3.2 CefV8Value類實現定JavaScript數據類型
3.2.1 一般對象
3.2.2 CEF實現帶access的JavaScript對象
3.2.3 CEF實現帶攔截器CefV8Interceptor的JavaScript對象
3.2 CefV8Value類實現定JavaScript數據類型
上面的實例中我們已經用到CefV8Value類的CreateString("My Value!")創建字符串和CreateFunction創建了函數。這個類還可以創建, null, bool, int, double, date string等數據類型，都有對應的函數。static CefRefPtr<CefV8Value> CreateArray(int length)創建JavaScript數組。下面詳細講解下給JavaScript提供創建對象。accessor就是給JavaScript提供調用的set和get方法設置或獲取屬性。interceptor是攔截器，攔截set和get方法。
///
// Create a new CefV8Value object of type object with optional accessor and/or
// interceptor. This method should only be called from within the scope of a
// CefRenderProcessHandler, CefV8Handler or CefV8Accessor callback, or in
// combination with calling Enter() and Exit() on a stored CefV8Context
// reference.
///
/*--cef(optional_param=accessor, optional_param=interceptor)--*/
static CefRefPtr<CefV8Value> CreateObject(
CefRefPtr<CefV8Accessor> accessor,
CefRefPtr<CefV8Interceptor> interceptor);
3.2.1 一般對象
如果不需要給JavaScript提供get和set方法，可以直接創建對象。
CefRefPtr<CefV8Value> obj = CefV8Value::CreateObject(NULL);
給對象設置屬性名稱為myval，屬性值為My String;字符串類型。
virtual bool SetValue(int index, CefRefPtr<CefV8Value> value) = 0;
obj->SetValue("myval", CefV8Value::CreateString("My String!"));
3.2.2 CEF實現帶access的JavaScript對象
如果要提供set和get方法，需要提供access實現類。
（1）實現access類
class MyV8Accessor : public CefV8Accessor {
public:
MyV8Accessor() {}
virtual bool Get(const CefString& name,
const CefRefPtr<CefV8Value> object,
CefRefPtr<CefV8Value>& retval,
CefString& exception) OVERRIDE {
if (name == "myval") {
// Return the value.
retval = CefV8Value::CreateString(myval_);
return true;
}
// Value does not exist.
return false;
}
virtual bool Set(const CefString& name,
const CefRefPtr<CefV8Value> object,
const CefRefPtr<CefV8Value> value,
CefString& exception) OVERRIDE {
if (name == "myval") {
if (value->IsString()) {
// Store the value.
myval_ = value->GetStringValue();
} else {
// Throw an exception.
exception = "Invalid value type";
}
return true;
}
// Value does not exist.
return false;
}
// Variable used for storing the value.
CefString myval_;
// Provide the reference counting implementation for this class.
IMPLEMENT_REFCOUNTING(MyV8Accessor);
};
（2）使用SetValue函數設置對象屬性采用access方式設置和獲取數據。把對象設置到窗口對象中。
virtual bool SetValue(const CefString& key,
AccessControl settings,
PropertyAttribute attribute) = 0;
typedef enum {
V8_ACCESS_CONTROL_DEFAULT = 0,
V8_ACCESS_CONTROL_ALL_CAN_READ = 1,
V8_ACCESS_CONTROL_ALL_CAN_WRITE = 1 << 1,
V8_ACCESS_CONTROL_PROHIBITS_OVERWRITING = 1 << 2
} cef_v8_accesscontrol_t;
///
// V8 property attribute values.
///
typedef enum {
V8_PROPERTY_ATTRIBUTE_NONE = 0, // Writeable, Enumerable,
// Configurable
V8_PROPERTY_ATTRIBUTE_READONLY = 1 << 0, // Not writeable
V8_PROPERTY_ATTRIBUTE_DONTENUM = 1 << 1, // Not enumerable
V8_PROPERTY_ATTRIBUTE_DONTDELETE = 1 << 2 // Not configurable
} cef_v8_propertyattribute_t;
obj->SetValue("myval", V8_ACCESS_CONTROL_DEFAULT,
V8_PROPERTY_ATTRIBUTE_NONE);
（3）JavaScript中調用set和get方法，就可以設置和獲取屬性值。
3.2.3 CEF實現帶攔截器CefV8Interceptor的JavaScript對象
攔截器CefV8Interceptor和Access的區別是，除了可以用字符串來映射屬性，還可以用index索引來映射屬性。其定義如下
// Interface that should be implemented to handle V8 interceptor calls. The
// methods of this class will be called on the thread associated with the V8
// interceptor. Interceptor's named property handlers (with first argument of
// type CefString) are called when object is indexed by string. Indexed property
// handlers (with first argument of type int) are called when object is indexed
// by integer.
