danabra.mov
+4
-3
app/Link.tsx
+4
-3
app/Link.tsx
···
27
27
...rest
28
28
}: {
29
29
className?: string;
30
-
children: React.ReactNode;
30
+
children?: React.ReactNode;
31
31
style?: React.CSSProperties;
32
32
href: string;
33
33
target?: string;
34
34
} & React.ComponentProps<typeof NextLink>) {
35
35
const router = useRouter();
36
36
const [isNavigating, trackNavigation] = useTransition();
37
-
if (!target && !href.startsWith("/") && !href.startsWith("#")) {
37
+
const isExternal = /^https?:\/\//.test(href);
38
+
if (!target && isExternal) {
38
39
target = "_blank";
39
40
}
40
41
return (
···
50
51
});
51
52
}
52
53
}}
53
-
className={[className, `scale-100 active:scale-100`].join(" ")}
54
+
className={[className, "scale-100 active:scale-100"].join(" ")}
54
55
style={{
55
56
...style,
56
57
transform: isNavigating ? "scale(1)" : "",
+16
app/TextLink.tsx
+16
app/TextLink.tsx
···
1
+
import Link from "./Link";
2
+
3
+
export default function TextLink({
4
+
className,
5
+
...props
6
+
}: React.ComponentProps<typeof Link>) {
7
+
return (
8
+
<Link
9
+
{...props}
10
+
className={[
11
+
"underline decoration-[--link] decoration-1 underline-offset-4 text-[--link]",
12
+
className,
13
+
].join(" ")}
14
+
/>
15
+
);
16
+
}
+1
-1
app/[slug]/layout.tsx
+1
-1
app/[slug]/layout.tsx
+29
-150
app/[slug]/markdown.css
+29
-150
app/[slug]/markdown.css
···
1
+
/* CSS vars for code block customization (used by Wrapper components) */
1
2
.markdown {
2
-
line-height: 28px;
3
-
--path: none;
4
-
--radius-top: 12px;
5
-
--radius-bottom: 12px;
6
-
--padding-top: 1rem;
7
-
--padding-bottom: 1rem;
8
-
}
9
-
10
-
.markdown p {
11
-
@apply pb-8;
12
-
}
13
-
14
-
.markdown a:not(.tip):not(.linked-heading) {
15
-
@apply border-b-[1px] border-[--link] text-[--link];
16
-
}
17
-
18
-
.markdown hr {
19
-
@apply pt-8 opacity-60 dark:opacity-10;
20
-
}
21
-
22
-
.markdown h2 {
23
-
@apply mt-2 pb-8 text-3xl font-bold;
24
-
}
25
-
26
-
.markdown h3 {
27
-
@apply mt-2 pb-8 text-2xl font-bold;
28
-
}
29
-
30
-
.markdown h4 {
31
-
@apply mt-2 pb-8 text-xl font-bold;
32
-
}
33
-
34
-
.markdown :is(h1, h2, h3, h4) a:is(:hover, :focus, :active)::before,
35
-
.markdown :is(h1, h2, h3, h4):is(:target, :focus) a::before {
36
-
content: "#";
37
-
position: absolute;
38
-
transform: translate(-1em);
39
-
opacity: 0.7;
40
-
}
41
-
42
-
.markdown :not(pre) > code {
43
-
border-radius: 10px;
44
-
background: var(--inlineCode-bg);
45
-
color: var(--inlineCode-text);
46
-
padding: 0.15em 0.2em 0.05em;
47
-
white-space: normal;
3
+
line-height: 28px;
4
+
--path: none;
5
+
--radius-top: 12px;
6
+
--radius-bottom: 12px;
7
+
--padding-top: 1rem;
8
+
--padding-bottom: 1rem;
48
9
}
49
10
50
-
.markdown pre {
51
-
@apply -mx-4 mb-8 overflow-y-auto p-4 text-sm;
52
-
clip-path: var(--path);
53
-
border-top-right-radius: var(--radius-top);
54
-
border-top-left-radius: var(--radius-top);
55
-
border-bottom-right-radius: var(--radius-bottom);
56
-
border-bottom-left-radius: var(--radius-bottom);
57
-
padding-top: var(--padding-top);
58
-
padding-bottom: var(--padding-bottom);
59
-
}
60
-
61
-
.markdown pre code {
62
-
width: auto;
63
-
}
64
-
65
-
.markdown blockquote {
66
-
@apply relative -left-2 -ml-4 mb-8 pl-4;
