From ktilton at nyc.rr.com  Tue Sep  6 14:37:01 2005
From: ktilton at nyc.rr.com (Kenny Tilton)
Date: Tue, 06 Sep 2005 10:37:01 -0400
Subject: [cells-devel] [Fwd: Re: some dumb? cells questions]
Message-ID: <431DA98D.1000000@nyc.rr.com>


> From: Friedrich Dominicus <frido at q-software-solutions.de>
> Subject: some dumb? cells questions
> To: cells-devel at common-lisp.net
> Date: Tue, 06 Sep 2005 15:16:14 +0200
> Organization: Q Software Solutions GmbH
>
> I'm trying to find my way into decent web-programming, and are now
> looking into the following simple? Problem. 
>
> The proofed way of doing web-programming seems the MVC stuff. Now the
> model may be a cl-sql class e.g and the view may come from any of the
> web"frameworks", however there is a need to get the data cleanly to
> the view and back I wonder if that would be a good? usage for cells.
>
> So here we go with the questions.
> How would I tell cells to populate the view with database data?
> How would I enforce a "direkt link", will say if the model data
> changes the view is modified accordingly and vice versa
> How would I write validation functions?
>
> Regards
> Friedrich
> ----------





From ktilton at nyc.rr.com  Tue Sep  6 15:15:49 2005
From: ktilton at nyc.rr.com (Kenny Tilton)
Date: Tue, 06 Sep 2005 11:15:49 -0400
Subject: [cells-devel] [Fwd: Re: some dumb? cells questions]
In-Reply-To: <431DA98D.1000000@nyc.rr.com>
References: <431DA98D.1000000@nyc.rr.com>
Message-ID: <431DB2A5.9070706@nyc.rr.com>



Kenny Tilton wrote:

>
>> From: Friedrich Dominicus <frido at q-software-solutions.de>
>> Subject: some dumb? cells questions
>> To: cells-devel at common-lisp.net
>> Date: Tue, 06 Sep 2005 15:16:14 +0200
>> Organization: Q Software Solutions GmbH
>>
>> I'm trying to find my way into decent web-programming, and are now
>> looking into the following simple? Problem.
>> The proofed way of doing web-programming seems the MVC stuff. Now the
>> model may be a cl-sql class e.g and the view may come from any of the
>> web"frameworks", however there is a need to get the data cleanly to
>> the view and back I wonder if that would be a good? usage for cells. 
>
Yes, it is a perfect fit because of the requirement that the model and 
view always be in synch. Of course on Windows they have the "refresh 
view" option so users can go quietly crazy not finding what they know is 
there, so there /are/ alternatives. :)

I did this with Franz's AllegroStore. What is needed is a bottleneck on 
DB writes, some place to put a custom hook which will cooperate with a 
Cell-powered mechanism to allow seamless declarative view code...uh, 
here is an example: a simple list view of all my cutomers. That will be 
a stack of text labels/controls, each showing the customer name. If the 
name changes we want the label to change, and if a customer is added or 
removed we want the list contents to grow or shrink. For the latter, we 
want to say:

        (aStack ()...
            :kids (c? (mapcar #'make-list-cell (^ps-table 'customer))))

...where ps-table is a layer of code I wrote to make it seems as if the 
AllegroStore (persistent CLOS) customer class had a cell called ps-table 
(maybe a bad name) which amounted to a list of all the instances of that 
class in the persistent DB.

The hook I used was easy: because it was a persistent CLOS 
implementation, I was able to use things like initialize-instance and 
slot-value-using-class to place hooks on my persistent classes. These 
hooks simulated Cell-like data propagation from DB writes, effectively 
gluing DB access to the larger Cell-based application model.

>>
>>
>> So here we go with the questions.
>> How would I tell cells to populate the view with database data? 
>
Does SQL have any kind of callback mechanism that lets you detect DB 
writes? If not, you must create bottleneck functions for DB writes and 
use them consistently, then do the gluing from there. And you IPC to 
"announce" DB changes. We used GUIDs to give DB instances object 
identity that can be shared amongst processes.

