https://maartenvanvliet.nl/tags/elixir/ Recent content in elixir on Maarten van Vliet Hugo -- gohugo.io en-us Maarten van Vliet Tue, 27 Dec 2022 00:08:54 +0100 https://maartenvanvliet.nl/2022/12/27/til-rustler-encoder/ Tue, 27 Dec 2022 00:08:54 +0100 https://maartenvanvliet.nl/2022/12/27/til-rustler-encoder/ I am currently using Rustler, a tool that allows for Elixir to interact with the Rust ecosystem. As a newcomer to Rust, working on Rust-Elixir crossover libraries helps me understand its quirks. Today, I was trying to use a SQL parser in Rust and convert the results to Elixir terms. Rustler’s NifStructs feature made this process convenient. However, I encountered an issue with a data structure defined as follows: #[derive(NifStruct)] #[module = "SqlParser. https://maartenvanvliet.nl/2022/04/28/absinthe_input_union/ Thu, 28 Apr 2022 11:08:54 +0100 https://maartenvanvliet.nl/2022/04/28/absinthe_input_union/ In this post I will explain how to create a type system directive in Absinthe to implement Input Unions in Graphql. The code for this post can be found on Github A common issue with GraphQL is the lack of input unions. This means an input object that lets you choose between a number of potential input types. For example (taken from a spec discussion): input PetInput { cat: CatInput dog: DogInput fish: FishInput } input CatInput { name: String! https://maartenvanvliet.nl/2022/01/26/absinthe_formatter/ Wed, 26 Jan 2022 11:08:54 +0100 https://maartenvanvliet.nl/2022/01/26/absinthe_formatter/ With the release of Elixir 1.13 it became possible to add plugins to the formatter. These plugins gives developers the option to hook into the Elixir formatter. I’ve created an Elixir formatter plugin to Absinthe to format GraphQL documents. With the release of Absinthe 1.7 this is available for everyone to use. To start, you’ll need Absinthe 1.7 or higher together with Elixir 1.13 or higher. The Absinthe project comes with Absinthe. https://maartenvanvliet.nl/project/subscriptions_transport_ws/ Sat, 02 Oct 2021 12:04:18 +0200 https://maartenvanvliet.nl/project/subscriptions_transport_ws/ Absinthe subscriptions-transport-ws websocket Support subscriptions-transport-ws websocket protocol for Absinthe https://github.com/maartenvanvliet/subscriptions-transport-ws https://maartenvanvliet.nl/2020/09/21/reason_urql_and_absinthe/ Mon, 21 Sep 2020 09:08:54 +0100 https://maartenvanvliet.nl/2020/09/21/reason_urql_and_absinthe/ Lately I’ve been looking into ReasonML as a language to pick up. In the past I’ve dabbled with Elm and really enjoyed it but it’s lack of interoperability with javascript hampers its development. ReasonML offers a far better story in this regards, there are excellent React and React-Native libraries/bindings available as well as bindings for popular Graphql clients. That, combinated with great type-safety makes it a compelling alternative to Elm and Typescript. https://maartenvanvliet.nl/2020/08/29/absinthe_and_urql/ Sat, 29 Aug 2020 11:08:54 +0100 https://maartenvanvliet.nl/2020/08/29/absinthe_and_urql/ Many Graphql stacks use Apollo as the javascript client library. It’s well maintained, popular and has lot’s of examples. It also works together with Absinthe, the Elixir Graphql library. If you need to use graphql subscriptions in combination with Apollo and Absinthe there is the socket-apollo-link to connect the two. There’s another interesting javascript client library for Graphql on the horizon, Urql. It’s a bit more lightweight and looks really promising. https://maartenvanvliet.nl/project/certbot/ Fri, 12 Jul 2019 10:04:18 +0200 https://maartenvanvliet.nl/project/certbot/ Certbot hex package Serve Letsencrypt certificates dynamically for Plug/Phoenix https://maartenvanvliet.nl/presentation/sketch_rcte/ Thu, 02 May 2019 12:04:18 +0200 https://maartenvanvliet.nl/presentation/sketch_rcte/ A presentation I gave at the Amsterdam Elixir Meetup. We faced a problem where we needed to recursively load records from a database. The application was doing the recursion itself, recursively querying the mariadb instance. I explained how we moved to RCTE’s and how this works in Ecto. Slides https://maartenvanvliet.nl/project/absinthe_sdl/ Wed, 02 Jan 2019 12:04:18 +0200 https://maartenvanvliet.nl/project/absinthe_sdl/ Absinthe SDL Create Graphql SDL