【 tulaoshi.com - Web开发 】
Douban是2.0 社区里面比较成功的一个产品, 里面ajax技术也做得不错, 把它的源码拿来研究了一下, 它在页面上使用了jquery, 我比较喜欢它的一体式的事件处理机制,不用写很多的事件绑定代码,只需要通过一定的命名规则就可以自动给页面元素加上一些功能, 它上面几乎所有的功能都通过这个实现, 配合jquery强大的选择器,代码看起来比较简洁清晰. 下面我们就来看看它的一些核心部分. 我使用的是jquery 1.2.3,压缩之后29kb大小, 速度感觉上比以前有比较大的改善.废话不多说了,直接看看代码吧. 另外推荐一下blueprint 这个css框架,还挺好用的.
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//定义命名空间
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var Bowtech=new Object();
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//注册全局的事件监视器.
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Bowtech.EventMonitor = function()
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{
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this.listeners = new Object();
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}
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//广播事件
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Bowtech.EventMonitor.prototype.broadcast=function(widgetObj, msg, data)
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{
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var lst = this.listeners[msg];
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if(lst != null)
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{
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for(var o in lst)
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{
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lst[o](widgetObj, data);
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}
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}
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}
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//绑定所有的事件.
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Bowtech.EventMonitor.prototype.subscribe=function(msg, callback)
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{
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var lst = this.listeners[msg];
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if (lst)
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{
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lst.push(callback);
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} else
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{
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this.listeners[msg] = [callback];
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}
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}
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//取消事件绑定.
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Bowtech.EventMonitor.prototype.unsubscribe=function(msg, callback)
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{
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var lst = this.listener[msg];
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if (lst != null)
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{
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lst = lst.filter(function(ele, index, arr)
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{return ele!=callback;});
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}
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}
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// Page scope event-monitor obj.
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var event_monitor = new Bowtech.EventMonitor();
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//对于所有 class="j a_xxx yyy" id="xxx-123"的元素执行事件绑定, xxx-123部分用来获取元素的ID,比如一个帖子的ID,
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// a_xxx 后面的部
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//分用来标识应用如 vote / review / blog 等.
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//绑定的事件就是 : Bowtech.init_vote / Bowtech.init_blog 等.
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function load_event_monitor(root)
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{
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var re = /a_(w+)/; //正则表达式获取ID.
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var fns =
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{};
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$(".j", root).each(function(i)
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{
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var m = re.exec(this.className);
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if (m)
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{
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var f = fns[m[1]];
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if (!f)
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{ //如果事件处理函数不存在则创建函数对象.
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f = eval("Bowtech.init_"+m[1]);
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fns[m[1]] = f;//调用绑定函数.
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}
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f && f(this);
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}
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});
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}
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//在文档加载完毕后将执行的方法(参见jquery文档)
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//一般来说文档加载的时候应该绑定所有的事件, 但是有一种情况例外.
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//比如 通过Ajax方法取回来的内容里面还含有动作按钮的,这时需要针对这部分功能执行绑定.
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//需要手动调用 load_event_monitor(element); 方法.
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$(function()
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{
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load_event_monitor(document);
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});
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//注意这里的o对象是一个html 元素而非是一个jquery对象,所以在调用它的方法时应该使用$(o)函数
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//把它转化为jquery对象.
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Bowtech.init_forder = function(o)
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{
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var eid = $(o).attr("id").split("-")[1];
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var fo = $("#f-"+eid);
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var unfo = $("#unf-"+eid);
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fo.click(function()
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{
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$(o).hide();
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unfo.show();
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fo.hide();
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});
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unfo.click(function()
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{
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$(o).show();
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fo.show();
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unfo.hide();
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});
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}
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jQuery.fn.extend(
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{
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set_caret: function()
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{
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if(!$.browser.msie) return;
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var initSetCaret = function()
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{this.caretPos = document.selection.createRange().duplicate()};
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this.click(initSetCaret).select(initSetCaret).keyup(initSetCaret);
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},
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insert_caret:function(textFeildValue)
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{
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var textObj = this[0];
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if(document.all && textObj.createTextRange && textObj.caretPos)
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{
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var caretPos=textObj.caretPos;
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caretPos.text = caretPos.text.charAt(caretPos.text.length-1) == '' ? textFeildValue+'' : textFeildValue;
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} else if(textObj.setSelectionRange)
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{
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var rangeStart=textObj.selectionStart;
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var rangeEnd=textObj.selectionEnd;
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var tempStr1=textObj.value.substring(0,rangeStart);
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var tempStr2=textObj.value.substring(rangeEnd);
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textObj.value=tempStr1+textFeildValue+tempStr2;
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textObj.focus();
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var len=textFeildValue.length;
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textObj.setSelectionRange(rangeStart+len,rangeStart+len);
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textObj.blur();
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} else
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{
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textObj.value+=textFeildValue;
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}
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}
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})
前台要用就比较简单了, 只需要这样写:
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div id="test2" class="mod"
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h3
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这里可以放标题
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/h3
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div class="j modb a_forder" id="modb-1002"
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这里是一些主要的内容
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dl
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dtHello world/dt
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dd
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hahaha/dd
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/dl
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这个实验在沙加的神舟本上完成
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/div
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div class="edit"
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a id="f-1002" class="forder" href="javascript:void(0);"[收起]/a a id="unf-1002"
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class="unforder" href="javascript:void(0);"[展开]/a
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/div
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/div
样式就省略了, 大家可以自己写, 最后发两个效果图:
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收起时的样子
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开发环境: 沙加的神舟本, VS2008, Framework 2.0