上传文件校验格式

<script type="text/javascript">
    function fileChange(target) {
        var name=target.value;
        var fileName = name.substring(name.lastIndexOf(".")+1).toLowerCase();
        if(fileName !=="doc" && fileName !=="docx" && fileName !== 'xlsx' && fileName !== 'xls' && fileName !== 'jpg' && fileName !=='png'){
            toastr.error("请选择doc/docx/xlsx/xls等格式的文件");
            target.value="";
            return false;   //阻止submit提交
        }
    }
    (function($) {
        $.fn.ajaxfileupload = function(options) {
            var settings = {
                params: {},
                action: '',
                onStart: function() { },
                onComplete: function(response) { },
                onCancel: function() { },
                validate_extensions : true,
                valid_extensions : ['doc','docx','xlsx','xls','jpg','png'],
                submit_button : null
            };

            var uploading_file = false;

            if ( options ) {
                $.extend( settings, options );
            }


            // 'this' is a jQuery collection of one or more (hopefully)
            //  file elements, but doesn't check for this yet
            return this.each(function() {
                var $element = $(this);

                // Skip elements that are already setup. May replace this
                //  with uninit() later, to allow updating that settings
                if($element.data('ajaxUploader-setup') === true) return;

                $element.change(function()
                {
                    // since a new image was selected, reset the marker
                    uploading_file = false;

                    // only update the file from here if we haven't assigned a submit button
                    if (settings.submit_button == null)
                    {
                        upload_file();
                    }
                });

                if (settings.submit_button == null)
                {
                    // do nothing
                } else
                {
                    settings.submit_button.click(function(e)
                    {
                        // Prevent non-AJAXy submit
                        e.preventDefault();

                        // only attempt to upload file if we're not uploading
                        if (!uploading_file)
                        {
                            upload_file();
                        }
                    });
                }

                var upload_file = function()
                {
                    if($element.val() == '') return settings.onCancel.apply($element, [settings.params]);

                    // make sure extension is valid
                    var ext = $element.val().split('.').pop().toLowerCase();
                    if(true === settings.validate_extensions && $.inArray(ext, settings.valid_extensions) == -1)
                    {
                        // Pass back to the user
                        settings.onComplete.apply($element, [{status: false, message: 'The select file type is invalid. File must be ' + settings.valid_extensions.join(', ') + '.'}, settings.params]);
                    } else
                    {
                        uploading_file = true;

                        // Creates the form, extra inputs and iframe used to
                        //  submit / upload the file
                        wrapElement($element);

                        // Call user-supplied (or default) onStart(), setting
                        //  it's this context to the file DOM element
                        var ret = settings.onStart.apply($element, [settings.params]);

                        // let onStart have the option to cancel the upload
                        if(ret !== false)
                        {
                            $element.parent('form').submit(function(e) { e.stopPropagation(); }).submit();
                        } else {
                            uploading_file = false;
                        }
                    }
                };

                // Mark this element as setup
                $element.data('ajaxUploader-setup', true);

                /*
                // Internal handler that tries to parse the response
                //  and clean up after ourselves.
                */
                var handleResponse = function(loadedFrame, element) {
                    var response, responseStr = $(loadedFrame).contents().text();
                    try {
                        //response = $.parseJSON($.trim(responseStr));
                        response = JSON.parse(responseStr);
                    } catch(e) {
                        response = responseStr;
                    }

                    // Tear-down the wrapper form
                    element.siblings().remove();
                    element.unwrap();

                    uploading_file = false;

                    // Pass back to the user
                    settings.onComplete.apply(element, [response, settings.params]);
                };

                /*
                // Wraps element in a <form> tag, and inserts hidden inputs for each
                //  key:value pair in settings.params so they can be sent along with
                //  the upload. Then, creates an iframe that the whole thing is
                //  uploaded through.
                */
                var wrapElement = function(element) {
                    // Create an iframe to submit through, using a semi-unique ID
                    var frame_id = 'ajaxUploader-iframe-' + Math.round(new Date().getTime() / 1000)
                    $('body').after('<iframe width="0" height="0" style="display:none;" name="'+frame_id+'" id="'+frame_id+'"/>');
                    $('#'+frame_id).get(0).onload = function() {
                        handleResponse(this, element);
                    };

                    // Wrap it in a form
                    element.wrap(function() {
                        return '<form action="' + settings.action + '" method="POST" enctype="multipart/form-data" target="'+frame_id+'" />'
                    })
                        // Insert <input type='hidden'>'s for each param
                        .before(function() {
                            var key, html = '';
                            for(key in settings.params) {
                                var paramVal = settings.params[key];
                                if (typeof paramVal === 'function') {
                                    paramVal = paramVal();
                                }
                                html += '<input type="hidden" name="' + key + '" value="' + paramVal + '" />';
                            }
                            return html;
                        });
                }
            });
        }
    })( jQuery )
    $('#analysisLogFile').ajaxfileupload({
        action: '/upload_log_object',
        valid_extensions : ['doc','docx','xlsx','xls','jpg','png'],
        params: {
            extra: 'info'
        },
        onComplete: function(response) {
            $("#analysisLogFilePath").attr("value",response.filePath);
        },
        onStart: function() {
            return true; // cancels upload
        },
        onCancel: function() {
            console.log('no file selected');
        }
    });

</script>