javascript - 由于 json 中的字体样式对象，fabric js 粗体斜体不起作用

Question

我在 fabric js 中面临 1 个典型问题，我正在使用 canvas.toJson 将 Canvas 转换为 json 并将其保存到数据库中。稍后我使用 loadFromJSON 将该 json 加载到 Canvas 中，一切正常。

现在的问题是，我有很多层的 json，一层是文本框，它有一些字体样式，所以该层的 json 就像，

 {
     "type":"textbox",
     "originX":"center",
     "originY":"top",
     "left":1200.84,
     "top":573.63,
     "width":312.81,
     "height":127.46,
     "fill":"rgb(0, 0, 0)",
     "stroke":null,
     "strokeWidth":1,
     "strokeDashArray":null,
     "strokeLineCap":"butt",
     "strokeLineJoin":"miter",
     "strokeMiterLimit":10,
     "scaleX":1,
     "scaleY":1,
     "angle":0,
     "flipX":false,
     "flipY":false,
     "opacity":1,
     "shadow":null,
     "visible":true,
     "clipTo":null,
     "backgroundColor":"",
     "fillRule":"nonzero",
     "globalCompositeOperation":"source-over",
     "transformMatrix":null,
     "lockMovementX":false,
     "lockMovementY":false,
     "evented":true,
     "overrideSecondary":1,
     "text":"NATURAL\nVENEERS",
     "fontSize":63,
     "fontWeight":"",
     "fontFamily":"'trebuchet ms'",
     "fontStyle":"",
     "lineHeight":0.9,
     "textDecoration":"",
     "textAlign":"left",
     "textBackgroundColor":"",
     "styles":{
        "0":{
           "0":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "1":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "2":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "3":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "4":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "5":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "6":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "7":{
              "fontSize":62.666651
           }
        },
        "1":{
           "0":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "1":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "2":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "3":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "4":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "5":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           },
           "6":{
              "fontSize":62.666651,
              "fontFamily":"'trebuchet ms'",
              "fontWeight":"",
              "fontStyle":""
           }
        }
     },
     "minWidth":20
  },

加载 json 后，我使用这段代码实现了粗体和斜体效果。

canvas.getActiveObject().set("fontWeight", "bold");
canvas.renderAll();

这是可行的，但是当我这样做时，

canvas.getActiveObject().set("fontWeight", "");
canvas.getActiveObject().set("fontWeight", "100");
canvas.getActiveObject().set("fontWeight", "normal");

它不会工作。经过一番调查后，我可以确定 json 中的 styles 属性导致了问题，如果我使用此代码从主 json 对象中删除样式，

delete index['styles'];

粗体、斜体 和普通 文本适合我。在删除 styles 之前和之后查看它的行为 HERE .

可能的解决方案是什么？

Answer 1

截至目前，当前的 fabricjs 版本存在此问题。

每次设置一个新的 fontWeight 属性时，您只需删除它即可。

例子:

function cleanFontWeightStyle(obj) {
    if (obj.styles) {
        var style = obj.styles;
        for (rowIndex in style) {
            var row = style[rowIndex];
            for (letterIndex in row) {
                letter = row[letterIndex];
                if (letter.fontWeight && letter.fontWeight=='') {
                    delete letter['fontWeight'];
                }
            }
        }
    }
}

丑陋的。这应该在库本身中修复，不应创建无意义的样式对象。