avalon.sync.js

(function($) {
    var DOC = document,
            r20 = /%20/g,
            rCRLF = /\r?\n/g,
            encode = encodeURIComponent,
            decode = decodeURIComponent,
            rheaders = /^(.*?):[ \t]*([^\r\n]*)\r?$/mg,
            // IE的换行符不包含 \r
            rlocalProtocol = /^(?:about|app|app-storage|.+-extension|file|res|widget):$/,
            rnoContent = /^(?:GET|HEAD)$/,
            rquery = /\?/,
            rurl = /^([\w.+-]+:)(?:\/\/([^\/?#:]*)(?::(\d+)|)|)/,
            //在IE下如果重置了document.domain，直接访问window.location会抛错，但用document.URL就ok了
            //http://www.cnblogs.com/WuQiang/archive/2012/09/21/2697474.html
            curl = DOC.URL,
            segments = rurl.exec(curl.toLowerCase()) || [],
            isLocal = rlocalProtocol.test(segments[1]),
            //http://www.cnblogs.com/rubylouvre/archive/2010/04/20/1716486.html
            s = ["XMLHttpRequest", "ActiveXObject('Msxml2.XMLHTTP.6.0')",
        "ActiveXObject('Msxml2.XMLHTTP.3.0')", "ActiveXObject('Msxml2.XMLHTTP')"];
    if (!"1" [0]) { //判定IE67
        s[0] = location.protocol === "file:" ? "!" : s[0];
    }
    for (var i = 0, axo; axo = s[i++]; ) {
        try {
            if (eval("new " + axo)) {
                $.xhr = new Function("return new " + axo);
                break;
            }
        } catch (e) {
        }
    }

    var accepts = {
        xml: "application/xml, text/xml",
        html: "text/html",
        text: "text/plain",
        json: "application/json, text/javascript",
        script: "text/javascript, application/javascript",
        "*": ["*/"] + ["*"] //避免被压缩掉
    },
    defaults = {
        type: "GET",
        contentType: "application/x-www-form-urlencoded; charset=UTF-8",
        async: true,
        jsonp: "callback"
    };
    //将data转换为字符串，type转换为大写，添加hasContent，crossDomain属性，如果是GET，将参数绑在URL后面

    function setOptions(opts) {
        opts = $.mix({}, defaults, opts);
        if (typeof opts.crossDomain !== "boolean") { //判定是否跨域
            var parts = rurl.exec(opts.url.toLowerCase());
            opts.crossDomain = !!(parts && (parts[1] !== segments[1] || parts[2] !== segments[2] || (parts[3]
                    || (parts[1] === "http:" ? 80 : 443)) !== (segments[3] || (segments[1] === "http:" ? 80 : 443))));
        }
        if (opts.data && typeof opts.data !== "object") {
            $.error("data必须为对象");
        }
        var querystring = $.param(opts.data);
        opts.querystring = querystring || "";
        opts.url = opts.url.replace(/#.*$/, "").replace(/^\/\//, segments[1] + "//");
        opts.type = opts.type.toUpperCase();
        opts.hasContent = !rnoContent.test(opts.type); //是否为post请求
        if (!opts.hasContent) {
            if (querystring) { //如果为GET请求,则参数依附于url上
                opts.url += (rquery.test(opts.url) ? "&" : "?") + querystring;
            }
            if (opts.cache === false) { //添加时间截
                opts.url += (rquery.test(opts.url) ? "&" : "?") + "_time=" + (+new Date);
            }
        }
        return opts;
    }
})(avalon)