使用 prismjs 生成静态 html - 如何启用行号？

Question

我正在使用 node.js 从代码中生成 static html 文件，并使用 prismjs 对其进行格式化。在我的应用程序中，我无法访问支持 Javascript 的 HTML 渲染器（我使用的是“htmllite”）。所以我需要能够生成不需要 Javascript 的 HTML。

const Prism = require('prismjs');
const loadLanguages = require('prismjs/components/');
loadLanguages(['csharp']);
const code = '<a bunch of C# code>';
const html = Prism.highlight(code, Prism.languages.csharp, 'csharp');

这很好用。但我想使用line-numbers 插件，但不知道如何使它工作。我的<pre> 有line-numbers 类，我的左边距更大，但没有行号。

Answer 1

PrismJS 需要 DOM 才能使大多数插件工作。查看plugins/line-numbers/prism-line-numbers.js#L109 中的代码后，我们可以看到行号只是一个span 元素和class="line-numbers-rows"，它的每一行都包含一个空的span。我们可以在没有 DOM 的情况下模拟这种行为，只需使用 prism-line-numbers 用于获取行号的相同正则表达式，然后编写一个包含 span.line-numbers-rows 的 html 代码的字符串，并为每一行添加一个空字符串 <span></span> .

Prism.highlight 仅运行 2 个挂钩，before-tokenize 和 after-tokenize。我们将使用after-tokenize 组成一个包含span.line-numbers-rows 元素和空span 行元素的lineNumbersWrapper 字符串：

const Prism = require('prismjs');
const loadLanguages = require('prismjs/components/');
loadLanguages(['csharp']);

const code = `Console.WriteLine();
Console.WriteLine("Demo: Prism line-numbers plugin with nodejs");`;

// https://github.com/PrismJS/prism/blob/master/plugins/line-numbers/prism-line-numbers.js#L109
var NEW_LINE_EXP = /\n(?!$)/g;
var lineNumbersWrapper;

Prism.hooks.add('after-tokenize', function (env) {
  var match = env.code.match(NEW_LINE_EXP);
  var linesNum = match ? match.length + 1 : 1;
  var lines = new Array(linesNum + 1).join('<span></span>');

  lineNumbersWrapper = `<span aria-hidden="true" class="line-numbers-rows">${lines}</span>`;
});

const formated = Prism.highlight(code, Prism.languages.csharp, 'csharp');
const html = formated + lineNumbersWrapper;

console.log(html);

这将输出：

Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span><span class="token string">"Demo: Generate invalid numbers"</span><span class="token punctuation">)</span><span class="token punctuation">;</span><span aria-hidden="true" class="line-numbers-rows"><span></span><span></span></span>

最后有span.line-numbers-rows：

<span aria-hidden="true" class="line-numbers-rows">
  <span></span>
  <span></span>
</span>

现在，如果我们在 pre.language-csharp.line-numbers code.language-csharp 元素中使用该输出，我们将得到正确的行号结果。检查这个只有themes/prism.css 和plugins/line-numbers/prism-line-numbers.css 的Codepen，并用上面输出的代码正确显示行号。

请注意，每一行（第一行除外）都必须是用于代码正确显示的标记，这是因为我们在 pre.code 块内，但我想你已经知道了。

更新

如果您不依赖 CSS 并且只希望在每行之前添加一个行号，那么您可以通过拆分所有行来添加一个，并在开头使用 padStart 添加每个带有空格填充的 index + 1 ：

const Prism = require('prismjs');
const loadLanguages = require('prismjs/components/');
loadLanguages(['csharp']);

const code = `Console.WriteLine();
Console.WriteLine("Demo: Prism line-numbers plugin with nodejs");`;

const formated = Prism.highlight(code, Prism.languages.csharp, 'csharp');

const html = formated
  .split('\n')
  .map((line, num) => `${(num + 1).toString().padStart(4, ' ')}. ${line}`)
  .join('\n');

console.log(html);

将输出：

   1. Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
   2. Console<span class="token punctuation">.</span><span class="token function">WriteLine</span><span class="token punctuation">(</span><span class="token string">"Demo: Prism line-numbers plugin with nodejs"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>

Answer 2

我有一个带有代码 sn-ps 的 React 网站，我使用了这样的 prismjs 节点模块：

SourceCode.js

import * as Prism from "prismjs";
export default function SourceCode(props) {
    return (
        <div>
            <div style={{ maxWidth: 900 }}>
                <pre className="language-javascript" style={{ backgroundColor: "#272822", fontSize: "0.8em" }}>
                    <code
                        style={{ fontFamily: "Consolas,Monaco,'Andale Mono','Ubuntu Mono',monospace" }}
                        dangerouslySetInnerHTML={{
                            __html: Prism.highlight(props.code, Prism.languages.javascript, "javascript"),
                        }}
                    />
                </pre>
            </div>
        </div>
    );
};

然后我决定添加行号插件，我很难弄清楚如何使它与 Node.js 和 React 一起工作。问题是行号使用了 DOM，而 Node.js 中并没有简单地使用 DOM。

我终于做到了。我卸载了 prismjs 模块并以老式方式完成了 :)。

index.html

<html lang="en-us">
    <head>
        <meta charset="utf-8" />
        <meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
        <title>SciChart Web Demo</title>
        <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,400,500,700&display=swap" />
        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/prism/1.21.0/themes/prism-okaidia.min.css" />
        <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/prism/1.21.0/plugins/line-numbers/prism-line-numbers.min.css" />
        <script async type="text/javascript" src="bundle.js"></script>
    </head>
    <body>
        <div id="react-root"></div>
        <script>
            window.Prism = window.Prism || {};
            Prism.manual = true;
        </script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.21.0/prism.min.js"></script>
        <script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.21.0/plugins/line-numbers/prism-line-numbers.min.js"></script>
    </body>
</html>

SourceCode.js

import * as React from "react";

export default function SourceCode(props) {
    React.useEffect(() => {
        window.Prism.highlightAll();
    }, []);
    return (
        <div>
            <div style={{ maxWidth: 900 }}>
                <pre
                    className="language-javascript line-numbers"
                    style={{ backgroundColor: "#272822", fontSize: "0.8em" }}
                >
                    <code style={{ fontFamily: "Consolas,Monaco,'Andale Mono','Ubuntu Mono',monospace" }}>
                        {props.code}
                    </code>
                </pre>
            </div>
        </div>
    );
};

Answer 3

也许这对你有帮助：

Codepen 出错：

link

（codepen 行超出了堆栈溢出的限制！）

Codepen 工作正常：

link

（codepen 行超出了堆栈溢出的限制！）

两者之间的变化：

pre.line-numbers {
	position: relative;
	padding-left: 3.8em;
	counter-reset: linenumber;
}

pre.line-numbers>code {
	position: relative;
}

.line-numbers .line-numbers-rows {
	position: absolute;
	pointer-events: none;
	top: 0;
	font-size: 100%;
	left: -3.8em;
	width: 3em;
	/* works for line-numbers below 1000 lines */
	letter-spacing: -1px;
	border-right: 1px solid #999;
	-webkit-user-select: none;
	-moz-user-select: none;
	-ms-user-select: none;
	user-select: none;
}

.line-numbers-rows>span {
	pointer-events: none;
	display: block;
	counter-increment: linenumber;
}

.line-numbers-rows>span:before {
	content: counter(linenumber);
	color: #999;
	display: block;
	padding-right: 0.8em;
	text-align: right;
}