Clojure/West is a three day conference about the Clojure and ClojureScript programming languages at the Gerding Theater. There will be keynotes by Rich Hickey (Clojure) and Matthew Flatt (Racket) as well as about 35 talks. View the full sessions list.

The conference is $350. Register now!

Kevin sez:

The domain problem is conceptually simple: you provide sets of images and are notified with visual diffs of changes. The motivating use case was regression testing a web data visualization product---taking screenshots is far easier and more comprehensive than unit testing JavaScript + DOM + CSS styling.

The application is about 1300 lines of code, which includes all of the (Clojure-generated) markup and styling.It's built with Clojure, ClojureScript, and Datomic. I'll touch on:

• designing an application around Stuart Sierra's "Reloaded" workflow: http://thinkrelevance.com/blog/2013/06/04/clojure-workflow-reloaded

• basics (and not-so-basics) of the Ring HTTP model

• using Chas Emerick's Friend library to handle web user and API authentication

• deploying/monitoring a Clojure application in (low-stakes) production

• structuring an application around protocols so that service backends (e.g., S3) can be easily swapped between development, staging, and production

If there's anything that seems particularly interesting to you (in the above list or otherwise), please reply to this thread so I can prepare a bit of material.

I'm planning on giving a 20 minute high-level overview of the application, and then opening it up to questions and focussing on whatever topics folks are interested in.

Come talk and ask/answer questions about Clojure ClojureScript and related topics.

Successful strategies for the self-organizing Clojure meetup:

http://blog.factual.com/clojure-office-hours

Please also review the Puppet Code of Conduct. As we reside in their space, we abide by their rules.

https://docs.puppetlabs.com/community/community_guidelines.html#event-code-of-conduct

We're going to have two talks this month. First Russell Mull will present:

Logic Programming from the Inside Out

Description: Learn about the guts of miniKanren and core.logic, obtaining a deeper understanding of the fundamental truths of logic programming. (And also some neat functional programming tricks)

Then I'll lead a workshop on:

Single Page Apps with ClojureScript, Figwheel, Reagent, etc.

Description: We'll do a quick high-level workshop to introduce using ClojureScript with Reagent to create a very simple web app. I'll show a work flow using Figwheel and we'll discuss some architectural decisions as time allows.

If you've been meaning to look into ClojureScript this is a great way to start and if you're experienced come and share your thoughts and help others.

Bring your laptop with leinengen installed or team up with others at the meeting.

Intersted in learning more about Clojure? Have questions or need help with a set up, library or Clojure/Functional Programming concept?

Come by the Office Hours meeting this month.

Bring any questions you may have or topics on your mind and we'll see how others can help.

Recently we at Little Bird had a series of issues trying to get another Clojure distributed computation library working in production. Learning from the frustrations involved in that process clarified exactly what we wanted out of a distributed computation system, and soon after Ibis was born. The goal was to simplify everything and leave the hard problems of synchronization to battle tested libraries that already do it well, namely Zookeeper and Kafka. Built on this solid foundation, Ibis was a natural expression of our intent when designing a distributed system. Providing seamless distribution in the face of adding and removing nodes on the fly, streaming, scheduling and unique tasks, Ibis is already serving us well in production and we consider it a great success.

ClojureScript has the best client side work flow available. Beating out JS (even with modern tooling), and other compile to JS languages. With ClojureScript and figwheel we have hot code reloading, stable application state across reloads, & an interactive browser connected REPL. You can develop your client side app as if you where inside the browser. In this short presentation we will go over what figwheel does, how to set it up, and demo what it is like to build an SPA in ClojureScript + Om.

Jordan Schatz is a polyglot software engineer, working in Clojure, ClojureScript, Python, Javascript, Racket, PHP among other languages to build and scale systems for the last 10 years. He has a particular love of functional programming, dev ops & NoSQL/new data stores. Outside of computer science he pursues interests in alternative energy systems, alternative architecture and the life sciences.

The Untangled web framework is a ClojureScript web framework that blends various web development libraries together with a good bit of glue code to make single-page webapps a breeze.

Untangled leverages a lot of things that were pioneered in Om 1.0 by David Nolen, and adds it's own layers of simplification and opinion.

It is a full-stack environment, but you can pick and choose the pieces you wish to use.

We'll discuss the basic idea of the bits you need to develop an Om.Next app and cover how Untangled provides a lot of that for you.

