Crate gelx

Generate fully typed rust code from your gel schema and inline queries with gelx.

Installation

To install the gelx crate, you can use the following commands.

cargo add gelx

Or, add the following directly to your Cargo.toml file.

[dependencies]
gelx = "0.8"

Make sure you’ve installed the gel CLI for your platform.

Once installed you should be able to run the following command to verify your installation.

gel --version

And then initialize in the project directory.

gel init

gelx!

Working with the default gel crate requires manually writing untyped queries and creating the rust structs and enums for both the input and output into these queries with. The correctness of your code can only be checked at runtime increasing the risk of bugs and errors.

gelx! transforms your queries into rust structs, types and functions, providing safety during development of your project.

Inline Queries

use gel_errors::Error;
use gel_tokio::create_client;
use gelx::gelx;

// Creates a module called `example` with a function called `query` and structs
// for the `Input` and `Output`.
gelx!(
	example,
	"select { hello := \"world\", custom := <str>$custom }"
);

#[tokio::main]
async fn main() -> Result<(), Error> {
	let client = create_client().await?;
	let input = example::Input {
		custom: String::from("custom"),
	};

	// For queries the following code can be used.
	let output = example::query(&client, &input).await?;

	Ok(())
}

The macro above generates the following code in the background:

pub mod example {
	use ::gelx::exports as __g;
	/// Execute the desired query.
	pub async fn query(
		client: &__g::gel_tokio::Client,
		props: &Input,
	) -> ::core::result::Result<Output, __g::gel_errors::Error> {
		client.query_required_single(QUERY, props).await
	}
	/// Compose the query as part of a larger transaction.
	pub async fn transaction(
		conn: &mut __g::gel_tokio::Transaction,
		props: &Input,
	) -> ::core::result::Result<Output, __g::gel_errors::Error> {
		conn.query_required_single(QUERY, props).await
	}
	#[derive(
		Clone,
		Debug,
		__g::serde::Serialize,
		__g::serde::Deserialize,
		__g::typed_builder::TypedBuilder,
		__g::gel_derive::Queryable,
	)]
	pub struct Input {
		#[builder(setter(into))]
		pub custom: String,
	}
	impl __g::gel_protocol::query_arg::QueryArgs for Input {
		fn encode(
			&self,
			encoder: &mut __g::gel_protocol::query_arg::Encoder,
		) -> core::result::Result<(), __g::gel_errors::Error> {
			let map = __g::gel_protocol::named_args! {
				"custom" => self.custom.clone(),
			};
			map.encode(encoder)
		}
	}
	#[derive(
		Clone, Debug, __g::serde::Serialize, __g::serde::Deserialize, __g::gel_derive::Queryable,
	)]
	pub struct Output {
		pub hello: String,
		pub custom: String,
	}
	/// The original query string provided to the macro. Can be reused in your
	/// codebase.
	pub const QUERY: &str = "select { hello := \"world\", custom := <str>$custom }";
}

Query Files

Define a query file in the queries directory of your crate called select_user.edgeql.

# queries/select_user.edgeql

select User {
  name,
  bio,
  slug,
} filter .slug = <str>$slug;

Then use the gelx macro to import the query.

use gel_errors::Error;
use gelx::create_client;
use gelx::gelx;

// Creates a module called `select_user` with public functions `transaction` and
// `query` as well as structs for the `Input` and `Output`.
gelx!(select_user);

#[tokio::main]
async fn main() -> Result<(), Error> {
	let client = create_client().await?;

	// Generated code can be run inside a transaction.
	let result = client
		.transaction(|mut txn| {
			async move {
				let input = select_user::Input {
					slug: String::from("test"),
				};
				let output = select_user::transaction(&mut txn, &input).await?;
				Ok(output)
			}
		})
		.await?;

	Ok(())
}

gelx_build

By default, macros can’t read from the Cargo.toml file of the consuming crate. The gelx_build crate provides a way to read the configuration from the Cargo.toml file using the build.rs script.

