Ask Questions only Once

[natescherer]

Hello!
I love Copier and have been slowly trying to rebase all of my projects onto it.

As I've started to get more complex question sets, I'm running into more and more questions where it only makes sense for the question to be asked once during the initial copy, and, in some cases, could actually cause issues if accidentally (or intentionally) changes on copier update.

For example, the GitHub Username and GitHub Organization for a project are going to be static, unchanging values over the life of the project, and I'd like them to still be recorded in the answers file, but not asked more than once.

I've spent a while thinking about how to do this and reading the doc and I can't come up with anything. I was hopeful the newish _copier_operation variable could help, but it isn't available during the question phase.

Is there a way to do this currently? If not, I'd love to have a conversation about potential ways to implement this, I would be happy to create a PR to add functionality in this regard, if there is desire for it from the maintainers.

Thanks!

[sisp]

I think you can modify the recipe for locking computed values to render when: true when no answer has been recorded yet and when: false otherwise:

github_username:
  type: str
  default: "{{ github_username | default('') }}"
  when: "{{ github_username is undefined }}"

# Changes here will be overwritten by Copier; NEVER EDIT MANUALLY
{{ dict(_copier_answers, github_username=github_username) | to_nice_yaml -}} 

There's one limitation though: You can't make this question required because default makes it optional, so if somebody runs copier copy --defaults ..., then the default value (empty string in the snippet above) will be used. If default supported a special value like unset or undefined, then we could dynamically make make a question required or optional. It's something I've had in mind for a while but not implemented yet. The explicit addition of this answer in the answers file is required because answers to when: false questions aren't recorded. I think this can only be improved by a first-class feature.

[natescherer]

Very cool. I love the flexibility of this tool! I will test and report back.

[natescherer]

Okay, I've been doing some testing on this and it seemed alright at first, but implementing this has caused copier update to break, as the second and third phases are getting rendered with different answers based on my testing:

 pwsh ❯ copier update --answers-file .config/copier-answers.yml --skip-answered --trust --vcs-ref update-troubleshooting
Updating to template version 0.5.12.post6.dev0+ea945df
*** 'copy-template-files' task start ***
*** 'copy-template-files' task end ***
*** 'delete-unneeded-template-files' task start ***
*** 'delete-unneeded-template-files' task end ***
run starting
operation is update
project is Template
answers are {"_commit": "v0.5.12-6-gea945df", "_src_path": "https://github.com/natescherer/postmodern-repo-copiertemplate", "author_name": "Nate Scherer", "license": "MIT", "lifecycle": "Pre-Alpha", "project_description": "Integration Test - NOT FOR PUBLIC USE", "project_name": "Integration Test"}
*** 'copy-template-files' task start ***
*** 'copy-template-files' task end ***
*** 'delete-unneeded-template-files' task start ***
*** 'delete-unneeded-template-files' task end ***
run ending
run starting
operation is update
project is Standard
answers are {"_commit": "v0.5.12-6-gea945df", "_src_path": "https://github.com/natescherer/postmodern-repo-copiertemplate", "author_name": "Nate Scherer", "license": "MIT", "lifecycle": "Pre-Alpha", "project_description": "Integration Test - NOT FOR PUBLIC USE", "project_name": "Integration Test", "repo_name": "copier._main.new_copy.h64_e8wc", "developer_platform": "GitHub", "repo_setup_actions": "Create Repo", "github_username": "natescherer", "github_org": "", "project_type": "Standard", "project_visibility": "Public", "mkdocs_target": "GitHub Pages"}
*** 'delete-unneeded-template-files' task start ***
*** 'delete-unneeded-template-files' task end ***
run ending

In this specific case, the value of project_type is different for phase 2 and phase 3. Here's how the question is written in copier.yml:

project_type:
  type: str
  help: If you are creating a basic repo, choose Standard. If you are creating a child template, choose Template.
  choices:
    - Standard
    - Template
  default: "{{ project_type | default('Standard') }}"
  when: "{{ project_type is undefined }}"

This seems like it might be a bug of some sort?

[natescherer]

I initially suspected this might just be a problem with str questions with choices, but I just confirmed this is also happening for questions without choices too. As far as I can tell, using this configuration causes all questions set up this way to have their answers reset to the default value in the third phase of copier update

[sisp]

Could you share a minimal reproducible example, so I can take a look and debug it?