renderer进程中的JS给CEF的browserC++进程发送消息
作者:互联网
1.1 renderer进程中的JS给CEF的browserC++进程发送消息
1.1.1 流程原理介绍
renderer进程中暴露一个query函数和cancel函数,在renderer进程运行的JavaScript代码调用window.cefQuery,cefQueryCancel函数将消息发给browser进程的c++代码处理消息,.cefQuery,cefQueryCancel是在C++代码中的CefMessageRouterConfig对象中注册的,如果你希望注册不同名字的函数,需要在CefMessageRouterConfig对象中设置,如果你要 设置两套注册函数,router也要两套。rendder进程和browser进程之间是通两端的消息路由传递消息的,render进程消息路由CefMessageRouterRendererSide,browser进程消息路由CefMessageRouterBrowserSide。在renderer进程的OnProcessMessageRecieved, OnContextCreated OnContextReleased函数中通过router对象调用CefMessageRouterRendererSide中同名的函数(OnContextCreated注册JavaScript的函数;OnContextReleased取消与上下文相关的正在进行中的query,调用OnQueryCanceled会被调用;OnProcessMessageRecieved消被router正确处理返回true),消息路由会将从renderer进程发送给browser进程中的CefMessageRouterBrowserSide路由。renderer进程支持一般的JavaScript回调函数注册和执行,browser进程中的路由router可以对消息采用一个或者多个不同逻辑的处理实例来处理。前端JavaScript调用window.cefQuery函数,renderder通过消息路由将消息发给browser进程,browser进程的一个或者多个queryhander就会接收到消息,每个handler可以选择处理或者忽略消息。如果处理了消息,如果响应有效,需要执行回调函数Callback::Success,如果出错,需要调用Callback::Failure。这两个函数会同步调用renderer进程中JavaScript的回调函数onSuccess和onFailure,返回执行结果。如果query没有被borwser进程的hander处理,则会自动取消,JavaScript的onFaillure回调函数会被执行,错误码-1;qurry可以是持续的或者非持续的
(1)如果是持续的,需要在browser进程中定义map<int64,CefRefPtr<callback>>保存持续的请求queryid和callback对象,在onquery函数中保存进入map,当JavaScript调用window.CefQueryCancel函数,或者C++代码中使用了CallFailure函数,或者上下文context销毁时,需要将query在C++的OnQueryCancel回调函数中从map中删除。
(2)如果query是非持续的,注册会在JavaScript的回调函数执行后自动清除。不用保存到map主要实现在CEF的cef_message_router.h文件中。
1.1.2 query请模式
(1) 一次请求模式,使用非持续query,handle执行请求,返回响应, query销毁。
(2) 广播模式。使用持久性query注册为一个广播接受者,handler一直追踪所有的注册回调,并执行他们来发送广播消息。
(3) 订阅模式。使用持续性query注册为JavaScript的订阅接受者,handler在第一次请求时初始化订阅feed,将响应发送给所有的订阅者。没有一个注册的JavaScript接收者时,handle会取消订阅feed。
render进程中一般只要一个router就可以了,如果需要注册不同的JavaScript函数名字,需要多个router。当browser进程需要多个hadler来处理不同的消息,这样做是非常有用的。
1.1.3 消息通讯具体开发步骤
(1) 在renderer进程的rendererApp类的构造函数中创建CefMessageRouterRendererSide对象。
CefMessageRouterConfig config;
m_messagerouter=CefMessageRouterRendererSide.Create(config);
(2) 在renderer进程的OnProcessMessageRecieved, OnContextReleased OnContextCreated函数中通过router对象调用CefMessageRouterRendererSide中同名的函数,消息就会发送给browser进程中的CefMessageRouterBrowserSide路由。
void RendererApp::OnContextCreated(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context)
{
m_messageRouter->OnContextCreated(browser, frame, context);
}
void RendererApp::OnContextReleased(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context)
{
m_messageRouter->OnContextReleased(browser, frame, context);
}
bool RendererApp::OnProcessMessageReceived(CefRefPtr<CefBrowser> browser, CefProcessId source_process, CefRefPtr<CefProcessMessage> message)
{
return m_messageRouter->OnProcessMessageReceived(
browser, source_process, message);
}
(3) 定义处理类QueryHand,继承类 CefMessageRouterBrowserSide ::Handler类,实现OnQuery函数。
#pragma once
#include <map>
#include "include/wrapper/cef_message_router.h"
#include "FrameCommunication/CefInterfaceCallback.h"
class CefQueryHandler : public CefBaseRefCounted
, public CefMessageRouterBrowserSide::Handler
{
protected:
virtual bool OnQuery(CefRefPtr<CefBrowser> browser,
CefRefPtr<CefFrame> frame,
int64 query_id,
const CefString& request,
bool persistent,
CefRefPtr<Callback> callback);
virtual void OnQueryCanceled(CefRefPtr<CefBrowser> browser,
CefRefPtr<CefFrame> frame,
int64 query_id);
void complete(int64 query_id, int error_code, const CefString response);
private:
std::map<int64, CefRefPtr<Callback>> m_pendings;
IMPLEMENT_REFCOUNTING(CefQueryHandler);
};
(4)在browser进程中clienthand类中创建对象CefMessageRouterConfig
CefMessageRouterConfig用来定义js调用的函数名称,下面给出的是默认函数名称。
CefMessageRouterConfig config;
// config.js_query_function = "cefQuery";
// config.js_cancel_function = "cefQueryCancel";
(5)在browser进程中根据配置创建CefMessageRouterBrowserSide对象管理QueryHand。创建QueryHand对象,并添加到CefMessageRouterBrowserSide。clienthandler的OnBeforeClose、OnBeforeBrowse、OnProcessMessageReceived函数中执行CefMessageRouterBrowserSide对象中对应名称的函数(在OnBeforeClose、OnBeforeBrowse中调用,这样做的目的是网页刷新或者关闭时,所有正在进行中的query会取消掉,OnQueryCanceled函数会被调用,取消所有正在进行的query。在OnProcessMessageReceived中调用,则是消息如果被router正确处理,则返回true,否则返回false)。定义CefMessageRouterBrowserSide对象用来管理QueryHand对象。
m_queryHand=new QueryHand();
m_browser_side_router= CefMessageRouterBrowserSide::Create(config);
m_browser_side_router ->AddHandler(my_handler.);
bool ClientHandler::OnBeforeBrowse(CefRefPtr<CefBrowser> browser,
CefRefPtr<CefFrame> frame,
CefRefPtr<CefRequest> request,
bool user_gesture,
bool is_redirect) {
