When building user interfaces you'll often find yourself working with lists of data. In this exercise, we've repeated the <button> markup multiple times — changing the colour each time — but there's still more to add.
Instead of laboriously copying, pasting and editing, we can get rid of all but the first button, then use an each block:
App.svelte
<div>
{#each colors as color}
<button
aria-current={selected === 'red'}
aria-label="red"
style="background: red"
on:click={() => selected = 'red'}
></button>
{/each}
</div>The expression (
colors, in this case) can be any array or array-like object (i.e. it has alengthproperty). You can loop over generic iterables witheach [...iterable].
Now we need to use the color variable in place of "red":
App.svelte
<div>
{#each colors as color}
<button
aria-current={selected === color}
aria-label={color}
style="background: {color}"
on:click={() => selected = color}
></button>
{/each}
</div>You can get the current index as a second argument, like so:
App.svelte
<div>
{#each colors as color, i}
<button
aria-current={selected === color}
aria-label={color}
style="background: {color}"
on:click={() => selected = color}
>{i + 1}</button>
{/each}
</div>1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
<script>
const colors = ['red', 'orange', 'yellow', 'green', 'blue', 'indigo', 'violet'];
let selected = colors[0];
</script>
<h1 style="color: {selected}">Pick a colour</h1><div>
<button
aria-current={selected === 'red'}aria-label="red"
style="background: red"
on:click={() => selected = 'red'}></button>
<button
aria-current={selected === 'orange'}aria-label="orange"
style="background: orange"
on:click={() => selected = 'orange'}></button>
<button
aria-current={selected === 'yellow'}aria-label="yellow"
style="background: yellow"
on:click={() => selected = 'yellow'}></button>
<!-- TODO add the rest of the colours -->
<button></button>
<button></button>
<button></button>
<button></button>
</div>
<style>
h1 {transition: color 0.2s;
}
div {display: grid;
grid-template-columns: repeat(7, 1fr);
grid-gap: 5px;
max-width: 400px;
}
button {aspect-ratio: 1;
border-radius: 50%;
background: var(--color, #fff);
transform: translate(-2px,-2px);
filter: drop-shadow(2px 2px 3px rgba(0,0,0,0.2));
transition: all 0.1s;
}
button[aria-current="true"] {transform: none;
filter: none;
box-shadow: inset 3px 3px 4px rgba(0,0,0,0.2);
}
</style>