You may want to checkout this overview, companion video as well as the Om.Next quick start and the Untangled tutorial.

Bio: Tony Kay works at NAVIS in Bend. He's been doing software development since the mid-80s in most of the common suspects: C, C++, Java, Scala, Clojure, Javascript. Tony is currently the technical lead on new software development, where he's driven the adoption of Clojure/Clojurescript and worked as the lead on the Untangled Web Framework project, which they use to develop our production software. His interests include fermenting random things for gluten-free sourdough bread, cooking, making software engineering better as a profession, and barefoot hiking.

Our scheduled speaker had to cancel unexpectedly so we'll have lighting talks and office hours.

The talks don't need to be formal at all. Just take 5-15 minutes sharing something you've learned or are working on.

To get the ball rolling I'll do:

"What I've learned about React Native and ClojureScript"

So what have you been working on? Don't be shy. Your group needs you.

And as for the office hours ... just come with your questions, problems and challenges and we'll try to help.

Thanks.

Julio

Have you ever wanted to extend your Clojure talents to the desktop? Turned off at the thought of digging into Swing or building native shims around your beautiful functional code? Then look no further than Github's Electron, a cross-platform toolkit for desktop apps using familiar Javascript techniques, which of course we can make much more fun and powerful with Clojurescript. Learn how to build desktop apps with all the custom menus, system notifications, and badges you've come to expect, right from your REPL.

About Josh Miller

Josh Miller has been building software professionally for over a decade, in fields ranging from Erlang-backed Twitter crawlers to Objective-C iOS apps, but his heart belongs to Clojure. Josh is a software consultant living in Portland, OR.

If you've ever had to interrupt a series of operations with ugly nested branching logic and thought, "there should be a better way", you're not alone. I'll show you how to use some basic category theory abstractions from funcool's cats library to write declarative code that's easier to read and reason about, and how to integrate it with their promesa library for declarative asynchronous programming.

Cats:

http://funcool.github.io/cats/latest

Promesa:

http://funcool.github.io/promesa/latest/

Bio: Matthew Lyon helps humans and computers communicate.

Using Clojure greenfield project is great but what about legacy projects full of toxic decay and code zombies lurking the repo?

Clojure is your post apocalyptic weapon. You don't have to re-write the whole monolith; by switching key parts of the infrastructure we can reduced the number of servers and costs.

Get bragging rights with your managers and higher ups by introducing Clojure and Clojure community practices in large legacy apps. In this installment we’ll explore how to reduce the high IO costs of large scale email processing with Clojure.

Bio: Paco is a developer in Portland Oregon and can be found on twitter at https://twitter.com/kidpollo

This talk will show you how to use Clojure and the new spec library to write programs that behave as expected, meet operational requirements, and have the flexibility to accommodate change. We will also discuss how developing with spec is declarative, predicative, layered and robust.

This is a live remote, interactive presentation where we will have time for questions.

Curious about Clojure? Have questions about Emacs or Cursive or Vim or Spacemacs or anything else? Come on out and we'll help.

Office hours are a great place to chat with other developers and help or get help with any questions that come up.

Everyone is always welcomed regardless of skill or experience. If you are curious come on out.

There are 6 difficult problems frameworks and libraries try to solve in JavaScript, but never quite get there. Learn how these problems (and more!) are solved by ClojureScript and how it can provide a platform for new solutions.

Are you tired of constantly chasing after the next framework? Do you ever feel like frameworks don't solve the hard problems, like callback hell, state management, and correctness checking? Are you looking for something that could make your software radically simpler and let you code better features? ClojureScript could be the answer. In this talk, you'll learn how ClojureScript solves really some tough problems in JavaScript and how it provides a platform for new solutions.

Note: This is a special edition meeting at a different time and place than normal

ClojureScript's React.JS wrappers have been around a while, and fighweel has really made the development experience shine. When I first started playing around with ClojureScript I really wanted to make browser games more than web apps and this got me thinking. Can a library exist which allows for creating and manipulating any object model similarly to how React interacts with the DOM? This talk is about a pair of libraries I've began writing which makes an attempt at proving this out.

This month I am happy to announce we will have a remote presentation from Zach Tellman. I've heard Zach speak several times and every time have learned a lot and been impressed by the breadth and depth of his knowledge and thinking.

