src/html.ts

Functions

Imports

It imports no other module of this repo. Imported by src/index.ts, src/lite/svg.ts, src/primitives/heat-strip.ts, src/primitives/progress-ring.ts, src/primitives/sparkline.ts, src/primitives/timeline.ts, src/primitives/uptime-strip.ts, src/render/figure.ts, src/render/plot.ts.

Source

1/**
2 * HTML string building. Every chart returns a string so it can be written into any server
3 * template, and every piece of caller text that reaches that string passes through these helpers.
4 */
5
6const ESCAPES: Readonly<Record<string, string>> = {
7  "&": "&amp;",
8  "<": "&lt;",
9  ">": "&gt;",
10  '"': "&quot;",
11  "'": "&#39;",
12};
13
14/** Escapes text for use as HTML element content or as a double-quoted attribute value. */
15export function escapeHtml(value: string): string {
16  return value.replace(/[&<>"']/g, (ch) => ESCAPES[ch] ?? ch);
17}
18
19/** An attribute value; `false` and `undefined` omit the attribute, `true` writes it bare. */
20export type AttributeValue = string | number | boolean | undefined;
21
22/** Serializes attributes in the order given, skipping omitted ones. */
23function attributes(attrs: Readonly<Record<string, AttributeValue>>): string {
24  let out = "";
25  for (const [name, value] of Object.entries(attrs)) {
26    if (value === undefined || value === false) continue;
27    out += value === true ? ` ${name}` : ` ${name}="${escapeHtml(String(value))}"`;
28  }
29  return out;
30}
31
32/** One element as a string. `children` is trusted markup: callers escape text before passing it. */
33export function element(
34  tag: string,
35  attrs: Readonly<Record<string, AttributeValue>>,
36  children = "",
37): string {
38  return `<${tag}${attributes(attrs)}>${children}</${tag}>`;
39}