bmfe-vue2-base/src/js/baseLibs/promiseAjax/ajax.js

BM 后台系统基础框架

/**
 * @Author: songqi
 * @Date:   2016-06-29
 * @Email:  songqi@benmu-health.com
* @Last modified by:   songqi
* @Last modified time: 2016-08-24
 */

var _ = require('lodash');

var jsonpID = 0,
    document = window.document,
    key,
    rscript = /<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi,
    scriptTypeRE = /^(?:text|application)\/javascript/i,
    xmlTypeRE = /^(?:text|application)\/xml/i,
    jsonType = 'application/json',
    htmlType = 'text/html',
    blankRE = /^\s*$/;

var ajax = module.exports = function(options) {
    var settings = extend({}, options || {});
    for (key in ajax.settings)
        if (settings[key] === undefined) settings[key] = ajax.settings[key];

    ajaxStart(settings);

    if (!settings.crossDomain) settings.crossDomain = /^([\w-]+:)?\/\/([^\/]+)/.test(settings.url) &&
        RegExp.$2 != window.location.host;

    var dataType = settings.dataType,
        hasPlaceholder = /=\?/.test(settings.url);
    if (dataType == 'jsonp' || hasPlaceholder) {
        if (!hasPlaceholder) settings.url = appendQuery(settings.url, 'callback=?');
        return ajax.JSONP(settings);
    }

    if (!settings.url) settings.url = window.location.toString();
    serializeData(settings);

    var mime = settings.accepts[dataType],
        baseHeaders = {},
        protocol = /^([\w-]+:)\/\//.test(settings.url) ? RegExp.$1 : window.location.protocol,
        xhr = ajax.settings.xhr(),
        abortTimeout;

    if (!settings.crossDomain) baseHeaders['X-Requested-With'] = 'XMLHttpRequest';
    if (mime) {
        baseHeaders['Accept'] = mime;
        if (mime.indexOf(',') > -1) mime = mime.split(',', 2)[0];
        xhr.overrideMimeType && xhr.overrideMimeType(mime);
    }
    if (settings.contentType || settings.data && settings.type.toUpperCase() != 'GET')
        baseHeaders['Content-Type'] = settings.contentType || 'application/x-www-form-urlencoded';
    settings.headers = extend(baseHeaders, settings.headers || {});

    xhr.onreadystatechange = function() {
        if (xhr.readyState == 4) {
            clearTimeout(abortTimeout);
            var result, error = false;
            if (xhr.status >= 200 && xhr.status < 300 || xhr.status == 304 || xhr.status == 0 && protocol == 'file:') {
                dataType = dataType || mimeToDataType(xhr.getResponseHeader('content-type'));
                result = xhr.responseText;
                try {
                    if (dataType == 'script')(1, eval)(result);
                    else if (dataType == 'xml') result = xhr.responseXML;
                    else if (dataType == 'json') result = blankRE.test(result) ? null : JSON.parse(result);
                } catch (e) {
                    error = e;
                }

                if (error) ajaxError(error, 'parsererror', xhr, settings);
                else ajaxSuccess(result, xhr, settings);
            } else {
                ajaxError(null, xhr.errType || 'error', xhr, settings);
            }
        }
    };

    var async = 'async' in settings ? settings.async : true;
    xhr.open(settings.type, settings.url, async);

    for (var name in settings.headers) xhr.setRequestHeader(name, settings.headers[name]);

    if (ajaxBeforeSend(xhr, settings) === false) {
        xhr.abort('error');
        return false;
    }

    if (settings.timeout > 0) abortTimeout = setTimeout(function() {
        xhr.onreadystatechange = empty;
        xhr.abort('timeout');
        ajaxError(null, 'timeout', xhr, settings);
    }, settings.timeout);

    // avoid sending empty string (#319)
    xhr.send(settings.data ? settings.data : null);

    var oldAbort = xhr.abort;
    xhr.abort = function(errType) {
        xhr.errType = errType || 'abort';
        if (xhr) {
            oldAbort.call(xhr);
        }
    };
    return xhr;
};


// trigger a custom event and return false if it was cancelled
function triggerAndReturn() {
    //todo: Fire off some events
    //var event = $.Event(eventName)
    //$(context).trigger(event, data)
    return true; //!event.defaultPrevented
}

// trigger an Ajax "global" event
function triggerGlobal(settings, context, eventName, data) {
    if (settings.global)
        return triggerAndReturn(context || document, eventName, data);
}

// Number of active Ajax requests
ajax.active = 0;

function ajaxStart(settings) {
    if (settings.global && ajax.active++ === 0) triggerGlobal(settings, null, 'ajaxStart');
}

function ajaxStop(settings) {
    if (settings.global && !--ajax.active) triggerGlobal(settings, null, 'ajaxStop');
}

