html_url,issue_url,id,node_id,user,user_label,created_at,updated_at,author_association,body,reactions,issue,issue_label,performed_via_github_app
https://github.com/simonw/datasette/issues/1552#issuecomment-996229007,https://api.github.com/repos/simonw/datasette/issues/1552,996229007,IC_kwDOBm6k_c47YT-P,3556,davidbgk,2021-12-16T22:04:39Z,2021-12-16T22:04:39Z,CONTRIBUTOR,"Wow, that was fast, thank you so much @simonw !

> I'm also not convinced that this configuration syntax is right. It's a bit weird having a `""facets""` list that can either by column-name-strings or `{""type-of-facet"": ""column-name""}` objects. Maybe there's a better design for this?

I agree that it's not ideal, my initial naive approach was to detect if it's an array, like what is done here:

https://github.com/simonw/datasette/blob/2c07327d23d9c5cf939ada9ba4091c1b8b2ba42d/datasette/facets.py#L312-L313

But it requires an extra query to determine the type, which is a bit problematic, especially for big tables I guess.

Taking a look at #510, I wonder if a `facet_delimiter` should be defined for that kind of columns (that would help our team not to have an intermediary conversion step from `foo|bar` to `[""foo"",""bar""]` for instance).

To be consistent with the `--extract-column` parameter, maybe an explicit casting/delimiter would be useful: `--set-column 'Foo:Array:|'`.

Throwing a lot of ideas without knowing the big picture… but sometimes newcomers have superpowers :).","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1078702875,Allow to set `facets_array` in metadata (like current `facets`),
https://github.com/simonw/datasette/issues/1552#issuecomment-996084899,https://api.github.com/repos/simonw/datasette/issues/1552,996084899,IC_kwDOBm6k_c47Xwyj,9599,simonw,2021-12-16T18:48:14Z,2021-12-16T18:48:14Z,OWNER,Updated documentation: https://github.com/simonw/datasette/blob/20a2ed6bec367d2f6759be4a879364a72780b59d/docs/facets.rst#facets-in-metadatajson,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1078702875,Allow to set `facets_array` in metadata (like current `facets`),
https://github.com/simonw/datasette/issues/1552#issuecomment-996077053,https://api.github.com/repos/simonw/datasette/issues/1552,996077053,IC_kwDOBm6k_c47Xu39,9599,simonw,2021-12-16T18:36:41Z,2021-12-16T18:36:41Z,OWNER,"... actually no, I WILL document this, because not documenting this is what got us to this point in the first place!","{""total_count"": 1, ""+1"": 0, ""-1"": 0, ""laugh"": 1, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1078702875,Allow to set `facets_array` in metadata (like current `facets`),
https://github.com/simonw/datasette/issues/1552#issuecomment-996076373,https://api.github.com/repos/simonw/datasette/issues/1552,996076373,IC_kwDOBm6k_c47XutV,9599,simonw,2021-12-16T18:35:40Z,2021-12-16T18:35:40Z,OWNER,"I'm going to ship your fix now, but I'm not going to add this to the documentation yet because I hope to improve the design prior to Datasette 1.0.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1078702875,Allow to set `facets_array` in metadata (like current `facets`),
https://github.com/simonw/datasette/issues/1552#issuecomment-996046304,https://api.github.com/repos/simonw/datasette/issues/1552,996046304,IC_kwDOBm6k_c47XnXg,9599,simonw,2021-12-16T17:53:40Z,2021-12-16T18:16:12Z,OWNER,"I'm also not convinced that this configuration syntax is right. It's a bit weird having a `""facets""` list that can either by column-name-strings or `{""type-of-facet"": ""column-name""}` objects. Maybe there's a better design for this?

Part of the problem here is that facets were designed to accept optional extra configuration - partly to support `m2m` facets in #495 - but I haven't actually shipped any facets that use that ability.

Facet by delimiter would be a good one to exercise that ability:
- #510","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1078702875,Allow to set `facets_array` in metadata (like current `facets`),
https://github.com/simonw/datasette/issues/1552#issuecomment-996045776,https://api.github.com/repos/simonw/datasette/issues/1552,996045776,IC_kwDOBm6k_c47XnPQ,9599,simonw,2021-12-16T17:52:54Z,2021-12-16T17:52:54Z,OWNER,"I tried that fix you suggested and now this `metadata.json` does the right thing:
```json
{
    ""databases"": {
        ""fixtures"": {
            ""tables"": {
                ""facetable"": {
                    ""facets"": [
                        {
                            ""array"": ""tags""
                        }
                    ]
                }
            }
        }
    }
}
```
It does further highlight the bug in #625 though - since then if you try to add `?_facet=tags` to facet by tags treating them NOT as an array your request to do so is ignored.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1078702875,Allow to set `facets_array` in metadata (like current `facets`),
https://github.com/simonw/datasette/issues/1552#issuecomment-996034408,https://api.github.com/repos/simonw/datasette/issues/1552,996034408,IC_kwDOBm6k_c47Xkdo,9599,simonw,2021-12-16T17:37:37Z,2021-12-16T17:37:37Z,OWNER,"I think you're right! I had completely forgotten that piece of code.

This just turned into a bug fix and a documentation update. Thanks for the research!","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1078702875,Allow to set `facets_array` in metadata (like current `facets`),
https://github.com/simonw/datasette/issues/1552#issuecomment-995296725,https://api.github.com/repos/simonw/datasette/issues/1552,995296725,IC_kwDOBm6k_c47UwXV,3556,davidbgk,2021-12-15T23:29:32Z,2021-12-15T23:29:32Z,CONTRIBUTOR,"@simonw thank you for your fast answer and your guidance!

While digging into the code, I found an undocumented way of doing it:

```yaml
facets: [""Facet for a column"", {""array"": ""Facet for an array""}]
```

The only remaining problem with that solution is here: https://github.com/simonw/datasette/blob/250db8192cb8aba5eb8cd301ccc2a49525bc3d24/datasette/facets.py#L33

We have:

```python
type, metadata_config = metadata_config.items()[0]
```

But it requires to cast the `dict_items` as a list prior to access the first element:

```python
type, metadata_config = list(metadata_config.items())[0]
```

I guess it's an unspotted bug? (I mean, independently of the facets-with-arrays issue.)","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1078702875,Allow to set `facets_array` in metadata (like current `facets`),
https://github.com/simonw/datasette/issues/1552#issuecomment-995034143,https://api.github.com/repos/simonw/datasette/issues/1552,995034143,IC_kwDOBm6k_c47TwQf,9599,simonw,2021-12-15T18:02:53Z,2021-12-15T18:02:53Z,OWNER,"This is definitely a missing feature. The ""different types of facet"" stuff feels incomplete to me generally - this is one issue, but this one as well:

- #625","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1078702875,Allow to set `facets_array` in metadata (like current `facets`),