Show the host for the iframe link

Instead of showing only: Click to visit embedded content

An embedded link now displays with the domain it's linking to: Embedded
content at example.com

This hopefully breaks up the links a bit so it'e easier to distinguish
between a bunch of them in a row (as long as they are on different
domains).

spec/components/page_content_spec.cr

@@ -156,7 +156,13 @@ describe PageContent do
 
     html = PageContent.new(page: page).render_to_string
 
-    html.should eq %(<p><div class="embedded"><a href="https://example.com">Click to visit embedded content</a></div></p>)
+    html.should eq stripped_html <<-HTML
+      <p>
+        <div class="embedded">
+          <a href="https://example.com">Embedded content at example.com</a>
+        </div>
+      </p>
+    HTML
   end
 
   it "renders an ordered list" do

spec/models/nodes_spec.cr

@@ -1,6 +1,14 @@
 require "../spec_helper"
 
 module Nodes
+  describe IFrame do
+    it "returns embedded url with subdomains" do
+      iframe = IFrame.new(href: "https://dev.example.com/page")
+
+      iframe.domain.should eq("dev.example.com")
+    end
+  end
+
   describe Image do
     it "adjusts the width and height proportionally" do
       image = Image.new(src: "image.png", originalWidth: 1000, originalHeight: 603)

src/components/page_content.cr

@@ -57,7 +57,7 @@ class PageContent < BaseComponent
   def render_child(child : IFrame)
     div class: "embedded" do
       a href: child.href do
-        text "Click to visit embedded content"
+        text "Embedded content at #{child.domain}"
       end
     end
   end

src/models/nodes.cr

@@ -123,6 +123,10 @@ module Nodes
     def initialize(@href : String)
     end
 
+    def domain
+      URI.parse(href).host
+    end
+
     def ==(other : IFrame)
       other.href == href
     end