基于逻辑运算的简单权限系统(实现) JS 版_javascript技巧

作者: slightboy, 时间: 2006-10-17
此篇为 JS 实现版本, 以前作已交待原理 故不在此多做解释
如需原理介绍 请查看 VBS 版.
var PermissionType =
{
    Read : 1,
    Write : 2,
    Delete : 4
}
function PermissionSetComponent(value)
{
    this.Value = value;
    this.getRead = function()
    {
        return this.getValue(PermissionType.Read);
    }
    this.setRead = function(value)
    {
        this.setValue(PermissionType.Read, value);
    }
    this.Read = function()
    {
        if (arguments.length > 0)
            this.setValue(PermissionType.Read, arguments[0]);
        else
            return this.getValue(PermissionType.Read);
    }
    this.Write = function()
    {
        if (arguments.length > 0)
            this.setValue(PermissionType.Write, arguments[0]);
        else
            return this.getValue(PermissionType.Write);
    }
    this.Delete = function()
    {
        if (arguments.length > 0)
            this.setValue(PermissionType.Delete, arguments[0]);
        else
            return this.getValue(PermissionType.Delete);
    }
    this.getValue = function(permissionType)
    {
        return (this.Value & permissionType) == permissionType;
    }
    this.setValue = function(permissionType, value)
    {
        if (value)
            this.Value |= permissionType;
        else
            this.Value &= ~permissionType;
    }
}
var PermissionSet = new PermissionSetComponent(0);
w("Read:");
PermissionSet.Read(false);
w(PermissionSet.Value +" "+ PermissionSet.Read());
PermissionSet.Read(true);
w(PermissionSet.Value +" "+ PermissionSet.Read());
w("Write:");
PermissionSet.Write(false);
w(PermissionSet.Value +" "+ PermissionSet.Write());
PermissionSet.Write(true);
w(PermissionSet.Value +" "+ PermissionSet.Write());
w("Delete:");
PermissionSet.Delete(false);
w(PermissionSet.Value +" "+ PermissionSet.Delete());
PermissionSet.Delete(true);
w(PermissionSet.Value +" "+ PermissionSet.Delete());
function w(o)
{
    Response.Write(o +"
");
}
注: 红色部分为 java 风格写法 不是本例所必须.
只是做一个展示, 如果你比较喜欢 java 风格也可以选择这种写法.