///
/*--cef(source=client,no_debugct_check)--*/
class CefV8Interceptor : public virtual CefBaseRefCounted {
public:
///
// Handle retrieval of the interceptor value identified by |name|. |object| is
// the receiver ('this' object) of the interceptor. If retrieval succeeds, set
// |retval| to the return value. If the requested value does not exist, don't
// set either |retval| or |exception|. If retrieval fails, set |exception| to
// the exception that will be thrown. If the property has an associated
// accessor, it will be called only if you don't set |retval|.
// Return true if interceptor retrieval was handled, false otherwise.
///
/*--cef(capi_name=get_byname)--*/
virtual bool Get(const CefString& name,
const CefRefPtr<CefV8Value> object,
CefRefPtr<CefV8Value>& retval,
CefString& exception) = 0;
///
// Handle retrieval of the interceptor value identified by |index|. |object|
// is the receiver ('this' object) of the interceptor. If retrieval succeeds,
// set |retval| to the return value. If the requested value does not exist,
// don't set either |retval| or |exception|. If retrieval fails, set
// |exception| to the exception that will be thrown.
// Return true if interceptor retrieval was handled, false otherwise.
///
/*--cef(capi_name=get_byindex,index_param=index)--*/
virtual bool Get(int index,
const CefRefPtr<CefV8Value> object,
CefRefPtr<CefV8Value>& retval,
CefString& exception) = 0;
///
// Handle assignment of the interceptor value identified by |name|. |object|
// is the receiver ('this' object) of the interceptor. |value| is the new
// value being assigned to the interceptor. If assignment fails, set
// |exception| to the exception that will be thrown. This setter will always
// be called, even when the property has an associated accessor.
// Return true if interceptor assignment was handled, false otherwise.
///
/*--cef(capi_name=set_byname)--*/
virtual bool Set(const CefString& name,
const CefRefPtr<CefV8Value> object,
const CefRefPtr<CefV8Value> value,
CefString& exception) = 0;
///
// Handle assignment of the interceptor value identified by |index|. |object|
// is the receiver ('this' object) of the interceptor. |value| is the new
// value being assigned to the interceptor. If assignment fails, set
// |exception| to the exception that will be thrown.
// Return true if interceptor assignment was handled, false otherwise.
///
/*--cef(capi_name=set_byindex,index_param=index)--*/
virtual bool Set(int index,
const CefRefPtr<CefV8Value> object,
const CefRefPtr<CefV8Value> value,
CefString& exception) = 0;
};
實例步驟如下
（1）實現Interceptor類
class Interceptor : public CefV8Interceptor {
public:
Interceptor() {}
virtual bool Get(const CefString& name,
const CefRefPtr<CefV8Value> object,
CefRefPtr<CefV8Value>& retval,
CefString& exception) OVERRIDE {
return true;
}
virtual bool Get(int index,
const CefRefPtr<CefV8Value> object,
CefRefPtr<CefV8Value>& retval,
CefString& exception) OVERRIDE {
return true;
}
virtual bool Set(const CefString& name,
const CefRefPtr<CefV8Value> object,
const CefRefPtr<CefV8Value> value,
CefString& exception) OVERRIDE {
return true;
}
virtual bool Set(int index,
const CefRefPtr<CefV8Value> object,
const CefRefPtr<CefV8Value> value,
CefString& exception) OVERRIDE {
return true;
}
IMPLEMENT_REFCOUNTING(Interceptor);
};
（2）創建Interceptor對象和JavaScript對象
CefRefPtr<CefV8Interceptor> interceptor = new Interceptor();
PERF_ITERATIONS_START()
CefRefPtr<CefV8Value> value = CefV8Value::CreateObject(nullptr, interceptor);
（3）SetValue（）函設置到窗口對象中（待驗證）
（4）JavaScript調用按照字符串名稱或者索引來設置獲取值。
自己開發了一個股票智能分析軟件，功能很強大，需要的點擊下面的鏈接獲取：