You can read the gelx_build readme for more information.

CLI

The gelx_cli crate exposes a binary called gelx transforms the typed code into *.rs files rather than inline queries.

It should be run from the crate directory and will read from the configuration specified in the next section.

gelx generate --cwd path/to/crate

Sometimes you will need to check that the generated code matches the current database schema and queries generated by gel. This is useful for CI pipelines to ensure the generated code is up to date.

gelx check --cwd path/to/crate

If there are changes that haven’t been accounted for, the check will fail with a diff and you should regenerate the code.

More information can be found in the gelx_cli readme.

Globals

The gelx_cli will generate a Globals struct for your project. It iterates over all the schema::Global types defined in your .gel schema to generate a Globals struct. This struct can be used to create a gel client.

For example if you have the following globals in your schema.

module default {
	global current_user_id: uuid;
	global current_user := (
  	select User filter .id = global current_user_id
	);
	global alternative: str;
}

The generated Globals struct will look like the following. Notice how the current_user global, which is an alias type, is ignored. This is because it can’t be set externally and is automatically derived from the current_user_id global (it only exists within the database).

// src/db/mod.rs
use ::gelx::exports as __g;
#[derive(
	::std::fmt::Debug,
	::core::clone::Clone,
	__g::serde::Serialize,
	__g::serde::Deserialize,
	__g::typed_builder::TypedBuilder,
)]
#[cfg_attr(feature = "ssr", derive(__g::gel_derive::Queryable))]
#[builder(crate_module_path = __g::typed_builder)]
#[builder(field_defaults(default, setter(into, strip_option(fallback_suffix = "_opt"))))]
pub struct Globals {
	pub alternative: Option<String>,
	pub current_user_id: Option<__g::uuid::Uuid>,
}
#[cfg(feature = "ssr")]
impl __g::gel_tokio::GlobalsDelta for Globals {
	fn apply(self, modifier: &mut __g::gel_tokio::state::GlobalsModifier<'_>) {
		modifier.set("additional::alternative", self.alternative);
		modifier.set("default::current_user_id", self.current_user_id);
	}
}
impl Globals {
	/// Create a gel client with the globals.
	pub async fn into_client(
		self,
	) -> ::core::result::Result<__g::gel_tokio::Client, __g::gel_tokio::Error> {
		let client = __g::gel_tokio::create_client().await?.with_globals(self);
		Ok(client)
	}

	/// Create a gel client with the globals.
	pub async fn to_client(
		&self,
	) -> ::core::result::Result<__g::gel_tokio::Client, __g::gel_tokio::Error> {
		let client = self.clone().into_client().await?;
		Ok(client)
	}
}

The above code can be used to create a gel client with the globals.

use crate::db::Globals;
use gelx::exports::uuid::Uuid;

// Using the builder pattern
let client = Globals::builder()
	.current_user_id(Uuid::new_v4())
	.alternative("test")
	.build()
	.into_client()
	.await?;

// Using the `to_client` method
let client = Globals {
	current_user_id: Some(Uuid::new_v4()),
	alternative: Some("test".to_string()),
}.into_client().await?;

Configuration

The following configuration options are supported. The provided defaults will be used if a value is not specified.

[package.metadata.gelx]
# The path to the directory containing the queries.
queries_path = "./queries"

# The features to enable and their aliases. By default all features are enabled.
# To disable a feature set its value to `false`. To alias a feature behind a
# feature flag use the following format `feature = { query = "ssr" }`. This will
# enable the query feature only when the `ssr` feature is enabled.
#
# The available features are:
#
# - `query` - When enabled you must include `gel-protocol` as a dependency.
# - `serde` - Enable `serde` for the generated code.
features = { query = true, serde = true }

# The location of the generated code when using the `gelx` CLI.
output_path = "./src/db"

# The name of the arguments input struct. Will be transformed to PascalCase.
input_struct_name = "Input"

# The name of the exported output struct for generated queries. Will be transformed to PascalCase.
output_struct_name = "Output"

