Feature: OG Social media cards

Not Original Gangsta, but ObjectGraph

Reason: images were showing on LinkedIn, but small.
This commit is contained in:
Willem van den Ende 2026-05-10 21:34:07 +01:00
parent 764585c642
commit 061787e897
13 changed files with 300 additions and 105 deletions

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@ -12,6 +12,27 @@ defmodule FirehoseWeb.Layouts do
embed_templates "layouts/*" embed_templates "layouts/*"
@doc """
Stores content in the connection for later rendering in layouts.
Used to inject dynamic meta tags into the `<head>` section.
"""
def put_content_for(conn, key, content) do
content_for = Map.get(conn.assigns, :content_for, %{})
new_content_for = Map.update(content_for, key, [content], &(&1 ++ [content]))
Plug.Conn.assign(conn, :content_for, new_content_for)
end
@doc """
Retrieves content stored via `put_content_for/3`.
Can be called from HEEx templates with `get_content_for(assigns, :meta_tags)`.
"""
def get_content_for(assigns, key) do
content_for = assigns[:content_for]
if is_map(content_for), do: Map.get(content_for, key, []), else: []
end
@doc """ @doc """
Shows the flash group with standard titles and content. Shows the flash group with standard titles and content.

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@ -31,6 +31,16 @@
window.addEventListener("phx:set-theme", (e) => setTheme(e.target.dataset.phxTheme)); window.addEventListener("phx:set-theme", (e) => setTheme(e.target.dataset.phxTheme));
})(); })();
</script> </script>
<%= for meta <- get_content_for(assigns, :meta_tags) do %>
<meta property="og:title" content={meta.og_title} />
<meta property="og:description" content={meta.og_description} />
<meta property="og:type" content={meta.og_type} />
<meta property="og:url" content={meta.og_url} />
<%= if meta.og_image do %>
<meta property="og:image" content={meta.og_image} />
<% end %>
<meta name="twitter:card" content={meta.twitter_card} />
<% end %>
</head> </head>
<body> <body>
{@inner_content} {@inner_content}

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@ -8,7 +8,11 @@ defmodule FirehoseWeb.BlogController do
page = parse_page(params["page"]) page = parse_page(params["page"])
result = blog.paginate(page) result = blog.paginate(page)
render(conn, :index, meta = Blogex.SEO.meta_tags_for_blog(blog, FirehoseWeb.Endpoint.url())
conn
|> FirehoseWeb.Layouts.put_content_for(:meta_tags, meta)
|> render(:index,
page_title: blog.title(), page_title: blog.title(),
blog_title: blog.title(), blog_title: blog.title(),
blog_description: blog.description(), blog_description: blog.description(),
@ -24,9 +28,14 @@ defmodule FirehoseWeb.BlogController do
post = blog.get_post!(slug) post = blog.get_post!(slug)
visibility = Blogex.Post.visibility(post) visibility = Blogex.Post.visibility(post)
render(conn, :show, meta = Blogex.SEO.meta_tags(post, FirehoseWeb.Endpoint.url(), blog)
conn
|> FirehoseWeb.Layouts.put_content_for(:meta_tags, meta)
|> render(:show,
page_title: post.title, page_title: post.title,
post: post, post: post,
meta: meta,
base_path: blog.base_path(), base_path: blog.base_path(),
visibility: visibility, visibility: visibility,
authenticated: !!(conn.assigns[:current_scope] && conn.assigns.current_scope.user) authenticated: !!(conn.assigns[:current_scope] && conn.assigns.current_scope.user)

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@ -3,6 +3,7 @@
author: "Willem van den Ende", author: "Willem van den Ende",
tags: ~w(meta ai), tags: ~w(meta ai),
description: "Why I built a separate personal blog, and what it has to do with drinking from the firehose.", description: "Why I built a separate personal blog, and what it has to do with drinking from the firehose.",
image: "/images/firehose-logo.png",
published: true published: true
} }
--- ---

