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Using ARIA roles and background-image

Here’s something I just learned about, so I’ll make a note here so I can remember it for later.

Here’s the main source: https://fae.disability.illinois.edu/rulesets/IMAGE_1/

Often, when adding an image to a web site, I need to have particular control over the images behavior. These needs lead me to use a div with a CSS background-image property, rather than an img.

This is great because it gives access to many powerful formatting rules, like background-cover and background-clip. Unfortunately, it also lowers accessibility. Screenreaders assume that background images are ignorable and decorative.

Here’s how you can fix that. Give the div the ARIA-role of img, and alt text, like this:

<div role="img" alt="description of the background image" />

And that’s it!

I’m using JSX and TypeScript, and TypeScript doesn’t expect a div to have an alt attribute, but as far as I can tell it’s perfectly valid and necessary HTML. You’ve just got to extend the types.

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I’m gonna go into that Dragon Ball Z trainingroom where gravity is like 100 times stronger and time slows down and I will become extremely powerful

I will become extremely powerful and noone will be able to stop me.

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I left Twitter

Around, like, 2013, I stopped eating meat. First I just cut out pork, then meat altogether, and eventually I was consistent about it. The meat industry is unfathomably horrible, and its horribleness extends in many dimensions. I didn’t want any part in it, and I still don’t. I still eat dairy, so I’m not perfect, but I’ve picked my battle and drawn my line. I stand by it. It is worth it to me to not cross that line.

In the same vein, I used to like Twitter. There’s a lot of cool stuff on there, like good jokes. There’s also a lot of amazing political activists who have done so much work to educate people about vital and critical issues. For example, I credit people I followed on Twitter with teaching me about trans rights, or the concepts of prison and police abolition. Women and nonbinary techies on Twitter became my unwitting mentors and exemplars. They did a lot to broaden my world. Also I read many many jokes about dogs. It was fun and useful.

Unfortunately, there’s also a lot of Nazis. There are an unjustifiable amount of Nazis.

Many other people have done very good jobs of explaining how Twitter is a bad website, but I really like Mike Monteiro’s blog post here. Twitter is sad, and it makes me sad. In that way it is a microcosm of entire tech industry. It could be, and very nearly is, so much more than the cesspool that it has consciously allowed itself to become.

The straw that broke the camel’s back, though, was that Twitter recently posted profit for the first time. So that means, in the shallowest and most cynical of use of the term, Jack Dorsey’s artificial controversy engine is “working”. I am aghast. I am revolted. And I am leaving.

I didn’t have a lot of followers. Just 159 at the time of this writing, and very few ever engaged with me, so I know I was never making @jack as much money the POTUS. Here’s my most successful tweet ever. @jack won’t notice, I think, another small account shutting off its lights in response to the sustained and unaddressed harassment encouraged by his platform.

So, folks, consider not being on Twitter anymore.

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The One Shot Podcast Network

I listen to several shows on the One Shot network. The content is kind of niche but I generally really dig it, and I always boost them to friends. Most of their shows focus on tabletop RPGs, either playing them or talking about them. It’s some nerd shit.

I used to support them on Patreon at $5 a month, but recently, one of their show hosts was accused of harassment. You can read their synopsis and response here. They handled the situation with bravery, grace, and an admirable commitment to justice. I’m proud of them.

They seem to be a good organization. Doing the right thing was undoubtedly expensive, but they did the right thing anyways. I want to support them. I want to live in a world in which doing the right thing is viable and rewarded. Thus, I’ve raised my Patreon subscription to $15 a month.

Give them a listen if you need to fill a podcast-shaped hole in your life. Their content is often trashy, but it is a light in my life.

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My plan to fight Trump

I am not writing this to brag about how amazing I am. I am writing this because I am scared and sad and I want to do everything I can to stop Trump from hurting people. And writing lists has always helped curb my anxiety.

