GraphQL | Can we implement search by programming language in GitHub GraphQL API using Directives? - github

Question

I'm experimenting with GraphQL and I want to create a GraphQL script for advanced search. I'm stuck at figuring out how to search for a repository containing a specific language. For example, I only want to search for repos written in Kotlin. This is what my query looks like
query AdvancedSearch($query: String!, $type: SearchType!, $numOfResults: Int!, $nextPageCursor: String) {
search(type: $type, query: $query, first: $numOfResults, after: $nextPageCursor) {
pageInfo {
hasNextPage
endCursor
}
repositoryCount
nodes {
... on Repository {
name
nameWithOwner
description
languages(first: 100) {
nodes {
name
}
}
}
}
}
}
I'm thinking along the lines of having a #skip directive in languages, something like
languages(first:100) #skip(if:$filterLanguage != "Kotlin")
I don't want to pass "language:kotlin" in the search query, I want to do this using Directives. Is something like this possible?

Answer 1

From the spec: http://spec.graphql.org/June2018/#sec--skip
The #skip directive may be provided for fields, fragment spreads, and inline fragments, and allows for conditional exclusion during execution as described by the if argument.
In other words, the #skip (and its #include counterpart) directive only determines whether a field is included in the request. Skipping a field this way is the same as not including it in the first place. Additionally, the if argument of the directive may only be passed true, false or a Boolean variable -- no sort of expression syntax is supported.
More importantly, including or omitting a particular field will have no impact on how any parent field is executed. If your intent is to modify what results are returned by the search field, then you need to provide the appropriate arguments to that field. The schema could provide some kind of argument to let you filter by languages specifically but that does not appear to be the case -- the only way to do it is through the query argument.