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@ -66,4 +66,64 @@ defmodule FirehoseWeb.BlogControllerTest do
refute response =~ "post-status-banner" refute response =~ "post-status-banner"
end end
end end
describe "GET /blog/:blog_id/:slug - Open Graph meta tags" do
test "meta tags include og_title", %{conn: conn} do
response = conn |> get(~p"/blog/engineering/hello-world") |> html_response(200)
assert response =~ ~s(<meta property="og:title")
assert response =~ "Hello World"
end
test "meta tags include og_description", %{conn: conn} do
response = conn |> get(~p"/blog/engineering/hello-world") |> html_response(200)
assert response =~ ~s(<meta property="og:description")
end
test "meta tags include og_type article", %{conn: conn} do
response = conn |> get(~p"/blog/engineering/hello-world") |> html_response(200)
assert response =~ ~s(<meta property="og:type" content="article")
end
test "meta tags include twitter:card", %{conn: conn} do
response = conn |> get(~p"/blog/engineering/hello-world") |> html_response(200)
assert response =~ ~s(<meta name="twitter:card" content="summary_large_image")
end
test "meta tags include og_image when post has image", %{conn: conn} do
response = conn |> get(~p"/blog/engineering/why-firehose") |> html_response(200)
assert response =~ ~s(<meta property="og:image")
assert response =~ "firehose-logo.png"
end
test "meta tags have correct og_url", %{conn: conn} do
response = conn |> get(~p"/blog/engineering/hello-world") |> html_response(200)
assert response =~ ~s(<meta property="og:url" content="http://localhost:4002/blog/engineering/hello-world")
end
end
describe "GET /blog/:blog_id - Open Graph meta tags" do
test "meta tags include og_title for blog listing", %{conn: conn} do
response = conn |> get(~p"/blog/engineering") |> html_response(200)
assert response =~ ~s(<meta property="og:title")
end
test "meta tags have og_type website for blog listing", %{conn: conn} do
response = conn |> get(~p"/blog/engineering") |> html_response(200)
assert response =~ ~s(<meta property="og:type" content="website")
end
test "meta tags use summary twitter card for blog listing", %{conn: conn} do
response = conn |> get(~p"/blog/engineering") |> html_response(200)
assert response =~ ~s(<meta name="twitter:card" content="summary")
end
end
end end

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@ -1,89 +1,44 @@
defmodule FirehoseWeb.BlogTagsTest do defmodule FirehoseWeb.BlogTagsTest do
use FirehoseWeb.ConnCase use FirehoseWeb.ConnCase
defp goto_engineering_tag_page(conn, tag) do
path = "/blog/engineering/tag/#{tag}"
conn_res = get(conn, path)
body = html_response(conn_res, 200)
assert body =~ ~s(tagged "#{tag}")
assert body =~ "Engineering Blog"
body
end
defp goto_releases_tag_page(conn, tag) do
path = "/blog/releases/tag/#{tag}"
conn_res = get(conn, path)
body = html_response(conn_res, 200)
assert body =~ ~s(tagged "#{tag}")
assert body =~ "Release Notes"
body
end
describe "engineering blog tags" do describe "engineering blog tags" do
test "GET /blog/engineering/tag/:tag shows tag page with all posts", %{conn: conn} do test "GET /blog/engineering/tag/:tag shows tag page with filtered posts", %{conn: conn} do
body = goto_engineering_tag_page(conn, "elixir") body = conn |> get("/blog/engineering/tag/elixir") |> html_response(200)
assert body =~ ~s(tagged "elixir")
assert body =~ "Engineering Blog"
assert body =~ "Hello World" assert body =~ "Hello World"
end end
test "GET /blog/engineering/tag/:tag page shows filtered posts", %{conn: conn} do test "GET /blog/engineering/tag/:tag shows empty list for nonexistent tag", %{conn: conn} do
body = goto_engineering_tag_page(conn, "phoenix") body = conn |> get("/blog/engineering/tag/nonexistent-tag") |> html_response(200)
assert body =~ "Hello World" assert body =~ ~s(tagged "nonexistent-tag")
end
test "GET /blog/engineering/tag/:tag page shows empty list for nonexistent tag", %{
conn: conn
} do
conn_res = get(conn, "/blog/engineering/tag/nonexistent-tag")
assert html_response(conn_res, 200) =~ ~s(tagged "nonexistent-tag")
end end
end end
describe "release notes blog tags" do describe "release notes blog tags" do
test "GET /blog/releases/tag/:tag shows tag page with all posts", %{conn: conn} do test "GET /blog/releases/tag/:tag shows tag page with filtered posts", %{conn: conn} do
body = goto_releases_tag_page(conn, "release") body = conn |> get("/blog/releases/tag/release") |> html_response(200)
assert body =~ ~s(tagged "release")
assert body =~ "Release Notes"
assert body =~ "v0.1.0 Released" assert body =~ "v0.1.0 Released"
end end
test "GET /blog/releases/tag/:tag page shows filtered posts", %{conn: conn} do test "GET /blog/releases/tag/:tag shows empty list for nonexistent tag", %{conn: conn} do
conn_res = get(conn, "/blog/releases/tag/nonexistent-tag") body = conn |> get("/blog/releases/tag/nonexistent-tag") |> html_response(200)
assert html_response(conn_res, 200) =~ ~s(tagged "nonexistent-tag") assert body =~ ~s(tagged "nonexistent-tag")
end
end
describe "tag URL pattern" do
test "tag URLs follow pattern /blog/:blog_id/tag/:tag for engineering blog", %{conn: conn} do
# Test that the tag route exists and works correctly
conn_res1 = get(conn, "/blog/engineering/tag/elixir")
assert html_response(conn_res1, 200) =~ ~s(tagged "elixir")
conn_res2 = get(conn, "/blog/engineering/tag/phoenix")
assert html_response(conn_res2, 200) =~ ~s(tagged "phoenix")
end
test "tag URLs follow pattern /blog/:blog_id/tag/:tag for releases blog", %{conn: conn} do
# Test that the tag route exists and works correctly
conn_res = get(conn, "/blog/releases/tag/release")
assert html_response(conn_res, 200) =~ ~s(tagged "release")
end
test "nonexistent tags return 200 with empty post list", %{conn: conn} do
conn_res = get(conn, "/blog/engineering/tag/nonexistent-tag")
assert html_response(conn_res, 200)
end end
end end
describe "tag page structure" do describe "tag page structure" do
test "tag page has proper layout and back link", %{conn: conn} do test "engineering tag page has proper layout and back link", %{conn: conn} do
body = goto_engineering_tag_page(conn, "elixir") body = conn |> get("/blog/engineering/tag/elixir") |> html_response(200)
assert body =~ "Engineering Blog" assert body =~ "Engineering Blog"
assert body =~ ~s(tagged "elixir") assert body =~ ~s(tagged "elixir")
assert body =~ "All posts" assert body =~ "All posts"
end end
test "release tag page has proper layout and back link", %{conn: conn} do test "release tag page has proper layout and back link", %{conn: conn} do
body = goto_releases_tag_page(conn, "release") body = conn |> get("/blog/releases/tag/release") |> html_response(200)
assert body =~ "Release Notes" assert body =~ "Release Notes"
assert body =~ ~s(tagged "release") assert body =~ ~s(tagged "release")
assert body =~ "All posts" assert body =~ "All posts"