m_messageRouter->OnBeforeBrowse(browser, frame);
}
bool ClientHandler::OnProcessMessageReceived(CefRefPtr<CefBrowser> browser, CefProcessId source_process, CefRefPtr<CefProcessMessage> message)
{
if (m_messageRouter->OnProcessMessageReceived(browser, source_process,
message)) {
return true;
}
(6)JavaScript调用cefQuery函数
<html>
<head>
<script src="https://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
<script>
$(document).ready(function(){
$(document).dblclick(function(){
//alert("get doubleclicked");
if(window==top.window){//判断是否是嵌入
window.cefQuery({发给CEF消息
request: "message-content",
persistent: false,
onSuccess: function(response) { alert(response); },
onFailure: function(code, msg) { alert(code + " - " + msg); }
});
}
});
});
</script>
</head>
<body>
</body>
</html>
(7)onquery函数接收消息,处理消息,执行回调将queryid和回调对象保存到map,OnQueryCanceled函数中从map中找到对应的queryid,调用callback对象的onfailure函数,然后从map中清除。
void MyHandler::OnQuery(int64 query_id,
CefRefPtr<CefBrowser> browser,
CefRefPtr<CefFrame> frame,
const CefString& request,
bool persistent,
CefRefPtr<Callback> callback) {
// 处理消息request
if (persistent)
{
bRet = m_pendings.insert(std::make_pair(query_id, callback)).second;
}
else
{
callback->Success("success");
bRet = true;
}
}
void CefQueryHandler::OnQueryCanceled(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, int64 query_id)
{
auto it = m_pendings.find(query_id);
if (it != m_pendings.end())
{
it->second->Failure(-1,"canceled");
m_pendings.erase(it);
}
}
Cef消息路由类定义如下:
// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following disclaimer // in the documentation and/or other materials provided with the // distribution. // * Neither the name of Google Inc. nor the name Chromium Embedded // Framework nor the names of its contributors may be used to endorse // or promote products derived from this software without specific prior // written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. // // --------------------------------------------------------------------------- // // The contents of this file are only available to applications that link // against the libcef_dll_wrapper target. // #ifndef CEF_INCLUDE_WRAPPER_CEF_MESSAGE_ROUTER_H_ #define CEF_INCLUDE_WRAPPER_CEF_MESSAGE_ROUTER_H_ #pragma once #include "include/base/cef_ref_counted.h" #include "include/cef_base.h" #include "include/cef_browser.h" #include "include/cef_process_message.h" #include "include/cef_v8.h" // The below classes implement support for routing aynchronous messages between // JavaScript running in the renderer process and C++ running in the browser // process. An application interacts with the router by passing it data from // standard CEF C++ callbacks (OnBeforeBrowse, OnProcessMessageRecieved, // OnContextCreated, etc). The renderer-side router supports generic JavaScript // callback registration and execution while the browser-side router supports // application-specific logic via one or more application-provided Handler // instances. // // The renderer-side router implementation exposes a query function and a cancel // function via the JavaScript 'window' object: // // // Create and send a new query. // var request_id = window.cefQuery({ // request: 'my_request', // persistent: false, // onSuccess: function(response) {}, // onFailure: function(error_code, error_message) {} // }); // // // Optionally cancel the query. // window.cefQueryCancel(request_id); // // When |window.cefQuery| is executed the request is sent asynchronously to one // or more C++ Handler objects registered in the browser process. Each C++ // Handler can choose to either handle or ignore the query in the // Handler::OnQuery callback. If a Handler chooses to handle the query then it // should execute Callback::Success when a response is available or // Callback::Failure if an error occurs. This will result in asynchronous // execution of the associated JavaScript callback in the renderer process. Any // queries unhandled by C++ code in the browser process will be automatically // canceled and the associated JavaScript onFailure callback will be executed // with an error code of -1. // // Queries can be either persistent or non-persistent. If the query is // persistent than the callbacks will remain registered until one of the // following conditions are met: // // A. The query is canceled in JavaScript using the |window.cefQueryCancel| // function. // B. The query is canceled in C++ code using the Callback::Failure function. // C. The context