Webtools parser does not support `CompositeIngredientAmount`

[strangetom]

Attempting to parse sentences such as "1 cup plus 2 tablespoons olive oil" results in HTTP 500 error with the traceback:

Traceback (most recent call last):
  File "/home/tom/Recipes/ingredient-parser/webtools/app.py", line 190, in parser
    quantity=str(amount.quantity),
                 ^^^^^^^^^^^^^^^
AttributeError: 'CompositeIngredientAmount' object has no attribute 'quantity'

This is because the amount parsed is returned as a CompositeIngredientAmount object:

[CompositeIngredientAmount(amounts=[IngredientAmount(quantity=Fraction(1, 1),
                                                     quantity_max=Fraction(1, 1),
                                                     unit=<Unit('cup')>,
                                                     text='1 cup',
                                                     confidence=0.999822,
                                                     starting_index=0,
                                                     APPROXIMATE=False,
                                                     SINGULAR=False,
                                                     RANGE=False,
                                                     MULTIPLIER=False,
                                                     PREPARED_INGREDIENT=False),
                                    IngredientAmount(quantity=Fraction(2, 1),
                                                     quantity_max=Fraction(2, 1),
                                                     unit=<Unit('tablespoon')>,
                                                     text='2 tablespoons',
                                                     confidence=0.997124,
                                                     starting_index=3,
                                                     APPROXIMATE=False,
                                                     SINGULAR=False,
                                                     RANGE=False,
                                                     MULTIPLIER=False,
                                                     PREPARED_INGREDIENT=False)],
                           join=' plus ',
                           subtractive=False,
                           text='1 cup plus 2 tablespoons',
                           confidence=0.9984729999999999,
                           starting_index=0)]

The webtools parser should be fixed to support amounts returned as ComposteIngredientAmount objects.

@mcioffi

[mcioffi]

Will put up a fix. The classes returned from the parser amounts will always be either CompositeIngredientAmount or IngredientAmount, is that correct?

I also noticed that flask's jsonify cannot serialize IngredientAmount by itself because Fraction is not serializable by default. There's added logic to circumvent that, it's not broken; but I'll try to refactor it as part of this broader fix.

[strangetom]

The classes returned from the parser amounts will always be either CompositeIngredientAmount or IngredientAmount, is that correct?

Yes, that's right.

I also noticed that flask's jsonify cannot serialize IngredientAmount by itself because Fraction is not serializable by default.

I'd noticed that we didn't just jsonify the IngredientAmount but I hadn't realised why, so that makes sense.