go-graphql-query

Complete Domain Specific Language (DSL) for GraphQL query in go. With this package you can to

generate a correct GraphQL query string from a go structures;
use and share similar Arguments, Variables and e.t.c between different queries;
easily add new fields to your query;
add Fragments and Directives to queries;

Quick start

Install package

$ go get github.com/denisart/go-graphql-query

Simple query

package main

import (
    "fmt"

    "github.com/denisart/go-graphql-query/pkg/graphqlQuery"
)

func main() {
    heroQuery := graphqlQuery.Field{
        Name: "hero",
        Fields: []graphqlQuery.Selection{
            &graphqlQuery.StringField{Value: "name"},
        },
    }

    operation := graphqlQuery.Operation{
        Type:   graphqlQuery.QUERY,
        Name:   nil,
        Fields: []graphqlQuery.Selection{&heroQuery},
    }

    fmt.Println(operation.RenderType())
}
/*
query {
  hero {
    name
  }
}
*/

How to use

go-graphql-query provides special structures for generate of GraphQL queries. Below are examples of using these classes for queries from GraphQL documentation https://graphql.org/learn/queries/

First query

Operation it is the general class for render of your GraphQL query or mutation. For the first query from https://graphql.org/learn/queries/#fields

{
  hero {
    name
  }
}

we can to use graphqlQuery.Operation as like that

package main

import (
    "fmt"

    "github.com/denisart/go-graphql-query/pkg/graphqlQuery"
)

func main() {
    heroQuery := graphqlQuery.Field{
        Name: "hero",
        Fields: []graphqlQuery.Selection{
            &graphqlQuery.StringField{Value: "name"},
        },
    }

    operation := graphqlQuery.Operation{
        Type:   graphqlQuery.QUERY,
        Name:   nil,
        Fields: []graphqlQuery.Selection{&heroQuery},
    }

    fmt.Println(operation.RenderType())
}
/*
query {
  hero {
    name
  }
}
*/

Same way for the query with sub-fields

"""
{
  hero {
    name
    # Queries can have comments!
    friends {
      name
    }
  }
}
"""

we can to use graphqlQuery.Selection as like that

package main

import (
    "fmt"

    "github.com/denisart/go-graphql-query/pkg/graphqlQuery"
)

func main() {
    friendsField := graphqlQuery.Field{
        Name: "friends",
        Fields: []graphqlQuery.Selection{
            &graphqlQuery.StringField{Value: "name"},
        },
    }

    heroQuery := graphqlQuery.Field{
        Name: "hero",
        Fields: []graphqlQuery.Selection{
            &graphqlQuery.StringField{Value: "name"},
            &friendsField,
        },
    }

    operation := graphqlQuery.Operation{
        Type:   graphqlQuery.QUERY,
        Name:   nil,
        Fields: []graphqlQuery.Selection{&heroQuery},
    }

    fmt.Println(operation.RenderType())
}
/*
query {
  hero {
    name
    friends {
      name
    }
  }
}
*/

Arguments

For arguments in your query or fields (https://graphql.org/learn/queries/#arguments) you can use graphqlQuery.Argument

package main

import (
    "fmt"

    "github.com/denisart/go-graphql-query/pkg/graphqlQuery"
)

func main() {
    // argument for your id
    idArg := graphqlQuery.Argument{
        Name:  "id",
        Value: &graphqlQuery.StringValue{Value: "1000"},
    }
    // argument for a field
    unitArg := graphqlQuery.Argument{
        Name:  "unit",
        Value: &graphqlQuery.EnumValue{Value: "FOOT"},
    }

    humanQuery := graphqlQuery.Field{
        Name: "human",
        // use argument in top-level
        Arguments: []*graphqlQuery.Argument{
            &idArg,
        },
        Fields: []graphqlQuery.Selection{
            &graphqlQuery.StringField{Value: "name"},
            &graphqlQuery.Field{
                Name: "height",
                // use arguments for some field
                Arguments: []*graphqlQuery.Argument{
                    &unitArg,
                },
            },
        },
    }

    operation := graphqlQuery.Operation{
        Type:   graphqlQuery.QUERY,
        Name:   nil,
        Fields: []graphqlQuery.Selection{&humanQuery},
    }
}
/*
query {
  human(
    id: "1000"
  ) {
    name
    height(
      unit: FOOT
    )
  }
}
*/

Aliases

graphqlQuery.Field has the special field for alias