Delbert  Ferry

Delbert Ferry

1622282049

Mapping GraphQL types to Swift

A tale of two type systems
Underlying many of the benefits of GraphQL is the fact that it is strongly typed. Servers define a schema, a type system that precisely describes what data is available to clients. And clients define queries specifying the structure they want a response to have in terms of this type system. This means that even though responses are usually transported as weakly-typed JSON, result types are in fact fully predictable. For each field, we have the type information to know exactly what data to expect. The schema thus acts as a strongly typed and self-documenting contract between client and server.

#graphql #swift #graphql types #mapping

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Buddha Community

Mapping GraphQL types to Swift
Delbert  Ferry

Delbert Ferry

1622282049

Mapping GraphQL types to Swift

A tale of two type systems
Underlying many of the benefits of GraphQL is the fact that it is strongly typed. Servers define a schema, a type system that precisely describes what data is available to clients. And clients define queries specifying the structure they want a response to have in terms of this type system. This means that even though responses are usually transported as weakly-typed JSON, result types are in fact fully predictable. For each field, we have the type information to know exactly what data to expect. The schema thus acts as a strongly typed and self-documenting contract between client and server.

#graphql #swift #graphql types #mapping

Houston  Sipes

Houston Sipes

1600430400

10 Free Online Resources To Learn Swift Language

Swift is a fast and efficient general-purpose programming language that provides real-time feedback and can be seamlessly incorporated into existing Objective-C code. This is why developers are able to write safer, more reliable code while saving time. It aims to be the best language that can be used for various purposes ranging from systems programming to mobile as well as desktop apps and scaling up to cloud services.

Below here, we list down the 10 best online resources to learn Swift language.

(The list is in no particular order)

#developers corner #free online resources to learn swift language #learn swift #learn swift free #learn swift online free #resources to learn swift #swift language #swift programming

Top Swift Development Companies | Top Swift Developers - TopDevelopers.co

A thoroughly researched list of top Swift developers with ratings & reviews to help find the best Swift development companies around the world.

#swift development service providers #best swift development companies #top swift development companies #swift development solutions #top swift developers #swift

Hire Dedicated Swift Developers

Want to create a native iOS application for your Startup?

Hire Dedicated Swift Developers for end-to-end services like development, migration, upgrade, testing, and support & maintenance. Trust HourlyDeveloper.io our Swift development team for iOS device apps that are high on performance and security.

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#hire dedicated swift developers #swift developers #swift development company #swift development services #swift development #swift

Elm Graphql: Autogenerate Type-safe GraphQL Queries in Elm

dillonkearns/elm-graphql  

Why use this package over the other available Elm GraphQL packages? This is the only one that generates type-safe code for your entire schema. Check out this blog post, Type-Safe & Composable GraphQL in Elm, to learn more about the motivation for this library. (It's also the only type-safe library with Elm 0.18 or 0.19 support, see this discourse thread).

I built this package because I wanted to have something that:

  1. Gives you type-safe GraphQL queries (if it compiles, it's valid according to the schema),
  2. Creates decoders for you in a seamless and failsafe way, and
  3. Eliminates GraphQL features in favor of Elm language constructs where possible for a simpler UX (for example, GraphQL variables & fragments should just be Elm functions, constants, lets).

See an example in action on Ellie. See more end-to-end example code in the examples/ folder.

Overview

dillonkearns/elm-graphql is an Elm package and accompanying command-line code generator that creates type-safe Elm code for your GraphQL endpoint. You don't write any decoders for your API with dillonkearns/elm-graphql, instead you simply select which fields you would like, similar to a standard GraphQL query but in Elm. For example, this GraphQL query

query {
  human(id: "1001") {
    name
    homePlanet
  }
}

would look like this in dillonkearns/elm-graphql (the code in this example that is prefixed with StarWars is auto-generated)

import Graphql.Operation exposing (RootQuery)
import Graphql.SelectionSet as SelectionSet exposing (SelectionSet)
import StarWars.Object
import StarWars.Object.Human as Human
import StarWars.Query as Query
import StarWars.Scalar exposing (Id(..))


query : SelectionSet (Maybe HumanData) RootQuery
query =
    Query.human { id = Id "1001" } humanSelection


type alias HumanData =
    { name : String
    , homePlanet : Maybe String
    }


humanSelection : SelectionSet HumanData StarWars.Object.Human
humanSelection =
    SelectionSet.map2 HumanData
        Human.name
        Human.homePlanet

GraphQL and Elm are a perfect match because GraphQL is used to enforce the types that your API takes as inputs and outputs, much like Elm's type system does within Elm. elm-graphql simply bridges this gap by making your Elm code aware of your GraphQL server's schema. If you are new to GraphQL, graphql.org/learn/ is an excellent way to learn the basics.