I also want to try and recruit others, especially my friends within the tech industry, to come up with their own plans and share them. I urge you to think about and enumerate what you are going to do. Your plan is allowed to change, but having one, at least for me, means you’re more likely to follow through.

To that end, I ask that you please consider sharing this post.

This is bad. This is a worst-case scenario. This is proto-fascism well on its way to fascism. Have you heard that Hitler Trump might continue to hold large rallies? Have you noticed that in addition to all three branches of government, the GOP controls nearly 2/3 of state governments, the amount needed to amend the constitution? I can’t even begin to talk about how bad this is because I won’t be able to stop, and this article will never get to its point. I trust you, reader, to have your own understanding of how bad this is.

I feel sick. I have had, for the past few days, a dark vortex of despair spinning in the pit of my stomach and the back of my mind. I feel anxious, I feel powerless, I feel totally ripped off.

I also understand that this is how oppressed peoples feel, like, a lot the time.

Many people will find themselves abused by the government and its actors, and stripped of their voices. Women, undocumented immigrants, people of color, LGBTQ folks. They are humans and they have worth. They matter. I will fight for them.

I know that my personal social network, and the tech industry, has no lack of individuals who look and think a lot like me: highly privileged, usually white, fairly liberal men with high incomes and few financial obligations. Let’s step up.

Here’s my plan.

  • I will donate $75 a month each to Planned Parenthood, the ACLU, the EFF, MSF (aka Doctors Without Borders), and the SPLC. That’s $375 a month, a significant, but far from huge chunk of my post-tax income of about $4000 a month. I will remain very comfortable. I may decide to up my contributions.
  • If my post-tax income increases as a result of Trump’s tax cuts, I will spend all of the gains on charitable organizations. This especially I urge you to do.
  • I will volunteer with organizations directly help people. I haven’t yet decided which organization, but I am considering either Big Brothers Big Sisters (a youth mentoring program) or Lines for Life (a suicide prevention hotline).
  • I will continue to strive to be an effective ally. This is a complicated and never-ending goal, but, for example, I will try to put myself between Trumpist abusers and their victims if I witness it. I will offer compassion and material help to those around me who need it.
  • I will contact Democratic congresspeople and ask them to obstruct the GOP.
  • I will continue to not eat meat and try to spread a culture of vegetarianism. I originally became a vegetarian out of compassion for animals, but concerns for the environment have become my strongest internal motivator. The environment will suffer greatly under Trump as he attempts to dismantle the EPA, and eating meat is, plain and simple, really awful for the environment.
    • Many of my liberal friends laugh at the idea of giving up meat, but please consider cutting back, like by only eating meat on weekends or holidays.
  • I will continue to avoid using my car, partially an act of protest against our endless oil wars. This is possible because I live in Portland, OR, which has very decent non-car transport infrastructure. I tend to bike everywhere.

As all this happens, I will continue to be imperfect and make mistakes. I will fall short. I will love myself in spite of that. I will treat myself well, and I will do my best to surround myself with people I love. I will treat them well.

In addition,

Here’s what I will not to do, and what I think you should consider also not doing.

CW: Discussion of things Donald Trump has done, like, allegedly, child rape.

  • Act like we are faced with a normal GOP presidency. He is an (alleged) child rapist, overt racist and misogynist, con-man, (alleged) rapist, braggadocios pussy-grabber, lying sociopathic wannabe autocrat, and (alleged, but come on) rapist. This is not normal, and it is not okay. He was helped into office by a coalition of white supremacists, a spineless GOP, a corrupt FBI director, and Vladimir Putin. Many of his electoral gains were made possible by SCOTUS’s gutting of the Voting Rights Act, and the subsequent widespread voter suppression. And though he won the electoral college, Trump lost the popular vote by around 2 million votes.
    • Let me repeat: This is not normal.
  • Pretend that he didn’t win the presidency. I don’t see denial of his ascendency as productive.
  • Hunt for a silver lining in a Trump presidency and firm GOP control of all three houses of government. This is just 100% bad.
    • Other good things happened on election day, though, like our first Latina senator, or the ouster of Joe Arpaio. About fucking time.
    • But these do not diminish the badness of Trump.
    • Specifically, I swear to god if I hear one more person say “I can’t wait for all the great protest music that comes out of this” I’m gonna flip.
  • Fail to recognize the central role of misogyny in Clinton’s (electoral) loss.
  • Give Trump the benefit of the doubt and offer appeasement, as some tech folks are already doing. Words are actions. Trump has already caused a huge amount of damage by mainstreaming our nation’s hip new rebranded white supremacy movement, the Alt Right. Already you’ve heard on social media of attacks on women and minorities by emboldened Trumpists, of swastikas drawn in school bathrooms, of queer folks beaten. There is no need to wait for his damaging legislation to oppose him. Trump does not have good intentions, and I wish him the worst.
    • Even if he doesn’t want to repeal Obamacare anymore, he will almost certainly ruin it. Anything he touches will turn to shit. Because he is a Shit Midas.
  • Fantasize about how Bernie Sanders would have beat Trump.
  • Blame Trump on Clinton.
    • Trump is  the fault of Donald Trump, the GOP, Russia, the FBI, and, by and large, white people.
  • Fawn over the working class whites who elected Trump, and discuss how the Democrats need to win their racist hearts and minds back over. They are not the future of our democracy.
  • Complain about protesters ruining my commute.
  • Cling to the safety blanket of my privilege. As a wealthy (for my age) white man with a foreign passport living in Portland, I among the safest in Trump’s America. I could put on blinders and hide from this terror, but I will not do that. I will stay informed, stay awake (woke, right?), and stay active in the fight against him for the next four years.

Once again, please share. Stay safe. Love is real.

Vincent, 11/12/2016

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No Man’s Sky birthday problem

Demo here. Code here.

My birthday is coming up in a couple days, so what better way to celebrate than by implementing a birthday problem calculator in JavaScript?

Don’t answer. I know the answer.

I actually started down this path after reading about how a pair of No Man’s Sky players have already found each other in-game, which was supposed to be nearly impossible. In fact, it’s happened a bunch. I suspect that the developers have underestimated a version of birthday problem. That’s the thing you might have heard about in elementary school, where a surprisingly small group of people will likely have a pair of individuals with the same birthday.

I’m not the only one to come to have this idea, as this comment by reddit user madbadanddangerous shows.

I’ve heard that there are about a billion planets a player can start out on (out of some quintillions of total planets). And the game has sold at least a couple hundred thousand copies, so let’s assume 150,000 players.

Aaaaand my calculator cannot handle those numbers. It just freezes, and I think it might be one of those heat death of the universe length calculations.

UPDATE: I added and approximating calculator. It’ll work for huge numbers.

Aside: factorials shouldn’t be terribly complex calculations, so I think the computer just gets bogged down with trying to handle massive numbers. If you have a fix to this problem, please submit a PR!

Check out this less accurate but actually functional calculator to get a sense of the probability. Going with 1,000,000,000 planets and 150,000 players yields a ~99.998% chance that at least 2 people will start on the same planet. Seems a little high, but that’s the math!

Technical Summary

This was a small project, so there’s not much of a postmortem! It took me maybe 3 or 4 hours to write, which is 2 hours more than I expected. Which sounds about right.

I find the probability with  1 - (d!/((d-n)!) * d^n) , where d is number of days, and n is number of people, from this Wolfram Mathworld article. Wikipedia indicates that there are some ways of approximating the value faster. I might try that.

Much of the time was spent setting up Math.js after realizing that even the standard case with 365 days overflows JS’s integer type. I am surprised to find that Math.js’s factorial function doesn’t cache its calculations, which means repeated calculations aren’t efficient.

Still, factorials shouldn’t have O(n!) time complexity or anything. I think the sluggishness comes from managing the huge numbers involved. A billion factorial is flipping huge.