associated with the query is released due to browser // destruction, navigation or renderer process termination. // // If the query is non-persistent then the registration will be removed after // the JavaScript callback is executed a single time. If a query is canceled for // a reason other than Callback::Failure being executed then the associated // Handler's OnQueryCanceled method will be called. // // Some possible usage patterns include: // // One-time Request. Use a non-persistent query to send a JavaScript request. // The Handler evaluates the request and returns the response. The query is // then discarded. // // Broadcast. Use a persistent query to register as a JavaScript broadcast // receiver. The Handler keeps track of all registered Callbacks and executes // them sequentially to deliver the broadcast message. // // Subscription. Use a persistent query to register as a JavaScript subscription // receiver. The Handler initiates the subscription feed on the first request // and delivers responses to all registered subscribers as they become // available. The Handler cancels the subscription feed when there are no // longer any registered JavaScript receivers. // // Message routing occurs on a per-browser and per-context basis. Consequently, // additional application logic can be applied by restricting which browser or // context instances are passed into the router. If you choose to use this // approach do so cautiously. In order for the router to function correctly any // browser or context instance passed into a single router callback must then // be passed into all router callbacks. // // There is generally no need to have multiple renderer-side routers unless you // wish to have multiple bindings with different JavaScript function names. It // can be useful to have multiple browser-side routers with different client- // provided Handler instances when implementing different behaviors on a per- // browser basis. // // This implementation places no formatting restrictions on payload content. // An application may choose to exchange anything from simple formatted // strings to serialized XML or JSON data. // // // EXAMPLE USAGE // // 1. Define the router configuration. You can optionally specify settings // like the JavaScript function names. The configuration must be the same in // both the browser and renderer processes. If using multiple routers in the // same application make sure to specify unique function names for each // router configuration. // // // Example config object showing the default values. // CefMessageRouterConfig config; // config.js_query_function = "cefQuery"; // config.js_cancel_function = "cefQueryCancel"; // // 2. Create an instance of CefMessageRouterBrowserSide in the browser process. // You might choose to make it a member of your CefClient implementation, // for example. // // browser_side_router_ = CefMessageRouterBrowserSide::Create(config); // // 3. Register one or more Handlers. The Handler instances must either outlive // the router or be removed from the router before they're deleted. // // browser_side_router_->AddHandler(my_handler); // // 4. Call all required CefMessageRouterBrowserSide methods from other callbacks // in your CefClient implementation (OnBeforeClose, etc). See the // CefMessageRouterBrowserSide class documentation for the complete list of // methods. // // 5. Create an instance of CefMessageRouterRendererSide in the renderer // process. // You might choose to make it a member of your CefApp implementation, for // example. // // renderer_side_router_ = CefMessageRouterRendererSide::Create(config); // // 6. Call all required CefMessageRouterRendererSide methods from other // callbacks in your CefRenderProcessHandler implementation // (OnContextCreated, etc). See the CefMessageRouterRendererSide class // documentation for the complete list of methods. // // 7. Execute the query function from JavaScript code. // // window.cefQuery({request: 'my_request', // persistent: false, // onSuccess: function(response) { print(response); }, // onFailure: function(error_code, error_message) {} }); // // 8. Handle the query in your Handler::OnQuery implementation and execute the // appropriate callback either immediately or asynchronously. // // void MyHandler::OnQuery(int64 query_id, // CefRefPtr<CefBrowser> browser, // CefRefPtr<CefFrame> frame, // const CefString& request, // bool persistent, // CefRefPtr<Callback> callback) { // if (request == "my_request") { // callback->Continue("my_response"); // return true; // } // return false; // Not handled. // } // // 9. Notice that the onSuccess callback is executed in JavaScript. /// // Used to configure the query router. The same values must be passed to both // CefMessageRouterBrowserSide and CefMessageRouterRendererSide. If using // multiple router pairs make sure to choose values that do not conflict. /// struct CefMessageRouterConfig { CefMessageRouterConfig(); // Name of the JavaScript function that will be added to the 'window' object // for sending a query. The default value is "cefQuery". CefString js_query_function; // Name of the JavaScript function that will be added to the 'window' object // for canceling a pending query. The default value is "cefQueryCancel". CefString js_cancel_function; }; /// // Implements the browser side of query routing. The methods of this class may // be called on any browser process thread unless otherwise indicated. /// class CefMessageRouterBrowserSide : public base::RefCountedThreadSafe<CefMessageRouterBrowserSide> { public: /// // Callback associated with a single pending asynchronous query. Execute the // Success or Failure method to send an asynchronous response to the // associated JavaScript handler. It is a runtime error to destroy a Callback // object associated with an uncanceled query without first executing one of // the callback methods. The methods of this class may be called on any // browser process thread. /// class Callback : public CefBaseRefCounted { public: /// // Notify the associated JavaScript onSuccess callback that the query has // completed successfully with the specified |response|. /// virtual void Success(const CefString& response) = 0; /// // Notify the associated JavaScript onFailure callback that the query has // failed with the specified |error_code| and |error_message|. /// virtual void Failure(int error_code, const CefString& error_message) = 0; }; /// // Implement this interface to handle queries. All methods will be executed on // the browser process UI thread. /// class Handler { public: typedef CefMessageRouterBrowserSide::Callback Callback; /// // Executed when a new query is received. |query_id| uniquely identifies the // query for the life span of the router. Return true to handle the query // or false to propagate the query to other registered handlers, if any. If // no handlers return true from this method then the query will be // automatically canceled with an error code of -1 delivered to the // JavaScript onFailure callback. If this method returns true then a // Callback method must be executed either in this method or asynchronously // to complete the query. /// virtual bool OnQuery(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, int64 query_id, const CefString& request, bool persistent, CefRefPtr<Callback> callback) { return false; } /// // Executed when a query has been canceled either explicitly using the // JavaScript cancel function or implicitly due to browser destruction, // navigation or renderer process termination. It will only be called for // the single handler that returned true from OnQuery for the same // |query_id|. No references to the associated Callback object should be // kept after this method is called, nor should any Callback methods be // executed. /// virtual void OnQueryCanceled(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, int64 query_id) {} virtual ~Handler() {} }; /// // Create a new router with the specified configuration. /// static CefRefPtr<CefMessageRouterBrowserSide> Create( const CefMessageRouterConfig& config); /// // Add a new query handler. If |first| is true it will be added as the first // handler, otherwise it will be added as the last handler. Returns true if // the handler is added successfully or false if the handler has already been // added. Must be called on the browser process UI thread. The Handler object // must either outlive the router or be removed before deletion. /// virtual bool AddHandler(Handler* handler, bool first) = 0; /// // Remove an existing query handler. Any pending queries associated with the // handler will be canceled. Handler::OnQueryCanceled will be called and the // associated JavaScript onFailure callback will be executed with an error // code of -1. Returns true if the handler is removed successfully or false // if the handler is not found. Must be called on the browser process UI // thread. /// virtual bool