r9722: Document the FDML.

[clsql.git] / sql / oodml.lisp

diff --git a/sql/oodml.lisp b/sql/oodml.lisp
index 399519cfa0bef8d9544cf3a9b458e4c90513deb4..82f166e1da642108a48556f958bf90abf61c143e 100644 (file)
--- a/sql/oodml.lisp
+++ b/sql/oodml.lisp
@@ -381,10 +381,18 @@
       (format nil "FLOAT(~A)" (car args))
       "FLOAT"))
 
+(deftype generalized-boolean () 
+  "A type which outputs a SQL boolean value, though any lisp type can be stored in the slot."
+  t)
+
 (defmethod database-get-type-specifier ((type (eql 'boolean)) args database db-type)
   (declare (ignore args database db-type))
   "BOOL")
 
+(defmethod database-get-type-specifier ((type (eql 'generalized-boolean)) args database db-type)
+  (declare (ignore args database db-type))
+  "BOOL")
+
 (defmethod database-get-type-specifier ((type (eql 'number)) args database db-type)
   (declare (ignore database db-type))
   (cond
@@ -442,6 +450,10 @@
   (declare (ignore database db-type))
   (if val "t" "f"))
 
+(defmethod database-output-sql-as-type ((type (eql 'generalized-boolean)) val database db-type)
+  (declare (ignore database db-type))
+  (if val "t" "f"))
+
 (defmethod database-output-sql-as-type ((type (eql 'string)) val database db-type)
   (declare (ignore database db-type))
   val)
@@ -510,6 +522,10 @@
   (declare (ignore database db-type))
   (equal "t" val))
 
+(defmethod read-sql-value (val (type (eql 'generalized-boolean)) database db-type)
+  (declare (ignore database db-type))
+  (equal "t" val))
+
 (defmethod read-sql-value (val (type (eql 'number)) database db-type)
   (declare (ignore database db-type))
   (etypecase val
@@ -1065,3 +1081,27 @@ as elements of a list."
   results)
 
 
+
+;;; Serialization functions
+
+(defun write-instance-to-stream (obj stream)
+  "Writes an instance to a stream where it can be later be read.
+NOTE: an error will occur if a slot holds a value which can not be written readably."
+  (let* ((class (class-of obj))
+        (alist '()))
+    (dolist (slot (ordered-class-slots (class-of obj)))
+      (let ((name (slot-definition-name slot)))
+       (when (and (not (eq 'view-database name))
+                  (slot-boundp obj name))
+         (push (cons name (slot-value obj name)) alist))))
+    (setq alist (reverse alist))
+    (write (cons (class-name class) alist) :stream stream :readably t))
+  obj)
+
+(defun read-instance-from-stream (stream)
+  (let ((raw (read stream nil nil)))
+    (when raw
+      (let ((obj (make-instance (car raw))))
+       (dolist (pair (cdr raw))
+         (setf (slot-value obj (car pair)) (cdr pair)))
+       obj))))