field_types | derive macros for deriving enums | SDK library

I'm trying to implement the builder pattern from the proc macro workshop I'm creating a proc macro which parses a struct, extracts its name, field_names and field_types. It should reproduce the struct itself and also create a builder struct with the same field_names but with optional types.

My problem is that field_name and field_type are iterators that I would have to use twice in order to create two structs out of one.

This is my source tree

I have four tables for a form-builder in my databse.

• fields (fieldID(PK), typeID, fieldName, ...) - This table is a row by row list of all fields to be in the form
• fields_types (typeID(PK), htmlType, ...) - This is a table that links fields to html types (and other settings)
• fields_meta (FieldMetaID(PK), FieldID, mName, mValue) - Additional settings for fields, but more specific. A textarea field might have a height attribute, but almost no other field would use that.
• fields_tyeps_meta (TypeMetaID(PK), typeID, tmName, tmValue) - Defines what extraneous settings a field can have, and also supplies default values if it's not explicitly set)

So my Query currently looks something like this

I have the code which worked well until the payload changed.

I'm trying to develop a class that cleans a dictionary based on field types incorporated into the class init function.

Its structure is something like this, but it doesn't work right now, as I can't figure out how to get a variable from the class instance dynamically, and how to apply the function to each variable:

This is not a duplicate of e.g. Referencing a template in Twig / Symfony2 because creating bundles as applications is deprecated/not recommended anymore and therefore the answer is not applicable anymore. How do I reference my own template in a Sylius grid?

What I tried:

1.