百度首页js代码，寻求详解

Question

(function() { //下面为帮助函数******************************************************
var M = navigator.userAgent.indexOf("MSIE") != -1 && !window.opera;//浏览器不是IE 同时不是opera[挪威浏览器] 返回true
var V = (document.compatMode == "BackCompat");//可以用来判断当前页面采用的渲染方式


alert('this browser is '+(M?'IE':'non-IE'));
alert('this browser version is IE5.5? '+V) ;    function I(C) {//得到一个对象
        return document.getElementById(C)
    }
    function K(C) {//创建一个对象
        return document.createElement(C)
    }
    function S(C) {//消除输入字符串前后的半角和全角空格 
        return String(C).replace(new RegExp("(^[\\s\\t\\xa0\\u3000]+)|([\\u3000\\xa0\\s\\t]+\x24)", "g"), "")
    }
    function U(C) {
        return String(C).replace(new RegExp("[\\s\\t\\xa0\\u3000]", "g"), "")
    }
    function P(X, G, C) {
        if (M) 
{
//ie浏览器下注册事件,attachEvent(事件类型, 处理函数);
X.attachEvent("on" + G, 
(
function(Y) 
{
return function() 
{
C.call(Y)
}
}
)(X))
        } else {
   //非ie浏览器下注册事件，对应的函数是addEventListener(事件类型, 处理函数, 使用捕获);
               X.addEventListener(G, C, false)
        }
    }
    function N(C) {
        if (M) {
//ie浏览器
            C.returnValue = false
        } else {
//非ie
            C.preventDefault()//preventDefault方法就是可以阻止它的默认行为的发生而发生其他的事情。 
        }
    }
    function R(G) {
        if (M) 
{
//ie浏览器,为元素添加样式
            var X = document.createStyleSheet();
            X.cssText = G
        } else {
//非ie
            var C = document.createElement("style");
            C.type = "text/css";
            C.appendChild(document.createTextNode(G));
            document.getElementsByTagName("HEAD")[0].appendChild(C)
        }
    }
    function H(Y) {

        var X = document.forms[0];
        for (var G in Y) {
            if (Y[G] == undefined) {
                if (I("bdsug_ipt_" + G)) {
                    X.removeChild(I("bdsug_ipt_" + G))
                }
            } else {
                if (!O(G)) {
                    X.appendChild(C(G, Y[G]))
                } else {
                    O(G).value = Y[G]
                }
            }
        }
        function C(b, Z) {
            var a = K("INPUT");
            a.type = "hidden";
            a.name = b;
            a.id = "bdsug_ipt_" + b;
            a.value = Z;
            return a
        }
    }
    function O(X) {//表单中input的name

        var Y = document.forms[0];//得到第一个表单
        var Z = false;
        var C = Y.getElementsByTagName("INPUT");//得到表单中的所有的input
        for (var G = 0; G < C.length; G++) {
            if (X == C[G].getAttribute("name")) {//循环匹配表单中的所有input,getAttribute("name")表示得到当前对象的name属性
                Z = C[G];
                return Z
            } else {
                Z = false
            }
        }
    }
    function L(X) {
        var G = document.forms[0];//得到第一个表单
        for (var C in X) {
            if (C == "f") 
{
                if (O("f"))
{
                    if (O("f").id == "bdsug_ipt_f") 
{
                        G.removeChild(I("bdsug_ipt_f"))
                    } else {
                        O("f").value = "8"
                    }
                }
            } else {
                if (I("bdsug_ipt_" + C)) {
                    G.removeChild(I("bdsug_ipt_" + C))
                }
            }
        }
    }
//上面为帮助函数******************************************************    var A = 0;
//window.bdsug自己声明的对象
    if (typeof window.bdsug != "object" || window.bdsug == null) {

        window.bdsug = {}//重新初始化该对象
    }
    bdsug.sug = {};
    bdsug.sugkeywatcher = {};
//声明J对象开始
    var J = (function() {
        function C(X) 
{
            var Z = this.__MSG_QS__;
            if (!Z[X]) {
                Z[X] = []
            }
            for (var Y = 1,b = arguments.length,a; Y < b; Y++) {
                Z[X].push(arguments[Y])
            }
        }
        function G(Z) 
{
            var Y = this.__MSG_QS__[Z.type];
            if (Y == null) {
                return
            }
            for (var X = 0,
            a = Y.length; X < a; X++) {
                Y[X].rm(Z)
            }
        }
        return {
            ini: function(X) {  //声明一个函数，名称为ini
                X.__MSG_QS__ = {};  //为传进来的对象添加属性
                X.on = C;           //为传进来的对象添加方法
                X.dm = G;           //为传进来的对象添加方法
                return X
            }
        } //var J = (function() { 
        //return {
           // zzl: function(X) {
              //  return ++X
           // }
        //     }
//})();
//alert(J.zzl(7));//输出8    })();

//声明J对象结束

Answer 1

//声明F对象开始 F.on("need_data", B);
    var F = (function() {
        var n = I("kw");//得到id为kw[搜索文本框]的对象
        var e;
        var b = 0;
        var p = 0;
        var g = "";
        var m = "";
        var h;
        var Y = false;
        var j = true;
        var c;
        var Z = I("su");//"百度一下"按钮对象
        P(Z, "mousedown", l);//为文本框注册事件,l为"L",而不是"1"
        P(Z, "keydown", l);//为文本框注册事件,l为"L",而不是"1"
        P(I("kw"), "paste",
        function() {
            H({
                rsv_n: 2
            });
            if (A == 0) {
                A = new Date().getTime()
            }
        });
        function l() {
            H({
                inputT: A > 0 ? (new Date().getTime() - A) : 0
            })
        }
        function k() {
            if (j) {
                F.dm({
                    type: "start"
                });
                j = false
            }
        }
        function f(q) {
            if (A == 0) {
                A = new Date().getTime()
            }
            if (j) {
                F.dm({
                    type: "start"
                });
                j = false
            }
            q = q || window.event;
            if (q.keyCode == 9 || q.keyCode == 27) {
                F.dm({
                    type: "hide_div"
                })
            }
            if (q.keyCode == 13) {
                N(q);
                F.dm({
                    type: "key_enter"
                })
            }
            if (q.keyCode == 86 && q.ctrlKey) {
                H({
                    rsv_n: 2
                })
            }
            if (e.style.display != "none") {
                if (q.keyCode == 38) {
                    N(q);
                    F.dm({
                        type: "key_up"
                    })
                }
                if (q.keyCode == 40) {
                    F.dm({
                        type: "key_down"
                    })
                }
            } else {
                if (q.keyCode == 38 || q.keyCode == 40) {
                    F.dm({
                        type: "need_data",
                        wd: n.value
                    })
                }
            }
        }
        function X() {
            var q = n.value;
            if (q == g && q != "" && q != m && q != h) {
                if (p == 0) {
                    p = setTimeout(function() {
                        F.dm({
                            type: "need_data",
                            wd: q
                        })
                    },
                    100)
                }
            } else {
                clearTimeout(p);
                p = 0;
                g = q;
                if (q == "") {
                    F.dm({
                        type: "hide_div"
                    })
                }
                if (m != n.value) {
                    m = ""
                }
            }
        }
        function G() {
            b = setInterval(X, 10)
        }
        function d() {
            clearInterval(b)
        }
        function a() {
            if (Y) {
                window.event.cancelBubble = true;
                window.event.returnValue = false;
                Y = false
            }
        }
        function i(q) {
            n.blur();
            n.setAttribute("autocomplete", q);
            n.focus()
        }
        function o(q) {
            var q = q || window.event;
            if (q.keyCode == 13) {
                N(q)
            }
        }
        n.setAttribute("autocomplete", "off");
        var C = false;
        bdsug.sugkeywatcher.on = function() {  //为bdsug注册函数
            if (!C) {
                if (M) {
                    n.attachEvent("onkeydown", f)
                } else {
                    n.addEventListener("keydown", f, false)
                }
                C = true
            }
        };
        bdsug.sugkeywatcher.off = function() { //为bdsug注册函数
            if (C) {
                if (M) {
                    n.detachEvent("onkeydown", f)
                } else {
                    n.removeEventListener("keydown", f, false)
                }
                C = false
            }
        };
        bdsug.sugkeywatcher.on();
        P(n, "mousedown", k);
        P(n, "beforedeactivate", a);
        if (window.opera) {
            P(n, "keypress", o)
        }


        return J.ini({
            rm: function(q) {
                switch (q.type) {
                case "div_ready":
                    e = q.sdiv;
                    m = n.value;
                    G();
                    break;
                case "clk_submit":
                    d();
                    n.blur();
                    n.value = q.wd;
                    break;
                case "ent_submit":
                    d();
                    n.blur();
                    break;
                case "key_select":
                    h = q.selected;
                    break;
                case "close":
                    d();
                    i("on");
                    break;
                case "mousedown_tr":
                    if (navigator.userAgent.toLowerCase().indexOf("webkit") != -1) {
                        d();
                        setTimeout(G, 2000)
                    }
                    Y = true;
                    break
                }
            }
        })
    })();
//声明F对象结束

