How to transition the height of elements with unknown/auto height

If you want to collapse/expand elements with dynamic content (and thus unknown height), you can not transition between height: 0 and height: auto.

Doing it properly, with modern CSS features

In the past, you might have resorted to bulky JavaScript solutions or CSS hacks like transitioning between max-height: 0 and max-height: 9999px. All of them were awkward and/or have several edge cases.

With modern CSS, there is actually a way to do it properly:
Just use a display: grid container which transitions its grid row height betwe...

How to prevent a 1fr grid column overflow

TL;DR:

Grid elements have min-width: auto in a 1fr column, which may lead to overflows. With minmax(0, $width) you can reset the min-width.


Say you have a simple grid layout:

.container
  .first-item
  .second-item
  .third-item
.container
  display: grid
  grid-template-columns: 100px 1fr 100px

Your expectation is now that

  • the first item will be located on the left hand side with a fixed width of 100px
  • the third item will be located on the right hand side, also with a width of 100px
  • ...

Use -webkit-line-clamp to natively truncate long (multi-line) texts with an ellipsis

Note: You won't need this for single lines of text. In this case it is better to just use the text-overflow property: Use CSS "text-overflow" to truncate long texts

You can use -webkit-line-clamp in your CSS/SASS to natively render an ellipsis (...) after a specific amount of lines for a multi-line text in your HTML.
Earlier, it was necessary to implement JavaScript solutions like Superclamp.js to enable this because the browser support has been rather limited...

Balance your texts today with text-wrap: balance

So you have a heading that is just barely wider than the container it should fit into, and it wraps a single word to a new line and it's not really pretty?
Cry no more, for you can use text-wrap: balance today to fix that. At least in some browsers.

When browsers encounter a text-wrapping element with text-wrap: balance style, they will try breaking to a new line sooner, if it balances out the width of lines.

text-wrap: unset text-wrap: balance
Image ![Image](/makandr...

Checklist for Implementing Design

We have a long-standing checklist for merge requests. However, it hardly matches the intricate requirements for design. This checklist fills the gap.

Before starting implementing, look at all designs: are there components similar to yours? Have they already been implemented? Can you build on this prior art when implementing yours?

Checklist: I confirm my design implementation

  • has been tested manually by me
  • adheres to the code style of the project (e.g. BEM)
  • avoids "magic numbers" (don't say e.g. ...

Allow capybara to click on labels instead of inputs for checkboxes

Within Capybara you most certainly use the #check- and #uncheck-method to (un)check checkboxes.
But there's one problem, if you want to test a custom styled checkbox, which hides its <input>-Tag:

  • The methods cannot (un)check checkboxes without an visible <input>.
  • The error message will be something like: Unable to find visible checkbox "Some label" that is not disabled

Solution 1

Use the keyword argument allow_label_click: true within the method call.
So instead of check('Some label'), use `check('Some label', allow...

Rails: Fixing ETags that never match

Every Rails response has a default ETag header. In theory this would enable caching for multiple requests to the same resource. Unfortunately the default ETags produced by Rails are effectively random, meaning they can never match a future request.

Understanding ETags

When your Rails app responds with ETag headers, future requests to the same URL can be answered with an empty response if the underlying content ha...

Modern CSS supports individual transform properties

tl;dr

Individual transform properties are great because they allow you to write more readable and maintainable CSS, especially when applying multiple transformations and/or when animating transforms.

For ages, CSS transforms had to be defined using the transform property. For a single transformation, this was something like transform: scale(1.5), and multiple transformations could be applied by chaining them.

.example {
  transform: scale(1.5) rotate(45deg) translateY(-50%);
}

All modern browsers (Chrome & Edge ...

CSP: strict-dynamic

tl;dr

The strict-dynamic source list keyword allows you to simplify your CSP policy by favoring hashes and nonces over domain host lists.

The key super power of strict-dynamic is that it will allow to load additional scripts via non-"parser-inserted" script elements.

For unsupported browsers, your script can be made backwards compatible by doing something like this:

script-src 'nonce-rAnd0m' 'strict-dynamic' https: 'self'
default-s...

Rails: Assigning associations via HTML forms

Let's say we have posts with an attribute title that is mandatory.

Our example feature request is to tag these posts with a limited number of tags. The following chapters explain different approaches in Rails, how you can assign such an association via HTML forms. In most cases you want to use Option 4 with assignable values.

The basic setup for all options looks like this:

config/routes.rb

Rails.application.routes.draw do
  root "posts#index"
  resources :posts, except: [:show, :destroy]
end

**db/migrate/...

SASS: Reusing styles from other files

SASS has an @extend keyword to inherit styles.

.alert
  color: red
  
  &.-framed
    border: 1px solid red
    padding: 5px
    
  &.-homepage
    @extend .-framed
    border-width: 5px

When compiling, SASS will simply join the selectors. Note how .-homepage is written where .-framed was defined:

...
.alert.-framed, .alert.-homepage {
  border: 1px solid red;
  padding: 5px;
}
.alert.-homepage {
  border-width: 5px;
}

Warning

Unfortunately, this does...

CSS: CSS Container Queries

Container queries enable you to apply styles to an element based on the size of the element's container. If, for example, a container has less space available in the surrounding context, you can hide certain elements or use smaller fonts. Container queries are an alternative to media queries, which apply styles to elements based on viewport size or other device characteristics.

This feature is now stable across browsers.

Warning

This feature landed in browsers in the beginning of 2023. According to our support policy this will bec...