67
-
font-style: italic;
68
-
border-left: 3px solid hsla(0, 0%, 0%, 0.9);
69
-
border-left-color: inherit;
70
-
opacity: 0.8;
71
-
}
72
-
73
-
.markdown blockquote p {
74
-
margin: 0;
75
-
padding: 0;
76
-
}
77
-
78
-
.markdown p img {
79
-
margin-bottom: 0;
80
-
}
81
-
82
-
.markdown ul:not(.unstyled) {
83
-
@apply list-inside md:list-outside list-disc;
84
-
margin-top: 0;
85
-
padding-bottom: 0;
86
-
padding-left: 0;
87
-
padding-right: 0;
88
-
padding-top: 0;
89
-
margin-bottom: 1.75rem;
90
-
list-style-image: none;
91
-
}
92
-
93
-
.markdown li:not(.unstyled) {
94
-
margin-bottom: calc(1.75rem / 2);
95
-
}
96
-
97
-
.markdown img {
98
-
@apply mb-8;
99
-
max-width: 100%;
100
-
}
101
-
102
-
.markdown iframe {
103
-
@apply mb-8;
104
-
max-width: 100%;
105
-
}
106
-
107
-
.markdown ol {
108
-
@apply mb-8 list-inside md:list-outside list-decimal;
109
-
}
110
-
111
-
.markdown input {
112
-
color: #222;
113
-
}
114
-
115
-
.markdown table {
116
-
width: 100%;
117
-
border-collapse: collapse;
118
-
margin-bottom: 1.5rem;
119
-
}
120
-
121
-
.markdown th,
122
-
.markdown td {
123
-
border: 1px solid #dcdcdc;
124
-
padding: 8px;
125
-
text-align: left;
126
-
}
127
-
128
-
@media (prefers-color-scheme: dark) {
129
-
.markdown input {
130
-
color: #111;
131
-
}
132
-
}
133
-
11
+
/* Code line highlighting - data-attribute from rehype-pretty-code */
134
12
.markdown pre [data-highlighted-line] {
135
-
margin-left: -16px;
136
-
margin-right: -16px;
137
-
padding-left: 12px;
138
-
border-left: 4px solid #ffa7c4;
139
-
background-color: #022a4b;
140
-
display: block;
141
-
padding-right: 1em;
13
+
margin-left: -16px;
14
+
margin-right: -16px;
15
+
padding-left: 12px;
16
+
border-left: 4px solid #ffa7c4;
17
+
background-color: #022a4b;
18
+
display: block;
19
+
padding-right: 1em;
142
20
}
143
21
22
+
/* Tip button styles */
144
23
.tip {
145
-
@apply inline-block px-8 py-4 font-sans font-semibold text-xl rounded-full shadow-xl transform hover:scale-105 focus:outline-none focus:ring-2 focus:ring-pink-300 focus:ring-opacity-50 border-b-[1px] text-white overflow-clip transition-transform;
146
-
border-color: var(--link);
24
+
@apply inline-block px-8 py-4 font-sans font-semibold text-xl rounded-full shadow-xl transform hover:scale-105 focus:outline-none focus:ring-2 focus:ring-pink-300 focus:ring-opacity-50 border-b-[1px] text-white overflow-clip transition-transform;
25
+
border-color: var(--link);
147
26
}
148
27
149
28
.tip.tip-sm {
150
-
@apply inline-block px-6 py-2 text-lg shadow-md;
29
+
@apply inline-block px-6 py-2 text-lg shadow-md;
151
30
}
152
31
153
32
.tip-bg {
154
-
background-image: linear-gradient(45deg, var(--purple), var(--pink));
155
-
position: absolute;
156
-
top: 0;
157
-
left: 0;
158
-
right: 0;
159
-
bottom: 0;
160
-
z-index: -1;
33
+
background-image: linear-gradient(45deg, var(--purple), var(--pink));
34
+
position: absolute;
35
+
top: 0;
36
+
left: 0;
37
+
right: 0;
38
+
bottom: 0;
39
+
z-index: -1;
161
40
}
162
41
163
42
@media (prefers-color-scheme: dark) {
164
-
.tip-bg {
165
-
filter: brightness(0.46);
166
-
}
43
+
.tip-bg {
44
+
filter: brightness(0.46);
45
+
}
167
46
}
+166
app/[slug]/markdown.tsx
+166
