src/rofl.lisp

   1 (in-package :lisp-on-lines)
   2
   3
   4 (defclass db-access-slot-definition ()
   5   ((column-name  :initform nil :initarg :db-name :accessor slot-definition-column-name
   6                :documentation
   7               "If non-NIL, contains the name of the column this slot is representing.")
   8    (primary-key :initform nil
   9                 :initarg :primary-key
  10                 :accessor slot-definition-primary-key-p)
  11    (transient  :initform nil :initarg :transient :accessor slot-definition-transient-p
  12                :documentation
  13               "If non-NIL, this slot should be treated as transient and
  14 ignored in all database related operations.")
  15    (not-null :initform nil :initarg :not-null :accessor slot-definition-not-null-p
  16              :documentation "If non-NIL, a NON NULL database
  17 constrained will be introduced.")
  18    (foreign-type
  19     :initform nil
  20     :initarg :foreign-type
  21     :initarg :references
  22     :accessor slot-definition-foreign-type)
  23    (unique :initform nil :initarg :unique :accessor slot-definition-unique)
  24
  25
  26    (on-delete :initform :cascade :initarg :on-delete :accessor slot-definition-on-delete
  27               :documentation "Action to be performed for this slot
  28 when the refering row in the database ceases to exist. Possible
  29 values: :CASCADE, :RESTRICT, :SET-NULL, :SET-DEFAULT. If this slot is
  30 not a foreign key, it does nothing.")
  31    (delayed-constraint :initform nil :accessor slot-definition-delayed-constraint
  32                         :documentation "Closures adding constraints
  33 that, for some reason, could not be executed. If there's a slot with
  34 this attribute not-NIL in a class definition, then there's something
  35 wrong with its SQL counterpart.")))
  36
  37 (defmethod slot-definition-column-name :around (slotd)
  38   (or (call-next-method) (slot-definition-name slotd)))
  39
  40
  41 (defclass db-access-class (standard-class)
  42   ((table-name :initarg :table-name :initform nil :accessor class-table-name)
  43    (indices :initarg :indices :initform () :reader class-indices)
  44    (unique :initarg :unique :initform () :reader class-unique)
  45    #+not!(connection-spec :initarg :connection-spec :initform nil :reader db-class-connection-spec)
  46
  47    (unfinished-classes :initform nil :allocation :class :accessor class-unfinished-classes
  48                        :documentation "A class allocated slot
  49 containing classes for whom not all the constraints could be
  50 applied.")
  51    (foreign-keys :initform nil :accessor class-foreign-keys
  52                  :documentation "List of foreign-key slots.")
  53    (unique-keys :initform nil :accessor class-unique-keys
  54                 :documentation "List of slots whose value should be unique."))
  55   (:documentation "Metaclass for PostgreSQL aware classes. It takes
  56 two additional arguments in DEFTABLE: :INDICES (which slots are used
  57 as indices) and :CONNECTION-SPEC, which specifies how the class should
  58 connect to the database (its format is the same as in
  59 POSTMODERN:CONNECT-TOPLEVEL). If :CONNECTION-SPEC is not provided,
  60 SUBMARINE assumes it is a class created just for the sake of
  61 inheritance and does not create any tables for it."))
  62
  63 (defmethod validate-superclass
  64            ((class db-access-class)
  65             (superclass standard-class))
  66   t)
  67
  68
  69 (defclass db-access-direct-slot-definition (standard-direct-slot-definition
  70                                             db-access-slot-definition)
  71   ())
  72
  73 (defmethod direct-slot-definition-class
  74            ((class db-access-class) &key &allow-other-keys)
  75   (find-class 'db-access-direct-slot-definition))
  76
  77 (defclass db-access-effective-slot-definition
  78     (standard-effective-slot-definition
  79      db-access-slot-definition)
  80   ())
  81
  82 (defmethod effective-slot-definition-class
  83            ((class db-access-class) &key &allow-other-keys)
  84   (find-class 'db-access-effective-slot-definition))
  85
  86 (defmethod compute-effective-slot-definition
  87            ((class db-access-class) name direct-slot-definitions)
  88   (declare (ignore name))
  89   (let ((slotd (call-next-method)))
  90     (setf (slot-definition-primary-key-p slotd)
  91           (some #'slot-definition-primary-key-p direct-slot-definitions)
  92           (slot-definition-transient-p slotd)
  93           (every #'slot-definition-transient-p direct-slot-definitions)
  94           (slot-definition-foreign-type slotd)
  95           (slot-definition-foreign-type (car direct-slot-definitions))
  96           (slot-definition-not-null-p slotd)
  97           (slot-definition-not-null-p (car direct-slot-definitions))
  98           (slot-definition-unique slotd) (slot-definition-unique (car direct-slot-definitions))
  99           (slot-definition-type slotd) (slot-definition-type (car direct-slot-definitions)))
 100     slotd))
 101
 102 (defun class-id-slot-definition (class)
 103   (find-if #'slot-definition-primary-key-p
 104            (class-slots class)))
 105
 106 (defmethod class-table-name :around (class)
 107   (or (call-next-method)
 108       (class-name class)))
 109
 110 (defclass standard-db-access-class (db-access-class)
 111   ())
 112
 113 (defun dao-id-column-name (class)
 114   (slot-definition-column-name
 115    (or (class-id-slot-definition class)
 116        (error "No ID slot (primary key) for ~A" class))))
 117
