fontWeight should support the wording as in Xcode

[fatuhoku]

In Xcode you can select out of a handful of values for font weight:

React Native's supported values for fontWeight looks like this: . It's not obvious what 200 or 900 means in relation to iOS font weight values like "Semibold" or "Thin".

How could the mapping be made clearer?

[vkurchatkin]

I think this is the way it is for compatibility with CSS: https://developer.mozilla.org/en-US/docs/Web/CSS/font-weight

[ericvicenti]

Yep, we're sticking to the web standards everywhere we can, but we don't want you to be restricted. Is there anything that you can do in Xcode that you can't do with the font-weight CSS spec?

Feel free to send a PR to clarify the docs and link to the spec

[fatuhoku]

@ericvicenti Hi, coming back to this, I guess it's possible to make a mapping for the following strings (essentially an enum) onto the relevant fontWeights... it's just that our designer would specify the font weight in terms of 'Medium' or 'Light' and translating into a number like 100 is simply not descriptive.

Based on the 9 selections you get from Xcode:

... here's what I make of the mapping:

100 = Thin
200 = Ultra Light
300 = Light
400 = Regular
500 = Medium
600 = Semibold
700 = Bold
800 = Heavy
900 = Black

It's worth noting that under Xcode it appears that Heavy and Black are actually the same font weight.