app/[slug]/markdown.tsx
···
1
+
"use client";
2
+
3
+
export function P(props: React.ComponentProps<"p">) {
4
+
return <p {...props} />;
5
+
}
6
+
7
+
export function H2({ id, children, ...props }: React.ComponentProps<"h2">) {
8
+
return (
9
+
<h2
10
+
id={id}
11
+
className="group relative text-3xl font-bold mt-2"
12
+
{...props}
13
+
>
14
+
<a href={`#${id}`} className="no-underline text-inherit">
15
+
<span
16
+
aria-hidden
17
+
className="absolute -translate-x-[1em] opacity-0 group-hover:opacity-70 group-focus-within:opacity-70 group-[:target]:opacity-70"
18
+
>
19
+
#
20
+
</span>
21
+
{children}
22
+
</a>
23
+
</h2>
24
+
);
25
+
}
26
+
27
+
export function H3({ id, children, ...props }: React.ComponentProps<"h3">) {
28
+
return (
29
+
<h3
30
+
id={id}
31
+
className="group relative text-2xl font-bold mt-2"
32
+
{...props}
33
+
>
34
+
<a href={`#${id}`} className="no-underline text-inherit">
35
+
<span
36
+
aria-hidden
37
+
className="absolute -translate-x-[1em] opacity-0 group-hover:opacity-70 group-focus-within:opacity-70 group-[:target]:opacity-70"
38
+
>
39
+
#
40
+
</span>
41
+
{children}
42
+
</a>
43
+
</h3>
44
+
);
45
+
}
46
+
47
+
export function H4({ id, children, ...props }: React.ComponentProps<"h4">) {
48
+
return (
49
+
<h4
50
+
id={id}
51
+
className="group relative text-xl font-bold mt-2"
52
+
{...props}
53
+
>
54
+
<a href={`#${id}`} className="no-underline text-inherit">
55
+
<span
56
+
aria-hidden
57
+
className="absolute -translate-x-[1em] opacity-0 group-hover:opacity-70 group-focus-within:opacity-70 group-[:target]:opacity-70"
58
+
>
59
+
#
60
+
</span>
61
+
{children}
62
+
</a>
63
+
</h4>
64
+
);
65
+
}
66
+
67
+
export function Blockquote(props: React.ComponentProps<"blockquote">) {
68
+
return (
69
+
<blockquote
70
+
className="relative -left-2 -ml-4 pl-4 italic opacity-80 border-l-[3px] border-current"
71
+
{...props}
72
+
/>
73
+
);
74
+
}
75
+
76
+
export function UL(props: React.ComponentProps<"ul">) {
77
+
return <ul className="list-inside md:list-outside list-disc" {...props} />;
78
+
}
79
+
80
+
export function OL(props: React.ComponentProps<"ol">) {
81
+
return (
82
+
<ol className="list-inside md:list-outside list-decimal" {...props} />
83
+
);
84
+
}
85
+
86
+
export function LI(props: React.ComponentProps<"li">) {
87
+
return <li className="mb-3 last:mb-0" {...props} />;
88
+
}
89
+
90
+
export function Pre({
91
+
style,
92
+
...props
93
+
}: React.ComponentProps<"pre">) {
94
+
return (
95
+
<pre
96
+
className="-mx-4 overflow-y-auto p-4 text-sm"
97
+
{...props}
98
+
style={{
99
+
...style,
100
+
clipPath: "var(--path, none)",
101
+
borderTopLeftRadius: "var(--radius-top, 12px)",
102
+
borderTopRightRadius: "var(--radius-top, 12px)",
103
+
borderBottomLeftRadius: "var(--radius-bottom, 12px)",
104
+
borderBottomRightRadius: "var(--radius-bottom, 12px)",
105
+
paddingTop: "var(--padding-top, 1rem)",
106
+
paddingBottom: "var(--padding-bottom, 1rem)",
107
+
}}
108
+
/>
109
+
);
110
+
}
111
+
112
+
export function Code({
113
+
className,
114
+
...props
115
+
}: React.ComponentProps<"code"> & { "data-language"?: string }) {
116
+
// Code blocks have data-language from rehype-pretty-code (defaultLang ensures all blocks have it)
