Include enum members in API endpoint

[guillett]

Some variables are EnumCol (cf. rsa_non_calculable in legislation explorer and rsa_non_calculable code).

As a user/consumer:

• I would like to have a better understanding of Enum variables in the legislation explorer.
• I would like to know the Enum members via the API.

Currently, I would use those details to validate a structure in a client application - MesAides that add metadata to openfisca variables.

Related to https://github.com/openfisca/legislation-explorer/issues/95.

[fpagnoux]

Hi @guillett,

Thanks for reporting this issue, indeed there is much progress to be done with enums, and exposing the value of the operands through the API is something we will consider.

[fpagnoux]

As a workaround, today the best way to get the enum members is to click on "Code source de cette variable" on the legislation explorer page. The first lines of the variable source code should be the definition of the enum :).

[thom4parisot]

Likewise for contrat_de_travail and categorie_de_salarie — and so any type of Enum we use a an index instead of their value.

[MattiSG]

Done via https://github.com/openfisca/openfisca-core/pull/550 :tada: