Today I Learned

vuex-class' documentation doesn't come with clear steps on how one could call a getter with one or more arguments.

Here's how you do it:

  @workspaces.Getter
  protected workspace: WorkspaceType | null = null;
  
  public byId!: (id: WorkspaceId) => WorkspaceType;
  
  mounted(): void {
    this.workspace = this.byId({ id: this.activeWorkspaceId });
  }

While you can find detailed information in the official docs, I dare to spoil the fun for you:

1. All app variables are pulled in if they are prefixed with VUE_APP_.

Example: VUE_APP_API_URL.

You can now access the variables in your application like this: process.env.APP_URL.

2. All e2e variables are fetched if they are prefixed withCYPRESS_.

Example: CYPRESS_APP_URL.

You can now access the variables in your tests like this: Cypress.env('APP_URL').

A very naive yet effective approach on metaprogramming that helps you dynamically call the right method in a very concise manner.

$method = $user instance of User ? 'save' : 'saveMany';

$this->members()->$method($user);

The example is an excerpt from a dummy Laravel app.

By making use of Sets and the spread operator, we can quickly strip the duplicates with a Set then turn it back into an array in no time.

[…new Set([1, 'Graffino', 1, 'Graffino', "Wha!"])];

Will return: [1, "Graffino", "Wha!"]

Phoenix schema: ArgumentError - invalid or unknown type :text for field

:text can be used in migrations, but not when describing the schema in the model. Use :string instead.

If you ever seen this in the wild:

{:ok, assign(socket,
      %{my_variable: @my_variable
        my_other_variable: nil.
        yet_another_variable: nil 
      })}

Remember that applying elixir's pipe operator makes everything better:

def mount(_session, socket) do
    socket =
      socket
      |> assign(:my_variable, @my_variable)
      |> assign(:my_other_variable, nil)
      |> assign(:yet_another_variable, nil)
    {:ok, socket}
end

Whenever a value is set in localStorage, a storage event will be dispatched on all other windows from the same origin. The event is not fired or catchable in the originator window when it is modified through a script.

This was a problem because I wanted to be able to have an Elm subscription as the only source of truth for my session.

In order to achieve this, I'm mimicking the storage event from within the command port as soon as the message is received through the port.

app.ports.commandPort.subscribe(session => {
  localStorage.session = JSON.stringify(session);
  app.ports.subscriptionPort.send(localStorage.session);
});

window.addEventListener(
    "storage",
    event => {
      if (event.storageArea === localStorage && event.key === "session") {
        app.ports.subscriptionPort.send(event.newValue);
      }
    },
    false
);

And in Elm:

port subscriptionPort : (Encode.Value -> msg) -> Sub msg

port commandPort : Maybe Encode.Value -> Cmd msg

closest: Int -> List Int -> Int
closest size sizes =
  sizes
      |> List.sort
      |> List.filter (\s -> s < size)
      |> List.reverse
      |> List.head
      |> Maybe.withDefault 0

This example is not meant to be exhaustive nor performant.

This is related to the MOOV atom that contains all the metadata and information about the frame locations other important information the browser needs to know about the video. For some reason, all other major browsers load it with no issues but Safari prefers to wait until the whole resource has downloaded in order to decide what to do with it.

For mp4 files, downloading FFMPEG and running the following command solved my issue:

./ffmpeg -y -i source.mp4 -movflags faststart dest.mp4

What it does is that it takes the MOOV atom from the end and adds it right at the start.

Imagine for a second this is something you're using a lot when programming Elixir and Phoenix:

Repo.one(
	from u in User,
		where: fragment("lower(?)", u.email) == ^email
)

You can write your own Elixir macro to improve your flow.

defmacro lower(arg) do
	quote do: fragment("lower(?)", unquote(arg))
end

Then your query can be rewritten like this:

Repo.one(
	from u in User,
		where: lower(u.email) == ^email
)

I recently ran into an issue where adding hackney and running mix deps.compile would throw the following error:

===> Rebar3 detected a lock file from a newer version. It will be loaded in compatibility mode, but important information may be missing or lost. It is recommended to upgrade Rebar3.

Running mix local.rebar fixed my issue.

There is no such thing as !True to get a False value in Elm.

The Elm way to achieve this is:

module Helpers.Bool exposing (flip)

flip: Bool -> Bool
flip bool = 
	if bool == True then
  	False
  else
  	True

And the use it as:

import Helpers.Bool

...

Helpers.Bool.flip True

Have you ever wondered why the textarea field adds <br>s in your frontend HTML instead of a paragraph tag?

It turns out this is the default behaviour and it's a rather common pitfall for many WordPress newcomers.

Here's the deal:

Hit Enter twice for a paragraph p.

Hit it just once for a regular single line break <br>.

You can also disable this behaviour via an wpautop filter.

Here's another reminder why expressive, namespaced ids are important. This time is about a label's for attribute.

<input id="phone">
<label for="phone"></label

This would work just as expected unless, for example, we have a svg sprite at the beginning of the document that includes an svg with a "phone" id.

<symbol id="phone" viewBox="0 0 61.4 48">...</symbol>
...
<input id="phone">
<label for="phone"></label

In this case, the label's for will match the first in a top-down order that has the target id.

And you will never know why clicking the label won't trigger the input.

If a property changes back and forth in the same tick, it won't trigger Vue's reactivity.

Here's how to do it dirty without a watcher:

this.$set(this, 'property', false)
this.$nextTick(() => {
  this.$set(this, 'property', true)
})

Now, don't ever do this.