feat(): dataURL export - filter objects

[ShaMan123]

Added a nice and simple option to filter objects for canvas export

This option is shallow, it doesn't filter objects under groups, yet...

[github-actions]

Code Coverage Summary

> fabric@5.1.0 coverage:report
> nyc report --reporter=lcov --reporter=text

-----------|---------|----------|---------|---------|-----------------------------------------------
File       | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s                             
-----------|---------|----------|---------|---------|-----------------------------------------------
All files  |   83.18 |     76.6 |   86.38 |    82.9 |                                               
 fabric.js |   83.18 |     76.6 |   86.38 |    82.9 | ...,29868,29993,30073-30138,30261,30360,30577 
-----------|---------|----------|---------|---------|-----------------------------------------------

[melchiar]

this is great!

[ShaMan123]

Thanks. So should I merge?

[ShaMan123]

I am thinking of supporting group as well.
But it might be simpler to clone the group and run toDataURL on the clone NOT supporting it under the hood.
What do you think?

[melchiar]

Thanks. So should I merge?

looks good to me

I am thinking of supporting group as well. But it might be simpler to clone the group and run toDataURL on the clone NOT supporting it under the hood. What do you think?

sounds good, as I recall that's how toDataURL works on a fabric canvas as well

[ShaMan123]

sounds good, as I recall that's how toDataURL works on a fabric canvas as well

It uses exiting objects on a new canvas
New group can easily accept a filtering function, basically it already does.

[salomonsanz]

"excludeFromExport" already exists. In the future, to "centralize" all export options, it might be nice to accept an object instead of a boolean

excludeFromExport = {
    json : true,
    dataUrl : true,
    svg : true
}

Even a filter function

excludeFromExport = {
    json : obj=>...,
    dataUrl : obj=>...,
    svg : obj=>...,
}

[ShaMan123]

I didn't think of excludeFromExport. Good point.
I'd prefer removing this strange but useful prop in favor of filtering functions everywhere.

[salomonsanz]

mmm, from my experience, most filters of that type are based on object properties, not on dynamic logic, so in the end it would be redundant to delete that property and pass everything to functions:

objects.filter(o=>o.excludeFromExport)

On the other hand, there is no need to choose between functions and boolean properties, in many frameworks a design pattern that allows a value or a function is common.

https://laravel.com/docs/9.x/helpers#method-value

[ShaMan123]

I want to make fabric more intuitive. That's why excludeFromExport is on my target (e.g. #7719).
As you said, it is unclear how it should behave in some cases. Should it apply for every export? toCanvasElement , toDataURL, toJSON, clone, cloneAsImage. A filter function, however, it very clear and easy to maintain.