Modify webapp backend to process all user input as files

[talumbau]

With the merge of PSLmodels/Tax-Calculator#1505, Tax-Calculator now supports a JSON reform interface that maps very naturally to the TaxBrain GUI interface. Currently, TaxBrain supports two separate but similar workflows: a GUI interface and a file upload interface. For the GUI interface, there is a significant amount of code that processes the user's input to create a job for submission to the worker nodes. There is a separate path of control to take a file-based input and submit that to the worker nodes. A way to reduce complexity of TaxBrain would be to unify these flows. To do this, code would be written to transform a user's input to a JSON reform (represented in memory as a dictionary) in the style of PSLmodels/Tax-Calculator#1505. For example, this user input:

Would be something like:

{
 "policy": {
   "_SS_thd50_joint": {"2019": [36000]}
 }
}

Once this works is completed, the workflows would look like this:

File based reform:

• take file from user POST and store in memory (already working)
• submit file contents to worker nodes (already working)

GUI-based reform:

• take params from user POST (already working)
• create in-memory representation of reform file based on user input (NEW WORK HERE)
• submit file contents to work nodes (already working)

After the new work is done, a lot of code could be removed from TaxBrain (e.g. the expand_arrays functions, package_up_vars, etc.) and there would only be one flow of control for submitting jobs to the worker nodes.

cc @MattHJensen, @brittainhard, @PeterDSteinberg, @martinholmer

[martinholmer]

Let me add something to the #619 comment by @talumbau.
In addition to the TaxBrain simplifications outlined by @talumbau, the merge of Tax-Calculator pull request 1502 and Tax-Calculator pull request 1503 offers another TaxBrain simplification: there is no longer a need for TaxBrain to do any policy parameter validations.

cc @MattHJensen, @hdoupe, @brittainhard, @PeterDSteinberg

[martinholmer]

Let me add something else to the #619 comment by @talumbau.
While #619 is labeled an enhancement, when implemented the ideas of @talumbau will fix at least one bug (#596) and perhaps other bugs as well.

cc @MattHJensen, @hdoupe, @brittainhard, @PeterDSteinberg

[martinholmer]

@brittainhard and @PeterDSteinberg,
It has been several days since @talumbau suggested the TaxBrain simplification described in #619, but neither of you have commented on the pros and cons of his suggestion. We would like to hear your views on his suggestion. Can you add your comments to #619?

@MattHJensen @GoFroggyRun @hdoupe

[hdoupe]

@martinholmer said

Let me add something else to the #619 comment by @talumbau. While #619 is labeled an enhancement, when implemented the ideas of @talumbau will fix at least one bug (#596) and perhaps other bugs as well.

I agree. I think this would take care of the TaxBrain GUI input bugs (#596, #598, #607, and #609).

[martinholmer]

TaxBrain 1.0.3, which is using Tax-Calculator 0.10.2, uses the new approach to processing the GUI input that @talumbau suggested in #619. @talumbau, thanks for the strategy, and @hdoupe, thanks for the
implementation. Closing #619.

@MattHJensen @GoFroggyRun