Omitted Optional Parameters fails with error.

[GeertWille]

Hello,

I have a case where I want to combine multiple parameters together to do a specific query. Some of them are optional but as soon as I trigger the query I always get a response that I have missing params to run the query. Is it possible that there is no support yet for optional params?

[fbartho]

@GeertWille If you can submit a test for us to explain what you mean, I’d love to take a look!

[HeyHugo]

I think I've encountered thing as well. Heres a small example:

gql`
  query FilterItems(
    $priceMin: Int
    $priceMax: Int
  ) {
    filterItems(
      priceMin: $priceMin
      priceMax: $priceMax
    )
      @rest(
        type: "Item"
        path: "filter?priceMax=:priceMax&priceMin=:priceMin"
      ) {
      id
      name
      price
    }
  }
`

So here I may or may not have priceMax and priceMin, but if I don't have them I will get the:
Missing params to run query error...

Maybe there is an easy way to dynamically build up the query string somehow?

[fbartho]

does that still happen if you pass null for that parameter to the variables hash?

[HeyHugo]

Yes confirmed now that it still happens with null values

[fbartho]

@HeyHugo What do you expect the path: to be turned into?
filter?priceMax=undefined&priceMin=5

If that's not what you expect, I don't think we can make the path omit undefined chunks and it would be clunky to provide a function to map the path.

[HeyHugo]

Hmm maybe this is crazy bad idea :)

..but what if instead of having the path inside the rest graphql directive the API was to provide a function somwhere taking the variables (and props?) as arguments and returning the path.

[fbartho]

I thought about that! -- We even have an example of the bodyBuilder as a function -- the problem is that a fundamental feature of apollo-link-rest is that you can @rest(path: "filter…") on any level of any GraphQL query. The result is that you'd have to provide your pathMapper-function as a variable that you pass in to all the queries that use @rest(path: "filter…") -- that would be really clunky. :(

[fbartho]

We could maybe have a registry of dynamic path-mappers at the RestLink-level, and have your @rest directive state the path-mapper-identifier to use, and pass the current variables in to the function, maybe?

[HeyHugo]

Cool, yes that would cover my use case at least 👍

[fbartho]

@HeyHugo -- I recommend opening a new GitHub issue to track that feature idea. If you have time & the inclination to help improve apollo-link-rest if you wanted to implement this, I could help you get it reviewed. -- Like I said, most of what you'll need to do is like the bodyBuilder

[HeyHugo]

Ok, I'll make an attempt at this.

Would be my first TypeScript code ever, so I'm expecting some bumps 😬

[GeertWille]

looks good to me! Thanks for the very fast response and PR 👍