He will share with us a discussion of what an abstractions are, what makes them fail, and how to make them better.

Zach is the author of Elements of Clojure https://leanpub.com/elementsofclojure , and a number of open source libraries.

Justin Smith will present his library, poirot, and explain why it was needed and demonstrate how it is used to simplify debugging and writing regression tests.

Bio:

Justin is a full time Clojure programmer and maker of weird music. He's remarkably active on #clojure IRC and the clojurians slack channel.

We've had a few presentations on using re-frame and continue to get many questions on this fantastic tool. There is a lot to learn but you will be rewarded when building single page apps. So this month our own Matthew Lyon will present:

Constructing Interfaces with re-frame

I’ve talked to many clojurists who are curious about front-end programming but don’t know where to start. They haven’t done front-end work before, they’re unfamiliar with JavaScript or React, and they don’t understand how those pieces fit together. I’ll walk through what a ClojureScript development environment looks like; what makes front-end programming different and how React, reagent, and re-frame fit into this; how to create views with Reagent; how to manage state and the outside world with re-frame; and how to effectively debug your front-end code.

Matthew Lyon has been building the front- and back-ends for web applications for over twelve years, and with Clojure for three years. He enjoys creating interfaces for helping people work through complex interactions.

Much has been said about building re-frame applications in the small, but how well do these same techniques perform building large applications? In practice, our team found traditional approaches to events and state management led to highly-coupled code that was difficult to maintain and test.

In this talk we'll explore why this happens and some simple techniques you can use to create more re-usable re-frame code without boilerplate or any 3rd party libraries.

Biography Ryan is a Clojure developer, author, and founder of Homegrown Labs (http://homegrownlabs.ca ), a consultancy and education company based in Winnipeg, Canada.

Since April 2017, Ryan & Homegrown have been working with Funding Circle building rich admin applications using ClojureScript & re-frame.

Beyond consulting, Ryan organizes Clojure Remote (http://clojureremote.com )–an online conference focussed on remote Clojure & ClojureScript developers. Keep an eye out for ClojureScript Days coming Summer of 2018.

Office hours are a great place to chat with other developers and help or get help with any questions that come up.

Everyone is always welcomed regardless of skill or experience. If you are curious come on out.

Curious about Clojure? Have questions about Emacs or Cursive or Vim or Spacemacs or anything else? Come on out and we'll help.

Portland has a fairly lively Clojure ecosystem -- how can we leverage that base and become a hub of Clojure culture?

The biggest opportunity appears to be in helping newcomers connect the dots. The language was designed to be clear, consistent, practical, and empowering -- this talk will explore how we can apply those principles to support the local scene and create an onboarding model other groups can use.

Bring your gripes and ideas.

Bio: New to the language and somewhat obsessed, Tom has worked as a writer, editor, and programmer. He hosts the Tuesday night Clojure Study Crew, and is currently building what he hopes will be the next best Clojure documentation tool.

Come join us in an evening of stimulating discussion where we explore an approach in developing an event-sourced, CQRS-based real time system. We’ll look at the reframe inspired events system on the server side, as well as how the interceptor pattern can be used to achieve a clean implementation.

Presenters:

Jesse Sherlock Startup veteran, incredibly broad and deep. https://github.com/infracanophile

Fenton Travers Organizer of the Vancouver Clojure meetup. 10 years experience at Oracle before drinking the Clojure kool-aid. https://github.com/ftravers

Paul Lucas Deeply involved at the intersection of music and functional programming. Has been booked for live coding gigs in UK and Japan. Front-end focus. https://github.com/paullucas

Gargoyle Software specializes in Clojure software development for the cannabis industry. We believe in mutualism, questioning assumptions, and honoring craftsmanship. We're located in Vancouver, BC and have a median of 9 years experience. We offer full-service project management or staff augmentation and in-house design. We are about to release our first Clojure open source contribution.

Vars are at the heart of how Clojure code is evaluated, but their primary features are subtle and their secondary features are many and obscure. Understanding Clojure's vars not only clarifies how the language works, but also opens up new ways of making the language do what you want, especially when building development tools.

BIO

Gary Fredericks is a software engineer who has been making Clojure-themed jokes for nearly ten years. He lives in Chicago and does programming things for DRW. He is writing these words from a playground swing and it is windy and cold. https://twitter.com/gfredericks_