Another chunk of the time was spent googling how to interact with the DOM without JQuery. Turns out it’s possible, who woulda thought?

Anyways, there you go. The Birthday Problem. No Man’s Sky. Hash collisions.

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Reusable behavior in Ruby objects

Though my Forest project is still in its infancy (a mere 150 commits in), I have spent a great deal of my time wrestling with objects and the bridges between them. The hardest parts of the design are yet to come, like when animals begin interacting with (attacking? eating?) each other. But I’ve made a few major design choices so far.

Note: this article ends up kind of being a recapitulation of David Copeland’s very well-written and informative Re-use in OO, but I come to a different conclusion.

In particular, I’ve come to final (I think!) decision on how objects obtain shared behaviors.

Here’s the problem, in the most general sense: both Wolf and Rabbit should be able to change their location. They should be able to move. The code for movement should be shared.

Module mixins are not the way

My initial solution was to include a Movable module in both Wolf and Rabbit. This is the solution for which Copeland advocates. I walked pretty far down this path, and even found solutions to some of my problems, like that private methods defined in the included module are accessible to every other included module and the parent class. I wrote a blog post about my solution, but I mention at the bottom a remaining qualm: there’s nothing preventing a module from calling another module’s public method, as in this gist. They can do so easily and inexplicitly.

I envisioned a bleak future for my project, with included modules calling each other willy nilly, in all directions, forming intractable dependencies. This problem could be worked around by carefully maintaining unidirectional dependencies, but it would be ad-hoc and easy to break, unensured against by nature of the construct.

So I asked for help. My friends Devon and Forrest, fellow Dev Bootcamp grads (RACCOONS!), helped out. Forrest showed me the Copeland article, and Devon illustrated a technique of sharing behavior through composition.

A few acceptable solutions

Decorating objects to #move! through composition

What I’m going with is Devon’s suggestion. It has the benefit of ensuring that dependencies are explicit and travel in one direction. Additionally, instances only gain these abilities when you want them, rather than having always-on, and thus abusable, abilities.

This is an implementation of the decorator pattern, where Movable is the decorator. I was actually already using decorators in my code to create presenters (with view-specific logic), but I didn’t at first make the connection that it could be used to share behavior.

class Movable < SimpleDelegator
  def move!; ...; end
end

wolf = Wolf.new
movable_wolf = Movable.new(wolf)
movable_wolf.move!

Data, Context, Integration (DCI)

Jim Gay discusses DCI in-depth here, and I don’t understand it totally. Anyhow, it relies on modules extending objects as needed, rather than mixed into the class’s definition itself.

Note that usage is very similar to the previous solution.

module Movable
  def move!; ...; end
end

wolf = Wolf.new
wolf.extend(Movable)
wolf.move!

Duck typing your way to movement

Another composition / duck-typing solution is as follows, where the actual moving is delegated to another object or module. This is a partial solution.

I don’t like this path as much; I intuitively think that an object should be in charge of its own movement. I could envisage plenty of cases when it would be preferable, however, like if there was a Map object in charge of collision detection. You’d have to be vigilant in preventing the Map from becoming a God Object, though.

As stated, this is a partial solution. It doesn’t solve the problem of how to ensure a Wolf is a Movable in the first place. One could do that through extension or composition, as in the above two examples. It just changes where the #move! method lives, and implies that movement is the responsibility of a third object.

I like how “movable” makes semantic sense, though. And duck typing is just fun.

module Mover
  def self.move!(movable); ...; end
end

Mover.move!(a_movable_wolf)

Unsurprisingly

There’s more than one way to do it.

Module mixin on its own, my naive approach, seems totally untenable. It is multiple inheritance, as demonstrated by the fact that included modules are listed in a class’s .ancestors method. And inheritance can be a mess to begin with, without dependencies being able to go in all directions.

Please let me know if I you’ve got corrections or feedback! For example, I’d love to hear more examples of when the last code example is appropriate. I feel like it’s more useful than I am realizing.

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