117
+
if ("data-language" in props) {
118
+
return <code className={className} {...props} />;
119
+
}
120
+
// Inline code styling
121
+
return (
122
+
<code
123
+
className="rounded-[10px] bg-[--inlineCode-bg] text-[--inlineCode-text] px-[0.2em] py-[0.15em] whitespace-normal"
124
+
{...props}
125
+
/>
126
+
);
127
+
}
128
+
129
+
export function Table(props: React.ComponentProps<"table">) {
130
+
return <table className="w-full border-collapse" {...props} />;
131
+
}
132
+
133
+
export function Th(props: React.ComponentProps<"th">) {
134
+
return (
135
+
<th
136
+
className="border border-gray-300 dark:border-gray-600 p-2 text-left"
137
+
{...props}
138
+
/>
139
+
);
140
+
}
141
+
142
+
export function Td(props: React.ComponentProps<"td">) {
143
+
return (
144
+
<td
145
+
className="border border-gray-300 dark:border-gray-600 p-2 text-left"
146
+
{...props}
147
+
/>
148
+
);
149
+
}
150
+
151
+
export function Hr(props: React.ComponentProps<"hr">) {
152
+
return <hr className="opacity-60 dark:opacity-10 mt-4" {...props} />;
153
+
}
154
+
155
+
export function Img(props: React.ComponentProps<"img">) {
156
+
return <img className="max-w-full" {...props} />;
157
+
}
158
+
159
+
export function A(props: React.ComponentProps<"a">) {
160
+
return (
161
+
<a
162
+
className="border-b border-[--link] text-[--link]"
163
+
{...props}
164
+
/>
165
+
);
166
+
}
+51
-49
app/[slug]/page.tsx
+51
-49
app/[slug]/page.tsx
···
2
2
import { readdir, readFile } from "fs/promises";
3
3
import matter from "gray-matter";
4
4
import { MDXRemote } from "next-mdx-remote-client/rsc";
5
-
import Link from "../Link";
5
+
import TextLink from "../TextLink";
6
6
import { sans } from "../fonts";
7
7
import remarkSmartpants from "remark-smartypants";
8
8
import rehypePrettyCode from "rehype-pretty-code";
9
9
import rehypeSlug from "rehype-slug";
10
-
import rehypeAutolinkHeadings from "rehype-autolink-headings";
11
10
import { remarkMdxEvalCodeBlock } from "./mdx";
12
11
import overnight from "overnight/themes/Overnight-Slumber.json";
13
12
import "./markdown.css";
14
13
import remarkGfm from "remark-gfm";
14
+
import * as markdown from "./markdown";
15
15
16
16
overnight.colors["editor.background"] = "var(--code-bg)";
17
17
···
54
54
year: "numeric",
55
55
})}
56
56
</p>
57
-
<div className="markdown">
58
-
<div className="mb-8 relative md:-left-6 flex flex-wrap items-baseline">
59
-
{!data.nocta && (
60
-
<a
61
-
href="https://ko-fi.com/gaearon"
62
-
target="_blank"
63
-
className="mt-10 tip tip-sm mr-4"
64
-
>
65
-
<span className="tip-bg" />
66
-
Pay what you like
67
-
</a>
68
-
)}
69
-
{data.youtube && (
70
-
<a
71
-
className="leading-tight mt-4"
72
-
href={data.youtube}
73
-
target="_blank"
74
-
>
75
-
<span className="hidden min-[400px]:inline">Watch on </span>
76
-
YouTube
77
-
</a>
78
-
)}
79
-
</div>
57
+
<div className="markdown flex flex-col gap-8 mt-12">
58
+
{(!data.nocta || data.youtube) && (
59
+
<div className="relative md:-left-6 flex flex-wrap items-baseline gap-4">
60
+
{!data.nocta && (
61
+
<a
62
+
href="https://ko-fi.com/gaearon"
63
+
target="_blank"
64
+
className="tip tip-sm"
65
+
>
66
+
<span className="tip-bg" />
67
+
