Zepto源代码学习一

最近开始学习Zepto源代码，分享出来，共同学习。前端新人，技术欠佳，多多见谅
参考的gitbook地址
感谢作者奉献

代码主体机构：

定义Zepto——核心自执行函数 函数里面的变量都为私有变量，防止污染全局
var zepto = (function (){})(); 自执行函数
定义全局Zepto

核心函数 函数常用示例 $('div');

init函数：

    zepto.init = function (selector, context) {        var dom        // If nothing given, return an empty Zepto collection        if (!selector) return zepto.Z()        // Optimize for string selectors        else if (typeof selector == 'string') {            selector = selector.trim()            // If it's a html fragment, create nodes from it            // Note: In both Chrome 21 and Firefox 15, DOM error 12            // is thrown if the fragment doesn't begin with <            if (selector[0] == '<' && fragmentRE.test(selector))                dom = zepto.fragment(selector, RegExp.$1, context), selector = null            // If there's a context, create a collection on that context first, and select            // nodes from there            else if (context !== undefined) return $(context).find(selector)            // If it's a CSS selector, use it to select nodes.            else dom = zepto.qsa(document, selector)        }        // If a function is given, call it when the DOM is ready        else if (isFunction(selector)) return $(document).ready(selector)        // If a Zepto collection is given, just return it        else if (zepto.isZ(selector)) return selector        else {            // normalize array if an array of nodes is given            if (isArray(selector)) dom = compact(selector)            // Wrap DOM nodes.            else if (isObject(selector))                dom = [selector], selector = null            // If it's a html fragment, create nodes from it            else if (fragmentRE.test(selector))                dom = zepto.fragment(selector.trim(), RegExp.$1, context), selector = null            // If there's a context, create a collection on that context first, and select            // nodes from there            else if (context !== undefined) return $(context).find(selector)            // And last but no least, if it's a CSS selector, use it to select nodes.            else dom = zepto.qsa(document, selector)        }        // create a new Zepto collection from the nodes found        return zepto.Z(dom, selector)    }

如果传递的第一个参数为string——首字母为< 并且时html标签 创建新的DOM
否则如果为正常的字符串直接获取DOM
如果有第二项参数 递归调用只有单参数本方法 并且执行find方法

如果传递的参数为函数——作为ready的回调传递

如果已经时zepto对象 直接返回

如果是DOM数组

如果是单个DOM

如果是html片段

返回一个执行的函数

zepto.Z函数：

// `$.zepto.Z` swaps out the prototype of the given `dom` array    // of nodes with `$.fn` and thus supplying all the Zepto functions    // to the array. This method can be overridden in plugins.    zepto.Z = function (dom, selector) {        return new Z(dom, selector)    }

Z函数

function Z(dom, selector) {        var i, len = dom ? dom.length : 0        for (i = 0; i < len; i++) this[i] = dom[i]        this.length = len        this.selector = selector || ''    }