schemas from Absinthe schemas https://maartenvanvliet.nl/2018/12/29/absinthe_macro_dsl/ Sat, 29 Dec 2018 11:08:54 +0100 https://maartenvanvliet.nl/2018/12/29/absinthe_macro_dsl/ Absinthe is a great library to do graphql in Elixir. However, when writing your resolvers you may find that you are writing some boilerplate multiple times. So, in the spirit of keeping your code DRY, in this post I’ll show how we can leverage middleware and a macro to write your own DSL for your Graphql api. I assume some basic knowledge on how Absinthe works, most of the information can be found on in the guides https://maartenvanvliet.nl/project/receivex/ Sat, 15 Dec 2018 23:04:18 +0200 https://maartenvanvliet.nl/project/receivex/ Receivex hex package Library to handle incoming email webhook from popular mail providers https://maartenvanvliet.nl/project/apq/ Sat, 01 Dec 2018 23:04:18 +0200 https://maartenvanvliet.nl/project/apq/ APQ hex package Cache Apollo graphql queries automatically on Absinthe https://maartenvanvliet.nl/2018/09/07/writing-an-absinthe-phase/ Fri, 07 Sep 2018 22:35:36 +0200 https://maartenvanvliet.nl/2018/09/07/writing-an-absinthe-phase/ Absinthe does a lot when you fire a GraphQL query at it. The incoming query is parsed into an internal representation, validated and finally executed. This process is done by phases, these are individual modules chained together in a pipeline that each do a single step in processing the queries. Phases in Absinthe do a lot of work. They are the building blocks in validating and executing the GraphQL query. E. https://maartenvanvliet.nl/2018/09/05/absinthe-tips-and-tricks/ Wed, 05 Sep 2018 22:18:38 +0200 https://maartenvanvliet.nl/2018/09/05/absinthe-tips-and-tricks/ Absinthe is a great package for building GraphQL api’s in Elixir. It is fast, good DSL and overall great implementation of the GraphQL spec for servers. Working with Absinthe I’ve come across some patterns that have helped clean up code. I’d like to share some of them here. The Self function Imagine you have an image object you want to expose, and for each image you want a separate object with just the dimensions of the image. https://maartenvanvliet.nl/project/swotex/ Sun, 12 Aug 2018 23:04:18 +0200 https://maartenvanvliet.nl/project/swotex/ Swotex hex package Identify email addresses or domains names that belong to colleges or universities. https://maartenvanvliet.nl/2017/12/30/tech_2017_looking_back/ Sat, 30 Dec 2017 22:34:06 +0200 https://maartenvanvliet.nl/2017/12/30/tech_2017_looking_back/ Retrospective Last year was an interesting year for me. I was able to try out a whole lot of new technologies, assess their capabilities and get a good look at their pros and cons. I want to go over a couple of them, and shortly summarize my findings. Typescript In short, Typescript made Javascript fun for me again. Although a lot of this can be attributed to the support of ES6/ES7 in Typescript. https://maartenvanvliet.nl/2017/12/15/upgrading_phoenix_to_http2/ Fri, 15 Dec 2017 21:30:43 +0100 https://maartenvanvliet.nl/2017/12/15/upgrading_phoenix_to_http2/ Upgrading phoenix framework to serve http2 Http2 is the next version of the http protocol and offers several advantages. It serves over a single connection, reducing the number of roundtrips necessary. With multiplexing it can handle multiple requests at the same time and as a whole is just better. As the internet slowly moves to support http2, Phoenix does not lag behind. The webserver Phoenix uses, Cowboy, has released version 2 with support for http2 and the updates to Phoenix and Plug have followed in its path. https://maartenvanvliet.nl/2017/08/05/arc_uploads_to_google_cloud_storage/ Sat, 05 Aug 2017 22:34:06 +0200 https://maartenvanvliet.nl/2017/08/05/arc_uploads_to_google_cloud_storage/ In this post I will demonstrate how to upload to Google Cloud Storage using Arc and Arc.Ecto in Phoenix. There are several examples on how to use Arc in combination with S3 or local file uploads but the GCS integration is a bit more unknown. I assume you have an up to date elixir installation and know your way around Phoenix and GCS. mix archive.install https://github.com/phoenixframework/archives/raw/master/phx_new.ez mix phx.new web --no-brunch Follow instructions to configure your postgres credentials in config/dev.