Pay what you like
68
+
</a>
69
+
)}
70
+
{data.youtube && (
71
+
<TextLink href={data.youtube}>
72
+
<span className="hidden min-[400px]:inline">Watch on </span>
73
+
YouTube
74
+
</TextLink>
75
+
)}
76
+
</div>
77
+
)}
80
78
81
79
<Wrapper>
80
+
<div className="flex flex-col gap-8">
82
81
<MDXRemote
83
82
source={content}
84
83
components={{
85
-
a: Link,
84
+
p: markdown.P,
85
+
h2: markdown.H2,
86
+
h3: markdown.H3,
87
+
h4: markdown.H4,
88
+
blockquote: markdown.Blockquote,
89
+
ul: markdown.UL,
90
+
ol: markdown.OL,
91
+
li: markdown.LI,
92
+
pre: markdown.Pre,
93
+
code: markdown.Code,
94
+
table: markdown.Table,
95
+
th: markdown.Th,
96
+
td: markdown.Td,
97
+
hr: markdown.Hr,
98
+
a: (props: React.ComponentProps<"a">) => (
99
+
<TextLink {...props} href={props.href ?? ""} />
100
+
),
86
101
img: async ({ src, ...rest }) => {
87
102
if (
88
103
src &&
···
121
136
finalSrc = `/${slug}/${src}`;
122
137
}
123
138
124
-
return <img src={finalSrc} {...rest} />;
139
+
return <markdown.Img src={finalSrc} {...rest} />;
125
140
},
126
141
Video: ({ src, ...rest }) => {
127
142
let finalSrc = src;
···
146
161
rehypePrettyCode,
147
162
{
148
163
theme: overnight,
164
+
defaultLang: { block: "text" },
149
165
},
150
166
],
151
167
[rehypeSlug],
152
-
[
153
-
rehypeAutolinkHeadings,
154
-
{
155
-
behavior: "wrap",
156
-
properties: {
157
-
className: "linked-heading",
158
-
target: "_self",
159
-
},
160
-
},
161
-
],
162
168
] as any,
163
169
} as any,
164
170
}}
165
171
/>
172
+
</div>
166
173
</Wrapper>
167
174
{!data.nocta && (
168
-
<div className="flex flex-wrap items-baseline">
175
+
<div className="flex flex-wrap items-baseline gap-4 relative md:-left-8">
169
176
<a
170
177
href="https://ko-fi.com/gaearon"
171
178
target="_blank"
172
-
className="tip mb-8 relative md:-left-8"
179
+
className="tip"
173
180
>
174
181
<span className="tip-bg" />
175
182
Pay what you like
176
183
</a>
177
-
<a
178
-
className="leading-tight ml-4 relative md:-left-8"
179
-
href="/hire-me-in-japan/"
180
-
>
181
-
Hire me
182
-
</a>
184
+
<TextLink href="/hire-me-in-japan/">Hire me</TextLink>
183
185
</div>
184
186
)}
185
-
<hr />
187
+
<hr className="opacity-60 dark:opacity-10" />
186
188
<p>
187
189
{data.bluesky && (
188
190
<>
189
-
<Link href={data.bluesky}>Discuss on Bluesky</Link>
191
+
<TextLink href={data.bluesky}>Discuss on Bluesky</TextLink>
190
192
·
191
193
</>
192
194
)}
193
195
{data.youtube && (
194
196
<>
195
-
<Link href={data.youtube}>Watch on YouTube</Link>
197
+
<TextLink href={data.youtube}>Watch on YouTube</TextLink>
196
198
·
197
199
</>
198
200
)}
199
201
{/* TODO: This should say Edit when Tangled adds an editor. */}
200
-
<Link href={editUrl}>Fork on Tangled</Link>
202
+
<TextLink href={editUrl}>Fork on Tangled</TextLink>
201
203
</p>
202
204
</div>
203
205
</article>
+6
-6
public/a-complete-guide-to-useeffect/index.md
+6
-6
public/a-complete-guide-to-useeffect/index.md
···
89
89
}
90
90
```
91
91
92
-
What does it mean? Does `count` somehow “watch” changes to our state and update automatically? That might be a useful first intuition when you learn React but it’s *not* an [accurate mental model](https://overreacted.io/react-as-a-ui-runtime/).
