Implement inherits for Schema.sql

[amitaibu]

• Parse inherits
• Schema compile should allow setting parent fields
• Allow saving revisions with triggers
• Mark on UI when we use inherit
  
• Support migrate. If parent field was changed, we should adapt also inherits.
• Inherited fields should copy constraints? Maybe not, since it saves data the was added. So if it passed a constraint some time in the past, it should remain.
• Inherited fields should not have unique? Since a revision may hold the same "unique" values on several records
• Update docs
• Add tests

[amitaibu]

@mpscholten I think the doc is outdated.

1. Is make console, mentioned above , needed?
2. I'm getting an error
   

[mpscholten]

It could just be ghci. make console is just an alias for ghci.

Can you try :set -iIHP/ihp-ide in the ghci? This will add the IHP/ihp-ide directory to the load path. After that it should load without the error.

[amitaibu]

Thanks, it helped (adapted docs)

But now I get

[mpscholten]

I can reproduce that. Just tried it locally and here's an approach how I got it working with latest IHP:

# Assuming workingDirectory is the project

cd IHP # switch to IHP
direnv allow # load direnv things if this is freshly cloned

ghci # Load ghci will all IHP dependencies
:cd .. # switch back to project directory
:set -iIHP
:set -iIHP/ihp-ide
 :l IHP/ihp-ide/exe/IHP/IDE/DevServer.hs

That should work now

locally i run into a ghc bug while doing that, I hope it works for you:

ghci> :l IHP/ihp-ide/exe/IHP/IDE/DevServer.hs
Ok, 164 modules loaded.
ghci> main
panic! (the 'impossible' happened)
  GHC version 9.8.2:
	nameModule
  internal $fHasQueryBuilderkJoinQueryBuilderWrapperjoinRegister1_iefl
  Call stack:
      CallStack (from HasCallStack):
        callStackDoc, called at compiler/GHC/Utils/Panic.hs:191:37 in ghc-9.8.2-inplace:GHC.Utils.Panic
        pprPanic, called at compiler/GHC/Types/Name.hs:341:3 in ghc-9.8.2-inplace:GHC.Types.Name
  CallStack (from HasCallStack):
    panic, called at compiler/GHC/Utils/Error.hs:503:29 in ghc-9.8.2-inplace:GHC.Utils.Error


Please report this as a GHC bug:  https://www.haskell.org/ghc/reportabug

[mpscholten]

As a workaround for the GHC bug I reverted the commit that introduced the bug by running git revert 4fe8b56e5a8c5dcb394a16b0dfb5eb2d6f77b18f from within the IHP directory

[mpscholten]

I've ran into more issues with the dev server right now and added a new helper called mainInParentDirectory to fix that.

After you've synced this branch with latest master it should now work like this:

# Assuming workingDirectory is the project

cd IHP # switch to IHP
direnv allow # load direnv things if this is freshly cloned

ghci # Load ghci will all IHP dependencies
 :l ihp-ide/exe/IHP/IDE/DevServer.hs
mainInParentDirectory # Will run the IHP project in the parent project directory

[amitaibu]

Thank you for looking into it 🙏

I'm confused about which URL should be in my flake.nix

ihp/CONTRIBUTING.md

Lines 43 to 67 in 27a696a

	### Nix Changes
	If you're testing local nix changes, you need to change your `flake.nix` to point to the IHP project instead of pulling it from github:
	```nix
	{
	inputs = {
	# The path needs to be absolute
	ihp.url = "path:///Users/myuser/someproject/IHP";
	# ...
	};
	```
	After that run `nix flake update`.
	### Running the latest IHP `master`
	When contributing to IHP core you will want to have your PRs synced with `master`. Your `flake.nix` should have this line:
	```nix
	{
	ihp.url = "github:digitallyinduced/ihp";
	}
	```

I'm guessing we should always tell folks to point to the local IHP, or is there a different use case?

[amitaibu]

Failing tests belong to https://github.com/digitallyinduced/ihp/blob/27a696af90efcd0f84260d84805dd2dc753e818c/Test/SchemaCompilerSpec.hs that require some trailing spaces. Let's see if we can remove those :)

[amitaibu]

Next, I want to see if we can have revisions created either manually or by using Postgress triggers.

Manual will be something like this:

CREATE TABLE post_revisions (
    revision_id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
    post_id UUID NOT NULL
) INHERITS (posts);

action CreatePostRevisionAction { .. } = do
    post <- fetch postId
    let revision = newRecord @PostRevision
            |> set #postId post.id
            |> set #title post.title
            |> set #body post.body
    createRecord revision

    redirectTo ShowPostAction { .. }

[amitaibu]

The INHERTIS keyword is now recognized in Schema.sql. Next is figuring how to auto-generate types/getter/setter based on the columns from the parent table

[amitaibu]

@mpscholten I've started working on the SchemaCompiler, but I've hit a panic

What are you doing in such cases?

