Author domluna
2 Stars
Updated Last
8 Months Ago
Started In
December 2020


Generates Julia types and functions from GraphQL schema. See the example for usage.

There's also an example of the official Github schema.


NOTE !!! If you're using enum GraphQL types you will need to include EnumX with your code. This is because the standard @enum macro does not allow for fields of an Enum to be redefined.

If an union GraphQLtype is detected as part of a graph cyle it's type is renamed to Any to get around parsing errors. An assert check may be added in the future so that there is some form of type checking.


    function generate(
        generate_types::Bool = true,
        generate_functions::Bool = true,
        generated_header::String = "",
        to_skip::Set{Symbol} = Set{Symbol}(),
        scalar_type_map::Dict = Dict(),

    function generate_from_schema(
        generate_types::Bool = true,
        generate_functions::Bool = true,
        generated_header::String = "",
        to_skip::Set{Symbol} = Set{Symbol}(),
        scalar_type_map::Dict = Dict(),

Generate Julia code files for GraphQL types and functions.

- "graphqlgen_types.jl": contains all the GraphQL types
- "graphqlgen_functions.jl": contains all the GraphQL functions (mutations, queries, subscriptions)

* `codegen_dir`: directory where the generated files will be saved
* `schema_paths`: list of paths to GraphQL schema files. This can be a file or a directory. If it's a directory, it will be recursively searched for GraphQL schema files.

* `generate_types`: whether to generate "graphqlgen_types.jl"
* `generate_functions`: whether to generate "graphqlgen_functions.jl"
* `generated_header`: header prepended to generated files
* `to_skip`: types or functions to skip generating
* `scalar_type_map`: mapping of GraphQL scalar types to their corresponding Julia types

generate_from_schema has the same API as generate but the second argument is the schema itself rather than the file(s) of the schema.

Quick Start

# Generate julia files in the GraphQLAPI directory based off all the files found in
# the schemas directory.
# NOTE: You should do one call for all schema files rather than N seperate calls.
julia> GraphQLGen.generate("GraphQLAPI", "schemas/")

# This generates a module in the GraphQLAPI (intended to be used as a submodule of a project)
# The file structure will be

# | GraphQLAPI
# --- GraphQLAPI.jl
# --- graphqlgen_types.jl
# --- graphqlgen_functions.jl

# The contents of GraphQLAPI will be:

module GraphQLAPI


end # module GraphQLAPI

You do not need to use GraphQLAPI.jl, in-fact it may be preferable to just include the types and functions files themselves or create your own submodule.

Generated files:

  • graphqlgen_types.jl: contains all the GraphQL types
  • graphqlgen_functions.jl: contains all the GraphQL functions (mutations, queries, subscriptions). The intended use of these functions at the moment is to create easily create queries and variables such that they can be easily serialized for an HTTP request.

Codegen Peculiarities

Types may be ordered differently in the Julia file than the schema file. This is because the Julia types must be ordered by usage. For example, if struct A uses struct B in a field then B must appear before A in Julia code. This is also why all schema files should be parsed at together. If there are types which reference eachother across files and code is generated for each file separately, then the codegen can't ensure they will be ordered correctly.

If there is a cycle then the types of the affected fields will be dropped altogether to ensure they are not referenced out of turn.

Used By Packages

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