toJSON 方法如何导出指定的属性，如Height？

[Shugonghua]

目的：创建Ract组件，toJSON导出结果中希望有height、width属性

import { Leafer, Image, Platform } from 'leafer-ui'

const leafer = new Leafer({ view: window })

const svg = `
<svg width="48" height="24" xmlns="http://www.w3.org/2000/svg">
<g>
<path d="M7.5 8.0H8.5V5.9L6.8 7.2L7.5 8.0ZM3 11.4L2.3 10.6L1.3 11.4L2.3 12.2L3 11.4ZM7.5 10.4H6.5V11.4H7.5V10.4ZM16.5 10.4V11.4H17.5V10.4H16.5ZM16.5 8.0L17.1 7.2L15.5 5.9V8.0H16.5ZM21 11.4L21.6 12.2L22.6 11.4L21.6 10.6L21 11.4ZM16.5 14.9H15.5V16.9L17.1 15.7L16.5 14.9ZM16.5 12.4H17.5V11.4H16.5V12.4ZM7.5 12.4V11.4H6.5V12.4H7.5ZM7.5 14.9L6.8 15.7L8.5 16.9V14.9H7.5ZM6.8 7.2L2.3 10.6L3.6 12.2L8.1 8.7L6.8 7.2ZM8.5 10.4V8.0H6.5V10.4H8.5ZM16.5 9.4H7.5V11.4H16.5V9.4ZM17.5 10.4V8.0H15.5V10.4H17.5ZM15.8 8.7L20.3 12.2L21.6 10.6L17.1 7.2L15.8 8.7ZM20.3 10.6L15.8 14.1L17.1 15.7L21.6 12.2L20.3 10.6ZM17.5 14.9V12.4H15.5V14.9H17.5ZM7.5 13.4H16.5V11.4H7.5V13.4ZM8.5 14.9V12.4H6.5V14.9H8.5ZM2.3 12.2L6.8 15.7L8.1 14.1L3.6 10.6L2.3 12.2Z" fill="white"/>
<path fill-rule="evenodd" d="M3 11.4L7.5 8.0V10.4H16.5V8.0L21 11.4L16.5 14.9V12.4H7.5V14.9L3 11.4Z" fill="black"/>
</g>
</svg>`

const image = new Image({
    url: Platform.toURL(svg, 'svg'),
    draggable: true
})

leafer.add(image)
console.log("数据导出:",leafer.toJson());

[leaferjs]

重写一下Image元素的toJSON方法，待图片加载完成后，可以通过image.width / image.height获取到，在重写的toJSON方法中设置到返回数据上即可。