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@ -3,34 +3,35 @@
defmodule FirehoseWeb.BlogTest do defmodule FirehoseWeb.BlogTest do
use FirehoseWeb.ConnCase use FirehoseWeb.ConnCase
defp visit_engineering_page(conn, suffix \\ "") do defp visit_blog_page(conn, blog_id, suffix \\ "") do
path = "/blog/engineering" <> suffix path = "/blog/#{blog_id}" <> suffix
body = conn |> get(path) |> html_response(200) body = conn |> get(path) |> html_response(200)
assert body =~ "Engineering Blog"
assert body =~ "firehose"
body
end
defp visit_engineering_path(conn, suffix) do
path = "/blog/engineering" <> suffix
body = conn |> get(path) |> html_response(200)
assert body =~ "firehose"
body body
end end
describe "engineering blog (HTML)" do describe "engineering blog (HTML)" do
test "GET /blog/engineering returns HTML index with layout", %{conn: conn} do test "GET /blog/engineering returns HTML index with layout", %{conn: conn} do
visit_engineering_page(conn) body = visit_blog_page(conn, "engineering")
assert body =~ "Engineering Blog"
assert body =~ "firehose"
end end
test "GET /blog/engineering/:slug returns HTML post with layout", %{conn: conn} do test "GET /blog/engineering/:slug returns HTML post with layout", %{conn: conn} do
body = visit_engineering_path(conn, "/hello-world") body = visit_blog_page(conn, "engineering", "/hello-world")
assert body =~ "Hello World" assert body =~ "Hello World"
end end
end
test "GET /blog/engineering/tag/:tag returns HTML tag page", %{conn: conn} do describe "release notes blog (HTML)" do
body = visit_engineering_path(conn, "/tag/elixir") test "GET /blog/releases returns HTML index", %{conn: conn} do
assert body =~ ~s(tagged "elixir") body = visit_blog_page(conn, "releases")
assert body =~ "Release Notes"
assert body =~ "v0.1.0 Released"
end
test "GET /blog/releases/:slug returns HTML post", %{conn: conn} do
body = visit_blog_page(conn, "releases", "/v0-1-0")
assert body =~ "v0.1.0 Released"
end end
end end
@ -58,24 +59,6 @@ defmodule FirehoseWeb.BlogTest do
end end
end end
describe "release notes blog (HTML)" do
test "GET /blog/releases returns HTML index", %{conn: conn} do
body = conn |> get("/blog/releases") |> html_response(200)
assert body =~ "Release Notes"
assert body =~ "v0.1.0 Released"
end
test "GET /blog/releases/:slug returns HTML post", %{conn: conn} do
body = conn |> get("/blog/releases/v0-1-0") |> html_response(200)
assert body =~ "v0.1.0 Released"
end
test "GET /blog/releases/tag/:tag returns HTML tag page", %{conn: conn} do
body = conn |> get("/blog/releases/tag/elixir") |> html_response(200)
assert body =~ ~s(tagged "elixir")
end
end
describe "engineering blog (JSON API)" do describe "engineering blog (JSON API)" do
test "GET /api/blog/engineering returns post index", %{conn: conn} do test "GET /api/blog/engineering returns post index", %{conn: conn} do
assert %{"blog" => "engineering", "posts" => posts} = assert %{"blog" => "engineering", "posts" => posts} =

