Build: replace CRLF with LF during minify

[jquery.git] / src / ajax.js

import jQuery from "./core.js";
import document from "./var/document.js";
import rnothtmlwhite from "./var/rnothtmlwhite.js";
import location from "./ajax/var/location.js";
import nonce from "./ajax/var/nonce.js";
import rquery from "./ajax/var/rquery.js";

import "./core/init.js";
import "./core/parseXML.js";
import "./event/trigger.js";
import "./deferred.js";
import "./serialize.js"; // jQuery.param

var
        r20 = /%20/g,
        rhash = /#.*$/,
        rantiCache = /([?&])_=[^&]*/,
        rheaders = /^(.*?):[ \t]*([^\r\n]*)$/mg,

        // trac-7653, trac-8125, trac-8152: local protocol detection
        rlocalProtocol = /^(?:about|app|app-storage|.+-extension|file|res|widget):$/,
        rnoContent = /^(?:GET|HEAD)$/,
        rprotocol = /^\/\//,

        /* Prefilters
         * 1) They are useful to introduce custom dataTypes (see ajax/jsonp.js for an example)
         * 2) These are called:
         *    - BEFORE asking for a transport
         *    - AFTER param serialization (s.data is a string if s.processData is true)
         * 3) key is the dataType
         * 4) the catchall symbol "*" can be used
         * 5) execution will start with transport dataType and THEN continue down to "*" if needed
         */
        prefilters = {},

        /* Transports bindings
         * 1) key is the dataType
         * 2) the catchall symbol "*" can be used
         * 3) selection will start with transport dataType and THEN go to "*" if needed
         */
        transports = {},

        // Avoid comment-prolog char sequence (trac-10098); must appease lint and evade compression
        allTypes = "*/".concat( "*" ),

        // Anchor tag for parsing the document origin
        originAnchor = document.createElement( "a" );

originAnchor.href = location.href;

// Base "constructor" for jQuery.ajaxPrefilter and jQuery.ajaxTransport
function addToPrefiltersOrTransports( structure ) {

        // dataTypeExpression is optional and defaults to "*"
        return function( dataTypeExpression, func ) {

                if ( typeof dataTypeExpression !== "string" ) {
                        func = dataTypeExpression;
                        dataTypeExpression = "*";
                }

                var dataType,
                        i = 0,
                        dataTypes = dataTypeExpression.toLowerCase().match( rnothtmlwhite ) || [];

                if ( typeof func === "function" ) {

                        // For each dataType in the dataTypeExpression
                        while ( ( dataType = dataTypes[ i++ ] ) ) {

                                // Prepend if requested
                                if ( dataType[ 0 ] === "+" ) {
                                        dataType = dataType.slice( 1 ) || "*";
                                        ( structure[ dataType ] = structure[ dataType ] || [] ).unshift( func );

                                // Otherwise append
                                } else {
                                        ( structure[ dataType ] = structure[ dataType ] || [] ).push( func );
                                }
                        }
                }
        };
}

// Base inspection function for prefilters and transports
function inspectPrefiltersOrTransports( structure, options, originalOptions, jqXHR ) {

        var inspected = {},
                seekingTransport = ( structure === transports );

        function inspect( dataType ) {
                var selected;
                inspected[ dataType ] = true;
                jQuery.each( structure[ dataType ] || [], function( _, prefilterOrFactory ) {
                        var dataTypeOrTransport = prefilterOrFactory( options, originalOptions, jqXHR );
                        if ( typeof dataTypeOrTransport === "string" &&
                                !seekingTransport && !inspected[ dataTypeOrTransport ] ) {

                                options.dataTypes.unshift( dataTypeOrTransport );
                                inspect( dataTypeOrTransport );
                                return false;
                        } else if ( seekingTransport ) {
                                return !( selected = dataTypeOrTransport );
                        }
                } );
                return selected;
        }

        return inspect( options.dataTypes[ 0 ] ) || !inspected[ "*" ] && inspect( "*" );
}

