Simple GraphQL client

Ps. It's Hasura friendly.

• Simple GraphQL client
  • Reasoning
  • Features
  • Usage example
    • Environment variables
    • Modifiers on the fly
    • Cache
    • Example reader code
    • Tips
  • Working with results

Reasoning

I've tried to run a few GraphQL clients with Hasura, all of them required conversion of the data into the appropriate structures, causing issues with non-existing types ( thanks to Hasura ), for example, bigint which was difficult to export. Therefore, I present you the simple client to which you can copy & paste your graphQL query, variables and you are good to go.

Features

• Executing GraphQL queries as they are, without types declaration
• HTTP2 support!
• Support for additional headers
• Query cache

Usage example

Environment variables

• GRAPHQL_ENDPOINT - Your GraphQL endpoint. Default: http://127.0.0.1:9090/v1/graphql
• GRAPHQL_CACHE_ENABLED - Should the query cache be enabled? Default: false
• GRAPHQL_CACHE_TTL - Cache TTL in seconds for SELECT type of queries. Default: 5
• GRAPHQL_OUTPUT - Output format. Default: string, available: byte, string, mapstring
• LOG_LEVEL - Logging level. Default: info available: debug, info, warn, error
• GRAPHQL_RETRIES_ENABLE - Should retries be enabled? Default: true
• GRAPHQL_RETRIES_NUMBER - Number of retries: Default: 1
• GRAPHQL_RETRIES_DELAY - Delay in retries in milliseconds. Default: 250

Modifiers on the fly

• gql.SetEndpoint('your-endpoint-url') - modifies endpoint, without the need to set the environment variable
• gql.SetOutput('byte') - modifies output format, without the need to set the environment variable

Cache

You have two options to enable the cache:

• Use GRAPHQL_CACHE_ENABLED environment variable which will enable the cache globally. It may be desired if you want to use the cache for all queries.
• Add gqlcache: true header for your query which will enable the cache for this query only with GRAPHQL_CACHE_TTL TTL.
• You can check the list of supported per-query modifiers below

Example:

// following values passed as headers will modify behaviour of the query
// and disregard settings provided via environment variables
headers := map[string]interface{}{
  ...
  "gqlcache": true, // sets the cache as on for this query only
  "gqlretries": false, // disables retries for this query only
}

Example reader code

import (
  fmt
  graphql "github.com/lukaszraczylo/go-simple-graphql"
)

func main() {
  headers := map[string]interface{}{
    "x-hasura-user-id":   37,
    "x-hasura-user-uuid": "bde1962e-b42e-1212-ac10-d43fa27f44a5",
  }

  variables := map[string]interface{}{
    "fileHash": "123deadc0w321",
  }

  query := `query searchFileKnown($fileHash: String) {
    tbl_file_scans(where: {file_hash: {_eq: $fileHash}}) {
    	racy
    	violence
    	virus
    }
  }`

  gql := graphql.NewConnection()
  result, err := gql.Query(query, variables, headers)
  if err != nil {
    fmt.Println("Query error", err)
    return
  }
  fmt.Println(result)
}

Tips

• Connection handler ( gql := graphql.NewConnection() ) should be created once and reused in the application especially if you run dozens of queries per second. It will allow you also to use cache and http2 to its full potential.

Result

{"tbl_user_group_admins":[{"id":109,"is_admin":1}]}

Working with results

Currently attempting to switch to the fork of the ask library

Before, I used an amazing library tidwall/gjson to parse the results and extract the information required in further steps and I strongly recommend this approach as the easiest and close to painless, for example:

result := gjson.Get(result, "tbl_user_group_admins.0.is_admin").Bool()
if result {
  fmt.Println("User is an admin")
}