92
+
What does it mean? Does `count` somehow “watch” changes to our state and update automatically? That might be a useful first intuition when you learn React but it’s *not* an [accurate mental model](/react-as-a-ui-runtime/).
93
93
94
94
**In this example, `count` is just a number.** It’s not a magic “data binding”, a “watcher”, a “proxy”, or anything else. It’s a good old number like this one:
95
95
···
140
140
141
141
The key takeaway is that the `count` constant inside any particular render doesn’t change over time. It’s our component that’s called again — and each render “sees” its own `count` value that’s isolated between renders.
142
142
143
-
*(For an in-depth overview of this process, check out my post [React as a UI Runtime](https://overreacted.io/react-as-a-ui-runtime/).)*
143
+
*(For an in-depth overview of this process, check out my post [React as a UI Runtime](/react-as-a-ui-runtime/).)*
144
144
145
145
## Each Render Has Its Own Event Handlers
146
146
···
190
190
191
191
Go ahead and [try it yourself!](https://codesandbox.io/s/w2wxl3yo0l)
192
192
193
-
If the behavior doesn’t quite make sense to you, imagine a more practical example: a chat app with the current recipient ID in the state, and a Send button. [This article](https://overreacted.io/how-are-function-components-different-from-classes/) explores the reasons in depth but the correct answer is 3.
193
+
If the behavior doesn’t quite make sense to you, imagine a more practical example: a chat app with the current recipient ID in the state, and a Send button. [This article](/how-are-function-components-different-from-classes/) explores the reasons in depth but the correct answer is 3.
194
194
195
195
The alert will “capture” the state at the time I clicked the button.
196
196
···
394
394
395
395
**Conceptually, you can imagine effects are a *part of the render result*.**
396
396
397
-
Strictly saying, they’re not (in order to [allow Hook composition](https://overreacted.io/why-do-hooks-rely-on-call-order/) without clumsy syntax or runtime overhead). But in the mental model we’re building up, effect functions *belong* to a particular render in the same way that event handlers do.
397
+
Strictly saying, they’re not (in order to [allow Hook composition](/why-do-hooks-rely-on-call-order/) without clumsy syntax or runtime overhead). But in the mental model we’re building up, effect functions *belong* to a particular render in the same way that event handlers do.
398
398
399
399
---
400
400
···
518
518
519
519
**It doesn’t matter whether you read from props or state “early” inside of your component.** They’re not going to change! Inside the scope of a single render, props and state stay the same. (Destructuring props makes this more obvious.)
520
520
521
-
Of course, sometimes you *want* to read the latest rather than captured value inside some callback defined in an effect. The easiest way to do it is by using refs, as described in the last section of [this article](https://overreacted.io/how-are-function-components-different-from-classes/).
521
+
Of course, sometimes you *want* to read the latest rather than captured value inside some callback defined in an effect. The easiest way to do it is by using refs, as described in the last section of [this article](/how-are-function-components-different-from-classes/).
522
522
523
523
Be aware that when you want to read the *future* props or state from a function in a *past* render, you’re swimming against the tide. It’s not *wrong* (and in some cases necessary) but it might look less “clean” to break out of the paradigm. This is an intentional consequence because it helps highlight which code is fragile and depends on timing. In classes, it’s less obvious when this happens.
524
524
···
628
628
629
629
## Synchronization, Not Lifecycle
630
630
631
-
One of my favorite things about React is that it unifies describing the initial render result and the updates. This [reduces the entropy](https://overreacted.io/the-bug-o-notation/) of your program.
631
+
One of my favorite things about React is that it unifies describing the initial render result and the updates. This [reduces the entropy](/the-bug-o-notation/) of your program.
