namespaces added and documentation

private/attachment-references.rkt

@@ -1,5 +1,9 @@
 #lang racket/base
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Tracking current and historical references to uploaded files.
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
 (require db
          racket/string)
 
@@ -14,7 +18,7 @@
 (define (attachment-rows db)
   (query-rows db
               #<<SQL
-SELECT a.id, p.slug, a.stored_name
+SELECT a.id, p.slug, a.stored_name, p.namespace
 FROM attachments a
 JOIN pages p ON p.id = a.page_id
 ORDER BY a.id
@@ -29,7 +33,13 @@ SQL
     (define attachment-id (vector-ref row 0))
     (define slug (vector-ref row 1))
     (define stored-name (vector-ref row 2))
-    (when (string-contains? markdown (attachment-url slug stored-name))
+    (define namespace (vector-ref row 3))
+    (define reference (if (string=? namespace "") slug (string-append namespace ":" slug)))
+    (define current-url (attachment-url reference stored-name))
+    (define legacy-url (attachment-url slug stored-name))
+    (when (or (string-contains? markdown current-url)
+              (and (not (string=? namespace ""))
+                   (string-contains? markdown legacy-url)))
       (query-exec db
                   #<<SQL
 INSERT INTO attachment_references