Index: headless/app/headless_example.cc |
diff --git a/headless/app/headless_example.cc b/headless/app/headless_example.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..56932ef45ba937630c5ff3ef41986bf4f855def6 |
--- /dev/null |
+++ b/headless/app/headless_example.cc |
@@ -0,0 +1,180 @@ |
+// Copyright 2017 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+// A small example application showing the use of the C++ Headless Chrome |
+// library. It navigates to a web site given on the command line, waits for it |
+// to load and prints out the DOM. |
+// |
+// Tip: start reading from the main() function below. |
+ |
+#include "base/bind.h" |
+#include "base/command_line.h" |
+#include "base/memory/weak_ptr.h" |
+#include "headless/public/devtools/domains/page.h" |
+#include "headless/public/devtools/domains/runtime.h" |
+#include "headless/public/headless_browser.h" |
+#include "headless/public/headless_devtools_client.h" |
+#include "headless/public/headless_devtools_target.h" |
+#include "headless/public/headless_web_contents.h" |
+#include "ui/gfx/geometry/size.h" |
+ |
+// This class contains the main application logic, i.e., waiting for a page to |
+// load and printing its DOM. Note that browser initialization happens outside |
+// this class. |
+class HeadlessExample : public headless::HeadlessWebContents::Observer, |
+ public headless::page::Observer { |
+ public: |
+ HeadlessExample(headless::HeadlessBrowser* browser, |
+ headless::HeadlessWebContents* web_contents); |
+ ~HeadlessExample() override; |
+ |
+ // headless::HeadlessWebContents::Observer implementation: |
+ void DevToolsTargetReady() override; |
+ |
+ // headless::page::Observer implementation: |
+ void OnLoadEventFired( |
+ const headless::page::LoadEventFiredParams& params) override; |
+ |
+ // Tip: Observe headless::inspector::ExperimentalObserver::OnTargetCrashed to |
+ // be notified of renderer crashes. |
+ |
+ void OnDomFetched(std::unique_ptr<headless::runtime::EvaluateResult> result); |
+ |
+ private: |
+ // The headless browser instance. Owned by the headless library. See main(). |
+ headless::HeadlessBrowser* browser_; |
+ // Our tab. Owned by |browser_|. |
+ headless::HeadlessWebContents* web_contents_; |
+ // The DevTools client used to control the tab. |
+ std::unique_ptr<headless::HeadlessDevToolsClient> devtools_client_; |
+ // A helper for creating weak pointers to this class. |
+ base::WeakPtrFactory<HeadlessExample> weak_factory_; |
+}; |
+ |
+namespace { |
+HeadlessExample* g_example; |
+} |
+ |
+HeadlessExample::HeadlessExample(headless::HeadlessBrowser* browser, |
+ headless::HeadlessWebContents* web_contents) |
+ : browser_(browser), |
+ web_contents_(web_contents), |
+ devtools_client_(headless::HeadlessDevToolsClient::Create()), |
+ weak_factory_(this) { |
+ web_contents_->AddObserver(this); |
+} |
+ |
+HeadlessExample::~HeadlessExample() { |
+ // Note that we shut down the browser last, because it owns objects such as |
+ // the web contents which can no longer be accessed after the browser is gone. |
+ devtools_client_->GetPage()->RemoveObserver(this); |
+ web_contents_->GetDevToolsTarget()->DetachClient(devtools_client_.get()); |
+ web_contents_->RemoveObserver(this); |
+ browser_->Shutdown(); |
+} |
+ |
+// This method is called when the tab is ready for DevTools inspection. |
+void HeadlessExample::DevToolsTargetReady() { |
+ // Attach our DevTools client to the tab so that we can send commands to it |
+ // and observe events. |
+ web_contents_->GetDevToolsTarget()->AttachClient(devtools_client_.get()); |
+ |
+ // Start observing events from DevTools's page domain. This lets us get |
+ // notified when the page has finished loading. Note that it is possible |
+ // the page has already finished loading by now. See |
+ // HeadlessShell::DevToolTargetReady for how to handle that case correctly. |
+ devtools_client_->GetPage()->AddObserver(this); |