// A special extend for ajax options
// that takes "flat" options (not to be deep extended)
// Fixes trac-9887
function ajaxExtend( target, src ) {
        var key, deep,
                flatOptions = jQuery.ajaxSettings.flatOptions || {};

        for ( key in src ) {
                if ( src[ key ] !== undefined ) {
                        ( flatOptions[ key ] ? target : ( deep || ( deep = {} ) ) )[ key ] = src[ key ];
                }
        }
        if ( deep ) {
                jQuery.extend( true, target, deep );
        }

        return target;
}

/* Handles responses to an ajax request:
 * - finds the right dataType (mediates between content-type and expected dataType)
 * - returns the corresponding response
 */
function ajaxHandleResponses( s, jqXHR, responses ) {

        var ct, type, finalDataType, firstDataType,
                contents = s.contents,
                dataTypes = s.dataTypes;

        // Remove auto dataType and get content-type in the process
        while ( dataTypes[ 0 ] === "*" ) {
                dataTypes.shift();
                if ( ct === undefined ) {
                        ct = s.mimeType || jqXHR.getResponseHeader( "Content-Type" );
                }
        }

        // Check if we're dealing with a known content-type
        if ( ct ) {
                for ( type in contents ) {
                        if ( contents[ type ] && contents[ type ].test( ct ) ) {
                                dataTypes.unshift( type );
                                break;
                        }
                }
        }

        // Check to see if we have a response for the expected dataType
        if ( dataTypes[ 0 ] in responses ) {
                finalDataType = dataTypes[ 0 ];
        } else {

                // Try convertible dataTypes
                for ( type in responses ) {
                        if ( !dataTypes[ 0 ] || s.converters[ type + " " + dataTypes[ 0 ] ] ) {
                                finalDataType = type;
                                break;
                        }
                        if ( !firstDataType ) {
                                firstDataType = type;
                        }
                }

                // Or just use first one
                finalDataType = finalDataType || firstDataType;
        }

        // If we found a dataType
        // We add the dataType to the list if needed
        // and return the corresponding response
        if ( finalDataType ) {
                if ( finalDataType !== dataTypes[ 0 ] ) {
                        dataTypes.unshift( finalDataType );
                }
                return responses[ finalDataType ];
        }
}

/* Chain conversions given the request and the original response
 * Also sets the responseXXX fields on the jqXHR instance
 */
function ajaxConvert( s, response, jqXHR, isSuccess ) {
        var conv2, current, conv, tmp, prev,
                converters = {},

                // Work with a copy of dataTypes in case we need to modify it for conversion
                dataTypes = s.dataTypes.slice();

        // Create converters map with lowercased keys
        if ( dataTypes[ 1 ] ) {
                for ( conv in s.converters ) {
                        converters[ conv.toLowerCase() ] = s.converters[ conv ];
                }
        }

        current = dataTypes.shift();

        // Convert to each sequential dataType
        while ( current ) {

                if ( s.responseFields[ current ] ) {
                        jqXHR[ s.responseFields[ current ] ] = response;
                }

                // Apply the dataFilter if provided
                if ( !prev && isSuccess && s.dataFilter ) {
                        response = s.dataFilter( response, s.dataType );
                }

                prev = current;
                current = dataTypes.shift();

                if ( current ) {

                        // There's only work to do if current dataType is non-auto
                        if ( current === "*" ) {

                                current = prev;

                        // Convert response if prev dataType is non-auto and differs from current
                        } else if ( prev !== "*" && prev !== current ) {

                                // Seek a direct converter
                                conv = converters[ prev + " " + current ] || converters[ "* " + current ];

                                // If none found, seek a pair
                                if ( !conv ) {
                                        for ( conv2 in converters ) {

                                                // If conv2 outputs current
                                                tmp = conv2.split( " " );
                                                if ( tmp[ 1 ] === current ) {

                                                        // If prev can be converted to accepted input
                                                        conv = converters[ prev + " " + tmp[ 0 ] ] ||
                                                                converters[ "* " + tmp[ 0 ] ];
                                                        if ( conv ) {

                                                                // Condense equivalence converters
                                                                if ( conv === true ) {
                                                                        conv = converters[ conv2 ];

                                                                // Otherwise, insert the intermediate dataType
                                                                } else if ( converters[ conv2 ] !== true ) {
                                                                        current = tmp[ 0 ];
                                                                        dataTypes.unshift( tmp[ 1 ] );
                                                                }
                                                                break;
                                                        }
                                                }
                                        }
                                }

                                // Apply converter (if not an equivalence)
                                if ( conv !== true ) {

