Render CSS/title/description tags on server side

1 files changed, 180 insertions, 0 deletions

diff --git a/server/lib/client-html.ts b/server/lib/client-html.ts
new file mode 100644
index 000000000..72984e778
--- /dev/null
+++ b/server/lib/client-html.ts
@@ -0,0 +1,180 @@
+import * as express from 'express'
+import * as Bluebird from 'bluebird'
+import { buildFileLocale, getDefaultLocale, is18nLocale, POSSIBLE_LOCALES } from '../../shared/models/i18n/i18n'
+import { CONFIG, EMBED_SIZE, CUSTOM_HTML_TAG_COMMENTS, STATIC_PATHS } from '../initializers'
+import { join } from 'path'
+import { escapeHTML, readFileBufferPromise } from '../helpers/core-utils'
+import { VideoModel } from '../models/video/video'
+import * as validator from 'validator'
+import { VideoPrivacy } from '../../shared/models/videos'
+
+export class ClientHtml {
+
+  private static htmlCache: { [path: string]: string } = {}
+
+  static invalidCache () {
+    ClientHtml.htmlCache = {}
+  }
+
+  static async getIndexHTML (req: express.Request, res: express.Response, paramLang?: string) {
+    const path = ClientHtml.getIndexPath(req, res, paramLang)
+    if (ClientHtml.htmlCache[path]) return ClientHtml.htmlCache[path]
+
+    const buffer = await readFileBufferPromise(path)
+
+    let html = buffer.toString()
+
+    html = ClientHtml.addTitleTag(html)
+    html = ClientHtml.addDescriptionTag(html)
+    html = ClientHtml.addCustomCSS(html)
+
+    ClientHtml.htmlCache[path] = html
+
+    return html
+  }
+
+  static async getWatchHTMLPage (videoId: string, req: express.Request, res: express.Response) {
+    let videoPromise: Bluebird<VideoModel>
+
+    // Let Angular application handle errors
+    if (validator.isUUID(videoId, 4)) {
+      videoPromise = VideoModel.loadByUUIDAndPopulateAccountAndServerAndTags(videoId)
+    } else if (validator.isInt(videoId)) {
+      videoPromise = VideoModel.loadAndPopulateAccountAndServerAndTags(+videoId)
+    } else {
+      return ClientHtml.getIndexHTML(req, res)
+    }
+
+    const [ html, video ] = await Promise.all([
+      ClientHtml.getIndexHTML(req, res),
+      videoPromise
+    ])
+
+    // Let Angular application handle errors
+    if (!video || video.privacy === VideoPrivacy.PRIVATE) {
+      return ClientHtml.getIndexHTML(req, res)
+    }
+
+    return ClientHtml.addOpenGraphAndOEmbedTags(html, video)
+  }
+
+  private static getIndexPath (req: express.Request, res: express.Response, paramLang?: string) {
+    let lang: string
+
+    // Check param lang validity
+    if (paramLang && is18nLocale(paramLang)) {
+      lang = paramLang
+
+      // Save locale in cookies
+      res.cookie('clientLanguage', lang, {
+        secure: CONFIG.WEBSERVER.SCHEME === 'https',
+        sameSite: true,
+        maxAge: 1000 * 3600 * 24 * 90 // 3 months
+      })
+
+    } else if (req.cookies.clientLanguage && is18nLocale(req.cookies.clientLanguage)) {
+      lang = req.cookies.clientLanguage
+    } else {
+      lang = req.acceptsLanguages(POSSIBLE_LOCALES) || getDefaultLocale()
+    }
+
+    return join(__dirname, '../../../client/dist/' + buildFileLocale(lang) + '/index.html')
+  }
+
+  private static addTitleTag (htmlStringPage: string) {
+    const titleTag = '<title>' + CONFIG.INSTANCE.NAME + '</title>'
+
+    return htmlStringPage.replace(CUSTOM_HTML_TAG_COMMENTS.TITLE, titleTag)