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@ -16,6 +16,13 @@ defmodule FirehoseWeb.UserSessionControllerTest do
assert response =~ "Log in with email" assert response =~ "Log in with email"
end end
test "renders login page with password mode", %{conn: conn} do
response = conn |> get(~p"/users/log-in?mode=password") |> html_response(200)
assert response =~ "Log in"
assert response =~ ~p"/users/register"
assert response =~ "Log in with email"
end
test "renders login page with email filled in (sudo mode)", %{conn: conn, user: user} do test "renders login page with email filled in (sudo mode)", %{conn: conn, user: user} do
html = html =
conn conn
@ -30,13 +37,6 @@ defmodule FirehoseWeb.UserSessionControllerTest do
assert html =~ assert html =~
~s(<input type="email" name="user[email]" id="login_form_magic_email" value="#{user.email}") ~s(<input type="email" name="user[email]" id="login_form_magic_email" value="#{user.email}")
end end
test "renders login page (email + password)", %{conn: conn} do
response = conn |> get(~p"/users/log-in?mode=password") |> html_response(200)
assert response =~ "Log in"
assert response =~ ~p"/users/register"
assert response =~ "Log in with email"
end
end end
describe "GET /users/log-in/:token" do describe "GET /users/log-in/:token" do

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@ -0,0 +1,58 @@
defmodule FirehoseWeb.LayoutsTest do
use ExUnit.Case, async: true
alias FirehoseWeb.Layouts
@conn %Plug.Conn{
assigns: %{}
}
describe "put_content_for/3" do
test "stores content under the given key" do
conn = put_content_for(@conn, :meta_tags, %{og_title: "Test"})
assert conn.assigns[:content_for][:meta_tags] == [%{og_title: "Test"}]
end
test "appends multiple calls to the same key" do
conn =
@conn
|> put_content_for(:meta_tags, %{og_title: "First"})
|> put_content_for(:meta_tags, %{og_title: "Second"})
assert length(conn.assigns[:content_for][:meta_tags]) == 2
assert Enum.at(conn.assigns[:content_for][:meta_tags], 0).og_title == "First"
assert Enum.at(conn.assigns[:content_for][:meta_tags], 1).og_title == "Second"
end
test "stores different keys independently" do
conn =
@conn
|> put_content_for(:meta_tags, %{og_title: "Meta"})
|> put_content_for(:scripts, "%(script)")
assert Map.has_key?(conn.assigns[:content_for], :meta_tags)
assert Map.has_key?(conn.assigns[:content_for], :scripts)
end
end
describe "get_content_for/2" do
test "returns stored content for a key" do
content_for = %{meta_tags: [%{og_title: "Test"}]}
assert Layouts.get_content_for(%{content_for: content_for}, :meta_tags) ==
[%{og_title: "Test"}]
end
test "returns empty list when key does not exist" do
assert Layouts.get_content_for(%{content_for: %{}}, :nonexistent) == []
end
test "returns empty list when content_for is nil" do
assert Layouts.get_content_for(%{content_for: nil}, :nonexistent) == []
end
end
# Re-export for use in tests
defp put_content_for(conn, key, content), do: Layouts.put_content_for(conn, key, content)
end

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@ -28,6 +28,7 @@ defmodule Blogex.Post do
:description, :description,
:date, :date,
:blog, :blog,
:image,
tags: [], tags: [],
published: true published: true
] ]
@ -39,6 +40,7 @@ defmodule Blogex.Post do
body: String.t(), body: String.t(),
description: String.t(), description: String.t(),
date: Date.t(), date: Date.t(),
image: String.t() | nil,
tags: [String.t()], tags: [String.t()],
blog: atom(), blog: atom(),
published: boolean() published: boolean()

