Articles API: filtering by tags

[jessleenyc]

Is your feature request related to a problem? Please describe.

Describe the solution you'd like
In response to #3509, we want to allow the API endpoint to filter by tags and include an 'anti-tag' list.

[bdbch]

Awesome, thanks a lot!

[cdvillard]

Closed #3668 after @rhymes pointed out that it basically mirrored this. Simply having an additional optional flag for the query string of something like nottagged= would be great, given that #discuss articles are still of type article. There might be an argument, though, to do some heavy lifting now and just create a type discussion, should that grow into its own, but I don't have a deeper understanding of dev.to's architecture, so I'll digress to stay on topic.

[caseyrollins]

Hi all, taking a stab at this issue! Does anyone have a preference on the name for the filter (anti_tag v. not_tagged)? @rhymes?

[rhymes]

@caseyrollins since the initial request is talking about filtering by multiple tags I would probably consider introducing two new parameters:

tags which takes a comma separated list of tags to include
tags_exclude which takes a comma separated list of tags to exclude

(right now we have only tag, we could consider extending this to support multiple tags but due to the naming I'm inclined to leave it alone and use two more explicit parameters)

If they both appear they'd have to be applied in and (pseudo SQL: WHERE tags in (a,b,c) AND tags not in (d,e,f))

Not 100% sure if multiple tags in each list should be in AND (I want articles that are tagged both discuss and python but not articles that are tagged both react and javascript) or using OR (I want articles that are tagged either discuss or python but not articles that are tagged either react and javascript)

I think OR inside one list and obviously AND between the two lists is the most logical but it could be up for debate. It's also the closest to how the single parameter tag works right now (It doesn't return articles that are only tagged python, but articles that have python in their tag list).

What do you all think? Should we introduce 2 new params or just extend tag plus the param for exclusion? Should we use AND or OR to join multiple tags in each list?

[caseyrollins]

@rhymes, I completely agree that tags and tags_exclude should take comma separated lists. I would also say that tags and tags_exclude should be an AND between each other and the tags within each list should be OR. It feels the most intuitive and resembles what I've seen in other APIs.

Do you think tags should be a new parameter (along with exclude_tags), or should tag be removed and replaced with tags? Does the API have a deprecation policy?

[rhymes]

@caseyrollins thanks!

Does the API have a deprecation policy?

No, not really, we've been operating with the assumption that we're just going to add things and trying not to break anything even though it's a v0