So, I've been using cl-prevalence, and like it, mostly. :) I have 3 systems active in my application (with at least 2 more expected before it will be completely converted).

Two of them restore correctly. One reliably does not, and while the fact that two work okay suggests that the problem is in my code, I can't find one.

When I change prevailed objects, they seem to update in the log. However, deeply nested objects seem not to be restored correctly.

The classes involved are:

(defclass page (object-with-id) ((name :initarg :name :initform "" :accessor name) (title :initarg :title :initform () :accessor title)) (:documentation ""))

(defclass xhtml-page (page) ((xhtml :initarg :xhtml :initform () :accessor xhtml)))

(defclass classroom (object-with-id) ((cover :initarg :cover :initform "" :accessor cover) (toc :initarg :toc :initform () :accessor toc) (pages :initarg :pages :initform (make-hash-table :test 'equal) :accessor pages)) (:documentation ""))

(defclass course (accessible) ((name :initarg :name :initform "" :accessor name) ; used as a human-readable id (title :initarg :title :initform "" :accessor title) ; shown to users as the title of the course (classroom :initarg :classroom :initform () :accessor classroom) (menu :initarg :menu :initform () :accessor menu)) (:documentation ""))

The "accessible" class just has some permissions control, which works okay; I'm sure it's not essential to this problem.

When I create a course, giving it a classroom, with a single xhtml-page in the pages hash, this is the XML output:

<OBJECT ID="1" CLASS="CL-PREVALENCE::TRANSACTION"><SLOT NAME="CL-PREVALENCE::ARGS"><NULL/></SLOT><SLOT NAME="CL:FUNCTION"><SYMBOL>CL-PREVALENCE::TX-CREATE-ID-COUNTER</ SYMBOL></SLOT></OBJECT> <OBJECT ID="1" CLASS="CL-PREVALENCE::TRANSACTION"><SLOT NAME="CL-PREVALENCE::ARGS"><SEQUENCE ID="2" CLASS="CL:LIST" SIZE="3"><SYMBOL>COM.RANDALLSQUARED.COOL::COURSE</SYMBOL><SYMBOL>CL- PREVALENCE::NAME</SYMBOL><SYMBOL>CL:EQUALP</SYMBOL></SEQUENCE></ SLOT><SLOT NAME="CL:FUNCTION"><SYMBOL>CL-PREVALENCE::TX-CREATE-OBJECTS-S LOT-INDEX</SYMBOL></SLOT></OBJECT> <OBJECT ID="1" CLASS="CL-PREVALENCE::TRANSACTION"><SLOT NAME="CL-PREVALENCE::ARGS"><SEQUENCE ID="2" CLASS="CL:LIST" SIZE="2"><SYMBOL>COM.RANDALLSQUARED.COOL::XHTML-PAGE</SYMBOL><SEQUENCE ID="3" CLASS="CL:LIST" SIZE="2"><SEQUENCE ID="4" CLASS="CL:LIST" SIZE="2"><SYMBOL>COM.RANDALLSQUARED.COOL::TITLE</SYMBOL><SEQUENCE ID ="5" CLASS="CL:LIST" SIZE="1"><STRING>default-page-title</STRING></SEQUENCE></ SEQUENCE><SEQUENCE ID="6" CLASS="CL:LIST" SIZE="2"><SYMBOL>COM.RANDALLSQUARED.COOL::XHTML</SYMBOL><SEQUENCE ID="7" CLASS="CL:LIST" SIZE="1"><STRING>default-page-content</STRING></SEQUENCE></SEQUENCE></ SEQUENCE></SEQUENCE></SLOT><SLOT NAME="CL :FUNCTION"><SYMBOL>CL-PREVALENCE::TX-CREATE-OBJECT</SYMBOL></SLOT></ OBJECT> <OBJECT ID="1" CLASS="CL-PREVALENCE::TRANSACTION"><SLOT NAME="CL-PREVALENCE::ARGS"><SEQUENCE ID="2" CLASS="CL:LIST" SIZE="1"><SYMBOL>COM.RANDALLSQUARED.COOL::CLASSROOM</SYMBOL></ SEQUENCE></SLOT><SLOT NAME="CL:FUNCTION"><SYMBOL>CL-PREVALENCE::TX-CREATE-OBJECT</SYMBOL></ SLOT></OBJECT> <OBJECT ID="1" CLASS="CL-PREVALENCE::TRANSACTION"><SLOT NAME="CL-PREVALENCE::ARGS"><SEQUENCE ID="2" CLASS="CL:LIST" SIZE="2"><SYMBOL>COM.RANDALLSQUARED.COOL::COURSE</SYMBOL><SEQUENCE ID="3" CLASS="CL:LIST" SIZE="3"><SEQUENCE ID="4" CLASS="CL:LIST" SIZE="2"><SYMBOL>COM.RANDALLSQUARED.COOL::CLASSROOM</SYMBOL><OBJECT ID="5" CLASS="COM.RANDALLSQUARED.COOL::CLASSROOM"><SLOT NAME="CL-PREVALENCE::ID"><INT>2</INT></SLOT><SLOT NAME="COM.RANDALLSQUARED.COOL::COVER"><STRING></STRING></SLOT><SLOT NAME="COM.RANDALLSQUARED.COOL::TOC"><NULL/></SLOT><SLOT NAME="COM.RANDALLSQUARED.COOL::PAGES"><HASH-TABLE ID="6" TEST="CL:EQUAL" SIZE="65"><ENTRY><KEY><STRING></STRING></KEY><VALUE><SEQUENCE ID="7" CLASS="CL:LIST" SIZE="1"><OBJECT ID="8" CLASS="COM.RANDALLSQUARED.COOL::XHTML-PAGE"><SLOT NAME="CL-PREVALENCE::ID"><INT>1</INT></SLOT><SLOT NAME="CL-PREVALENCE::NAME"><STRING></STRING></SLOT><SLOT NAME="COM.RANDALLSQUARED.COOL::TITLE"><SEQUENCE ID="9" CLASS="CL:LIST" SIZE="1"><STRING>default-page-title</STRING></SEQUENCE></SLOT><SLOT NAME="COM.RANDALLSQUARED.COOL::XHTML"><SEQUENCE ID="10" CLASS="CL:LIST" SIZE="1"><STRING>default-page-content</STRING></SEQUENCE></SLOT></ OBJECT></SEQUENCE></VALUE></ENTRY></HASH-TABLE></SLOT></OBJECT></ SEQUENCE><SEQUENCE ID="11" CLASS="CL:LIST" SIZE="2"><SYMBOL>COM.RANDALLSQUARED.PSIUSER::HANDLES</SYMBOL><SEQUENCE ID="12" CLASS="CL:LIST" SIZE="2"><INT>78</INT><INT>75</INT></SEQUENCE></SEQUENCE><SEQUENCE ID="13" CLASS="CL:LIST" SIZE="2"><SYMBOL>CL-PREVALENCE::NAME</SYMBOL><STRING>course</STRING></ SEQUENCE></SEQUENCE></SEQUENCE></SLOT><SLOT NAME="CL:FUNCTION"><SYMBOL>CL- PREVALENCE::TX-CREATE-OBJECT</SYMBOL></SLOT></OBJECT>

So far, so good, I think. In case it's not clear from the above (it isn't to me), the course has id 3, the classroom id 2, and the xhtml-page id 1, since the default contents get created just before they're passed to tx-create-object in managed-prevalence.lisp.

But upon restarting the system, while all the id integers are correct, the xhtml-page isn't attached to the pages hash anymore: * (find-courses) ; a standin for (find-all-objects *system* 'course)

(#<COURSE {49115E15}>) T * (get-id (car (find-courses)))

3 * (get-id (classroom (car (find-courses))))

2 * (pages (classroom (car (find-courses))))

#<EQUAL hash table, 1 entry {491146FD}> * (gethash "" (pages (classroom (car (find-courses)))))

NIL NIL * (find-object-with-id *system* 'xhtml-page 1)

#<XHTML-PAGE {49110995}> T

So, the obvious question is, how come the hash doesn't get it's xhtml-page back?

-- Randall Randall randall@randallsquared.com "And no practical definition of freedom would be complete without the freedom to take the consequences. Indeed, it is the freedom upon which all the others are based." - Terry Pratchett, _Going Postal_