+ devtools_client_->GetPage()->Enable(); |
+} |
+ |
+void HeadlessExample::OnLoadEventFired( |
+ const headless::page::LoadEventFiredParams& params) { |
+ // The page has now finished loading. Let's grab a snapshot of the DOM by |
+ // evaluating the outerHTML property on the body element. |
+ devtools_client_->GetRuntime()->Evaluate( |
+ "document.body.outerHTML", |
+ base::Bind(&HeadlessExample::OnDomFetched, weak_factory_.GetWeakPtr())); |
+} |
+ |
+void HeadlessExample::OnDomFetched( |
+ std::unique_ptr<headless::runtime::EvaluateResult> result) { |
+ std::string dom; |
+ // Make sure the evaluation succeeded before reading the result. |
+ if (result->HasExceptionDetails()) { |
+ LOG(ERROR) << "Failed to evaluate document.body.outerHTML: " |
+ << result->GetExceptionDetails()->GetText(); |
+ } else if (result->GetResult()->GetValue()->GetAsString(&dom)) { |
+ printf("%s\n", dom.c_str()); |
+ } |
+ |
+ // Shut down the browser (see ~HeadlessExample). |
+ delete g_example; |
+ g_example = nullptr; |
+} |
+ |
+// This function is called by the headless library after the browser has been |
+// initialized. It runs on the UI thread. |
+void OnHeadlessBrowserStarted(headless::HeadlessBrowser* browser) { |
+ // In order to open tabs, we first need a browser context. It corresponds to a |
+ // user profile and contains things like the user's cookies, local storage, |
+ // cache, etc. |
+ headless::HeadlessBrowserContext::Builder context_builder = |
+ browser->CreateBrowserContextBuilder(); |
+ |
+ // Here we can set options for the browser context. As an example we enable |
+ // incognito mode, which makes sure profile data is not written to disk. |
+ context_builder.SetIncognitoMode(true); |
+ |
+ // Construct the context and set it as the default. The default browser |
+ // context is used by the Target.createTarget() DevTools command when no other |
+ // context is given. |
+ headless::HeadlessBrowserContext* browser_context = context_builder.Build(); |
+ browser->SetDefaultBrowserContext(browser_context); |
+ |
+ // Get the URL from the command line. |
+ base::CommandLine::StringVector args = |
+ base::CommandLine::ForCurrentProcess()->GetArgs(); |
+ if (args.empty()) { |
+ LOG(ERROR) << "No URL to load"; |
+ browser->Shutdown(); |
+ return; |
+ } |
+ GURL url(args[0]); |
+ |
+ // Open a tab (i.e., HeadlessWebContents) in the newly created browser |
+ // context. |
+ headless::HeadlessWebContents::Builder tab_builder( |
+ browser_context->CreateWebContentsBuilder()); |
+ |
+ // We can set options for the opened tab here. In this example we are just |
+ // setting the initial URL to navigate to. |
+ tab_builder.SetInitialURL(url); |
+ |
+ // Create an instance of the example app, which will wait for the page to load |
+ // and print its DOM. |
+ headless::HeadlessWebContents* web_contents = tab_builder.Build(); |
+ g_example = new HeadlessExample(browser, web_contents); |
+} |
+ |
+int main(int argc, const char** argv) { |
+ // This function must be the first thing we call to make sure child processes |
+ // such as the renderer are started properly. The headless library starts |
+ // child processes by forking and exec'ing the main application. |
+ headless::RunChildProcessIfNeeded(argc, argv); |
+ |
+ // Create a headless browser instance. There can be one of these per process |
+ // and it can only be initialized once. |
+ headless::HeadlessBrowser::Options::Builder builder(argc, argv); |
+ |
+ // Here you can customize browser options. As an example we set the window |
+ // size. |
+ builder.SetWindowSize(gfx::Size(800, 600)); |
+ |
+ // Pass control to the headless library. It will bring up the browser and |
+ // invoke the given callback on the browser UI thread. Note: if you need to |
+ // pass more parameters to the callback, you can add them to the Bind() call |
+ // below. |
+ return headless::HeadlessBrowserMain(builder.Build(), |
+ base::Bind(&OnHeadlessBrowserStarted)); |
+} |