How to read the current breakpoint tier(s) in JavaScript

To read the current breakpoint tier in JavaScript, employ this CSS:

:root {
  --current-breakpoint-tier: xs;
  
  @media (min-width: $screen-sm-min) {
    --current-breakpoint-tier: sm;
  }
  @media (min-width: $screen-md-min) {
    --current-breakpoint-tier: md;
  }
  @media (min-width: $screen-lg-min) {
    --current-breakpoint-tier: lg;
  }
  @media (min-width: $screen-xl-min) {
    --current-breakpoint-tier: xl;
  }
  @media (min-width: $screen-xxl-min) {
    --current-breakpoint-tier: xxl;
  }
}

Then use this JavaScript:

subscript, superscript and line-heights

By default subscript (<sub></sub>) and superscript (<sup></sup>) tags are styled with vertical-align: sub, respectively vertical-align: super by most browsers.
However, without adaptations, this will probably break your line-heights.

A common suggestion is to style those two tags accordingly:

sup, sub {
  vertical-align: baseline;
  position: relative;
  top: -0.4em;  /* can be adapted according to preferences */
}
sub {  
...

A modern approach to SVG icons

You have some SVG files you want to use as icons on your website. How would you embed them?

Common options are:

  1. Use them with an image: <img src='path-to-icon.svg'>
  2. Embed them inline with <svg>$ICON</svg>
  3. Embed them using CSS and background-image: url(path-to-icon.svg) or even background-image: url(data:$ICON).
  4. Build your own icon font.

All of these have drawbacks:

  • Image and background-image do not allow to recolor the image using CSS.
  • Inline-<svg> are unnecessary work for the server and are...

Using path aliases in esbuild

In esbuild, you usually import other files using relative paths:

import './some-related-module'
import `../../utils/some-utility-module`
import `../../../css/some-css.sass`

This is totally fine if you import closely related files, but a bit clunky when you're trying to import some "global" module, like a utility module. When moving a file, your imports also need to change.

To get around this, esbuild support a mechanism first introduced in TypeScript called "path aliases". It works like this:

First, you create a file called `js...

Jasmine: Creating DOM elements efficiently

Jasmine specs for the frontend often need some DOM elements to work with. Because creating them is such a common task, we should have an efficient way to do it.

Let's say I need this HTML structure:

<ul type="square">
  <li>item 1</li>
  <li>item 2</li>
</ul>

This card compares various approaches to fabricating DOM elements for testing.

Constructing individual elements

While you can use standard DOM functions to individually create and append elements, this is extremely verbose:

let list = document.createElement('...

Inspect and Debug CSS Flexbox and Grid Layouts by using the Layouts Tab in Dev Tools

tl;dr

In Chrome DevTools in the Layouts tab you have handy options to debug CSS Flexbox and Grid. Including:

  • Display size and lines along with labels
  • Changing their attributes
  • Change how overlay is colored and fastly switch nested elements in the Elements panel

This guide will only cover some example gif recordings on how to use with Grid, since it's basically straight forward to apply this for Flexbox by yourself afterwards.

For this purpose a the link to documentation and a simple code pen have been added...

Do not use unitless zeros in CSS calc functions

While in CSS zero is usually referenced without specifying a unit (e.g. padding: 0), you must not use a unitless zero in calc functions.

You would probably not write something like calc(1rem + 0) yourself, but it might be the result of a CSS preprocessor (like Sass) or when using custom properties.

The following is invalid:

.example {
  --extra-padding: 0;
  padding: calc(1rem + var(--extra-padding));
}

That is simply because it is unsupported, as per docum...

Chrome DevTools: Treasure (Overview)

tl;dr

The Chrome DevTools are a neat collection of tools for the daily work as a web developer. If you're lucky, you'll maybe find some handy stuff in here.

Analysing

Breakpoints

  • [Breakpoints on HTML Elements](https://makandracards.com/makandra/517982-chrome-devtools...

Sass: How to get rid of deprecation warnings in dependencies

sass >= 1.35.0 has the option quietDeps and silenceDeprecations to silence deprecation warnings from dependencies.

Below there are a few examples for different build tools how to set the Sass options.

Webpacker

const sassLoaderConfig = environment.loaders.get('sass')
const...

What Sass means by "@function rules may not contain style rules."

When writing a Sass function, you may run into an error message that may be confusing:

@function rules may not contain style rules.

What Sass is trying to tell you is that a line in your Sass function is computing a result that is neither assigned to a variable nor returned.

Keep in mind that all functions in Sass return something, Sass does not mutate objects.

RubyMine: Find and Replace with Regex (Capture Groups and Backreferences)

tl;dr

In RubyMine you can use find and replace with capture groups (.*?) and backreferences $1 (if you have several groups: $[Capture-Group ID]).
Named captures (?<text>.*) are also supported.

Examples

Replace double quotes with single quotes

If you want to replace double quotes with single quotes, replacing every " with a ' is prone to errors. Regular expressions can help you out here.

  1. Open find and replace
  2. Activate the regex mode (click on the .* icon next to the "find" field).
  3. Fill in f...

JSON APIs: Default design for common features

When you build a JSON API you need to come up with a style to represent attributes, pagination, errors or including associated objects. Instead of reinventing the wheel, you may reuse successful API designs.

JSON API

JSON:API specifies common features found in most JSON APIs, like pagination, ordering and nested resources. The spec looks very similar to how one would build an API with Rails and uses similar patterns. Even if you don't plan on supporting the whole spec, it can still make sense to know how th...