Weekly Status Log: Python API

[domoritz]

This is for uwdata#395. Code changes in #10.

[mhli1260]

Oct 2:

• created a simple version of the schema in testingSchema.json to test out the generation of classes
• when running "python generated_wrapper_schema.py", outputs classes into generated_classes.py
• working on creating a test.py to test calls on these classes
• tested running on the actual mosaic schema (v0.10.0), and seemed to be generating classes upon first glance (but will need to look more in depth at the classes that are being generated to see if classes are missing/incorrect that should exist/need to be corrected based on schema?)

Issues:

• $ref outputs the classes beneath the classes that reference them in generated_classes.py -> leads to many classes not defined errors

[harrylojames]

Just to say really excited about this and thank you for providing a weekly status log!

[Hamzu24]

I built upon this to:

• Load the python classes in topological order of references
• Fixed the download schema so it works fully

The Altair schema sorted the references by topological order, so I assumed we had to do the same. However, I realized that some of the references are cyclical? I would like to ask about this in the meeting.

[Xinyue-Yang]

My last week's progress:

• created utils.py, which includes utilities for working with schemas
• Implemented jsonschema_to_python_types to do type conversion between JSON and python types
• Implemented get_type_hint to determine the appropriate type hint based on the property schema
• Generate__init__method parameters

[Hamzu24]

This week's progress for the team:

• Added lots of test cases
• Fixed typing and reference errors
• Extended the typing in the schema generator
• Made the schema generator into a package

[mhli1260]

11/6 Updates:

• virtual environment
• created a to_dict function that would correctly create a spec using calls to our generated python classes
• got an example running using Mosaic widget after generating spec

[domoritz]

Eventually, we want to use a submodule to import schemaapi as in gosling-lang/gos#101.

[Hamzu24]

11/12 Updates:

• I tried using altair's to_dict function instead of our own one. This proved to be difficult because of their exclusive use of SchemaBase objects to encapsulate data in a specification. I'm not completely sure how or if it is even possible to convert an object, such as the one we made using our schema wrapper's classes, to a SchemaBase object. To further look into this, could you direct me to the start of the existing mosaic pipeline (that uses altair's functions) for generating schemas from yaml or JS?
• updated tests using assert statements to check for generation of correct specs

[Hamzu24]

Disregard this- got it working using altair's _todict function

[domoritz]

modify https://github.com/cmudig/mosaic/blob/main/bin/prepare-examples.js to use new astToPython (you need to write).

roughly what the generated python should look like

# line.py

from mosaic import Plot, PlotMark, LineY, PlotFrom, ChannelValueSpec, ChannelValue

plot = Plot(
    plot = [PlotMark(LineY(
        mark="lineY", 
        data=PlotFrom(from_="aapl"), 
        x=ChannelValueSpec(ChannelValue("Date")), 
        y=ChannelValueSpec(ChannelValue("Close"))
    ))],
    width = 680,
    height = 200
)

# in tests

assert json_spec == plot.to_dict()