::Value> module) {
  41   v8::Isolate* isolate = runner->GetContextHolder()->isolate();
  42   v8::Handle<v8::Function> start;
  43   CHECK(gin::ConvertFromV8(isolate, module, &start));
  44   v8::Handle<v8::Value> args[] = {
  45       gin::ConvertToV8(isolate, mojo::Handle(handle->release().value())) };
  46   runner->Call(start, runner->global(), 1, args);
  47 }
  48
  49 }  // namespace
  50
  51 // WebUIMojo -------------------------------------------------------------------
  52
  53 WebUIMojoContextState::WebUIMojoContextState(blink::WebFrame* frame,
  54                                              v8::Handle<v8::Context> context)
  55     : frame_(frame),
  56       module_added_(false) {
  57   gin::PerContextData* context_data = gin::PerContextData::From(context);
  58   gin::ContextHolder* context_holder = context_data->context_holder();
  59   runner_.reset(new WebUIRunner(frame_, context_holder));
  60   gin::Runner::Scope scoper(runner_.get());
  61   gin::ModuleRegistry::From(context)->AddObserver(this);
  62   runner_->RegisterBuiltinModules();
  63   gin::ModuleRegistry::InstallGlobals(context->GetIsolate(), context->Global());
  64   // Warning |frame| may be destroyed.
  65   // TODO(sky): add test for this.
  66 }
  67
  68 WebUIMojoContextState::~WebUIMojoContextState() {
  69   gin::Runner::Scope scoper(runner_.get());
  70   gin::ModuleRegistry::From(
  71       runner_->GetContextHolder()->context())->RemoveObserver(this);
  72 }
  73
  74 void WebUIMojoContextState::SetHandle(mojo::ScopedMessagePipeHandle handle) {
  75   gin::ContextHolder* context_holder = runner_->GetContextHolder();
  76   mojo::ScopedMessagePipeHandle* passed_handle =
  77       new mojo::ScopedMessagePipeHandle(handle.Pass());
  78   gin::ModuleRegistry::From(context_holder->context())->LoadModule(
  79       context_holder->isolate(),
  80       "main",
  81       base::Bind(RunMain, runner_->GetWeakPtr(), base::Owned(passed_handle)));
  82 }
  83
  84 void WebUIMojoContextState::FetchModules(const std::vector<std::string>& ids) {
  85   gin::Runner::Scope scoper(runner_.get());
  86   gin::ContextHolder* context_holder = runner_->GetContextHolder();
  87   gin::ModuleRegistry* registry = gin::ModuleRegistry::From(
  88       context_holder->context());
  89   for (size_t i = 0; i < ids.size(); ++i) {
  90     if (fetched_modules_.find(ids[i]) == fetched_modules_.end() &&
  91         registry->available_modules().count(ids[i]) == 0) {
  92       FetchModule(ids[i]);
  93     }
  94   }
  95 }
  96
  97 void WebUIMojoContextState::FetchModule(const std::string& id) {
  98   const GURL url(kModulePrefix + id);
  99   // TODO(sky): better error checks here?
 100   DCHECK(url.is_valid() && !url.is_empty());
 101   DCHECK(fetched_modules_.find(id) == fetched_modules_.end());
 102   fetched_modules_.insert(id);
 103   ResourceFetcher* fetcher = ResourceFetcher::Create(url);
 104   module_fetchers_.push_back(fetcher);
 105   fetcher->Start(frame_, blink::WebURLRequest::TargetIsScript,
 106                  base::Bind(&WebUIMojoContextState::OnFetchModuleComplete,
 107                             base::Unretained(this), fetcher));
 108 }
 109
 110 void WebUIMojoContextState::OnFetchModuleComplete(
 111     ResourceFetcher* fetcher,
 112     const blink::WebURLResponse& response,
 113     const std::string& data) {
 114   DCHECK_EQ(kModulePrefix,
 115       response.url().string().utf8().substr(0, arraysize(kModulePrefix) - 1));
 116   const std::string module =
 117       response.url().string().utf8().substr(arraysize(kModulePrefix) - 1);
 118   // We can't delete fetch right now as the arguments to this function come from
 119   // it and are used below. Instead use a scope_ptr to cleanup.
 120   scoped_ptr<ResourceFetcher> deleter(fetcher);
 121   module_fetchers_.weak_erase(
 122       std::find(module_fetchers_.begin(), module_fetchers_.end(), fetcher));
 123   if (data.empty()) {
 124     NOTREACHED();
 125     return;  // TODO(sky): log something?
 126   }
 127
 128   runner_->Run(data, module);
 129 }
 130
 131 void WebUIMojoContextState::OnDidAddPendingModule(
 132     const std::string& id,
 133     const std::vector<std::string>& dependencies) {
 134   FetchModules(dependencies);
 135
 136   gin::ContextHolder* context_holder = runner_->GetContextHolder();
 137   gin::ModuleRegistry* registry = gin::ModuleRegistry::From(
 138       context_holder->context());
 139   registry->AttemptToLoadMoreModules(context_holder->isolate());
 140 }
 141
 142 }  // namespace content