Answer 2

//声明W对象开始
    var W = (function() {
        var d;
        var k = I("kw");
        var Z;
        var h = -1;
        var p;
        var Y;
        var G;
        function X() {
            var q = Z.rows;
            for (var r = 0; r < q.length; r++) {
                q[r].className = "ml"
            }
        }
        function g() {
            if (typeof(Z) != "undefined" && Z != null && d.style.display != "none") {
                var q = Z.rows;
                for (var r = 0; r < q.length; r++) {
                    if (q[r].className == "mo") {
                        return [r, q[r].cells[0].innerHTML]
                    }
                }
            }
            return [ - 1, ""]
        }
        function c() {
            if (M) {
                G.style.display = "none"
            }
            d.style.display = "none"
        }
        function o() {
            X();
            this.className = "mo"
        }
        function j(q) {
            W.dm({
                type: "mousedown_tr"
            });
            if (!M) {
                q.stopPropagation();
                q.preventDefault();
                return false
            }
        }
        function i(r) {
            var q = r;
            return function() {
                var s = p[q];
                c();
                W.dm({
                    type: "clk_submit",
                    oq: I("kw").value,
                    wd: s,
                    rsp: q
                })
            }
        }
        function f(q) {
            q = q || window.event;
            N(q);
            W.dm({
                type: "close"
            });
            c(); (new Image()).src = "http://sclick.baidu.com/w.gif?fm=suggestion&title=%B9%D8%B1%D5&t=" + new Date().getTime()
        }
        function n() {
            var q = [k.offsetWidth + 15, k.offsetHeight + 10];
            d.style.width = ((M && V) ? q[0] : q[0] - 2) + "px";
            d.style.top = ((M && V) ? q[1] : q[1] - 1) + "px";
            d.style.display = "block";
            if (M) {
                G.style.top = ((M && V) ? q[1] : q[1] - 1) + "px";
                G.style.width = ((M && V) ? q[0] : q[0] - 2) + "px"
            }
        }
        function m(s, t) {
            if (s && t) {
                var r = S(s);
                if (t.indexOf(r) == 0) {
                    t = C(t, r)
                } else {
                    if (t.indexOf(U(s)) == 0) {
                        r = U(s);
                        t = C(t, r)
                    } else {}
                }
            }
            t = t.replace("&", "&amp;");
            return t
        }
        function C(u, s) {
            var r = "<span>" + s + "</span>";
            var q = s.length;
            var t = "<b>" + u.substring(q) + "</b>";
            return (r + t)
        }
        function b() {
            Z = K("TABLE");
            Z.id = "st";
            Z.cellSpacing = 0;
            Z.cellPadding = 2;
            var s = K("tbody");
            Z.appendChild(s);
            for (var r = 0,
            q = p.length; r < q; r++) {
                var t = s.insertRow( - 1);
                P(t, "mouseover", o);
                P(t, "mouseout", X);
                P(t, "mousedown", j);
                P(t, "click", i(r));
                var u = t.insertCell( - 1);
                u.innerHTML = m(Y, p[r])
            }
            d.innerHTML = "";
            d.appendChild(Z);
            n();
            if (M) {
                G.style.display = "block";
                G.style.left = 0 + "px";
                G.style.top = k.offsetHeight + 15 + "px";
                G.style.width = k.offsetWidth + "px";
                G.style.height = d.offsetHeight - 1 + "px"
            }
        }
        function l() {
            h = g()[0];
            if (h == -1) {
                W.dm({
                    type: "submit"
                })
            } else {
                W.dm({
                    type: "ent_submit",
                    oq: Y,
                    wd: g()[1],
                    rsp: h
                })
            }
        }
        function a() {
            h = g()[0];
            X();
            if (h == 0) {
                W.dm({
                    type: "key_select",
                    selected: ""
                });
                I("kw").value = Y;
                h--;
                L({
                    oq: Y,
                    sug: p[h],
                    rsv_n: 1,
                    rsp: h,
                    f: 3,
                    rsv_sug: rsv_sug
                })
            } else {
                if (h == -1) {
                    h = p.length
                }
                h--;
                var q = Z.rows[h];
                q.className = "mo";
                W.dm({
                    type: "key_select",
                    selected: p[h]
                });
                I("kw").value = p[h];
                H({
                    oq: Y,
                    sug: p[h],
                    rsv_n: 1,
                    rsp: h,
                    f: 3,
                    rsv_sug: rsv_sug
                })
            }
        }
        function e() {
            h = g()[0];
            X();
            if (h == p.length - 1) {
                W.dm({
                    type: "key_select",
                    selected: ""
                });
                I("kw").value = Y;
                h = -1;
                L({
                    oq: Y,
                    sug: p[h],
                    rsv_n: 1,
                    rsp: h,
                    f: 3,
                    rsv_sug: rsv_sug
                })
            } else {
                h++;
                var q = Z.rows[h];
                q.className = "mo";
                W.dm({
                    type: "key_select",
                    selected: p[h]
                });
                I("kw").value = p[h];
                H({
                    oq: Y,
                    sug: p[h],
                    rsv_n: 1,
                    rsp: h,
                    f: 3,
                    rsv_sug: rsv_sug
                })
            }
        }
        return J.ini({
            rm: function(q) {
                switch (q.type) {
                case "div_ready":
                    d = q.sdiv;
                    G = q.frm;
                    break;
                case "give_data":
                    Y = q.data.q;
                    p = q.data.s;
                    rsv_sug = q.data.t;
                    if (p.length != 0) {
                        b()
                    } else {
                        c()
                    }
                    break;
                case "key_enter":
                    l();
                    break;
                case "key_up":
                    a();
                    break;
                case "key_down":
                    e();
                    break;
                case "hide_div":
                    c();
                    break;
                case "mousedown_other":
                    c();
                    break;
                case "window_blur":
                    c();
                    break;
                case "need_resize":
                    n();
                    break
                }
            }
        })
    })();