                                        // Unless errors are allowed to bubble, catch and return them
                                        if ( conv && s.throws ) {
                                                response = conv( response );
                                        } else {
                                                try {
                                                        response = conv( response );
                                                } catch ( e ) {
                                                        return {
                                                                state: "parsererror",
                                                                error: conv ? e : "No conversion from " + prev + " to " + current
                                                        };
                                                }
                                        }
                                }
                        }
                }
        }

        return { state: "success", data: response };
}

jQuery.extend( {

        // Counter for holding the number of active queries
        active: 0,

        // Last-Modified header cache for next request
        lastModified: {},
        etag: {},

        ajaxSettings: {
                url: location.href,
                type: "GET",
                isLocal: rlocalProtocol.test( location.protocol ),
                global: true,
                processData: true,
                async: true,
                contentType: "application/x-www-form-urlencoded; charset=UTF-8",

                /*
                timeout: 0,
                data: null,
                dataType: null,
                username: null,
                password: null,
                cache: null,
                throws: false,
                traditional: false,
                headers: {},
                */

                accepts: {
                        "*": allTypes,
                        text: "text/plain",
                        html: "text/html",
                        xml: "application/xml, text/xml",
                        json: "application/json, text/javascript"
                },

                contents: {
                        xml: /\bxml\b/,
                        html: /\bhtml/,
                        json: /\bjson\b/
                },

                responseFields: {
                        xml: "responseXML",
                        text: "responseText",
                        json: "responseJSON"
                },

                // Data converters
                // Keys separate source (or catchall "*") and destination types with a single space
                converters: {

                        // Convert anything to text
                        "* text": String,

                        // Text to html (true = no transformation)
                        "text html": true,

                        // Evaluate text as a json expression
                        "text json": JSON.parse,

                        // Parse text as xml
                        "text xml": jQuery.parseXML
                },

                // For options that shouldn't be deep extended:
                // you can add your own custom options here if
                // and when you create one that shouldn't be
                // deep extended (see ajaxExtend)
                flatOptions: {
                        url: true,
                        context: true
                }
        },

        // Creates a full fledged settings object into target
        // with both ajaxSettings and settings fields.
        // If target is omitted, writes into ajaxSettings.
        ajaxSetup: function( target, settings ) {
                return settings ?

                        // Building a settings object
                        ajaxExtend( ajaxExtend( target, jQuery.ajaxSettings ), settings ) :

                        // Extending ajaxSettings
                        ajaxExtend( jQuery.ajaxSettings, target );
        },

        ajaxPrefilter: addToPrefiltersOrTransports( prefilters ),
        ajaxTransport: addToPrefiltersOrTransports( transports ),

        // Main method
        ajax: function( url, options ) {

                // If url is an object, simulate pre-1.5 signature
                if ( typeof url === "object" ) {
                        options = url;
                        url = undefined;
                }

                // Force options to be an object
                options = options || {};

                var transport,

                        // URL without anti-cache param
                        cacheURL,

                        // Response headers
                        responseHeadersString,
                        responseHeaders,

                        // timeout handle
                        timeoutTimer,

                        // Url cleanup var
                        urlAnchor,

                        // Request state (becomes false upon send and true upon completion)
                        completed,

                        // To know if global events are to be dispatched
                        fireGlobals,

                        // Loop variable
                        i,

                        // uncached part of the url
                        uncached,

                        // Create the final options object
                        s = jQuery.ajaxSetup( {}, options ),

                        // Callbacks context
                        callbackContext = s.context || s,

                        // Context for global events is callbackContext if it is a DOM node or jQuery collection
                        globalEventContext = s.context &&
                                ( callbackContext.nodeType || callbackContext.jquery ) ?
                                jQuery( callbackContext ) :
                                jQuery.event,

                        // Deferreds
                        deferred = jQuery.Deferred(),
                        completeDeferred = jQuery.Callbacks( "once memory" ),

                        // Status-dependent callbacks
                        statusCode = s.statusCode || {},

                        // Headers (they are sent all at once)
                        requestHeaders = {},
                        requestHeadersNames = {},

                        // Default abort message
                        strAbort = "canceled",

                        // Fake xhr
                        jqXHR = {
                                readyState: 0,

                                // Builds headers hashtable if needed
                                getResponseHeader: function( key ) {
                                        var match;
                                        if ( completed ) {
                                                if ( !responseHeaders ) {
                                                        responseHeaders = {};
                                                        while ( ( match = rheaders.exec( responseHeadersString ) ) ) {

