webview_cef/common/webview_js_handler.cc

#include "webview_js_handler.h"
#include <atomic>

std::atomic_long s_nReqID {1001};

bool CefJSHandler::Execute(const CefString& name,
	CefRefPtr<CefV8Value> object,
	const CefV8ValueList& arguments,
	CefRefPtr<CefV8Value>& retval,
	CefString& exception)
{
	if (name == "jsCmd")
	{
		if (arguments.size() < 2) {
			exception = "Invalid arguments.";
			return true;
		}
		//the first param is function name,the last param is callback function,and allow most 2 custom params between them.
		CefString function_name = arguments[0]->GetStringValue();
		CefString params = "";
		CefRefPtr<CefV8Value> callback;
		CefRefPtr<CefV8Value> rawdata;
		if (arguments[0]->IsString() && arguments[1]->IsFunction())
		{
			callback = arguments[1];
		}
		else if (arguments[0]->IsString() && arguments[1]->IsString() && arguments[2]->IsFunction())
		{
			params = arguments[1]->GetStringValue();
			callback = arguments[2];
		}
		else if (arguments[0]->IsString() && arguments[1]->IsString() && arguments[3]->IsFunction())
		{
			params = arguments[1]->GetStringValue();
			rawdata = arguments[2];
			callback = arguments[3];
		}
		else
		{
			exception = "Invalid arguments.";
			return true;
		}

		//call c++ funtion
		if (!js_bridge_->CallCppFunction(function_name, params, callback, rawdata))
		{
			std::ostringstream strStream;
			strStream << "Failed to call function:  " << function_name.c_str() << ".";
			strStream.flush();

			exception = strStream.str();
		}

	}
	else if (name == "StartRequest")
	{
		if (arguments.size() < 5) {
			exception = "Invalid arguments.";
			return true;
		}
		// args[0]
		int reqId = (int)arguments[0]->GetIntValue();

		// args[1]
		CefString strCmd = arguments[1]->GetStringValue();

		//// args[2]
		CefString strCallback = arguments[2]->GetStringValue();

		//// args[3]
		CefString strArgs = arguments[3]->GetStringValue();

		// call c++ function
		if (!js_bridge_->StartRequest(reqId, strCmd, strCallback, strArgs))
		{
			std::ostringstream strStream;
			strStream << "Failed to call function:  " << strCmd.c_str() << ".";
			strStream.flush();

			exception = strStream.str();
		}

	}
	else if (name == "GetNextReqID")
	{
		int reqID = CefJSBridge::GetNextReqID();
		retval = CefV8Value::CreateInt(reqID);
	}
	else {
		exception = "NativeHost no this fun.";
	}

	return true;
}

bool CefJSBridge::StartRequest(int reqId,
	const CefString& strCmd,
	const CefString& strCallback,
	const CefString& strArgs)
{
	if (reqId > 0) {
		reqId *= -1;
	}

	auto it = startRequest_callback_.find(reqId);
	if (it == startRequest_callback_.cend())
	{
		CefRefPtr<CefV8Context> context = CefV8Context::GetCurrentContext();
		if (context)
		{
			CefRefPtr<CefFrame> frame = context->GetFrame();
			if (frame)
			{
				CefRefPtr<CefProcessMessage> message = CefProcessMessage::Create(kJSCallCppFunctionMessage);
				message->GetArgumentList()->SetString(0, strCmd);
				message->GetArgumentList()->SetString(1, strArgs);
				message->GetArgumentList()->SetInt(2, reqId);
				startRequest_callback_.emplace(reqId, std::make_pair(frame, strCallback));
				frame->SendProcessMessage(PID_BROWSER, message);
				return true;
			}
		}
	}

	return false;
}

int CefJSBridge::GetNextReqID()
{
	long nRet = ++s_nReqID;
	if (nRet < 0)
	{
		nRet = 0;
	}

	while (nRet == 0)
	{
		nRet = ++s_nReqID;
	}

	return nRet;
}

bool CefJSBridge::CallCppFunction(const CefString& function_name,
	const CefString& params,
	CefRefPtr<CefV8Value> callback,
	CefRefPtr<CefV8Value> rawdata)
{
	auto it = render_callback_.find(js_callback_id_);
	if (it == render_callback_.cend())
	{
		CefRefPtr<CefV8Context> context = CefV8Context::GetCurrentContext();
		if (context)
		{
			CefRefPtr<CefFrame> frame = context->GetFrame();
			if (frame)
			{
				CefRefPtr<CefProcessMessage> message = CefProcessMessage::Create(kJSCallCppFunctionMessage);
				message->GetArgumentList()->SetString(0, function_name);
				message->GetArgumentList()->SetString(1, params);
				message->GetArgumentList()->SetInt(2, js_callback_id_);
				render_callback_.emplace(js_callback_id_++, std::make_pair(context, std::make_pair(callback, rawdata)));
				frame->SendProcessMessage(PID_BROWSER, message);
				return true;
			}
		}
	}

	return false;
}


void CefJSBridge::RemoveCallbackFuncWithFrame(CefRefPtr<CefFrame> frame)
{
	if (!render_callback_.empty()) {
		for (auto it = render_callback_.begin(); it != render_callback_.end();) {
			if (it->second.first->IsSame(frame->GetV8Context())) {
				it = render_callback_.erase(it);
			}
			else {
				++it;
			}
		}
	}

	if (!startRequest_callback_.empty()) {
		for (auto it = startRequest_callback_.begin(); it != startRequest_callback_.end();) {
			if (it->second.first->GetIdentifier() == frame->GetIdentifier()) {
				it = startRequest_callback_.erase(it);
			}
			else {
				++it;
			}
		}
	}
}

bool CefJSBridge::ExecuteJSCallbackFunc(int callbackId, bool error, const CefString& result)
{
	if (callbackId < 0)
	{
		auto it = startRequest_callback_.find(callbackId);
		if (it != startRequest_callback_.cend())
		{
			auto frame = it->second.first;
			CefString callback = it->second.second;

			if (callback != "" && frame.get())
			{
				std::ostringstream strStream;
				strStream <<"window['" << callback.ToString() << "'](" << callbackId * -1 << ", " << result.ToString() << ");";
				strStream.flush();

				CefString strCode = strStream.str();
				frame->ExecuteJavaScript(strCode, frame->GetURL(), 0);
				startRequest_callback_.erase(callbackId);

				return true;
			}
			else
			{
				return false;
			}
		}
	}
	else
	{
		auto it = render_callback_.find(callbackId);
		if (it != render_callback_.cend())
		{
			auto context = it->second.first;
			auto callback = it->second.second.first;
			auto rawdata = it->second.second.second;
			if (context.get() && callback.get())
			{
				context->Enter();

				CefV8ValueList arguments;

				//the first param marks whether the function execution result was successful
				arguments.push_back(CefV8Value::CreateBool(error));

				// the second prarm take the return data
				arguments.push_back(CefV8Value::CreateString(result));
				if (rawdata.get()) {
					arguments.push_back(rawdata);
				}

				// call js function
				CefRefPtr<CefV8Value> retval = callback->ExecuteFunction(nullptr, arguments);
				context->Exit();
				render_callback_.erase(callbackId);

				return true;
			}
			else
			{
				return false;
			}
		}

	}

	return false;
}