extractLang()

從 code 元素的 className 中擷取程式語言識別字。

import { extractLang } from "@unifast/core";

函式簽名

function extractLang(code: HastElement): string | null

參數

code

屬性	型別	預設值	說明
`type`	`"element"`	—	節點型別識別字
`tagName`	`string`	—	HTML 標籤名稱（通常為 `"code"`）
`properties`	`Record<string, unknown>`	—	元素屬性，其中包含 `className`
`children`	`HastNode[]`	—	元素的子節點

回傳值

string | null — 從第一個 language-* class 中擷取出的語言識別字；若找不到語言 class 則為 null。

用法

import { extractLang } from "@unifast/core";
import type { HastElement } from "@unifast/core";

const codeElement: HastElement = {
  type: "element",
  tagName: "code",
  properties: { className: ["language-typescript"] },
  children: [{ type: "text", value: "const x = 1;" }],
};

const lang = extractLang(codeElement);

console.log(lang);
// typescript

範例

從 code 元素擷取語言

import { extractLang } from "@unifast/core";
import type { HastElement } from "@unifast/core";

const code: HastElement = {
  type: "element",
  tagName: "code",
  properties: { className: ["language-js", "highlight"] },
  children: [{ type: "text", value: "console.log('hello');" }],
};

console.log(extractLang(code));
// js

沒有語言 class 時

import { extractLang } from "@unifast/core";
import type { HastElement } from "@unifast/core";

const code: HastElement = {
  type: "element",
  tagName: "code",
  properties: { className: ["highlight"] },
  children: [{ type: "text", value: "plain text" }],
};

console.log(extractLang(code));
// null

當 className 並非陣列時

import { extractLang } from "@unifast/core";
import type { HastElement } from "@unifast/core";

const code: HastElement = {
  type: "element",
  tagName: "code",
  properties: {},
  children: [{ type: "text", value: "no classes" }],
};

console.log(extractLang(code));
// null

搭配 findCodeChild 使用

import { extractLang, findCodeChild } from "@unifast/core";
import type { HastElement } from "@unifast/core";

const pre: HastElement = {
  type: "element",
  tagName: "pre",
  properties: {},
  children: [
    {
      type: "element",
      tagName: "code",
      properties: { className: ["language-python"] },
      children: [{ type: "text", value: "print('hello')" }],
    },
  ],
};

const code = findCodeChild(pre);
if (code) {
  console.log(extractLang(code));
  // python
}