                                                                // Support: IE 11+
                                                                // `getResponseHeader( key )` in IE doesn't combine all header
                                                                // values for the provided key into a single result with values
                                                                // joined by commas as other browsers do. Instead, it returns
                                                                // them on separate lines.
                                                                responseHeaders[ match[ 1 ].toLowerCase() + " " ] =
                                                                        ( responseHeaders[ match[ 1 ].toLowerCase() + " " ] || [] )
                                                                                .concat( match[ 2 ] );
                                                        }
                                                }
                                                match = responseHeaders[ key.toLowerCase() + " " ];
                                        }
                                        return match == null ? null : match.join( ", " );
                                },

                                // Raw string
                                getAllResponseHeaders: function() {
                                        return completed ? responseHeadersString : null;
                                },

                                // Caches the header
                                setRequestHeader: function( name, value ) {
                                        if ( completed == null ) {
                                                name = requestHeadersNames[ name.toLowerCase() ] =
                                                        requestHeadersNames[ name.toLowerCase() ] || name;
                                                requestHeaders[ name ] = value;
                                        }
                                        return this;
                                },

                                // Overrides response content-type header
                                overrideMimeType: function( type ) {
                                        if ( completed == null ) {
                                                s.mimeType = type;
                                        }
                                        return this;
                                },

                                // Status-dependent callbacks
                                statusCode: function( map ) {
                                        var code;
                                        if ( map ) {
                                                if ( completed ) {

                                                        // Execute the appropriate callbacks
                                                        jqXHR.always( map[ jqXHR.status ] );
                                                } else {

                                                        // Lazy-add the new callbacks in a way that preserves old ones
                                                        for ( code in map ) {
                                                                statusCode[ code ] = [ statusCode[ code ], map[ code ] ];
                                                        }
                                                }
                                        }
                                        return this;
                                },

                                // Cancel the request
                                abort: function( statusText ) {
                                        var finalText = statusText || strAbort;
                                        if ( transport ) {
                                                transport.abort( finalText );
                                        }
                                        done( 0, finalText );
                                        return this;
                                }
                        };

                // Attach deferreds
                deferred.promise( jqXHR );

                // Add protocol if not provided (prefilters might expect it)
                // Handle falsy url in the settings object (trac-10093: consistency with old signature)
                // We also use the url parameter if available
                s.url = ( ( url || s.url || location.href ) + "" )
                        .replace( rprotocol, location.protocol + "//" );

                // Alias method option to type as per ticket trac-12004
                s.type = options.method || options.type || s.method || s.type;

                // Extract dataTypes list
                s.dataTypes = ( s.dataType || "*" ).toLowerCase().match( rnothtmlwhite ) || [ "" ];

                // A cross-domain request is in order when the origin doesn't match the current origin.
                if ( s.crossDomain == null ) {
                        urlAnchor = document.createElement( "a" );

                        // Support: IE <=8 - 11+
                        // IE throws exception on accessing the href property if url is malformed,
                        // e.g. http://example.com:80x/
                        try {
                                urlAnchor.href = s.url;

                                // Support: IE <=8 - 11+
                                // Anchor's host property isn't correctly set when s.url is relative
                                urlAnchor.href = urlAnchor.href;
                                s.crossDomain = originAnchor.protocol + "//" + originAnchor.host !==
                                        urlAnchor.protocol + "//" + urlAnchor.host;
                        } catch ( e ) {

                                // If there is an error parsing the URL, assume it is crossDomain,
                                // it can be rejected by the transport if it is invalid
                                s.crossDomain = true;
                        }
                }

                // Apply prefilters
                inspectPrefiltersOrTransports( prefilters, s, options, jqXHR );

                // Convert data if not already a string
                if ( s.data && s.processData && typeof s.data !== "string" ) {
                        s.data = jQuery.param( s.data, s.traditional );
                }

                // If request was aborted inside a prefilter, stop there
                if ( completed ) {
                        return jqXHR;
                }

                // We can fire global events as of now if asked to
                // Don't fire events if jQuery.event is undefined in an ESM-usage scenario (trac-15118)
                fireGlobals = jQuery.event && s.global;

                // Watch for a new set of requests
                if ( fireGlobals && jQuery.active++ === 0 ) {
                        jQuery.event.trigger( "ajaxStart" );
                }

                // Uppercase the type
                s.type = s.type.toUpperCase();

                // Determine if request has content
                s.hasContent = !rnoContent.test( s.type );

