我最近在使用jquery Fancy产品设计器时遇到了以下问题。我想使用产品价格进行计算，但我找不到方法。
代码为：
//价格变动时的事件处理程序

$('#clothing-designer').bind('priceChange', function(evt, price, currentPrice) {
    $('#thsirt-price').text(currentPrice);
});

HTML为：

<div class="col-md-3">
PRICE <span class="price badge badge-inverse"><span id="thsirt-price"></span> €</span>
</div>

如何以数字形式获取价格？
额外的代码是

FancyProductDesigner.prototype.removeElement = function(element) {
    if(typeof element === 'string') {
        element = thisClass.getElementByTitle(element);
    }
    if(element.params.price != 0 && !element.params.uploadZone) {
        currentPrice -= element.params.price;
        $elem.trigger('priceChange', [element.params.price, currentPrice]);
    }
    $contextDialog.find('.fpd-content-layers .fpd-list').children('[id="'+element.id+'"]').remove();
    stage.remove(element);
    if(element.params.hasUploadZone) {
        //check if upload zone contains objects
        var objects = stage.getObjects(),
            uploadZoneEmpty = true;
        for(var i=0; i < objects.length; ++i) {
            var object = objects[i];
            if(object.visible && object.params.replace == element.params.replace) {
                uploadZoneEmpty = false;
                break;
            }
        }
        var uploadZoneObject = _getUploadZone(element.params.replace);
        uploadZoneObject.opacity = uploadZoneEmpty ? 1 : 0;
    }
    /**
     * Gets fired as soon as an element has been removed.
     *
     * @event FancyProductDesigner#elementRemove
     * @param {Event} event
     * @param {fabric.Object} element - The fabric object that has been removed.
     */
    $elem.trigger('elementRemove', [element]);
    thisClass.deselectElement();
};
/**
 * Returns an fabric object by title.
 * @param {string} title The title of an element.
 */
FancyProductDesigner.prototype.getElementByTitle = function(title) {
    var objects = stage.getObjects();
    for(var i = 0; i < objects.length; ++i) {
        if(objects[i].title == title) {
            return objects[i];
            break;
        }
    }
};
/**
 * Sets the zoom of the stage. 1 is equal to no zoom.
 * @param {number} value The zoom value.
 */
FancyProductDesigner.prototype.setZoom = function(value) {
    thisClass.deselectElement();
    var point = new fabric.Point(stage.getWidth() * 0.5, stage.getHeight() * 0.5);
    stage.zoomToPoint(point, value);
    if(value == 1) {
        thisClass.resetZoom();
    }
};
/**
 * Resets the zoom.
 */
FancyProductDesigner.prototype.resetZoom = function() {
    thisClass.deselectElement();
    stage.zoomToPoint(new fabric.Point(0, 0), 1);
    stage.absolutePan(new fabric.Point(0, 0));
};
/**
 * Sets the dimensions of the stage(canvas). todo: check
 * @param {number} width The width for the stage.
 * @param {number} height The height for the stage.
 */
FancyProductDesigner.prototype.setStageDimensions = function(width, height) {
    options.width = width;
    options.stageHeight = height;
    $elem.width(width);
    $productStage.height(height * responsiveScale);
    stage.setDimensions({width: $elem.width(), height: options.stageHeight * responsiveScale})
    .calcOffset().renderAll();
    _refreshDesignerSize();
};
/**
 * Shows a message in the snackbar.
 * @param {string} text The text for the message.
 */
FancyProductDesigner.prototype.showMessage = function(text) {
    var $snackbar;
    if($body.children('.fpd-snackbar-internal').size() > 0) {
        $snackbar = $body.children('.fpd-snackbar');
    }
    else {
        $snackbar = $body.append('<div class="fpd-snackbar-internal fpd-snackbar fpd-shadow-1"><p></p></div>').children('.fpd-snackbar-internal');
    }
    $snackbar.removeClass('fpd-show-up').children('p').html(text).parent().addClass('fpd-show-up');
    setTimeout(function() {
        $snackbar.removeClass('fpd-show-up');
    }, 3000);
};
/**
 * Calls a specified content in the context dialog.
 * @param {string} target An unique target name. Possible values: 'layers', 'adds', 'products', 'saved-products', 'edit'.
 * @param {string} title The title for the context dialog, which appears in the head of the context dialog.
 * @param {string} [subTarget] An unique sub-target name. The 'adds' dialog has following sub-dialogs: 'facebook', 'instagram', 'designs'.
 * @param {boolean} [deselectElement] Deselects the current selected element.
 */
FancyProductDesigner.prototype.callDialogContent = function(target, title, subTarget, deselectElement) {