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@ -3,11 +3,33 @@ defmodule Blogex.SEO do
SEO helpers for generating meta tags and sitemaps. SEO helpers for generating meta tags and sitemaps.
""" """
@doc """
Returns a map of meta tag attributes for a blog listing page.
Useful for setting OpenGraph and Twitter card tags on blog index pages.
<meta property="og:title" content={@meta.og_title} />
"""
def meta_tags_for_blog(blog_module, base_url) do
url = "#{base_url}#{blog_module.base_path()}"
%{
title: blog_module.title(),
description: blog_module.description(),
og_title: blog_module.title(),
og_description: blog_module.description(),
og_type: "website",
og_url: url,
og_image: nil,
twitter_card: "summary"
}
end
@doc """ @doc """
Returns a map of meta tag attributes for a post. Returns a map of meta tag attributes for a post.
Useful for setting OpenGraph and Twitter card tags in your layout. Useful for setting OpenGraph and Twitter card tags in your layout.
<meta property="og:title" content={@meta.og_title} /> <meta property="og:title" content={@meta.og_title} />
<meta property="og:image" content={@meta.og_image} />
""" """
def meta_tags(post, base_url, blog_module) do def meta_tags(post, base_url, blog_module) do
url = "#{base_url}#{blog_module.base_path()}/#{post.id}" url = "#{base_url}#{blog_module.base_path()}/#{post.id}"
@ -19,6 +41,7 @@ defmodule Blogex.SEO do
og_description: post.description, og_description: post.description,
og_type: "article", og_type: "article",
og_url: url, og_url: url,
og_image: if(post.image, do: "#{base_url}#{post.image}", else: nil),
article_published_time: Date.to_iso8601(post.date), article_published_time: Date.to_iso8601(post.date),
article_author: post.author, article_author: post.author,
article_tags: post.tags, article_tags: post.tags,

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@ -58,6 +58,20 @@ defmodule Blogex.PostTest do
assert post.published == false assert post.published == false
end end
test "preserves image from frontmatter" do
attrs = Map.put(valid_attrs(), :image, "/images/cover.png")
post = Post.build("x/2026/01-01-x.md", attrs, "<p>x</p>")
assert post.image == "/images/cover.png"
end
test "defaults image to nil when not in frontmatter" do
post = Post.build("x/2026/01-01-x.md", valid_attrs(), "<p>x</p>")
assert post.image == nil
end
end end
defp valid_attrs do defp valid_attrs do

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@ -6,6 +6,8 @@ defmodule Blogex.SEOTest do
defmodule StubBlog do defmodule StubBlog do
def base_path, do: "/blog/eng" def base_path, do: "/blog/eng"
def title, do: "Engineering Blog"
def description, do: "Our engineering insights"
end end
@base_url "https://example.com" @base_url "https://example.com"
@ -38,6 +40,63 @@ defmodule Blogex.SEOTest do
assert meta.article_published_time == "2026-06-15" assert meta.article_published_time == "2026-06-15"
assert meta.article_tags == ["a", "b"] assert meta.article_tags == ["a", "b"]
end end
test "includes og_image when post has an image" do
post = build(image: "/images/cover.png")
meta = SEO.meta_tags(post, @base_url, StubBlog)
assert meta.og_image == "https://example.com/images/cover.png"
end
test "og_image is nil when post has no image" do
post = build()
meta = SEO.meta_tags(post, @base_url, StubBlog)
assert meta.og_image == nil
end
test "og_image uses absolute URL with base_url prefix" do
post = build(image: "/assets/post-hero.jpg")
meta = SEO.meta_tags(post, "https://myapp.dev", StubBlog)
assert meta.og_image == "https://myapp.dev/assets/post-hero.jpg"
end
end
describe "meta_tags_for_blog/2" do
test "returns website type" do
meta = SEO.meta_tags_for_blog(StubBlog, @base_url)
assert meta.og_type == "website"
end
test "includes blog title and description" do
meta = SEO.meta_tags_for_blog(StubBlog, @base_url)
assert meta.og_title == "Engineering Blog"
assert meta.og_description == "Our engineering insights"
end
test "has no og_image for blog listing" do
meta = SEO.meta_tags_for_blog(StubBlog, @base_url)
assert meta.og_image == nil
end
test "builds correct blog URL" do
meta = SEO.meta_tags_for_blog(StubBlog, @base_url)
assert meta.og_url == "https://example.com/blog/eng"
end
test "uses summary twitter card for blog listing" do
meta = SEO.meta_tags_for_blog(StubBlog, @base_url)
assert meta.twitter_card == "summary"
end
end end
describe "sitemap/2" do describe "sitemap/2" do