632
632
633
633
Say my component looks like this:
634
634
+1
-1
public/hire-me-in-japan/index.md
+1
-1
public/hire-me-in-japan/index.md
···
61
61
- Mentoring the application team on how to root cause particularly gnarly issues.
62
62
- Pushing for a closer collaboration with the backend team so that the seams from the client/server organizational split don't "show up" as poor UX in the product.
63
63
64
-
I've also helped the team explain the AT protocol to a broader community--first in a [talk](https://www.youtube.com/watch?v=F1sJW6nTP6E) last year, which then crystallized into my recent article called [Open Social](https://overreacted.io/open-social/).
64
+
I've also helped the team explain the AT protocol to a broader community--first in a [talk](https://www.youtube.com/watch?v=F1sJW6nTP6E) last year, which then crystallized into my recent article called [Open Social](/open-social/).
65
65
66
66
#### 2015–2023: React at Meta/Facebook
67
67
+1
-1
public/how-imports-work-in-rsc/index.md
+1
-1
public/how-imports-work-in-rsc/index.md
···
196
196
197
197
In that sense, when you `import` some code, you bring it *into* your program.
198
198
199
-
But what if we want to write *both our backend and frontend* in JavaScript? (Or, alternatively, what if we realize that adding a [JS BFF can make our app better?](https://overreacted.io/jsx-over-the-wire/#backend-for-frontend))
199
+
But what if we want to write *both our backend and frontend* in JavaScript? (Or, alternatively, what if we realize that adding a [JS BFF can make our app better?](/jsx-over-the-wire/#backend-for-frontend))
200
200
201
201
---
202
202
+2
-4
public/impossible-components/client.js
+2
-4
public/impossible-components/client.js
···
171
171
className="block border-2 px-1 mb-4"
172
172
/>
173
173
</div>
174
-
<ul className="unstyled gap-2 flex flex-col">
174
+
<ul className="gap-2 flex flex-col">
175
175
{sortedItems.map((item) => (
176
-
<li className="unstyled" key={item.id}>
177
-
{item.content}
178
-
</li>
176
+
<li key={item.id}>{item.content}</li>
179
177
))}
180
178
</ul>
181
179
</>
+1
-1
public/impossible-components/index.md
+1
-1
public/impossible-components/index.md
···
1143
1143
1144
1144
### A Note on Terminology
1145
1145
1146
-
As in my other [recent](https://overreacted.io/react-for-two-computers/) [articles](https://overreacted.io/jsx-over-the-wire/), I've tried to avoid using the "Server Components" and "Client Components" terminology in this post because it brings up distracting connotations and knee-jerk reactions. (In particular, people tend to assume the "client loads from the server" rather than the "server renders the client" model.)
1146
+
As in my other [recent](/react-for-two-computers/) [articles](/jsx-over-the-wire/), I've tried to avoid using the "Server Components" and "Client Components" terminology in this post because it brings up distracting connotations and knee-jerk reactions. (In particular, people tend to assume the "client loads from the server" rather than the "server renders the client" model.)
1147
1147
1148
1148
The "backend components" in this post are officially called Server Components, and the "frontend components" are officially called Client Components. If I could change the official terminology, I probably still would *not.* However, I find that introducing it when you already understand the model (as I hope you do by this point) works better than starting with the terminology. This may eventually stop being a problem if the Server/Client split as modeled by React Server Components ever becomes the generally accepted model of describing distributed composable user interfaces. I think we may get there at some point within the next ten years.
