Add twitter meta-data to posts

This depends on a pending change to add-injection

plugins/twitter-summary-card.lisp

@@ -0,0 +1,22 @@
+(defpackage :coleslaw-twitter-summary-card
+  (:use :cl)
+  (:export #:enable))
+
+(in-package :coleslaw-twitter-summary-card)
+
+(defun summary-card (post twitter-handle)
+  "TODO: Figure if and how to include twitter:url meta property."
+  (format nil "<meta property=\"twitter:card\" content=\"summary\" />
+~@[<meta property=\"twitter:author\" content=~A />~]
+<meta property=\"twitter:title\" content=~A />
+<meta property=\"twitter:description\" content=~A />"
+          twitter-handle
+          (title-of post)
+          (content-text post)))
+
+(defun enable (&key twitter-handle)
+  (add-injection
+   (lambda (x)
+     (when (typep x 'post)
+       (summary-card x twitter-handle)))
+                 :head))

src/packages.lisp

@@ -39,4 +39,5 @@
            #:purge-all
            #:add-document
            #:delete-document
-           #:write-document))
+           #:write-document
+           #:content-text))