Answer 3

//声明W对象结束 //声明T对象开始
    var T = (function() {
        var C = document.forms[0];
        function Y() {
            if (I("bdsug_ipt_sug")) {
                if (I("bdsug_ipt_sug").value == S(I("kw").value)) {
                    L({
                        rsv_n: 1,
                        sug: 1
                    })
                } else {
                    L({
                        f: 1
                    })
                }
            }
        }
        P(C, "submit", Y);
        function X() {
            Y();
            H({
                inputT: A > 0 ? (new Date().getTime() - A) : 0
            });
            C.submit()
        }
        function G(Z) {
            H(Z);
            H({
                inputT: A > 0 ? (new Date().getTime() - A) : 0
            });
            L({
                sug: 1,
                rsv_n: 1
            });
            C.submit()
        }
        return J.ini({
            rm: function(Z) {
                switch (Z.type) {
                case "clk_submit":
                    G({
                        oq:
                        Z.oq,
                        rsp: Z.rsp,
                        f: 3,
                        rsv_sug: rsv_sug,
                        rsv_sug2: 1
                    });
                    break;
                case "ent_submit":
                    G({
                        oq:
                        Z.oq,
                        rsp: Z.rsp,
                        f: 3,
                        rsv_sug: rsv_sug,
                        rsv_sug2: 0
                    });
                    break;
                case "submit":
                    X();
                    break
                }
            }
        })
    })();
//声明T对象结束 //声明B对象开始
    var B = (function() {
        var C = {};
        function X(Y) {
            if (typeof C[Y] == "undefined") {
                B.dm({
                    type: "request_data",
                    wd: Y
                })
            } else {
                B.dm({
                    type: "give_data",
                    data: C[Y]
                })
            }
        }
        function G(Y) {
            C[Y.q] = Y;
            B.dm({
                type: "give_data",
                data: C[Y.q]
            })
        }
        return J.ini({
            rm: function(Y) {
                switch (Y.type) {
                case "response_data":
                    G(Y.data);
                    break;
                case "need_data":
                    X(Y.wd);
                    break
                }
            }
        })
    })();
//声明B对象结束 //声明Q对象开始
    var Q = (function() {
        var C;
        var G;
        function X(Y) {
            Q.dm({
                type: "need_cookie"
            });
            if (C) {
                document.body.removeChild(C)
            }
            C = K("SCRIPT");
            C.src = "http://suggestion.baidu.com/su?wd=" + encodeURIComponent(Y) + "&p=" + G + "&cb=window.bdsug.sug&t=" + (new Date()).getTime();
//window.bdsug.sug({q:"d",p:true,s:["dnf","dnf官网","dota","dota视频","dj","dream high2","dota英雄出装","dnf70级加点模拟器","dnf双开","dj舞曲"]});
            C.charset = "gb2312";
            document.body.appendChild(C)
        }
        return J.ini({
            rm: function(Z) {
                switch (Z.type) {
                case "request_data":
                    X(Z.wd);
                    break;
                case "give_cookie":
                    var Y = Z.sug;
                    if (Y > 0) {
                        Y = 3
                    }
                    G = Y;
                    break
                }
            }
        })
    })();
//声明Q对象结束
    bdsug.sug = function(C) {
        bdsug.dm({
            type: "response_data",
            data: C
        })
    };
    bdsug.initSug = function() {
        bdsug.dm({
            type: "init"
        })
    };
    J.ini(bdsug); //声明E对象开始
    var E = (function() {
        function C() {
            if (navigator.cookieEnabled) {
                document.cookie = "su=0; domain=www.baidu.com"
            }
        }
        function G() {
            var X = (navigator.cookieEnabled && /sug=(\d)/.test(document.cookie) ? RegExp.$1: 3);
            E.dm({
                type: "give_cookie",
                sug: X
            })
        }
        return J.ini({
            rm: function(X) {
                switch (X.type) {
                case "close":
                    C();
                    break;
                case "need_cookie":
                    G();
                    break
                }
            }
        })
    })();
//声明E对象结束

