Support for other units in paperHeight/Width & margins

[FrankHeijden]

Would be great if other units such as mm, px, cm could be used! Puppeteer does support supplying a string (value + unit), so it would be great if that could be used as well in gotenberg.

[gulien]

Hello @FrankHeijden,

See #591 (comment) for the reason of non implementation (for now).

[FrankHeijden]

For now I will just convert my values to inches like so:

export interface UnitValue {
  value: number;
  unit: 'pt' | 'px' | 'in' | 'mm' | 'cm' | 'pc';
}

export const unitConversions: { [U in UnitValue['unit']]: number } = {
  pt: 1 / 72,
  px: 1 / 96,
  in: 1,
  mm: 1 / 25.4,
  cm: 1 / 2.54,
  pc: 1 / 6,
};

export function parseUnitValueAsInches(uv: UnitValue): number {
  return uv.value * unitConversions[uv.unit];
}

The only issue is that for example with the relative units like em, ex, I cannot calculate them directly.

[gulien]

Thanks for the details! I think I'll avoid relative units, too many caveats.

[FrankHeijden]

Hm @gulien in the commit eb05414, I see that you also use the above conversion logic for units; is there a hard requirement in Gotenberg to know the exact measurements before using it as input to Puppeteer? The current implementation would still not work for dynamic/relative CSS units like em and ex.

[gulien]

@FrankHeijden gotenberg/gotenberg:edge (https://github.com/gotenberg/gotenberg/actions/runs/8315842453/job/22754688797) should soon be available with support for this feature. For instance:

• 15pt
• 8.25in or 8.25
• 300px
• etc.

[gulien]

Yep as I said, I don't want to deal with relative units. What use cases do you have in mind?

[gulien]

Gotenberg to know the exact measurements before using it as input to Puppeteer

I'm not using Puppeteer 😅

[FrankHeijden]

We're using pdf generation for barcodes; I could see dynamic sizes related to the font size being useful there if clients don't use a fixed size paper width/height. What's the reason that Gotenberg needs to calculate the exact sizes of the paper/width before entering it into puppeteer?

[gulien]

Again, I'm not using Puppeteer, but the Chrome DevTools protocol. No idea how Puppeteer works with relative units 🤔