+  }
+
+  private static addDescriptionTag (htmlStringPage: string) {
+    const descriptionTag = `<meta name="description" content="${CONFIG.INSTANCE.SHORT_DESCRIPTION}" />`
+
+    return htmlStringPage.replace(CUSTOM_HTML_TAG_COMMENTS.DESCRIPTION, descriptionTag)
+  }
+
+  private static addCustomCSS (htmlStringPage: string) {
+    const styleTag = '<style class="custom-css-style">' + CONFIG.INSTANCE.CUSTOMIZATIONS.CSS + '</style>'
+
+    return htmlStringPage.replace(CUSTOM_HTML_TAG_COMMENTS.CUSTOM_CSS, styleTag)
+  }
+
+  private static addOpenGraphAndOEmbedTags (htmlStringPage: string, video: VideoModel) {
+    const previewUrl = CONFIG.WEBSERVER.URL + STATIC_PATHS.PREVIEWS + video.getPreviewName()
+    const videoUrl = CONFIG.WEBSERVER.URL + '/videos/watch/' + video.uuid
+
+    const videoNameEscaped = escapeHTML(video.name)
+    const videoDescriptionEscaped = escapeHTML(video.description)
+    const embedUrl = CONFIG.WEBSERVER.URL + video.getEmbedStaticPath()
+
+    const openGraphMetaTags = {
+      'og:type': 'video',
+      'og:title': videoNameEscaped,
+      'og:image': previewUrl,
+      'og:url': videoUrl,
+      'og:description': videoDescriptionEscaped,
+
+      'og:video:url': embedUrl,
+      'og:video:secure_url': embedUrl,
+      'og:video:type': 'text/html',
+      'og:video:width': EMBED_SIZE.width,
+      'og:video:height': EMBED_SIZE.height,
+
+      'name': videoNameEscaped,
+      'description': videoDescriptionEscaped,
+      'image': previewUrl,
+
+      'twitter:card': CONFIG.SERVICES.TWITTER.WHITELISTED ? 'player' : 'summary_large_image',
+      'twitter:site': CONFIG.SERVICES.TWITTER.USERNAME,
+      'twitter:title': videoNameEscaped,
+      'twitter:description': videoDescriptionEscaped,
+      'twitter:image': previewUrl,
+      'twitter:player': embedUrl,
+      'twitter:player:width': EMBED_SIZE.width,
+      'twitter:player:height': EMBED_SIZE.height
+    }
+
+    const oembedLinkTags = [
+      {
+        type: 'application/json+oembed',
+        href: CONFIG.WEBSERVER.URL + '/services/oembed?url=' + encodeURIComponent(videoUrl),
+        title: videoNameEscaped
+      }
+    ]
+
+    const schemaTags = {
+      '@context': 'http://schema.org',
+      '@type': 'VideoObject',
+      name: videoNameEscaped,
+      description: videoDescriptionEscaped,
+      thumbnailUrl: previewUrl,
+      uploadDate: video.createdAt.toISOString(),
+      duration: video.getActivityStreamDuration(),
+      contentUrl: videoUrl,
+      embedUrl: embedUrl,
+      interactionCount: video.views
+    }
+
+    let tagsString = ''
+
+    // Opengraph
+    Object.keys(openGraphMetaTags).forEach(tagName => {
+      const tagValue = openGraphMetaTags[tagName]
+
+      tagsString += `<meta property="${tagName}" content="${tagValue}" />`
+    })
+
+    // OEmbed
+    for (const oembedLinkTag of oembedLinkTags) {
+      tagsString += `<link rel="alternate" type="${oembedLinkTag.type}" href="${oembedLinkTag.href}" title="${oembedLinkTag.title}" />`
+    }
+
+    // Schema.org
+    tagsString += `<script type="application/ld+json">${JSON.stringify(schemaTags)}</script>`
+
+    // SEO
+    tagsString += `<link rel="canonical" href="${videoUrl}" />`
+
+    return htmlStringPage.replace(CUSTOM_HTML_TAG_COMMENTS.OPENGRAPH_AND_OEMBED, tagsString)
+  }
+}