Calling onchain view new syntax with old syntax

Development
1

The following question has been asked on Telegram:

can I create a contract in new syntax and
call the onchain view of that contract
from the contract that is being written on old syntax ?

2

Yes, here is an example that shows all the configuration: new syntax calling legacy, legacy calling new syntax and even legacy calling legacy and new syntax calling new syntax:

import smartpy as sp

class OldSyntax(sp.Contract):
    def __init__(self):
        self.init(res=sp.none)

    @sp.entry_point
    def call_view(self, addr):
        self.data.res = sp.view("the_view", addr, sp.unit, t = sp.TString)

    @sp.onchain_view()
    def the_view(self):
        sp.result("legacy")

@sp.module
def main():
    class NewSyntax(sp.Contract):
        def __init__(self):
            self.data.res = None

        @sp.entrypoint
        def call_view(self, addr):
            self.data.res = sp.view("the_view", addr, (), sp.string)

        @sp.onchain_view()
        def the_view(self):
            return "new syntax"

if "templates" not in __name__:
    @sp.add_test(name="MyContract")
    def test():
        sc = sp.test_scenario(main)
        c1 = OldSyntax()
        sc += c1
        c2 = main.NewSyntax()
        sc += c2
        sc.h2("Legacy calling own view")
        c1.call_view(c1.address)
        sc.verify(c1.data.res == sp.some("legacy"))
        sc.h2("Legacy calling new syntax view")
        c1.call_view(c2.address)
        sc.verify(c1.data.res == sp.some("new syntax"))
        sc.h2("New syntax calling own view")
        c2.call_view(c2.address)
        sc.verify(c2.data.res == sp.some("new syntax"))
        sc.h2("New syntax calling legacy view")
        c2.call_view(c1.address)
        sc.verify(c2.data.res == sp.some("legacy"))