Please note that this all /does/ involve creating a nice little layer of 
code to connect SQL with Cells. So it is no free lunch. But I have 
written a lot of code like this before and after Cells and I can confirm 
that it is a huge win for this type of DB browser/updater application. 
The view just stays in synch with the DB with no further effort from the 
developer than the original one-time effort to glue the DB to the Cells. 
Hellasweet.

>>
>> How would I enforce a "direkt link", will say if the model data
>> changes the view is modified accordingly and vice versa 
>
"changes the view" I covered above. vice-versa (getting the model to 
follow the view) is no magic. Well, the output methods probably help a 
little. But at some point the user has to confirm an update, so the 
write itself ends up being procedural, not some rule on a persistent 
model instance slot that automatically copies a changed view instance slot.


>>
>> How would I write validation functions? 
>
I actually arranged for persistent slots of persistent instances to have 
rules associated with them. There was an "error" slot that could handle 
things like DB inconsistency, if one wanted to allow the DB write but 
raise a flag for the user to address. Otherwise, I was also able to have 
a non-persistent slot on a persistent class. That could be a validation 
rule, then the GUI code would refuse to commit the changes of an invalid 
record.

I know SQL does not work like an object database, but if I had to do 
this I would first look for one of the rough hacks done to fake 
persistent CLOS with SQL and see if they would work, because CLOS itself 
offers so many hooks.  Or I might do my own perisstent CLOS hack. I 
think you really need /some/ CLOS correlate of your DB to make this 
work-- well, not "need", but I think it would be the easiest way to go.

kt




From frido at q-software-solutions.de  Wed Sep  7 07:33:58 2005
From: frido at q-software-solutions.de (Friedrich Dominicus)
Date: Wed, 07 Sep 2005 09:33:58 +0200
Subject: [cells-devel] cells in Web applications
In-Reply-To: <431DB3DC.8060207@nyc.rr.com> (Kenny Tilton's message of "Tue,
	06 Sep 2005 11:21:00 -0400")
References: <431DB3DC.8060207@nyc.rr.com>
Message-ID: <87vf1dmivt.fsf@flarge.here>

Kenny Tilton <ktilton at nyc.rr.com> writes:

>>>
>>> I'm trying to find my way into decent web-programming, and are now
>>> looking into the following simple? Problem.
>>> The proofed way of doing web-programming seems the MVC stuff. Now the
>>> model may be a cl-sql class e.g and the view may come from any of the
>>> web"frameworks", however there is a need to get the data cleanly to
>>> the view and back I wonder if that would be a good? usage for
>>> cells.
>>
> Yes, it is a perfect fit because of the requirement that the model and
> view always be in synch. Of course on Windows they have the "refresh
> view" option so users can go quietly crazy not finding what they know
> is there, so there /are/ alternatives. :)
>
> I did this with Franz's AllegroStore. What is needed is a bottleneck
> on DB writes, some place to put a custom hook which will cooperate
> with a Cell-powered mechanism to allow seamless declarative view
> code...uh, here is an example: a simple list view of all my
> cutomers. That will be a stack of text labels/controls, each showing
> the customer name. If the name changes we want the label to change,
> and if a customer is added or removed we want the list contents to
> grow or shrink. For the latter, we want to say:
>
>        (aStack ()...
>            :kids (c? (mapcar #'make-list-cell (^ps-table 'customer))))
>
> ...where ps-table is a layer of code I wrote to make it seems as if
> the AllegroStore (persistent CLOS) customer class had a cell called
> ps-table (maybe a bad name) which amounted to a list of all the
> instances of that class in the persistent DB.
Well I just started looking into cells, and have yet not the
"slighest" idea on it's usage in any environment, so I wrote down a
stripped down example (tested with ucw (actual dev tree),
araneida,
       cl-sql, SBCL 0.9.4.24, on
a Debian unstable box) 

Of course I can not expect anyone having all this things installed,
it's just to have  "more" concrete example

(in-package :qss.web)


(defparameter *example-app*
  (make-instance 'cookie-session-application
                 :url-prefix "/ucw/examples/"
                 :tal-generator (make-instance 'yaclml:file-system-generator
                                               :cachep t
                                               :root-directories (list *ucw-tal-root*))
                 :www-roots (list *ucw-tal-root*)))





(clsql:def-view-class example-app ()
  ((mid :type integer :db-kind :key :accessor mid :initarg :mid)
   (mtag :type string :accessor mtag :initarg :mtag)
   (mdescription :type string :accessor mdescription :initarg :mdescription)
   (msome-fk :type integer :accessor msome-fk :initarg :msome-fk)
   (msome-objects :accessor msome-objects
                  :db-kind :join
                  :db-info (:join-class other-class
                                        :retrieval :deferred
                                        :set nil
                                        :foreign-key mexample-id
                                        :home-key mid))))


(clsql:def-view-class other-class ()
  ((mexample-id :type integer :accessor mexample-id :initarg :mexample-id)
   (mval :type string :accessor mval  :initarg :mval)))

(defun populate-db ()
  (let ((other (make-instance 'other-class
                              :mexample-id 1
                              :mval "some text")))
    (clsql:update-records-from-instance other)
    (let ((mobj (make-instance 'example-app
                               :mid 1
                               :mtag "some tag"
                               :mdescription "this is the description"
                               :msome-fk 1)))
      (setf (msome-objects mobj) other)
      (clsql:update-records-from-instance mobj))))


;; 
;; (clsql:create-view-from-class 'example-app)
;; (clsql:create-view-from-class 'other-class)
;; (populate-db)
    
        


(defcomponent example-view (simple-window-component)
  ((db-obj :accessor db-obj :initarg :db-obj :initform (car (clsql:select 'example-app
                                                                           :where [= [mid] 1]
                                                                           :flatp t)))
   ;; view link to the database object
                                                             
   (vtag :accessor vtag :initarg :vtag
         :component (text-field :size 20 :maxlength 20))
   (vdescription :type string :accessor vdescription :initarg :vdescription
                 :component (text-area-field :width 20 :height 10))
   (vother :accessor vother :component (text-field :size 20 :maxlength 20))))


(defun setup-db ()
  (qss.db:db-connect :database "test" :user "user" :password "password") ;; open a connectoin to DB
  (clsql:enable-sql-reader-syntax))


;; (setup-db)

(defcomponent text (simple-window-component)
  ((view-text :initarg :view-text :reader view-text)
   (db-text :initarg :db-text :reader db-text)))
         
     

(defmethod render-on ((res response) (text text))
  (<:p "view data"
       (<:as-is (view-text text)))
  (<:p "database data"
       (<:as-is (db-text text))))


(defmethod populate-view ((view example-view))
  (let ((db-obj (db-obj view)))
    (setf (ucw::client-value (vtag view)) (mtag db-obj)
          (ucw::client-value (vdescription view)) (mdescription db-obj)
          (ucw::client-value (vother view)) (mval (msome-objects db-obj)))
    (values)))
   
    

(defmethod render-on ((res response) (view example-view))
  ;; this is not perfect but for the example it should be enough
  (populate-view view)
  ;; (inspect view)
  (<ucw:form :action (save-and-show-data view)
             (<:table 
              (<:tr
               (<:td "tag")
               (<:td "Description")
               (<:td "Other text"))
              (<:tr
               (<:td (render-on res (vtag view)))
               (<:td (render-on res (vdescription view)))
               (<:td (render-on res (vother view)))))
             (<:p (<:input :type "submit" :value "Accept"))))


(defmethod update-model-from-view ((view example-view))
  (let* ((db-obj (db-obj view)) ;; I know with-accessor would be fine...
         (other (msome-objects db-obj)))
    (setf (mtag db-obj) (read-client-value (vtag view))
          (mdescription db-obj) (read-client-value (vdescription view))
          (mval other) (read-client-value (vother view)))
    (clsql:update-records-from-instance db-obj)
    (values)))
  
          
              
  
(defaction save-and-show-data ((view example-view))
  (update-model-from-view view)

  (call 'text :view-text (format nil "tag = ~a, descripton = ~a, other-text = ~a~%"
                                 (read-client-value (vtag view))
                                 (read-client-value (vdescription view))
                                 (read-client-value (vother view)))
         :db-text (format nil "tag = ~a, descripton = ~a, other-text = ~a~%"
                                 (mtag (db-obj view))
                                 (mdescription (db-obj view))
                                 (mval (msome-objects (db-obj view))))))

  
          
    



(defentry-point "index.ucw" (:application *example-app*) ()
  (call 'example-view))

I guess one can see the "duplication" of code here I have my model
data in the database declard with clsql-def-view class, there is one
join slot which links to other-obj. clsql arranges it such way that if
you query the Database that it will remember the link between the both
tables. So if the join slot has a number then you can simple reach
into the other table without the need for a new query you just say
(other-class example-app-obj) and got the object constructed from
other_class with example-id = 1

The view does not show all the elements of the table because they are
"supposed" to be uninterested. Of course I'm aware that I could
abstract away the assignment of data, but for that I was thinking to
use cells. However I do not have any clue on how to hook it
into this application. 

I guess one can see how I think UCW should be used you have a chain
view-action-view-action ..... And you can see that I used the view to
contain a link to the object this is probably not the "right" approach
but it seems to be ok for showing the idea nevertheless. 

Probaly one should use e.g methods specialiced on a view and a
model (which would make the controller, in MVC terms)
but the main problem is the manual need to get the data from the
database to the view and back. If I forget to update either the view
or the database, the whole stuff will break down, and what I
especially dislike is the duplication of code, there *must* be a
better way. 

You'll see also that not validation checks are done, they must be
considered also but for now I just drop them. 

So my "concrete" question is on how to hook in cells to avoid the
manual assignments and e.g hook in the validation tests (wouldn't that
be cells task?)

As I understand cells is there to establich links between objects to
express relationships between different slots in the same or different
classes. Now in this example there is a very strong link in both
directions (view -> db and db -> view), the rules are very simple if
all will go well but what happens if the link is somehow broken?

Regards
Friedrich


From frido at q-software-solutions.de  Thu Sep  8 06:43:50 2005
From: frido at q-software-solutions.de (Friedrich Dominicus)
Date: Thu, 08 Sep 2005 08:43:50 +0200
Subject: [cells-devel] files missing in cell-cultures
Message-ID: <87aciof49l.fsf@flarge.here>

the subdirectroy utils-kt is empty in the cells-culture CVS tree, I
guess that is not ok.

Regards
Friedrich


From frido at q-software-solutions.de  Thu Sep  8 07:11:59 2005
From: frido at q-software-solutions.de (Friedrich Dominicus)
Date: Thu, 08 Sep 2005 09:11:59 +0200
Subject: [cells-devel] [Fwd: Re: some dumb? cells questions]
In-Reply-To: <431DB2A5.9070706@nyc.rr.com> (Kenny Tilton's message of "Tue,
	06 Sep 2005 11:15:49 -0400")
References: <431DA98D.1000000@nyc.rr.com> <431DB2A5.9070706@nyc.rr.com>
Message-ID: <8764tcf2yo.fsf@flarge.here>

Kenny Tilton <ktilton at nyc.rr.com> writes:

> Please note that this all /does/ involve creating a nice little layer
> of code to connect SQL with Cells. So it is no free lunch. But I have
> written a lot of code like this before and after Cells and I can
> confirm that it is a huge win for this type of DB browser/updater
> application. The view just stays in synch with the DB with no further
> effort from the developer than the original one-time effort to glue
> the DB to the Cells. Hellasweet.
Well that is exactly what I like to do but, I have no idea on how to
do that. what does the "needed" glue look like? 

Regards
Friedrich


From frido at q-software-solutions.de  Thu Sep  8 10:02:45 2005
From: frido at q-software-solutions.de (Friedrich Dominicus)
Date: Thu, 08 Sep 2005 12:02:45 +0200
Subject: [cells-devel] my very first baby steps with cells
Message-ID: <871x3zg9mi.fsf@flarge.here>

Ok, the learning curve is steep and my idea on what I'm doing is less
then basic. However here we go, this is the code
(defmodel foobar (model)
  ((val-1 :cell t :accessor val-1 :initform "" :initarg :val-1)
   (val-3 :cell t :accessor val-3 :initarg :val-3 :initform (c-in "Initialize"))))

                     


(def-c-output val-1 ()
  (format t "val-1 is ~a, val-3 is ~a~%" 
          (val-1 self) (val-3 self)))



(defun foo-test ()
  (cell-reset)
  (let ((obj (make-instance 'foobar
                            :val-1 (c? (if (val-3 self)
                                           (setf (val-1 self) (val-3 self))
                                           "val-3 not set")))))
    
    (setf (val-3 obj) "another val-3")
    (setf (val-3 obj) "yet another val for val-3"))
  (values))

In this utterly primitive example the val3 slot "steers" the slot-1
slot. Translated to my need to sync db-view and "user-view", I assume
I have to write  model with the two objects in it do the
initialization from one side (e.g populating from the database), I
probably also have to write a function to feed to the :unchanged (or
so slot), if that yiels true, then the view and database data are in
sync if not I have to update the database data from the view. 

Is this the way to go, or am I overlooking something (I guess I do,
just cells is too new for me....)

Regards
Friedrich


From ktilton at nyc.rr.com  Thu Sep  8 14:04:35 2005
From: ktilton at nyc.rr.com (Kenny Tilton)
Date: Thu, 08 Sep 2005 10:04:35 -0400
Subject: [Fwd: Re: [cells-devel] files missing in cell-cultures]
Message-ID: <432044F3.5060109@nyc.rr.com>



-------- Original Message --------
Subject: 	Re: [cells-devel] files missing in cell-cultures
Date: 	Thu, 08 Sep 2005 10:03:56 -0400
From: 	Kenny Tilton <ktilton at nyc.rr.com>
To: 	Friedrich Dominicus <frido at q-software-solutions.de>
References: 	<87aciof49l.fsf at flarge.here>



Friedrich Dominicus wrote:

>the subdirectroy utils-kt is empty in the cells-culture CVS tree, I
>guess that is not ok.
>
Well, the only thing wrong is that I have not gotten around to deleting the cell-cultures tree, which has been deprecated for some time now.

utils-kt is a subdirectory of cells:

  http://common-lisp.net/cgi-bin/viewcvs.cgi/cells/utils-kt/?cvsroot=cells

-- 
Kenny

Why Lisp? http://wiki.alu.org/RtL_Highlight_Film

"I've wrestled with reality for 35 years, Doctor, and I'm happy to state I finally won out over it."
   Elwood P. Dowd, "Harvey", 1950




-- 
Kenny

Why Lisp? http://wiki.alu.org/RtL_Highlight_Film

"I've wrestled with reality for 35 years, Doctor, and I'm happy to state I finally won out over it."
    Elwood P. Dowd, "Harvey", 1950





From ktilton at nyc.rr.com  Thu Sep  8 14:32:49 2005
From: ktilton at nyc.rr.com (Kenny Tilton)
Date: Thu, 08 Sep 2005 10:32:49 -0400
Subject: [cells-devel] my very first baby steps with cells
In-Reply-To: <871x3zg9mi.fsf@flarge.here>
References: <871x3zg9mi.fsf@flarge.here>
Message-ID: <43204B91.3010706@nyc.rr.com>



Friedrich Dominicus wrote:

>Ok, the learning curve is steep and my idea on what I'm doing is less
>then basic. However here we go, this is the code
>(defmodel foobar (model)
>  ((val-1 :cell t :accessor val-1 :initform "" :initarg :val-1)
>   (val-3 :cell t :accessor val-3 :initarg :val-3 :initform (c-in "Initialize"))))
>
>                     
>
>
>(def-c-output val-1 ()
>  (format t "val-1 is ~a, val-3 is ~a~%" 
>          (val-1 self) (val-3 self)))
>
>
>
>(defun foo-test ()
>  (cell-reset)
>  (let ((obj (make-instance 'foobar
>                            :val-1 (c? (if (val-3 self)
>                                           (setf (val-1 self) (val-3 self))
>                                           "val-3 not set")))))
>
Just use: (c? (or (val-3 self) "val-3 not set"))
There is also a handy macro for cells of oneself: (c? (or (^val-3) 
"val-3 not set"))

The Cell engine populates the slot at the right time (long story, but 
the timing is delicate) initially and as val-3 changes.

Note that there is a runtime error generated when you attempt to SETF a 
ruled Cell, as your rule is doing (SETFing itself!), but I think at some 
point recently I changed things so the error is enforced only if 
*c-debug* is non-nil. Recall is fuzzy on why I did that.

Anyway, the idea is to have a declarative approach in which one supplies 
a rule for a slot and then the Cells engine takes over and keeps things 
in synch.

>    
>    (setf (val-3 obj) "another val-3")
>    (setf (val-3 obj) "yet another val for val-3"))
>  (values))
>
>In this utterly primitive example the val3 slot "steers" the slot-1
>slot. 
>
Think of it as slot-1 "following" val3. Note that there is no val-3 
logic to change val-1. val-3 does not know anything about val-1. But 
val-1 has a rule that uses val-3. val-1 could have also used any number 
of other vals. This is important, and really constitutes the paradigm 
shift away from a procedural, manual SETFing of other values to a 
declarative "just worry about the rule for one value at a time".

>Translated to my need to sync db-view and "user-view", I assume
>I have to write  model with the two objects in it do the
>initialization from one side (e.g populating from the database), I
>probably also have to write a function to feed to the :unchanged (or
>so slot), if that yiels true, then the view and database data are in
>sync if not I have to update the database data from the view. 
>
I am afraid you lost me there. "two objects"? "one side"? Maybe once you 
have absorbed the above correction and otherwise gottten a better 
understanding of the declarative model we can try some actual 
unambiguous code using a simple text file as a database, with each line 
constituting a row in an SQL table. I guess the principle will be the 
same, and this would be a rather extreme but illuminating Use Case to 
share with others.

Note that the original code I described was proprietary, so we would 
develop new code from scratch (and I cannot share the old code).

-- 
Kenny

Why Lisp? http://wiki.alu.org/RtL_Highlight_Film

"I've wrestled with reality for 35 years, Doctor, and I'm happy to state I finally won out over it."
    Elwood P. Dowd, "Harvey", 1950





From frido at q-software-solutions.de  Fri Sep  9 06:38:33 2005
From: frido at q-software-solutions.de (Friedrich Dominicus)
Date: Fri, 09 Sep 2005 08:38:33 +0200
Subject: [cells-devel] my very first baby steps with cells
In-Reply-To: <43204B91.3010706@nyc.rr.com> (Kenny Tilton's message of "Thu,
	08 Sep 2005 10:32:49 -0400")
References: <871x3zg9mi.fsf@flarge.here> <43204B91.3010706@nyc.rr.com>
Message-ID: <87ll26d9ue.fsf@flarge.here>

thanks for your comments. I'll spend some time of the day to implement
the idea I have on my mind and will post it then. I'm sure someone
using cells will find it "obscurred" programmed and will know a better
way on how to approache the problem. I probably will drop the view
stuff for now and just use formatted output. But I will use a database
as "backend". I hope it won't be all too bad.