    subTarget = typeof subTarget !== 'undefined' ? subTarget : null;
    deselectElement = typeof deselectElement !== 'undefined' ? deselectElement : true;
    if(deselectElement) {
        thisClass.deselectElement();
    }
    //hide sub contents
    $contextDialog.find('.fpd-content-sub.fpd-show').removeClass('fpd-show');
    //hide content-back button
    $contextDialog.find('.fpd-content-back').removeClass('fpd-show');
    //get target div
    var $target = $contextDialog.find('.fpd-dialog-content .fpd-content-'+target);
    if($target.is(':hidden')) {
        $target.siblings('div').stop().hide()
        //show requested content div
        $target.stop().fadeIn(300);
    }
    $contextDialog.show();
    //lazy load for products
    if(target == 'products' && options.lazyLoad) {
        $currentLazyLoadContainer = $target;
        _refreshLazyLoad(false);
    }
    if(subTarget) {
        var $subTarget = $contextDialog.find('.fpd-content-sub[data-subContext="'+subTarget+'"]').addClass('fpd-show');
        $contextDialog.find('.fpd-content-back').data('parentTitle', $contextDialog.find('.fpd-dialog-title').text())
        .addClass('fpd-show');
        //lazy load for designs
        $currentLazyLoadContainer = null;
        if(subTarget == 'designs' && options.lazyLoad) {
            $currentLazyLoadContainer = $subTarget;
            _refreshLazyLoad(false);
        }
    }
    _setDialogTitle(title);
};
/**
 * Defines the current upload zone by using the title of a visible upload zone.
 * @param {string} title The title of a visible upload zone.
 */
FancyProductDesigner.prototype.setUploadZone = function(title) {
    currentUploadZone = title;
    thisClass.closeDialog();
};
/**
 * Closes the context dialog box
 */
FancyProductDesigner.prototype.closeDialog = function() {
    $contextDialog.hide();
    $colorPicker.find('input').spectrum('hide');
    $currentLazyLoadContainer = null;
    currentUploadZone = null;
};
/**
 * Defines a clipping rectangle for an element.
 * @param {fabric.Object | string} element A fabric object or the title of an element.
 * @param {object} clippingRect Ob object containg x, y, width and height values to define the rectangle.
 * @example
 * yourDesigner.setClippingRect("Element Title", {x: 100, y: 200, width: 300, height: 400});
 * @version 3.0.2
 */
FancyProductDesigner.prototype.setClippingRect = function(element, clippingRect) {
    //if element is string, get by title
    if(typeof element == 'string') {
        element = thisClass.getElementByTitle(element);
    }
    element.clippingRect = clippingRect;
    stage.renderAll();
};
/**
 * Sets the parameters for a specified element.
 * @param {fabric.Object | string} element A fabric object or the title of an element.
 * @param {object} parameters An object with the parameters that should be applied to the element.
 */
FancyProductDesigner.prototype.setElementParameters = function(element, parameters) {
    if(element === undefined || parameters === undefined) {
        return false;
    }
    //if element is string, get by title
    if(typeof element == 'string') {
        element = thisClass.getElementByTitle(element);
    }
    //store undos
    if(productCreated) {
        var oldParameters = {};
        for (var key in parameters) {
            oldParameters[key] = element.params[key];
        }
        undos.push({element: element, parameters: oldParameters});
    }
    //adds the element into a upload zone
    if(currentUploadZone && currentUploadZone != '') {
        parameters.z = -1;
        var uploadZoneObj = thisClass.getElementByTitle(currentUploadZone),
            bbRect = uploadZoneObj.getBoundingRect();
        $.extend(parameters, {
                boundingBox: currentUploadZone,
                scale: thisClass.getScalingByDimesions(element.getWidth(), element.getHeight(), (bbRect.width / responsiveScale)-1, (bbRect.height / responsiveScale)-1),
                autoCenter: true,
                removable: true,
                zChangeable: false,
                rotatable: uploadZoneObj.params.rotatable,
                draggable: uploadZoneObj.params.draggable,
                resizable: uploadZoneObj.params.resizable,
                price: uploadZoneObj.params.price,
                replace: currentUploadZone,
                hasUploadZone: true
            }
        );
        uploadZoneObj.opacity = 0;
    }
    //check if a upload zone contains an object
    var objects = stage.getObjects();
    for(var i=0; i < objects.length; ++i) {
        var object = objects[i];
        if(object.params && object.params.uploadZone && object.title == parameters.replace) {
            object.opacity = 0;
        }
    }
    //if topped, z-index can not be changed
    if(parameters.topped) {
        parameters.zChangeable = false;
    }
    //new element added
    if( typeof parameters.colors === 'object' ||
        parameters.removable ||
        parameters.draggable ||
        parameters.resizable ||
        parameters.rotatable ||
        parameters.zChangeable ||
        parameters.editable ||
        parameters.patternable
        || parameters.uploadZone) {
        element.isEditable = element.evented = true;
        element.set('selectable', true);
        if(element.viewIndex == currentViewIndex && $contextDialog.find('.fpd-content-layers .fpd-list-row[id="'+element.id+'"]').size() == 0) {
            _appendLayerItem(element.id, element.title, parameters.zChangeable, parameters.removable, parameters.uploadZone, !element.evented);
        }
    }
    if(parameters.opacity !== undefined) {
        element.set('opacity', parameters.opacity);
        //needs to be called for curved text
        if(element.params.curved) {
            element.setFill(element.fill);
        }
    }
    //upload zones have no controls
    if(!parameters.uploadZone || options.editorMode) {
        if(parameters.draggable) {
            element.lockMovementX = element.lockMovementY = false;
        }
        if(parameters.rotatable) {
            element.lockRotation = false;
        }
        if(parameters.resizable) {
            element.lockScalingX = element.lockScalingY = false;
        }
        if((parameters.resizable || parameters.rotatable || parameters.removable)) {
            element.hasControls = true;
        }
    }
    if(parameters.originX) {
        element.setOriginX(parameters.originX);
    }
    if(parameters.originY) {
        element.setOriginY(parameters.originY);
    }
    if(parameters.x !== undefined) {
        element.set('left', parameters.x);
    }
    if(parameters.y !== undefined) {
        element.set('top', parameters.y);
    }
    if(parameters.scale !== undefined) {
        element.set('scaleX', parameters.scale);
        element.set('scaleY', parameters.scale);
    }
    if(parameters.degree !== undefined) {
        element.set('angle', parameters.degree);
    }
    //replace element
    if(parameters.replace && parameters.replace != '' && element.viewIndex === currentViewIndex) {
        var objects = stage.getObjects();
        for(var i = 0; i < objects.length; ++i) {
            var object = objects[i];
            if(object.params != undefined && object.clipFor == undefined && object.params.replace == parameters.replace && object.visible && element !== object) {
                parameters.z = _getZIndex(object);
                parameters.x = object.params.x;
                parameters.y = object.params.y;
                parameters.autoCenter = false;
                thisClass.removeElement(object);
                break;
            }
        }
    }
    //center element
    if(parameters.autoCenter) {
        _doCentering(element);
    }
    if(parameters.flipX !== undefined) {
        element.set('flipX', parameters.flipX);
    }
    if(parameters.flipY !== undefined) {
        element.set('flipY', parameters.flipY);
    }
    if(parameters.price && !parameters.uploadZone) {
        currentPrice += parameters.price;
        /**
         * Gets fired as soon as the price has changed.
         *
         * @event FancyProductDesigner#priceChange
         * @param {Event} event
         * @param {number} elementPrice - The price of the element.
         * @param {number} totalPrice - The total price.
         */
        $elem.trigger('priceChange', [parameters.price, currentPrice]);
    }
    //change element color
    if(parameters.currentColor !== undefined && parameters.pattern == null) {
        _changeColor(element, parameters.currentColor);
    }
    //set pattern
    if(parameters.pattern !== undefined) {
        _setPattern(element, parameters.pattern);
    }
    //set filter
    if(parameters.filter) {
        element.filters = [];
        var fabricFilter = _getFabircFilter(parameters.filter);
        if(fabricFilter != null) {
            element.filters.push(fabricFilter);
        }
        element.applyFilters(function() {
            stage.renderAll();
            $body.mouseup();
        });
    }