// triggers an extra global event "ajaxBeforeSend" that's like "ajaxSend" but cancelable
function ajaxBeforeSend(xhr, settings) {
    var context = settings.context;
    if (settings.beforeSend.call(context, xhr, settings) === false ||
        triggerGlobal(settings, context, 'ajaxBeforeSend', [xhr, settings]) === false)
        return false;

    triggerGlobal(settings, context, 'ajaxSend', [xhr, settings]);
}

function ajaxSuccess(data, xhr, settings) {
    var context = settings.context,
        status = 'success';
    settings.success.call(context, data, status, xhr);
    triggerGlobal(settings, context, 'ajaxSuccess', [xhr, settings, data]);
    ajaxComplete(status, xhr, settings);
}
// type: "timeout", "error", "abort", "parsererror"
function ajaxError(error, type, xhr, settings) {
    var context = settings.context;
    settings.error.call(context, xhr, type, error);
    triggerGlobal(settings, context, 'ajaxError', [xhr, settings, error]);
    ajaxComplete(type, xhr, settings);
}
// status: "success", "notmodified", "error", "timeout", "abort", "parsererror"
function ajaxComplete(status, xhr, settings) {
    var context = settings.context;
    settings.complete.call(context, xhr, status);
    triggerGlobal(settings, context, 'ajaxComplete', [xhr, settings]);
    ajaxStop(settings);
}

// Empty function, used as default callback
function empty() {}

ajax.JSONP = function(options) {
    if (!('type' in options)) return ajax(options);

    var callbackName = 'jsonp' + ++jsonpID,
        script = document.createElement('script'),
        abort = function() {
            //todo: remove script
            //$(script).remove()
            if (callbackName in window) window[callbackName] = empty;
            ajaxComplete('abort', xhr, options);
        },
        xhr = {
            abort: abort
        },
        abortTimeout,
        head = document.getElementsByTagName('head')[0] || document.documentElement;

    if (options.error) script.onerror = function() {
        xhr.abort();
        options.error();
    };

    window[callbackName] = function(data) {
        clearTimeout(abortTimeout);
            //todo: remove script
            //$(script).remove()
        delete window[callbackName];
        ajaxSuccess(data, xhr, options);
    };

    serializeData(options);
    script.src = options.url.replace(/=\?/, '=' + callbackName);

    // Use insertBefore instead of appendChild to circumvent an IE6 bug.
    // This arises when a base node is used (see jQuery bugs #2709 and #4378).
    head.insertBefore(script, head.firstChild);

    if (options.timeout > 0) abortTimeout = setTimeout(function() {
        xhr.abort();
        ajaxComplete('timeout', xhr, options);
    }, options.timeout);

    return xhr;
};

ajax.settings = {
    // Default type of request
    type: 'GET',
    // Callback that is executed before request
    beforeSend: empty,
    // Callback that is executed if the request succeeds
    success: empty,
    // Callback that is executed the the server drops error
    error: empty,
    // Callback that is executed on request complete (both: error and success)
    complete: empty,
    // The context for the callbacks
    context: null,
    // Whether to trigger "global" Ajax events
    global: true,
    // Transport
    xhr: function() {
        return new window.XMLHttpRequest();
    },
    // MIME types mapping
    accepts: {
        script: 'text/javascript, application/javascript',
        json: jsonType,
        xml: 'application/xml, text/xml',
        html: htmlType,
        text: 'text/plain'
    },
    // Whether the request is to another domain
    crossDomain: false,
    // Default timeout
    timeout: 0
};

function mimeToDataType(mime) {
    return mime && (mime == htmlType ? 'html' :
        mime == jsonType ? 'json' :
        scriptTypeRE.test(mime) ? 'script' :
        xmlTypeRE.test(mime) && 'xml') || 'text';
}

function appendQuery(url, query) {
    return (url + '&' + query).replace(/[&?]{1,2}/, '?');
}

// serialize payload and append it to the URL for GET requests
function serializeData(options) {
    var bodyData;
    if(options.data && options.type.toUpperCase() === 'POST'){
        options.data = JSON.stringify(options.data);
    }else if(options.body && options.type.toUpperCase() === 'POST'){
        bodyData = options.body;
        options.data = new FormData();
        options.data.append( 'json', JSON.stringify( bodyData ) );
    }else{
        if(!options.cache){
            options.data = options.data || {};
            options.data['v'] = +new Date();
        }
        if (_.isPlainObject(options.data)) options.data = param(options.data);
        if (options.data && (!options.type || options.type.toUpperCase() == 'GET'))
            options.url = appendQuery(options.url, options.data);
    }
}

ajax.get = function(url, success) {
    return ajax({
        url: url,
        success: success
    });
};

ajax.post = function(url, data, success, dataType) {
    if (_.isFunction(data)) {
        dataType = dataType || success;
        success = data;
        data = null;
    }

    return ajax({
        type: 'POST',
        url: url,
        data: data,
        success: success,
        dataType: dataType
    });
};

ajax.getJSON = function(url, success) {
    return ajax({
        url: url,
        success: success,
        dataType: 'json'
    });
};

var escape = encodeURIComponent;

function serialize(params, obj, traditional, scope) {
    var array = _.isArray(obj);

    for (var key in obj) {
        var value = obj[key];

        if (scope) key = traditional ? scope : scope + '[' + (array ? '' : key) + ']';
            // handle data in serializeArray() format
        if (!scope && array) params.add(value.name, value.value);
            // recurse into nested objects
        else if (traditional ? _.isArray(value) : _.isPlainObject(value))
            serialize(params, value, traditional, key);
        else params.add(key, value);
    }
}

function param(obj, traditional) {
    var params = [];
    params.add = function(k, v) {
        this.push(escape(k) + '=' + escape(v));
    };
    serialize(params, obj, traditional);
    return params.join('&').replace('%20', '+');
}

function extend(target) {
    var slice = Array.prototype.slice;
    slice.call(arguments, 1).forEach(function(source) {
        for (key in source)
            if (source[key] !== undefined)
                target[key] = source[key];
    });
    return target;
}