RemoveHandler(Handler* handler) = 0; /// // Cancel all pending queries associated with either |browser| or |handler|. // If both |browser| and |handler| are NULL all pending queries will be // canceled. Handler::OnQueryCanceled will be called and the associated // JavaScript onFailure callback will be executed in all cases with an error // code of -1. /// virtual void CancelPending(CefRefPtr<CefBrowser> browser, Handler* handler) = 0; /// // Returns the number of queries currently pending for the specified |browser| // and/or |handler|. Either or both values may be empty. Must be called on the // browser process UI thread. /// virtual int GetPendingCount(CefRefPtr<CefBrowser> browser, Handler* handler) = 0; // The below methods should be called from other CEF handlers. They must be // called exactly as documented for the router to function correctly. /// // Call from CefLifeSpanHandler::OnBeforeClose. Any pending queries associated // with |browser| will be canceled and Handler::OnQueryCanceled will be // called. No JavaScript callbacks will be executed since this indicates // destruction of the browser. /// virtual void OnBeforeClose(CefRefPtr<CefBrowser> browser) = 0; /// // Call from CefRequestHandler::OnRenderProcessTerminated. Any pending queries // associated with |browser| will be canceled and Handler::OnQueryCanceled // will be called. No JavaScript callbacks will be executed since this // indicates destruction of the context. /// virtual void OnRenderProcessTerminated(CefRefPtr<CefBrowser> browser) = 0; /// // Call from CefRequestHandler::OnBeforeBrowse only if the navigation is // allowed to proceed. If |frame| is the main frame then any pending queries // associated with |browser| will be canceled and Handler::OnQueryCanceled // will be called. No JavaScript callbacks will be executed since this // indicates destruction of the context. /// virtual void OnBeforeBrowse(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame) = 0; /// // Call from CefClient::OnProcessMessageReceived. Returns true if the message // is handled by this router or false otherwise. /// virtual bool OnProcessMessageReceived( CefRefPtr<CefBrowser> browser, CefProcessId source_process, CefRefPtr<CefProcessMessage> message) = 0; protected: // Protect against accidental deletion of this object. friend class base::RefCountedThreadSafe<CefMessageRouterBrowserSide>; virtual ~CefMessageRouterBrowserSide() {} }; /// // Implements the renderer side of query routing. The methods of this class must // be called on the render process main thread. /// class CefMessageRouterRendererSide : public base::RefCountedThreadSafe<CefMessageRouterRendererSide> { public: /// // Create a new router with the specified configuration. /// static CefRefPtr<CefMessageRouterRendererSide> Create( const CefMessageRouterConfig& config); /// // Returns the number of queries currently pending for the specified |browser| // and/or |context|. Either or both values may be empty. /// virtual int GetPendingCount(CefRefPtr<CefBrowser> browser, CefRefPtr<CefV8Context> context) = 0; // The below methods should be called from other CEF handlers. They must be // called exactly as documented for the router to function correctly. /// // Call from CefRenderProcessHandler::OnContextCreated. Registers the // JavaScripts functions with the new context. /// virtual void OnContextCreated(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context) = 0; /// // Call from CefRenderProcessHandler::OnContextReleased. Any pending queries // associated with the released context will be canceled and // Handler::OnQueryCanceled will be called in the browser process. /// virtual void OnContextReleased(CefRefPtr<CefBrowser> browser, CefRefPtr<CefFrame> frame, CefRefPtr<CefV8Context> context) = 0; /// // Call from CefRenderProcessHandler::OnProcessMessageReceived. Returns true // if the message is handled by this router or false otherwise. /// virtual bool OnProcessMessageReceived( CefRefPtr<CefBrowser> browser, CefProcessId source_process, CefRefPtr<CefProcessMessage> message) = 0; protected: // Protect against accidental deletion of this object. friend class base::RefCountedThreadSafe<CefMessageRouterRendererSide>; virtual ~CefMessageRouterRendererSide() {} }; #endif // CEF_INCLUDE_WRAPPER_CEF_MESSAGE_ROUTER_H_
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标签:CEF,CefRefPtr,JavaScript,C++,will,router,进程,query,browser 来源: https://www.cnblogs.com/bclshuai/p/12796490.html