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Diffstat (limited to 'internal/api/util/opengraph.go')
| -rw-r--r-- | internal/api/util/opengraph.go | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/internal/api/util/opengraph.go b/internal/api/util/opengraph.go new file mode 100644 index 000000000..185dc8132 --- /dev/null +++ b/internal/api/util/opengraph.go @@ -0,0 +1,184 @@ +// GoToSocial +// Copyright (C) GoToSocial Authors admin@gotosocial.org +// SPDX-License-Identifier: AGPL-3.0-or-later +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU Affero General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Affero General Public License for more details. +// +// You should have received a copy of the GNU Affero General Public License +// along with this program. If not, see <http://www.gnu.org/licenses/>. + +package util + +import ( + "html" + "strconv" + "strings" + + apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model" + "github.com/superseriousbusiness/gotosocial/internal/text" +) + +const maxOGDescriptionLength = 300 + +// OGMeta represents supported OpenGraph Meta tags +// +// see eg https://ogp.me/ +type OGMeta struct { + // vanilla og tags + Title string // og:title + Type string // og:type + Locale string // og:locale + URL string // og:url + SiteName string // og:site_name + Description string // og:description + + // image tags + Image string // og:image + ImageWidth string // og:image:width + ImageHeight string // og:image:height + ImageAlt string // og:image:alt + + // article tags + ArticlePublisher string // article:publisher + ArticleAuthor string // article:author + ArticleModifiedTime string // article:modified_time + ArticlePublishedTime string // article:published_time + + // profile tags + ProfileUsername string // profile:username +} + +// OGBase returns an *ogMeta suitable for serving at +// the base root of an instance. It also serves as a +// foundation for building account / status ogMeta on +// top of. +func OGBase(instance *apimodel.InstanceV1) *OGMeta { + var locale string + if len(instance.Languages) > 0 { + locale = instance.Languages[0] + } + + og := &OGMeta{ + Title: text.SanitizeToPlaintext(instance.Title) + " - GoToSocial", + Type: "website", + Locale: locale, + URL: instance.URI, + SiteName: instance.AccountDomain, + Description: ParseDescription(instance.ShortDescription), + + Image: instance.Thumbnail, + ImageAlt: instance.ThumbnailDescription, + } + + return og +} + +// WithAccount uses the given account to build an ogMeta +// struct specific to that account. It's suitable for serving +// at account profile pages. +func (og *OGMeta) WithAccount(account *apimodel.Account) *OGMeta { + og.Title = AccountTitle(account, og.SiteName) + og.Type = "profile" + og.URL = account.URL + if account.Note != "" { + og.Description = ParseDescription(account.Note) + } else { + og.Description = `content="This GoToSocial user hasn't written a bio yet!"` + } + + og.Image = account.Avatar + og.ImageAlt = "Avatar for " + account.Username + + og.ProfileUsername = account.Username + + return og +} + +// WithStatus uses the given status to build an ogMeta +// struct specific to that status. It's suitable for serving +// at status pages. +func (og *OGMeta) WithStatus(status *apimodel.Status) *OGMeta { + og.Title = "Post by " + AccountTitle(status.Account, og.SiteName) + og.Type = "article" + if status.Language != nil { + og.Locale = *status.Language + } + og.URL = status.URL + switch { + case status.SpoilerText != "": + og.Description = ParseDescription("CW: " + status.SpoilerText) + case status.Text != "": + og.Description = ParseDescription(status.Text) + default: + og.Description = og.Title + } + + if !status.Sensitive && len(status.MediaAttachments) > 0 { + a := status.MediaAttachments[0] + + og.ImageWidth = strconv.Itoa(a.Meta.Small.Width) + og.ImageHeight = strconv.Itoa(a.Meta.Small.Height) + + if a.PreviewURL != nil { + og.Image = *a.PreviewURL + } + + if a.Description != nil { + og.ImageAlt = *a.Description + } + } else { + og.Image = status.Account.Avatar + og.ImageAlt = "Avatar for " + status.Account.Username + } + + og.ArticlePublisher = status.Account.URL + og.ArticleAuthor = status.Account.URL + og.ArticlePublishedTime = status.CreatedAt + og.ArticleModifiedTime = status.CreatedAt + + return og +} + +// AccountTitle parses a page title from account and accountDomain +func AccountTitle(account *apimodel.Account, accountDomain string) string { + user := "@" + account.Acct + "@" + accountDomain + + if len(account.DisplayName) == 0 { + return user + } + + return account.DisplayName + ", " + user +} + +// ParseDescription returns a string description which is +// safe to use as a template.HTMLAttr inside templates. +func ParseDescription(in string) string { + i := text.SanitizeToPlaintext(in) + i = strings.ReplaceAll(i, "\n", " ") + i = strings.Join(strings.Fields(i), " ") + i = html.EscapeString(i) + i = strings.ReplaceAll(i, `\`, "\") + i = truncate(i, maxOGDescriptionLength) + return `content="` + i + `"` +} + +// truncate trims given string to +// specified length (in runes). +func truncate(s string, l int) string { + r := []rune(s) + if len(r) < l { + // No need + // to trim. + return s + } + + return string(r[:l]) + "..." +} |