After following the installation instructions to install the @dillonkearns/elm-graphql NPM package and the proper Elm packages (see the Setup section for details). Once you've installed everything, running the elm-graphql code generation tool is as simple as this:

npx elm-graphql https://elm-graphql.herokuapp.com --base StarWars --output examples/src

If headers are required, such as a Bearer Token, the --header flag can be supplied.

npx elm-graphql https://elm-graphql.herokuapp.com --base StarWars --output examples/src --header 'headerKey: header value'

Learning Resources

There is a thorough tutorial in the SelectionSet docs. SelectionSets are the core concept in this library, so I recommend reading through the whole page (it's not very long!).

The examples/ folder is another great place to start.

If you want to learn more GraphQL basics, this is a great tutorial, and a short read: graphql.org/learn/

My Elm Conf 2018 talk goes into the philosophy behind dillonkearns/elm-graphql

Types Without Borders Elm Conf Talk

(Skip to 13:06 to go straight to the dillonkearns/elm-graphql demo).

If you're wondering why code is generated a certain way, you're likely to find an answer in the Frequently Asked Questions (FAQ).

There's a very helpful group of people in the #graphql channel in the Elm Slack. Don't hesitate to ask any questions about getting started, best practices, or just general GraphQL in there!

Setup

dillonkearns/elm-graphql generates Elm code that allows you to build up type-safe GraphQL requests. Here are the steps to setup dillonkearns/elm-graphql.

Add the dillonkearns/elm-graphql elm package as a dependency in your elm.json. You will also need to make sure that elm/json is a dependency of your project since the generated code has lots of JSON decoders in it.

elm install dillonkearns/elm-graphql
elm install elm/json

Install the @dillonkearns/elm-graphql command line tool through npm. This is what you will use to generate Elm code for your API. It is recommended that you save the @dillonkearns/elm-graphql command line tool as a dev dependency so that everyone on your project is using the same version.

npm install --save-dev @dillonkearns/elm-graphql
# you can now run it locally using `npx elm-graphql`,
# or by calling it through an npm script as in this project's package.json

Run the @dillonkearns/elm-graphql command line tool installed above to generate your code. If you used the --save-dev method above, you can simply create a script in your package.json like the following:

{
  "name": "star-wars-elm-graphql-project",
  "version": "1.0.0",
  "scripts": {
    "api": "elm-graphql https://elm-graphql.herokuapp.com/api --base StarWars"
  }

With the above in your package.json, running npm run api will generate dillonkearns/elm-graphql code for you to call in ./src/StarWars/. You can now use the generated code as in this Ellie example or in the examples folder.

Subscriptions Support

You can do real-time APIs using GraphQL Subscriptions and dillonkearns/elm-graphql. Just wire in the framework-specific JavaScript code for opening the WebSocket connection through a port. Here's a live demo and its source code. The demo server is running Elixir/Absinthe.

Contributors

Thank you Mario Martinez (martimatix) for all your feedback, the elm-format PR, and for the incredible logo design!

Thank you Mike Stock (mikeastock) for setting up Travis CI!

Thanks for the reserved words pull request @madsflensted!

A huge thanks to @xtian for doing the vast majority of the 0.19 upgrade work! :tada:

Thank you Josh Adams (@knewter) for the code example for Subscriptions with Elixir/Absinthe wired up through Elm ports!

Thank you Romario for adding OptionalArgument.map!

Thank you Aaron White for your pull request to improve the performance and stability of the elm-format step! 🎉

Roadmap

All core features are supported. That is, you can build any query or mutation with your dillonkearns/elm-graphql-generated code, and it is guaranteed to be valid according to your server's schema.

dillonkearns/elm-graphql will generate code for you to generate subscriptions and decode the responses, but it doesn't deal with the low-level details for how to send them over web sockets. To do that, you will need to use custom code or a package that knows how to communicate over websockets (or whichever protocol) to setup a subscription with your particular framework. See this discussion for why those details are not handled by this library directly.

I would love to hear feedback if you are using GraphQL Subscriptions. In particular, I'd love to see live code examples to drive any improvements to the Subscriptions design. Please ping me on Slack, drop a message in the #graphql channel, or open up a Github issue to discuss!

I would like to investigate generating helpers to make pagination simpler for Connections (based on the Relay Cursor Connections Specification). If you have ideas on this chime in on this thread.

See the full roadmap on Trello.


Author: dillonkearns
Source Code: https://github.com/dillonkearns/elm-graphql
License: View license

#graphql