[FYI] Changes to dispatch in dbt v0.20

[jtcohen6]

Hi Alex & team! I wanted to give you a heads up about a change to dispatch functionality coming in the next version of dbt. Let me know if you have questions, I'm more than happy to help.

Required code change

We've made a change to adapter.dispatch: Instead of passing a _get_namespaces() macro to the packages arg, you should pass the name of this package (as a string) to the macro_namespace arg, which is now the second positional argument.

In practice, this just looks like switching each macro like:
https://github.com/Datavault-UK/dbtvault/blob/d15aeab5691056348c0ccafe4e4f153cc7e84710/macros/internal/alias_all.sql#L1-L5
To:

{%- macro alias_all(columns=none, prefix=none) -%}


    {{- adapter.dispatch('alias_all', 'dbtvault')(columns=columns, prefix=prefix) -}}


{%- endmacro %}

I hope this could be as simple as Find + Replace for packages = dbtvault.get_dbtvault_namespaces() → 'dbtvault'.

If you prefer more explicit syntax, you could also make this:

{%- macro alias_all(columns=none, prefix=none) -%}


    {{- adapter.dispatch(macro_name = 'alias_all', macro_namespace = 'dbtvault')(columns=columns, prefix=prefix) -}}


{%- endmacro %}

For the README

If a user wishes to override/shim this package, instead of defining a var named adapter_packages, they should now define a config in dbt_project.yml, for instance:

dispatch:
  - macro_namespace: dbtvault
    search_order: ['my_project', 'dbtvault']  # enable override

Notes

This change is in dbt v0.19.2 as well. Both v0.19.2 and v0.20.0 have backwards compatibility for the old syntax, so there's no huge rush to upgrade.

However:

• The old syntax will start raising a deprecation warning in v0.20.
• You've named your override var adapter_packages, rather than the convention of dbtvault_dispatch_list, so we don't have backwards compatibility for checking that variable in dbt v0.19.2 + v0.20.0 as of now. Do you know if folks are relying on this today? If so, we can add (hard-coded) logic to check a var named adapter_packages IFF the dispatching package is named dbtvault.

As soon as you do upgrade to the new syntax, you'll need to require dbt >= 0.19.2 (or just >=0.20.0, for simplicity, since you're already making compatibility changes in #69).

See also:

• Rework adapter.dispatch(), remove packages arg dbt-labs/dbt-core#3383
• https://next.docs.getdbt.com/reference/dbt-jinja-functions/dispatch

[DVAlexHiggs]

Thank you @jtcohen6 Really appreciate your efforts to inform us of this. We will ensure these changes are included our next release

[DVAlexHiggs]

Actioned and added in dbvault v0.7.6