gf draft rearchitecture

fontbakery_sample.py

@condition
...
def gf_family(ttFont):
  from gfcore.font import family_name
  from gfcore.site import download_family, family_exists
  name = family_name(ttFont)
  if family_exists(name):
    return download_family(name)
  return None


@condition
...
def expected_name_table(ttFont):
  from gfcore.font import build_name_table
  return build_name_table(ttFont)


@condition
...
def expected_metadata(family_dir):
  return gfcore.addfont.MakeMetadata(family_dir)


@check
...
def check_nametable(ttFont, expected_name_table):
  current = ttFont['name']
  expected = expected_name_table
  # Simply compare them. No need for 400 checks

@check
...
def check_metadata(metadata, expected_metadata):
  ...

gftools_sample.py

## FIXING
# For fixing we use the constants and helper funcs from the gfcore.font
from gfcore.font import *

def fix_fstype(ttFont):
  ttFont['OS/2'].fsType = GF_FS_TYPE


def fix_nametable(ttFont):
  from gftools.font import family_name, style_name
  ttFont['name'] = build_name_table(family_name(ttFont), style_name(ttFont)


# QA
# for gftools QA we can use gfcore.site to fetch fonts from fonts.google.com
from gfcore.site import download_family, family_exists

if family_exists("Comfortaa"):
  existing_family = download_family("Comfortaa")

Also, I'm only happy with the docs being the single-source-of-truth if those docs are generated from a machine-readable source so that the "truth" can be used in our Python code without having to copy it out of the spec.

Sounds very sensible. I guess something similar to sphinx which is able to generate documentation from func docstrings etc?

More likely some kind of templating to add the Python constants into English prose.

Hmm, backing up a bit (possibly too far):

gfdocs/otspec.yaml

tables:
  - "OS/2": 
     description: "..."
     fields:
       - fsType:
         description: |
              Indicates font embedding licensing rights for the font. 
         glyphs_custom_parameter: fsType
         ufo_info_key: openTypeOS2Type
         values:
           # ...
         gf_requires: 0
         gf_rationale: "No DRM restrictions can be enabled on the Google Fonts collection"

fontdoctor

@doctor_from_otspec("OS/2", "fsType")
class FsType(Doctor):
    pass

It would be interesting to see how you'd tackle tables which do not have constants such as the name table.

Sure. I don't imagine you would be able to do this for everything. But what you could do it for, you should. I think this is what Dave is getting at here:

...in a way the googlefonts profile is a coded version of the GF Spec...
Given topically-unrelated efforts... - to make better structured docs for the font format spec... - perhaps there's something we can do to deduplicate and pattern things so there's a common approach that makes contribution skills more transferrable.