Add custom display functions for certain model entities.

1 files changed, 16 insertions, 1 deletions

diff --git a/models/fertilizer-product.rkt b/models/fertilizer-product.rkt
index bd6bba9..0a6c03d 100644
--- a/models/fertilizer-product.rkt
+++ b/models/fertilizer-product.rkt
@@ -30,7 +30,22 @@
          "nutrient.rkt")
 
 ;; Instances of this struct are persisted in the fertilizer_products table.
-(struct fertilizer-product (id canonical-name nutrient-values brand-name) #:transparent)
+(struct fertilizer-product (id canonical-name nutrient-values brand-name)
+  #:transparent
+  #:property prop:custom-write
+  (λ (v out _mode)
+    (fprintf out "Fertilizer #~a\n" (fertilizer-product-id v))
+    (if (fertilizer-product-brand-name v)
+        (fprintf out "~a (~a)\n"
+                 (fertilizer-product-canonical-name v)
+                 (fertilizer-product-brand-name v))
+        (fprintf out "~a\n"
+                 (fertilizer-product-canonical-name v)))
+    (for ([nv (in-list (fertilizer-product-nutrient-values v))])
+      (match-define (cons n v) nv)
+      (fprintf out "~a ~a\n"
+               (~a (nutrient-name n) #:min-width 14)
+               (~a v #:max-width 6 #:align 'right)))))
 
 
 ;; CREATE