[mpscholten]

try git revert 4fe8b56e5a8c5dcb394a16b0dfb5eb2d6f77b18f (that commit causes the GHC panic). After that restart the ghc and it should work

[amitaibu]

try git revert 4fe8b56

Thanks. How did you know it was that commit? So I'll know for next time 😄

[mpscholten]

When this specific bug happend the first time I was looking through the git history and just tried out various commits until I found the one that reproduced it. This was like a week or two weeks after that commit was created, so it was only a few commits I had to try out

[amitaibu]

Got it to compile with this code! 🎈

[amitaibu]

Next is adapting instance CanCreate and instance CanUpdate

[amitaibu]

I've updated the OP with a checklist. I'm not sure about some of the stuff, as I think it's not a small feature 😄

[mpscholten]

Happy to help if there's more questions :)

[amitaibu]

Using triggers

CREATE TABLE posts (
    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
    title TEXT NOT NULL,
    body TEXT NOT NULL,
    user_id UUID NOT NULL
);

CREATE TABLE post_revisions (
    id UUID DEFAULT uuid_generate_v4() PRIMARY KEY NOT NULL,
    post_id UUID NOT NULL
) INHERITS (posts);

CREATE OR REPLACE FUNCTION create_post_revision() RETURNS TRIGGER AS $$
BEGIN
    INSERT INTO post_revisions (id, post_id, title, body, user_id)
    ### Notice we use `ihp_user_id()` user here to capture the acting user.
    VALUES (uuid_generate_v4(), NEW.id, NEW.title, NEW.body, ihp_user_id());
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER post_revision_trigger
AFTER UPDATE ON posts
FOR EACH ROW
EXECUTE FUNCTION create_post_revision();

I've logged in, and when I update a Post I get

What should I do in order to get ihp_user_id() working?

[mpscholten]

The ihp_user_id() function can only be used together with row level security (which requires some setup described here https://ihp.digitallyinduced.com/Guide/realtime-spas.html ).

In our case we can just use NEW.user_id instead, so:

-- old
VALUES (uuid_generate_v4(), NEW.id, NEW.title, NEW.body, ihp_user_id());

-- new
VALUES (uuid_generate_v4(), NEW.id, NEW.title, NEW.body, NEW.user_id);

[amitaibu]

Thanks.

NEW.user_id

Right. I guess I wanted to have another column called revision_user_id and have that populated with the ihp_user_id().

Is there a technical reason not to inject the user ID also if row level security isn't used?

[mpscholten]

Is there a technical reason not to inject the user ID also if row level security isn't used?

Yes, right now the ihp_user_id() requires a second database role to be available. You can see some code here https://github.com/digitallyinduced/ihp/blob/master/IHP/ModelSupport.hs#L437 In theory we could also support ihp_user_id() without that second database role, but that would require some rework of the RLS code.

Initially ihp_user_id() was designed to be always used with Row level security. So we need to refactor it a bit to make it work independently.

[amitaibu]

Indicate inherits on the UI

[amitaibu]

I'm trying to see how migration works. I'm assuming inherits isn't enough to update columns, in case the parent columns have changed.

So I've added a new col to the parent table.

But on migrate db I get this error

Server is running via the new mainInParentDirectory on ghci

[mpscholten]

Could it be that the postgres server is not running? If that's the case, you could manually start one by running make postgres in a different tab

[amitaibu]

No, it's running. The app and ide run well. Just the migrate fails

…

On Fri, Sep 13, 2024, 06:06 Marc Scholten ***@***.***> wrote: Could it be that the postgres server is not running? If that's the case, you could manually start one by running make postgres in a different tab — Reply to this email directly, view it on GitHub <#1998 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAA6WCY2TXICBIZQZI74SWLZWJJDJAVCNFSM6AAAAABMO2EGXOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDGNBXHE2DQNZRGU> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[mpscholten]

If you run the pg_dump command from the error message in a terminal yourself, does it output some SQL?

[amitaibu]

➜  IHP git:(core-inherits) ✗ pg_dump
pg_dump: [archiver (db)] connection to database "amitaibu" failed: connection to server on socket "/var/run/postgresql/.s.PGSQL.5432" failed: FATAL:  role "amitaibu" does not exist

But it's running on ghci, and the IDE & app are running

[amitaibu]

To workaround the error, I'm checking it by running devenv up, and then the migration doesn't error due to missing connection