# The name of the query function exported.
query_function_name = "query"

# The name of the transaction function exported.
transaction_function_name = "transaction"

# The name of the query constant exported.
query_constant_name = "QUERY"

# The alias used for the `gelx::exports` module.
exports_alias = "__g"

# The macros which are always derived for the generated structs.
struct_derive_macros = [
	"::std::fmt::Debug",
	"::core::clone::Clone",
]

# The macros which are always derived for the generated scalar types which are wrapper structs.
# As envisiaged by <https://github.com/ifiokjr/gelx/issues/29>
scalar_derive_macros = [
	"::std::fmt::Debug",
	"::core::clone::Clone",
]

# The macros which are always derived for the generated enums.
enum_derive_macros = [
	"::std::fmt::Debug",
	"::core::clone::Clone",
	"::core::marker::Copy",
]

# The relative path to the `gel` config file. This is optional, and if not
# provided, the `gel` config will be read from the environment variables.
gel_config_path = "./gel.toml"

# The name of the `gel` instance to use. This is optional, and if not provided,
# the environment variable `$GEL_INSTANCE` will be used.
gel_instance = "$GEL_INSTANCE"

# The name of the `gel` branch to use. This is optional, and if not provided,
# the environment variable `$GEL_BRANCH` will be used.
gel_branch = "$GEL_BRANCH"

Geometry and Geography

The gelx crate provides wrapper types for the Geometry and Geography types from the geo crate.

# queries/insert_location.edgeql

with NewLocation := (insert Location {
	point := <ext::postgis::geometry>$point,
	area := <ext::postgis::geography>$area,
})
select NewLocation {
	point,
	area,
};

use gel_errors::Error;
use gelx::Geography;
use gelx::Geometry;
use gelx::create_client;
use gelx::gelx;
use gelx::geo::point;
use gelx::geo::polygon;

// Creates a module called `insert_location` with public functions `transaction`
// and `query` as well as structs for the `Input` and `Output`.
gelx!(insert_location);

#[tokio::main]
async fn main() -> Result<(), Error> {
	let client = create_client().await?;
	let point = point!(x: 1.0, y: 1.0);
	let polygon = polygon![
		(x: -111., y: 45.),
		(x: -111., y: 41.),
		(x: -104., y: 41.),
		(x: -104., y: 45.),
	];
	let output = insert_location::query(
		&client,
		&insert_location::Input {
			point: Geometry(point.into()),
			area: Geography(polygon.into()),
		},
	)
	.await?;

	println!("{:?}", output);

	Ok(())
}

Missing Types

The following types are not currently supported:

• MultiRange - The CLI/macro will panic if a multirange is used.

MultiRange

These are not currently exported by gel-protocol and should be added in a PR to the gel-protocol crate if they are still supported in the new protocol.

Crate Features

• default — The default feature is with_all.
• with_bigint — Include the num-bigint dependency.
• with_bigdecimal — Use the bigdecimal crate.
• with_chrono — Use the chrono crate for all dates.
• with_geo — Use the geo crate for all geometry and geography types.
• with_all (enabled by default) — Include all additional types. This is included by default. Use default-features = false to disable.
• builder — Use the typed-builder crate to generate the builders for the generated Input structs.
• query — Turn on the query and transaction methods and anything that relies on gel-tokio. The reason to separate this feature is to enable usage of this macro in browser environments where gel-tokio is not feasible.
• serde — Enable serde for the generated code.
• strum - Use the strum crate for deriving strings from the created enums.

Recommended Setup

Create a gel.toml in the root of your project with the following configuration. The following configuration will work for a single crate project.