 118 (defclass described-db-access-class (standard-db-access-class described-class)
 119   ())
 120
 121 (defmethod initialize-instance :around ((class standard-db-access-class) &rest initargs &key (direct-superclasses '()))
 122   (declare (dynamic-extent initargs))
 123   (if (loop for direct-superclass in direct-superclasses
 124          thereis (ignore-errors (subtypep direct-superclass 'standard-db-access-object)))
 125       (call-next-method)
 126       (apply #'call-next-method
 127              class
 128              :direct-superclasses
 129              (append direct-superclasses
 130                      (list (find-class 'standard-db-access-object)))
 131              initargs)))
 132
 133 (defmethod reinitialize-instance :around ((class standard-db-access-class) &rest initargs &key (direct-superclasses '() direct-superclasses-p))
 134   (declare (dynamic-extent initargs))
 135   (if (or (not direct-superclasses-p)
 136           (loop for direct-superclass in direct-superclasses
 137              thereis (ignore-errors (subtypep direct-superclass 'standard-db-access-object))))
 138       (call-next-method)
 139       (apply #'call-next-method
 140              class
 141              :direct-superclasses
 142              (append direct-superclasses
 143                      (list (find-class 'standard-db-access-object)))
 144              initargs)))
 145
 146 (defclass standard-db-access-object (standard-object)
 147   ())
 148
 149
 150
 151 (defun find-dao (type id
 152                  &key (table (class-table-name (find-class type)))
 153                       id-column-name)
 154
 155   "Get the dao corresponding to the given primary key,
 156 or return nil if it does not exist."
 157   (let ((row (first (query
 158               (:select '*
 159                :from table
 160                :where (:= id (or id-column-name
 161                                  (dao-id-column-name
 162                                   (find-class type)))))))))
 163     (make-dao-from-row type row)))
 164
 165 (defmethod shared-initialize :after ((dao standard-db-access-object)
 166                                      slots &rest initargs)
 167   (let ((class (class-of dao)))
 168     (dolist (slotd (class-slots class))
 169       (with-slots (foreign-type) slotd
 170         (when foreign-type
 171           (if (slot-boundp-using-class class dao slotd)
 172               (let ((value (slot-value-using-class class dao slotd)))
 173                 (unless (typep value foreign-type)
 174                   (if (connected-p *database*)
 175                       (setf (slot-value-using-class class dao slotd)
 176                             (find-dao foreign-type value))
 177                       (let ((obj (make-instance foreign-type)))
 178                         (setf (slot-value-using-class
 179                                (class-of obj)
 180                                obj
 181                                (class-id-slot-definition (class-of obj)))
 182                               value)))))))))))
 183
 184 (defgeneric dao-id (dao)
 185   (:method ((dao standard-db-access-object))
 186     (let ((class (class-of dao)))
 187
 188       (slot-value-using-class class dao (class-id-slot-definition class)))))
 189
 190 (postmodern::def-row-reader symbol-plist-row-reader (fields)
 191
 192   (let ((symbols (map 'list (lambda (desc)
 193                    (postmodern::from-sql-name (postmodern::field-name desc))) fields)))
 194     (loop :while (postmodern::next-row)
 195           :collect (loop :for field :across fields
 196                          :for symbol :in symbols
 197                          :nconc (list symbol (postmodern::next-field field))))))
 198
 199
 200 (setf postmodern::*result-styles*
 201       (nconc (list '(:plists symbol-plist-row-reader nil)
 202                    '(:plist symbol-plist-row-reader t))
 203              postmodern::*result-styles*))
 204
 205 (defun select (&rest query)
 206     (query (sql-compile (cons :select query)) :plists))
 207
 208 (defun select-only (num &rest query)
 209   (query (sql-compile `(:limit ,(cons :select query) ,num))
 210          :plists))
 211
 212 (defun make-dao-from-row (type row &key slots)
 213   (let* ((class (find-class type))
 214          (dao (make-instance class))
 215          (slotds (class-slots class)))
 216     (loop
 217          :for val :in row
 218          :for slotd
 219        :in (or
 220             (loop
 221                :for slot :in slots
 222                :collect (find slot slotds
 223                               :key #'slot-definition-name))
 224             slotds)
 225          :do (setf (slot-value-using-class class dao slotd) val)
 226          :finally (return (reinitialize-instance dao)))))
 227
 228 ;(defgeneric make-dao (type &rest initargs)
 229 #+nil(defun make-dao (type initargs)
 230   "Create a DAO of the given `TYPE' and initialize it according
 231   to the values of the alist `INITARGS'. `Initargs' may contain
 232   additional values, not used in the initialization proccess."
 233   (let ((instance (make-instance type)))
 234     (iter (for slot in (slots-of instance))
 235           (setf (slot-value instance (slot-definition-name slot))
 236                 (let ((the-value (cdr (assoc (intern (symbol-name (slot-definition-name slot)) 'keyword) initargs))))
 237                   (if (foreign-type-p slot)
 238                       (make-instance (sb-pcl:slot-definition-type slot) :id the-value)
 239                       the-value))))
 240     instance))
 241
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 243
 244
 245