sa.js

// Copyright Paolo Galeone 2014-2022 - Licensed under MIT License

class XHRException extends Error {
    constructor(...params) {
        super(...params);
        if (Error.captureStackTrace) {
            Error.captureStackTrace(this, XHRException)
        }
    }
}

// Define namespace
var AJAX = function(CORS) {
    var xhr = false;

    //Closure - init XHR object on AJAX object creation
    (function() {
        var _xhr,
            activeXoptions = ["Microsoft.XmlHttp", "MSXML4.XmlHttp", "MSXML3.XmlHttp", "MSXML2.XmlHttp", "MSXML.XmlHttp"];

        try {
            _xhr = new XMLHttpRequest();
        } catch (e) {}

        if (!_xhr) {
            var created = false;
            for (var i = 0; i < activeXoptions.length && !created; i++) {
                try {
                    _xhr = new ActiveXObject(activeXoptions[i]);
                    created = true;
                } catch (e) {}
            }
        }

        if (!_xhr) {
            throw new XHRException("Your browser does not support XmlHttpRequestObject." +
                "Please update it.");
        }

        xhr = _xhr;
    })();

    // define private functions, used to make request handling smarter
    var _smartQueryString = function(parameters) {
        if (typeof(parameters) == 'string') {
            return parameters;
        }

        if (typeof(parameters) == 'object') {
            //Translate JSON object to a query string
            // { foo:bar, what:yellow} becomes: foo=bar&what=yellow
            var str = '';
            for (var key in parameters) {
                str += key + '=' + encodeURIComponent(parameters[key]) + '&';
            }

            if (str === '') {
                return false;
            }

            return str.slice(0, str.length - 1);
        }

        return false;
    };

    // Generic request
    var _request = function(req) {
        //abort after 30 seconds of delay in response
        var timeout = setTimeout(function() {
            xhr.abort();
        }, 30000);
        //Handle CORS
        if (typeof(CORS) == 'undefined') {
            var port = location.port != 80 ? ":" + location.port : "";
            req.url = window.location.protocol + "//" + document.domain + port + req.url;
        }
        //console.log("log from _request, req.url = ", req.url);
        xhr.onreadystatechange = function() {
            //console.log("log from xhr.onreadystatechange", xhr.responseText);
            //console.log(xhr.readyState, xhr.status);
            if (xhr.readyState == 4 && xhr.status == 200) {
                if (typeof(req.success) == 'function') {
                    clearTimeout(timeout);
                    req.success(req.dataType && req.dataType.toUpperCase() == 'JSON' ?
                        JSON.parse(xhr.responseText) :
                        req.dataType && req.dataType && req.dataType.toUpperCase() == 'XML' ?
                        xhr.responseXML :
                        xhr.responseText);
                }
            } else {
                if (xhr.readyState == 4) { //call error function only when request has completed
                    //console.log("uhm, failing, but... ", xhr.responseText.length);
                    if (xhr.responseText.length > 0) {
                        //fix some shit in FF31 and previous with local files
                        // or better, fix the fact that all the world is crazy and even if there is a body inside the response, the error code preveals and the body is ignored (that's so stupid).
                        clearTimeout(timeout);
                        req.success(req.dataType && req.dataType.toUpperCase() == 'JSON' ?
                            JSON.parse(xhr.responseText) :
                            req.dataType && req.dataType.toUpperCase() == 'XML' ? xhr.responseXML :
                            xhr.responseText);
                        return;
                    }
                    if (typeof(req.failure) == 'function') {
                        clearTimeout(timeout);
                        if (req.failure.length == 2) {
                            req.failure(xhr.status, req.dataType && req.dataType.toUpperCase() == 'JSON' ?
                                JSON.parse(xhr.responseText) :
                                req.dataType && req.dataType.toUpperCase() == 'XML' ? xhr.responseXML :
                                xhr.responseText
                            );
                        } else if (req.failure.length == 1) {
                            req.failure(xhr.status);
                        } else {
                            req.failure();
                        }
                    }
                }
            }
        };

        var req_type = req.type.toUpperCase();
        if (req_type == 'GET') {
            xhr.open("GET", req.url, true);
            // Set header so the called script knows that it's an XMLHttpRequest
            xhr.setRequestHeader("X-Requested-With", "XMLHttpRequest");
            xhr.send();
        } else if (req_type == 'POST' || req_type == 'PUT' || req_type == 'DELETE') {
            req.data = _smartQueryString(req.data);
            xhr.open(req_type, req.url, true);
            // Set header so the called script knows that it's an XMLHttpRequest
            xhr.setRequestHeader("X-Requested-With", "XMLHttpRequest");
            xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
            xhr.send(req.data ? req.data : '');
        } else {
            throw new XHRException('Invalid (or unhandled) request type');
        }
    }; // _request

    return {
        setProgress: function(progress_function) {
            xhr.onprogress = progress_function;
        },

        // generic request
        request: function(req) {
            _request(req);
        },

        // get request (shortcut for request)
        get: function(url, success, failure) {
            _request({
                type: 'GET',
                url: url,
                success: success,
                failure: failure
            });
        },
        // get json
        getJSON: function(url, success, failure) {
            _request({
                type: 'GET',
                url: url,
                success: success,
                failure: failure,
                dataType: 'JSON'
            });
        },
        // post request (shortcut for request)
        post: function(url, success, failure, parameters) {
            _request({
                type: 'POST',
                url: url,
                success: success,
                failure: failure,
                data: parameters
            });
        },
        // delete request (shortcut for request)
        delete: function(url, success, failure, parameters) {
            _request({
                type: 'DELETE',
                url: url,
                success: success,
                failure: failure,
                data: parameters
            });
        }
    };
};