[Bug]: When I have a custom attribute with "type" in it, I get an error Error: fabric: No class registered for any

[hqw567]

CheckList

• I agree to follow this project's Code of Conduct
• I have read and followed the Contributing Guide
• I have read and followed the Issue Tracker Guide
• I have searched and referenced existing issues and discussions
• I am filing a BUG report.
• I have managed to reproduce the bug after upgrading to the latest version
• I have created an accurate and minimal reproduction

Version

6.0.2

In What environments are you experiencing the problem?

Chrome

Node Version (if applicable)

None

Link To Reproduction

https://github.com/hqw567/fabric-issues-react

Steps To Reproduce

1. Custom attributes contain "type"

Expected Behavior

Custom attributes contain any attributes without error

Actual Behavior

When I have a custom attribute with "type" in it, I get an error Error: fabric: No class registered for any

Error Message & Stack Trace

No response

[hqw567]

import * as fabric from 'fabric'
import { useEffect, useRef } from 'react'
import dataJson from './data.json'
const App = () => {
  const canvasRef = useRef()

  useEffect(() => {
    if (!canvasRef.current) return
    const canvas = new fabric.Canvas(canvasRef.current)

    dataJson.objects.forEach((item) => {
      // issues 1: When I have a custom attribute with "type" in it, I get an error `Error: fabric: No class registered for any`
      //
      // Comment the following code to see the error
      delete item.myData.type
    })

    // issues 2: When using it in react, there will still be an error message `TypeError: Cannot read properties of undefined (reading 'clearRect')`
    canvas.loadFromJSON(dataJson).then(() => {
      canvas.requestRenderAll()
    })
    return () => {
      canvas.dispose()
    }
  }, [])

  return (
    <canvas
      width={document.body.clientWidth}
      height={document.body.clientHeight}
      ref={canvasRef}
    />
  )
}

export default App

[zhe-he]

fabric.js/src/util/misc/objectEnlive.ts

Lines 158 to 166 in 8219e92

	// clipPath or shadow or gradient
	if (value.type) {
	return enlivenObjects<FabricObject | Shadow | TFiller>([value], {
	signal,
	}).then(([enlived]) => {
	instances.push(enlived);
	return enlived;
	});
	}

bug1: The issue here is that during import, it loops through each property and checks if it is an object. If it is, it then checks for a type. Hmm... I think the source code should add an error check.

bug2: The issue is with asynchronous operations. You can solve it by making the following modifications.

const controller = new AbortController(); 
canvas.loadFromJSON(dataJson, undefined, { signal: controller.signal }).then(() => {
      canvas.requestRenderAll()
}).catch(e => {
      console.error(e.message ?? "aborted");
});
return () => {
      controller.abort();
      canvas.dispose()
}
// let flag = false;
// canvas.loadFromJSON(dataJson).then(() => {
      // if (flag) return false;
      // canvas.requestRenderAll();
// })
// return () => {
//      flag = true;
//      canvas.dispose()
// }

[hqw567]

@zhe-he Thanks for the reply, but issues 1 is still not solved in the latest version.
myData.type
When I have a custom attribute with "type" in it, I get an error Error: fabric: No class registered for any

[hqw567]

@zhe-he View online

[zhe-he]

@hqw567
The second-to-last commit's code is good, but the last commit's code was reverted, and the main branch merged the reverted code. So I am also quite confused.

[asturur]

let me see maybe i misunderstood how i used the class registry

[asturur]

Yes sorry i should have added 'hasClass' rather than getClass. I ll fix it quickly

[asturur]

#10039

[hqw567]

@asturur I have upgraded to v6.2.0, The problem is still not solved. There is a new error reported when my custom attribute "myData": { "type": "text" }

 Uncaught TypeError: Cannot read properties of undefined (reading 'split')
  at _Io._splitTextIntoLines (fabric.js?v=32e06e8c:5297:19)
  at _Io._splitText (fabric.js?v=32e06e8c:5007:21)
  at _Io.initDimensions (fabric.js?v=32e06e8c:5011:10)
  at new _Io (fabric.js?v=32e06e8c:5000:216)
  at fabric.js?v=32e06e8c:2155:16
  at async Promise.all (/index 0)
  at async Promise.all (/index 49)
  at async Promise.all (/index 0)
  at async Promise.all (/index 0)

[hqw567]

{
  "version": "6.0.2",
  "objects": [
    {
      "fontSize": 50,
      "fontWeight": "normal",
      "fontFamily": "Times New Roman",
      "fontStyle": "normal",
      "lineHeight": 1.16,
      "text": "fabric issues",
      "charSpacing": 0,
      "textAlign": "left",
      "styles": [],
      "pathStartOffset": 0,
      "pathSide": "left",
      "pathAlign": "baseline",
      "underline": false,
      "overline": false,
      "linethrough": false,
      "textBackgroundColor": "",
      "direction": "ltr",
      "minWidth": 20,
      "splitByGrapheme": false,
      "type": "Textbox",
      "version": "6.0.2",
      "originX": "left",
      "originY": "top",
      "left": 50,
      "top": 50,
      "width": 119.458,
      "height": 122.04,
      "fill": "black",
      "stroke": null,
      "strokeWidth": 1,
      "strokeDashArray": null,
      "strokeLineCap": "butt",
      "strokeDashOffset": 0,
      "strokeLineJoin": "miter",
      "strokeUniform": false,
      "strokeMiterLimit": 4,
      "scaleX": 1,
      "scaleY": 1,
      "angle": 0,
      "flipX": false,
      "flipY": false,
      "opacity": 1,
      "shadow": null,
      "visible": true,
      "backgroundColor": "lightgrey",
      "fillRule": "nonzero",
      "paintFirst": "fill",
      "globalCompositeOperation": "source-over",
      "skewX": 0,
      "skewY": 0,
      "myData": {
        "type": "text"
      }
    }
  ]
}

[zhe-he]

Well... the new logic now allows custom types to build internal objects. If your type value is 'rect' or 'text', it will be parsed as 'Rect' and 'Text'. So your type values should avoid these.

[asturur]

Or at least they have to serialize differently.
I m not sure how you handle unwanted mutations when you restore properties that are custom objects.

[hqw567]

Can this problem be solved once and for all? @asturur

[asturur]

The current version supports it.
Just don't use 'type' with values that are already used by fabricJS classes ( 'rect', 'text', 'image' and so on ).
Or if you really have to do that change the type in the normal fabricJS classes and register them with a different name.