Include examples of components rendered as HTML

x-govuk · Dec 19, 2023 · 8942e10 · 8942e10
1 parent 699275d
commit 8942e10
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diff --git a/docs/_components/example/template.njk b/docs/_components/example/template.njk
@@ -1,34 +1,38 @@
 {%- from "govuk/components/tabs/macro.njk" import govukTabs -%}
 
-{%- set nunjucksHtml -%}
-
-```js
-{{ getNunjucksCode(params.example) }}
-```
-{%- endset -%}
-
 {%- set examplePath = "/examples/" + params.example -%}
 
-{%- set previewHtml -%}
-<iframe class="app-example__frame" data-module="app-example-frame" src="{{ examplePath | url }}"></iframe>
-<p class="app-example__toolbar">
-  <a class="app-example__new-window" href="{{ examplePath | url }}" target="_blank">Open this example in a new tab</a>
-</p>
-{%- endset -%}
-
-{{- govukTabs({
-  classes: "app-example__tabs",
-  items: [{
-    label: "Preview",
-    id: params.example + "-preview",
-    panel: {
-      html: previewHtml
-    }
-  }, {
-    label: "Nunjucks",
-    id: params.example + "-nunjucks",
-    panel: {
-      html: nunjucksHtml
-    }
-  }]
-}) -}}
+<div class="govuk-tabs app-example__tabs" data-module="govuk-tabs">
+  <h2 class="govuk-tabs__title">
+    Contents
+  </h2>
+  <ul class="govuk-tabs__list">
+    <li class="govuk-tabs__list-item govuk-tabs__list-item--selected">
+      <a class="govuk-tabs__tab" href="#{{ params.example }}-preview">
+        Preview
+      </a>
+    </li>
+    <li class="govuk-tabs__list-item">
+      <a class="govuk-tabs__tab" href="#{{ params.example }}-html">
+        HTML
+      </a>
+    </li>
+    <li class="govuk-tabs__list-item">
+      <a class="govuk-tabs__tab" href="#{{ params.example }}-nunjucks">
+        Nunjucks
+      </a>
+    </li>
+  </ul>
+  <div class="govuk-tabs__panel" id="{{ params.example }}-preview">
+    <iframe class="app-example__frame" data-module="app-example-frame" src="{{ examplePath | url }}"></iframe>
+    <p class="app-example__toolbar">
+      <a class="app-example__new-window" href="{{ examplePath | url }}" target="_blank">Open this example in a new tab</a>
+    </p>
+  </div>
+  <div class="govuk-tabs__panel govuk-tabs__panel--hidden" id="{{ params.example }}-html">
+    {{ getHtmlCode(params.example) }}
+  </div>
+  <div class="govuk-tabs__panel govuk-tabs__panel--hidden" id="{{ params.example }}-nunjucks">
+    {{ getNunjucksCode(params.example) }}
+  </div>
+</div>
diff --git a/eleventy.config.js b/eleventy.config.js
@@ -1,7 +1,17 @@
+const fs = require('node:fs')
 const govukEleventyPlugin = require('@x-govuk/govuk-eleventy-plugin')
-const fs = require('fs')
+const beautify = require('js-beautify')
+const nunjucks = require('nunjucks')
 const matter = require('gray-matter')
 
+const getComponentContent = (componentName) => {
+  const componentPath = `docs/examples/${componentName}.njk`
+  const componentFile = fs.readFileSync(componentPath, 'utf-8')
+  const { content } = matter(componentFile)
+
+  return content
+}
+
 module.exports = function (eleventyConfig) {
   // Plugins
   eleventyConfig.addPlugin(govukEleventyPlugin, {
@@ -50,18 +60,45 @@ module.exports = function (eleventyConfig) {
    * This is needed as Nunjucks `include` tag parses included code, and
    * currently provides no way to fetch it un-rendered.
    * @param {string} componentName - Name of component
-   * @returns {string} - Rendered Nunjucks template
+   * @returns {string} - Nunjucks template rendered as raw template
    * @see {@link https://github.com/mozilla/nunjucks/issues/788}
    */
   eleventyConfig.addNunjucksGlobal('getNunjucksCode', (componentName) => {
-    const componentPath = `docs/examples/${componentName}.njk`
-    const componentFile = fs.readFileSync(componentPath, 'utf-8')
-    const { content } = matter(componentFile)
+    const content = getComponentContent(componentName)
 
     // Remove `{% from "..." import ... %}` line as this is not needed by users
     const nunjucksCode = content.replaceAll(/{%\sfrom\s[^\n]+\n/g, '')
 
-    return nunjucksCode
+    // Use configured Markdown filter to generate syntax highlighted HTML
+    const markdown = eleventyConfig.getFilter('markdown')
+    return markdown(`\`\`\`js\n${nunjucksCode}\n\`\`\``)
+  })
+
+  /**
+   * Fetch Nunjucks code for given `componentName` and return an HTML string.
+   * @param {string} componentName - Name of component
+   * @returns {string} - Nunjucks template rendered as HTML
+   */
+  eleventyConfig.addNunjucksGlobal('getHtmlCode', (componentName) => {
+    const content = getComponentContent(componentName)
+
+    // Create Nunjucks environment to render example as HTML
+    const nunjucksEnv = nunjucks.configure([
+      './node_modules/govuk-frontend/dist',
+      './node_modules/@x-govuk/govuk-prototype-components'
+    ])
+    const html = nunjucksEnv.renderString(content).trim()
+
+    // Beautify HTML code
+    const htmlCode = beautify.html(html, {
+      indent_size: 2,
+      max_preserve_newlines: 0,
+      wrap_attributes: 'preserve'
+    })
+
+    // Use configured Markdown filter to generate syntax highlighted HTML
+    const markdown = eleventyConfig.getFilter('markdown')
+    return markdown(`\`\`\`html\n${htmlCode}\n\`\`\``)
   })
 
   // Collections