Query: Query

In ghql: General Purpose 'GraphQL' Client

Description

ghql query class

Value

a 'Query' class (R6 class)

Public fields

queries

(list) list of queries

Methods

Public methods

• Query$print()

• Query$query()

• Query$add_fragment()

• Query$parse2json()

---

Method print()

print method for the 'Query' class

Usage

Query$print(x, ...)

Arguments

x

self

...

ignored

---

Method query()

define query in a character string

Usage

Query$query(name, x)

Arguments

name

(character) name of the query

x

(character) the query

Returns

nothing returned; sets query with 'name' internally

---

Method add_fragment()

add a fragment to a query

Usage

Query$add_fragment(query_name, fragment)

Arguments

query_name

(character) the query name to add the fragment to

fragment

(character) the fragment itself

Returns

nothing returned; sets the fragment with the query

---

Method parse2json()

parse query string with libgraphqlparser and get back JSON

Usage

Query$parse2json(query, parse_schema = FALSE)

Arguments

query

(character) a query to parse

parse_schema

(logical) enable schema definition parsing? default: 'FAlSE'

Returns

adf

Note

we run an internal method 'check_query()' that runs the public method ‘parse2json()' - if the query doesn’t pass the libgraphqlparser parser, we return the error message

Examples

# make a client
qry <- Query$new()

## define query
qry$query('query2', '{
  viewer {
    repositories(last: 10, isFork: false, privacy: PUBLIC) {
      edges {
        node {
          isPrivate
          id
          name
        }
      }
    }
  }
}')
qry
qry$queries
qry$queries$query2

# fragments
## by hand
qry$query('querywithfrag', '{
  ropensci: repositoryOwner(login:"ropensci") {
    repositories(first: 3) {
      edges {
        node {
          ...Watchers
        }
      }
    }
  }
  ropenscilabs: repositoryOwner(login:"ropenscilabs") {
    repositories(first: 3) {
      edges {
        node {
          ...Watchers
        }
      }
    }
  }
}
fragment Watchers on Repository {
  watchers(first: 3) {
    edges {
      node {
        name
      }
    }
  }
}')
qry
qry$queries
qry$queries$querywithfrag


## Not run: 
token <- Sys.getenv("GITHUB_GRAPHQL_TOKEN")
con <- GraphqlClient$new(
  url = "https://api.github.com/graphql",
  headers = list(Authorization = paste0("Bearer ", token))
)
jsonlite::fromJSON(con$exec(qry$queries$querywithfrag))

## use Fragment class fragments generator
### define query without fragment, but referring to it
qry$query('queryfrag', '{
  ropensci: repositoryOwner(login:"ropensci") {
    repositories(first: 3) {
      edges {
        node {
          ...Watchers
        }
      }
    }
  }
  ropenscilabs: repositoryOwner(login:"ropenscilabs") {
    repositories(first: 3) {
      edges {
        node {
          ...Watchers
        }
      }
    }
  }
}')

### define a fragment, and use it later
frag <- Fragment$new()
frag$fragment('Watchers', '
  fragment on Repository {
    watchers(first: 3) {
      edges {
        node {
          name
       }
    }
  }
}')
frag$fragments
frag$fragments$Watchers

### add the fragment to the query 'queryfrag'
qry$add_fragment('queryfrag', frag$fragments$Watchers)
qry
qry$queries
qry$queries$queryfrag

## End(Not run)

ghql documentation built on March 26, 2020, 6:26 p.m.