[instance]
server-version = "6.7"

[project]
schema-dir = "dbschema"

[hooks]
project.init.after = "gelx generate"
branch.switch.after = "gelx generate"
schema.update.after = "gelx generate"

[[watch]]
files = ["dbschema/*.gel"]
script = "gelx generate"

[[watch]]
files = ["queries/*.edgeql"]
script = "gelx generate"

By default this will generate the code into the src/db directory. You can change this by setting the output_path in the configuration.

Contributing

devenv is used to provide a reproducible development environment for this project. Follow the getting started instructions.

To automatically load the environment you should install direnv and then run direnv allow ..

direnv allow .

You now have a shell with all the dependencies installed and project-specific commands available.

Run the following commands to install all the required dependencies.

install:all

This installs all the cargo binaries locally so you don’t need to worry about polluting your global namespace.

At this point you must setup the gel instance.

db:setup # setup the gel instance

The above command will setup the local database and install the postgis extension.

Now you can make your changes and run tests.

test:all

Available Commands

You can view all the available scripts, packages, tasks and environment variables by running devenv info.

• build:all: Build all crates with all features activated.
• build:docs: Build documentation site.
• coverage:all: Test all files and generate a coverage report for upload to codecov.
• db:destroy: Destroy the local database.
• db:reset: Reset the local database.
• db:setup: Setup the local database.
• db:up: Watch changes to the local database.
• fix:all: Fix all fixable lint issues.
• fix:clippy: Fix fixable lint issues raised by rust clippy.
• fix:format: Fix formatting for entire project.
• fix:gelx: Fix fixable lint issues raised by gelx.
• install:all: Install all dependencies.
• install:cargo:bin: Install cargo binaries locally.
• lint:all: Lint all project files.
• lint:clippy: Check rust clippy lints.
• lint:format: Check all formatting is correct.
• lint:gelx: Check gelx is formatted correctly.
• test:all: Test all project files.
• update:deps: Update all project dependencies.

Upgrading devenv

If you have an outdated version of devenv, you can update it by running the following commands. If you know of an easier way, please create a PR to update these docs.

nix profile list # find the index of the devenv package
nix profile remove <index>
nix profile install ---accept-flake-config nixpkgs#devenv

Editor Setup

To setup recommended configuration for your favorite editor run the corresponding command.

setup:vscode # Setup vscode with recommended configuration

setup:helix # Setup helix with recommended configuration

License

Unlicense, see the license file.

Features

• default — The default feature is with_all.

• with_bigint (enabled by default) — Include the num-bigint dependency.

• with_bigdecimal (enabled by default) — Use the bigdecimal crate.

• with_chrono (enabled by default) — Use the chrono crate for all dates.

• with_geo (enabled by default) — Use the geo-types crate for all geo types.

• with_all (enabled by default) — Include all additional types. This is included by default. Use default-features = false to disable.

• builder (enabled by default) — Use the typed-builder crate to generate the builders for the generated Input structs.

• query — Turn on the query and transaction methods and anything that relies on gel-tokio. The reason to separate this feature is to enable usage of this macro in browser environments where gel-tokio is not feasible.

  Adding this feature requires adding the gel-protocol dependency to your project. This is because the Queryable derive macro requires the gel-protocol crate to be present in the consuming crate.

• serde — Enable serde for the generated code.

• strum (enabled by default) — Enable strum for the generated code.

  Adding this feature requires adding the strum dependency to your project.

Re-exports

pub use geo;

pub use geo_types;

pub use geo_traits;

pub use wkb;

Modules

exports

Macros

gelx

Generates a query module from a query string.

gelx_fileDeprecated

Generates a query module from a query string relative to the root of the crate this is defined in. This is useful for queries that are not placed in the queries folder at the root of the crate.

Structs

Geography

Another wrapper struct for the geo::Geometry enum with support for WKB encoding and interop with the ext::postgis::geography type.

Geometry

A wrapper for thegeo::Geometry enum with support for WKB encoding and interop with the ext::postgis::geometry type.

Functions

check_scalar

create_client

Create a connection to the database with default parameters

create_client_with_globals

Create a gel client with the provided globals trait.