//声明D对象开始
    var D = (function() {
        var c = I("kw");
        var X;
        var Z = document.forms[0];
        var d;
        function b() {
            if (X.offsetWidth != 0 && c.offsetWidth != X.offsetWidth) {
                D.dm({
                    type: "need_resize"
                })
            }
        }
        function Y() {
            X = K("DIV");
            X.id = "sd_" + new Date().getTime();
            X.style.display = "none";
            Z.appendChild(X);
            if (M) {
                d = K("IFRAME");
                d.style.display = "none";
                d.style.position = "absolute";
                X.parentNode.insertBefore(d, X)
            }
        }
        function a(f) {
            f = f || window.event;
            var g = f.target || f.srcElement;
            if (g == c) {
                return
            }
            while (g = g.parentNode) {
                if (g == X) {
                    return
                }
            }
            D.dm({
                type: "mousedown_other"
            })
        }
        function C() {
            D.dm({
                type: "window_blur"
            })
        }
        function G() {
            var f = "#" + X.id;
            var e = [];
            D.dm({
                type: "div_ready",
                sdiv: X,
                frm: d
            });
            setInterval(b, 100);
            P(document, "mousedown", a);
            P(window, "blur", C);
            e.push(f + "{border:1px solid #817F82;position:absolute;top:32px;left:0}");
            e.push(f + " table{width:100%;background:#fff;cursor:default}");
            e.push(f + " td{color:#000;font:14px arial;height:25px;line-height:25px;padding:0 8px}");
            e.push(f + " td b{color:#000}");
            e.push(f + " .mo{background:#ebebeb}");
            e.push(f + " .ml{background:#fff}");
            R(e.join(""))
        }
        bdsug.sug.initial = G;
        return J.ini({
            rm: function(e) {
                switch (e.type) {
                case "start":
                    G();
                    break;
                case "init":
                    Y();
                    break
                }
            }
        })
    })();
//声明D对象结束
    F.on("need_data", B);
    F.on("close_div", W);
    F.on("key_enter", W);
    F.on("key_up", W);
    F.on("key_down", W);
    F.on("hide_div", W);
    F.on("start", D);
    B.on("request_data", Q);
    B.on("give_data", W);
    bdsug.on("response_data", B);
    bdsug.on("init", D);
    W.on("clk_submit", F, T);
    W.on("ent_submit", F, T);
    W.on("submit", T);
    W.on("key_select", F);
    W.on("close", F, E);
    W.on("mousedown_tr", F);
    D.on("mousedown_other", W);
    D.on("need_resize", W);
    D.on("div_ready", F, W);
    D.on("window_blur", W);
    Q.on("need_cookie", E);
    E.on("give_cookie", Q);
    window.bdsug.initSug()
})();谁能帮我分析一下上面的js脚本，越详细越好,还有就是
F.on()
B.on()
....
这个on函数哪里来的，一直找不到，同事说继承了其他类，可是我不是很信.

Answer 4

 bdsug.sugkeywatcher.on = function () {
            if (!p) {
                if (M) {
                    X.attachEvent("onkeydown", f)
                } else {
                    X.addEventListener("keydown", f, false)
                }
                p = true
            }
        };
return {
  ini: function(X) { //声明一个函数，名称为ini
  X.__MSG_QS__ = {}; //为传进来的对象添加属性
  X.on = C; //为传进来的对象添加方法
  X.dm = G; //为传进来的对象添加方法
  return X
  }
  }
on 是绑定事件，这是压缩后的代码，变量名全是一个字母，大概知道就可以了