                // Save the URL in case we're toying with the If-Modified-Since
                // and/or If-None-Match header later on
                // Remove hash to simplify url manipulation
                cacheURL = s.url.replace( rhash, "" );

                // More options handling for requests with no content
                if ( !s.hasContent ) {

                        // Remember the hash so we can put it back
                        uncached = s.url.slice( cacheURL.length );

                        // If data is available and should be processed, append data to url
                        if ( s.data && ( s.processData || typeof s.data === "string" ) ) {
                                cacheURL += ( rquery.test( cacheURL ) ? "&" : "?" ) + s.data;

                                // trac-9682: remove data so that it's not used in an eventual retry
                                delete s.data;
                        }

                        // Add or update anti-cache param if needed
                        if ( s.cache === false ) {
                                cacheURL = cacheURL.replace( rantiCache, "$1" );
                                uncached = ( rquery.test( cacheURL ) ? "&" : "?" ) + "_=" +
                                        ( nonce.guid++ ) + uncached;
                        }

                        // Put hash and anti-cache on the URL that will be requested (gh-1732)
                        s.url = cacheURL + uncached;

                // Change '%20' to '+' if this is encoded form body content (gh-2658)
                } else if ( s.data && s.processData &&
                        ( s.contentType || "" ).indexOf( "application/x-www-form-urlencoded" ) === 0 ) {
                        s.data = s.data.replace( r20, "+" );
                }

                // Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
                if ( s.ifModified ) {
                        if ( jQuery.lastModified[ cacheURL ] ) {
                                jqXHR.setRequestHeader( "If-Modified-Since", jQuery.lastModified[ cacheURL ] );
                        }
                        if ( jQuery.etag[ cacheURL ] ) {
                                jqXHR.setRequestHeader( "If-None-Match", jQuery.etag[ cacheURL ] );
                        }
                }

                // Set the correct header, if data is being sent
                if ( s.data && s.hasContent && s.contentType !== false || options.contentType ) {
                        jqXHR.setRequestHeader( "Content-Type", s.contentType );
                }

                // Set the Accepts header for the server, depending on the dataType
                jqXHR.setRequestHeader(
                        "Accept",
                        s.dataTypes[ 0 ] && s.accepts[ s.dataTypes[ 0 ] ] ?
                                s.accepts[ s.dataTypes[ 0 ] ] +
                                        ( s.dataTypes[ 0 ] !== "*" ? ", " + allTypes + "; q=0.01" : "" ) :
                                s.accepts[ "*" ]
                );

                // Check for headers option
                for ( i in s.headers ) {
                        jqXHR.setRequestHeader( i, s.headers[ i ] );
                }

                // Allow custom headers/mimetypes and early abort
                if ( s.beforeSend &&
                        ( s.beforeSend.call( callbackContext, jqXHR, s ) === false || completed ) ) {

                        // Abort if not done already and return
                        return jqXHR.abort();
                }

                // Aborting is no longer a cancellation
                strAbort = "abort";

                // Install callbacks on deferreds
                completeDeferred.add( s.complete );
                jqXHR.done( s.success );
                jqXHR.fail( s.error );

                // Get transport
                transport = inspectPrefiltersOrTransports( transports, s, options, jqXHR );

                // If no transport, we auto-abort
                if ( !transport ) {
                        done( -1, "No Transport" );
                } else {
                        jqXHR.readyState = 1;

                        // Send global event
                        if ( fireGlobals ) {
                                globalEventContext.trigger( "ajaxSend", [ jqXHR, s ] );
                        }

                        // If request was aborted inside ajaxSend, stop there
                        if ( completed ) {
                                return jqXHR;
                        }

                        // Timeout
                        if ( s.async && s.timeout > 0 ) {
                                timeoutTimer = window.setTimeout( function() {
                                        jqXHR.abort( "timeout" );
                                }, s.timeout );
                        }

                        try {
                                completed = false;
                                transport.send( requestHeaders, done );
                        } catch ( e ) {

                                // Rethrow post-completion exceptions
                                if ( completed ) {
                                        throw e;
                                }

                                // Propagate others as results
                                done( -1, e );
                        }
                }

                // Callback for when everything is done
                function done( status, nativeStatusText, responses, headers ) {
                        var isSuccess, success, error, response, modified,
                                statusText = nativeStatusText;

                        // Ignore repeat invocations
                        if ( completed ) {
                                return;
                        }

                        completed = true;