1149
1149
+15
-3
public/impossible-components/server.js
+15
-3
public/impossible-components/server.js
···
62
62
return (
63
63
<section className="rounded-md bg-black/5 p-2">
64
64
<h5 className="font-bold">
65
-
<a href={"/" + slug} target="_blank">
65
+
<a
66
+
href={"/" + slug}
67
+
target="_blank"
68
+
className="underline decoration-[--link] decoration-1 underline-offset-4 text-[--link]"
69
+
>
66
70
{data.title}
67
71
</a>
68
72
</h5>
···
80
84
return (
81
85
<section className="rounded-md bg-black/5 p-2">
82
86
<h5 className="font-bold">
83
-
<a href={"/" + slug} target="_blank">
87
+
<a
88
+
href={"/" + slug}
89
+
target="_blank"
90
+
className="underline decoration-[--link] decoration-1 underline-offset-4 text-[--link]"
91
+
>
84
92
{data.title}
85
93
</a>
86
94
</h5>
···
103
111
}
104
112
>
105
113
<h5 className="font-bold">
106
-
<a href={"/" + slug} target="_blank">
114
+
<a
115
+
href={"/" + slug}
116
+
target="_blank"
117
+
className="underline decoration-[--link] decoration-1 underline-offset-4 text-[--link]"
118
+
>
107
119
{data.title}
108
120
</a>
109
121
</h5>
+1
-1
public/react-as-a-ui-runtime/index.md
+1
-1
public/react-as-a-ui-runtime/index.md
···
1083
1083
1084
1084
**Of course, `use` is not actually a syntax.** (It wouldn’t bring much benefit and would create a lot of friction.)
1085
1085
1086
-
However, React *does* expect that all calls to Hooks happen only at the top level of a component and unconditionally. These [Rules of Hooks](https://reactjs.org/docs/hooks-rules.html) can be enforced with [a linter plugin](https://www.npmjs.com/package/eslint-plugin-react-hooks). There have been heated arguments about this design choice but in practice, I haven’t seen it confusing people. I also wrote about why commonly proposed alternatives [don’t work](https://overreacted.io/why-do-hooks-rely-on-call-order/).
1086
+
However, React *does* expect that all calls to Hooks happen only at the top level of a component and unconditionally. These [Rules of Hooks](https://reactjs.org/docs/hooks-rules.html) can be enforced with [a linter plugin](https://www.npmjs.com/package/eslint-plugin-react-hooks). There have been heated arguments about this design choice but in practice, I haven’t seen it confusing people. I also wrote about why commonly proposed alternatives [don’t work](/why-do-hooks-rely-on-call-order/).
1087
1087
1088
1088
Internally, Hooks are implemented as [linked lists](https://dev.to/aspittel/thank-u-next-an-introduction-to-linked-lists-4pph). When you call `useState`, we move the pointer to the next item. When we exit the component’s [“call tree” frame](#call-tree), we save the resulting list there until the next render.
1089
1089
+1
-1
public/the-math-is-haunted/index.md
+1
-1
public/the-math-is-haunted/index.md
···
30
30
31
31
To a mathematician's eye, this syntax looks like stating a theorem. We have the `theorem` keyword, the name of our theorem, a colon `:` before its statement, the statement that we'd like to prove, and `:= by` followed by the proof (`sorry` means that we haven't completed the actual proof yet but we're planning to fill it in later).
32
32
33
-
But if you're a programmer, you might notice a hint of something else. That `theorem` looks suspiciously like a function. But then what is `2 = 2`? It looks like a return type of that function. But how can `2 = 2` be a *type*? Isn't `2 = 2` just a boolean? And if `2 = 2` really *is* a type, what are the *values* of that `2 = 2` type? [These are very interesting questions](https://overreacted.io/beyond-booleans/), but we'll have to forget about them for now.
33
+
But if you're a programmer, you might notice a hint of something else. That `theorem` looks suspiciously like a function. But then what is `2 = 2`? It looks like a return type of that function. But how can `2 = 2` be a *type*? Isn't `2 = 2` just a boolean? And if `2 = 2` really *is* a type, what are the *values* of that `2 = 2` type? [These are very interesting questions](/beyond-booleans/), but we'll have to forget about them for now.
34
34
35
35
Instead, we'll start by inspecting the proof:
36
36
+5
-1
public/the-two-reacts/post-preview.js
+5
-1
public/the-two-reacts/post-preview.js
···
9
9
return (
10
10
<section className="rounded-md bg-black/5 p-2">
11
11
<h5 className="font-bold">
12
-
<a href={"/" + slug} target="_blank">
12
+
<a
13
+
href={"/" + slug}
14
+
target="_blank"
15
+
className="underline decoration-[--link] decoration-1 underline-offset-4 text-[--link]"
16
+
>
13
17
{data.title}
14
18
</a>
15
19
</h5>