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content / renderer / web_ui_extension.cc [blame]
// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/renderer/web_ui_extension.h"
#include <memory>
#include <utility>
#include "base/functional/bind.h"
#include "base/values.h"
#include "content/public/common/bindings_policy.h"
#include "content/public/common/url_constants.h"
#include "content/public/renderer/chrome_object_extensions_utils.h"
#include "content/public/renderer/render_frame.h"
#include "content/public/renderer/render_thread.h"
#include "content/public/renderer/v8_value_converter.h"
#include "content/renderer/web_ui_extension_data.h"
#include "gin/arguments.h"
#include "gin/function_template.h"
#include "third_party/blink/public/platform/scheduler/web_agent_group_scheduler.h"
#include "third_party/blink/public/web/web_document.h"
#include "third_party/blink/public/web/web_local_frame.h"
#include "third_party/blink/public/web/web_view.h"
#include "url/gurl.h"
#include "v8/include/v8-context.h"
#include "v8/include/v8-function.h"
#include "v8/include/v8-local-handle.h"
#include "v8/include/v8-object.h"
namespace content {
namespace {
bool ShouldRespondToRequest(blink::WebLocalFrame** frame_ptr,
RenderFrame** render_frame_ptr) {
blink::WebLocalFrame* frame = blink::WebLocalFrame::FrameForCurrentContext();
if (!frame || !frame->View())
return false;
GURL frame_url = frame->GetDocument().Url();
RenderFrame* render_frame = RenderFrame::FromWebFrame(frame);
if (!render_frame)
return false;
bool webui_enabled =
(render_frame->GetEnabledBindings().Has(BindingsPolicyValue::kWebUi)) &&
(frame_url.SchemeIs(kChromeUIScheme) ||
frame_url.SchemeIs(url::kDataScheme));
if (!webui_enabled)
return false;
*frame_ptr = frame;
*render_frame_ptr = render_frame;
return true;
}
// Get or create a `child_name` object in the `parent` object.
v8::Local<v8::Object> GetOrCreateChildObject(v8::Local<v8::Object> parent,
const std::string& child_name,
v8::Isolate* isolate,
v8::Local<v8::Context> context) {
v8::Local<v8::Object> child;
v8::Local<v8::Value> child_value;
if (!parent->Get(context, gin::StringToV8(isolate, child_name))
.ToLocal(&child_value) ||
!child_value->IsObject()) {
child = v8::Object::New(isolate);
parent->Set(context, gin::StringToSymbol(isolate, child_name), child)
.Check();
} else {
child = v8::Local<v8::Object>::Cast(child_value);
}
return child;
}
} // namespace
// Exposes three methods:
// - chrome.send: Used to send messages to the browser. Requires the message
// name as the first argument and can have an optional second argument that
// should be an array.
// - chrome.getVariableValue: Returns value for the input variable name if such
// a value was set by the browser. Else will return an empty string.
// - chrome.timeTicks.nowInMicroseconds: Returns base::TimeTicks::Now() in
// microseconds. Used for performance measuring.
void WebUIExtension::Install(blink::WebLocalFrame* frame) {
v8::Isolate* isolate = frame->GetAgentGroupScheduler()->Isolate();
v8::HandleScope handle_scope(isolate);
v8::Local<v8::Context> context = frame->MainWorldScriptContext();
if (context.IsEmpty())
return;
v8::Context::Scope context_scope(context);
v8::Local<v8::Object> chrome = GetOrCreateChromeObject(isolate, context);
chrome
->Set(context, gin::StringToSymbol(isolate, "send"),
gin::CreateFunctionTemplate(
isolate, base::BindRepeating(&WebUIExtension::Send))
->GetFunction(context)
.ToLocalChecked())
.Check();
chrome
->Set(context, gin::StringToSymbol(isolate, "getVariableValue"),
gin::CreateFunctionTemplate(
isolate, base::BindRepeating(&WebUIExtension::GetVariableValue))
->GetFunction(context)
.ToLocalChecked())
.Check();
v8::Local<v8::Object> timeTicks =
GetOrCreateChildObject(chrome, "timeTicks", isolate, context);
timeTicks
->Set(context, gin::StringToSymbol(isolate, "nowInMicroseconds"),
gin::CreateFunctionTemplate(
isolate, base::BindRepeating(&base::TimeTicks::Now))
->GetFunction(context)
.ToLocalChecked())
.Check();
}
// static
void WebUIExtension::Send(gin::Arguments* args) {
blink::WebLocalFrame* frame;
RenderFrame* render_frame;
if (!ShouldRespondToRequest(&frame, &render_frame))
return;
std::string message;
if (!args->GetNext(&message)) {
args->ThrowError();
return;
}
// If they've provided an optional message parameter, convert that into a
// Value to send to the browser process.
base::Value::List content;
if (!args->PeekNext().IsEmpty() && !args->PeekNext()->IsUndefined()) {
v8::Local<v8::Object> obj;
if (!args->GetNext(&obj)) {
args->ThrowError();
return;
}
std::unique_ptr<base::Value> value =
V8ValueConverter::Create()->FromV8Value(
obj, frame->MainWorldScriptContext());
DCHECK(value->is_list());
content = std::move(*value).TakeList();
// The conversion of |obj| could have triggered arbitrary JavaScript code,
// so check that the frame is still valid to avoid dereferencing a stale
// pointer.
if (frame != blink::WebLocalFrame::FrameForCurrentContext()) {
NOTREACHED_IN_MIGRATION();
return;
}
}
auto* webui = WebUIExtensionData::Get(render_frame);
if (!webui)
return;
// Send the message up to the browser.
webui->SendMessage(message, std::move(content));
}
// static
std::string WebUIExtension::GetVariableValue(const std::string& name) {
blink::WebLocalFrame* frame;
RenderFrame* render_frame;
if (!ShouldRespondToRequest(&frame, &render_frame))
return std::string();
auto* webui = WebUIExtensionData::Get(render_frame);
if (!webui)
return std::string();
return webui->GetValue(name);
}
} // namespace content