                        // Clear timeout if it exists
                        if ( timeoutTimer ) {
                                window.clearTimeout( timeoutTimer );
                        }

                        // Dereference transport for early garbage collection
                        // (no matter how long the jqXHR object will be used)
                        transport = undefined;

                        // Cache response headers
                        responseHeadersString = headers || "";

                        // Set readyState
                        jqXHR.readyState = status > 0 ? 4 : 0;

                        // Determine if successful
                        isSuccess = status >= 200 && status < 300 || status === 304;

                        // Get response data
                        if ( responses ) {
                                response = ajaxHandleResponses( s, jqXHR, responses );
                        }

                        // Use a noop converter for missing script but not if jsonp
                        if ( !isSuccess &&
                                jQuery.inArray( "script", s.dataTypes ) > -1 &&
                                jQuery.inArray( "json", s.dataTypes ) < 0 ) {
                                s.converters[ "text script" ] = function() {};
                        }

                        // Convert no matter what (that way responseXXX fields are always set)
                        response = ajaxConvert( s, response, jqXHR, isSuccess );

                        // If successful, handle type chaining
                        if ( isSuccess ) {

                                // Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
                                if ( s.ifModified ) {
                                        modified = jqXHR.getResponseHeader( "Last-Modified" );
                                        if ( modified ) {
                                                jQuery.lastModified[ cacheURL ] = modified;
                                        }
                                        modified = jqXHR.getResponseHeader( "etag" );
                                        if ( modified ) {
                                                jQuery.etag[ cacheURL ] = modified;
                                        }
                                }

                                // if no content
                                if ( status === 204 || s.type === "HEAD" ) {
                                        statusText = "nocontent";

                                // if not modified
                                } else if ( status === 304 ) {
                                        statusText = "notmodified";

                                // If we have data, let's convert it
                                } else {
                                        statusText = response.state;
                                        success = response.data;
                                        error = response.error;
                                        isSuccess = !error;
                                }
                        } else {

                                // Extract error from statusText and normalize for non-aborts
                                error = statusText;
                                if ( status || !statusText ) {
                                        statusText = "error";
                                        if ( status < 0 ) {
                                                status = 0;
                                        }
                                }
                        }

                        // Set data for the fake xhr object
                        jqXHR.status = status;
                        jqXHR.statusText = ( nativeStatusText || statusText ) + "";

                        // Success/Error
                        if ( isSuccess ) {
                                deferred.resolveWith( callbackContext, [ success, statusText, jqXHR ] );
                        } else {
                                deferred.rejectWith( callbackContext, [ jqXHR, statusText, error ] );
                        }

                        // Status-dependent callbacks
                        jqXHR.statusCode( statusCode );
                        statusCode = undefined;

                        if ( fireGlobals ) {
                                globalEventContext.trigger( isSuccess ? "ajaxSuccess" : "ajaxError",
                                        [ jqXHR, s, isSuccess ? success : error ] );
                        }

                        // Complete
                        completeDeferred.fireWith( callbackContext, [ jqXHR, statusText ] );

                        if ( fireGlobals ) {
                                globalEventContext.trigger( "ajaxComplete", [ jqXHR, s ] );

                                // Handle the global AJAX counter
                                if ( !( --jQuery.active ) ) {
                                        jQuery.event.trigger( "ajaxStop" );
                                }
                        }
                }

                return jqXHR;
        },

        getJSON: function( url, data, callback ) {
                return jQuery.get( url, data, callback, "json" );
        },

        getScript: function( url, callback ) {
                return jQuery.get( url, undefined, callback, "script" );
        }
} );

jQuery.each( [ "get", "post" ], function( _i, method ) {
        jQuery[ method ] = function( url, data, callback, type ) {

                // Shift arguments if data argument was omitted.
                // Handle the null callback placeholder.
                if ( typeof data === "function" || data === null ) {
                        type = type || callback;
                        callback = data;
                        data = undefined;
                }

                // The url can be an options object (which then must have .url)
                return jQuery.ajax( jQuery.extend( {
                        url: url,
                        type: method,
                        dataType: type,
                        data: data,
                        success: callback
                }, jQuery.isPlainObject( url ) && url ) );
        };
} );

jQuery.ajaxPrefilter( function( s ) {
        var i;
        for ( i in s.headers ) {
                if ( i.toLowerCase() === "content-type" ) {
                        s.contentType = s.headers[ i ] || "";
                }
        }
} );

export default jQuery;