WebKit custom Property Get function and property delete function implementation

Overview: [Customenumerateproperty] when a given interface is enumerated, allows you to write your own implementation for the property fetch function for the specified interface. Similarly, when the properties of an interface are removed,[Customdeleteproperty] allows you to write your own implementation .

Customenumerateproperty] (i), [Customdeleteproperty] (i)

Usage: These two modifiers can be used in interface, as follows:

    [        customenumerateproperty,        customdeleteproperty    ] interface datatransferitemlist {    };

• [Customenumerateproperty] in JavaScriptCore: You can write Datatransferitemlist Property Get function, specifically, you can write this function jsxxx:: Getownpropertynames (...), which comes from webcore/bindings/js/jsdatatransferitemlistCustom.cpp:

void Jsdatatransferitemlist::getownpropertynames (Jsobject* object, execstate* exec, propertynamearray& PropertyNames, Enumerationmode mode) {jsdatatransferitemlist* Thisobject = jscast<jsdatatransferitemlist*> (    object);    Assert_gc_object_inherits (Thisobject, &s_info); for (unsigned i = 0; i < static_cast<datatransferitemlist*> (Thisobject->impl ())->length (); ++i) prop     Ertynames.add (Identifier::from (exec, i)); Base::getownpropertynames (Thisobject, exec, propertynames, mode);}

    [        customdeleteproperty    ] interface Storage {    };

• [Customdeleteproperty] : When the storage property is deleted, we can write our own property delete function, specifically, that is, like this write jsstorage::d eleteproperty (... ) function, which is located in Webcore/bindings/js/jsStorageCustom.cpp:

BOOL Jsstorage::d eleteproperty (jscell* cell, execstate* exec, PropertyName PropertyName) {    jsstorage* Thisobject = jscast<jsstorage*> (cell);   //Only perform the custom delete if the object doesn ' t has a n Ative-name.   //Since Hasproperty () would end up calling Cangetitemsforname () and is fooled, We need to check   //The native property slots manually.    Propertyslot slot;    if (GetS Taticvalueslot<jsstorage, base> (exec, s_info.prophashtable (exec), Thisobject, PropertyName, slot))         return false;            Jsvalue prototype = Thisobject->protot Ype ();    if (Prototype.isobject () && Asobject (prototype)->hasproperty (exec, PropertyName))         return false;    Thisobject->m_impl->removeitem (propertynametostring ( PropertyName));    return true;}

Reference: 1 http://trac.webkit.org/wiki/WebKitIDL#CustomEnumerateProperty2 souce Code of WebKit

WebKit custom Property Get function and property delete function implementation