GraphQL Backend Integration: Substituing Boolean Variables

[DpKass]

I am trying to define a config, where a GraphQL Backend is called using a boolean variable, which comes from the query variables. See the following:

{{ define "graphql-backend" }}
"backend/graphql": {
  "type": "query",
  "query_path": "./output.graphql",
  "variables": {
    "locale": "{locale}",
    "preview": "{preview}"
    {{- with .variables -}},
    {{- $vars := . -}}
    {{- $length := len $vars -}}
    {{- range $i, $key := keys $vars }}
    "{{ $key }}": "{{ index $vars $key }}"{{ if lt $i (sub $length 1) }},{{ end }}
    {{- end }}
    {{- end }}
},
  "operationName": "{{ .operation }}"
}
{{- end }}

The problematic line is "preview": "{preview}" as the substitution will always be a string. {preview} is a query param, i.e. what comes behind the ? in the URL, e.g. ?locale=en-US&preview=false. Thus it is supposed to be recognized at runtime. Is there a way to fix this? I could also adjust the GraphQL if needed, but I don't think there is a solution there.

The only (kinda ugly) solution i am seeing is creating two separate endpoints. Though if more such variables are added,  the complexity will explode.

Also, is there a way to set a default value for locale and variables?