Regards
Friedrich


From frido at q-software-solutions.de  Mon Sep 12 08:09:50 2005
From: frido at q-software-solutions.de (Friedrich Dominicus)
Date: Mon, 12 Sep 2005 10:09:50 +0200
Subject: [cells-devel] my very first baby steps with cells
In-Reply-To: <87ll26d9ue.fsf@flarge.here> (Friedrich Dominicus's message of
	"Fri, 09 Sep 2005 08:38:33 +0200")
References: <871x3zg9mi.fsf@flarge.here> <43204B91.3010706@nyc.rr.com>
	<87ll26d9ue.fsf@flarge.here>
Message-ID: <87slwazoz5.fsf@flarge.here>

I spend nearly the whole weekend on gettign a bit further. My code is
not this:

(in-package :qss.web)

;; (use-package :cells)
(eval-when (:compile-toplevel :execute)
(defparameter *example-app*
  (make-instance 'cookie-session-application
                 :url-prefix "/ucw/examples/"
                 :tal-generator (make-instance 'yaclml:file-system-generator
                                               :cachep t
                                               :root-directories (list *ucw-tal-root*))
                 :www-roots (list *ucw-tal-root*))))

;; (register-application *default-server* *example-app*)

(cells:defmodel controller (cells:model)
  ((view-obj :accessor view-obj :cell t
             :initarg :view-obj :initform (cells:c-in nil))
   (db-obj :accessor db-obj :initarg :db-obj :cell t 
           :initform (cells:c? (update-from-view cells:self)))))


(clsql:def-view-class example-app ()
  ((id :type integer :db-kind :key :accessor id :initarg :id)
   (tag :type string :accessor tag :initarg :tag)
   (description :type string :accessor description :initarg :description)
   (some-fk :type integer :accessor some-fk :initarg :some-fk)
   (some-objects :accessor some-objects
                  :db-kind :join
                  :db-info (:join-class other-class
                                        :retrieval :deferred
                                        :set nil
                                        :foreign-key example-id
                                        :home-key id))))


(clsql:def-view-class other-class ()
  ((example-id :type integer :accessor example-id :initarg :example-id)
   (val :type string :accessor val  :initarg :val)))



;; (clsql:create-view-from-class 'simple-db)


                               

(defmethod update-from-view ((controller controller))
  (with-accessors ((db-obj db-obj) (view-obj view-obj))
    controller
    (inspect controller)
    ;; view should steer the database object usually
    (let ((other (some-objects db-obj)))
      (setf (tag db-obj) (read-client-value (tag view-obj))
            (description db-obj) (read-client-value (description view-obj))
            (val other) (read-client-value (other view-obj)))
      (clsql:update-records-from-instance db-obj))
    (values)))
          

   
   
   




(defun populate-db ()
  (let ((other (make-instance 'other-class
                              :example-id 1
                              :val "some text")))
    (clsql:update-records-from-instance other)
    (let ((mobj (make-instance 'example-app
                               :id 1
                               :tag "some tag"
                               :description "this is the description"
                               :some-fk 1)))
      (setf (some-objects mobj) other)
      (clsql:update-records-from-instance mobj))))

;; (clsql:drop-view-from-class 'other-class)
;; (clsql:drop-view-from-class 'example-app)

;; 
;; (clsql:create-view-from-class 'example-app)
;; (clsql:create-view-from-class 'other-class)
;; (populate-db)


    
        


(defcomponent example-view (simple-window-component)
  ((db-obj :initarg :db-obj :reader db-obj)
   (tag :accessor tag :initarg :tag
        :component (text-field :size 20 :maxlength 20))
   (description :type string :accessor description :initarg :description
                :component (text-area-field :width 20 :height 10))
   (other :accessor other :component (text-field :size 20 :maxlength 20))))


(defun setup-db ()
        ;; open a connectoin to DB
  (clsql:enable-sql-reader-syntax))


;; (setup-db)

(defcomponent text (simple-window-component)
  ((view-text :initarg :view-text :reader view-text)
   (db-text :initarg :db-text :reader db-text)))
         
     

(defmethod render-on ((res response) (text text))
  (inspect text)
  (<:p "view data: "
       (<:as-is (view-text text)))
  (<:p "database data: "
       (<:as-is (db-text text))))

(defmethod initialize-vfd ((view example-view) (controller controller))
  (let ((db-obj (db-obj controller)))

    (setf (some-objects db-obj) (car (clsql:select 'other-class 
                                                  :where [= [example-id] 1]
                                                  :flatp t)))
    ;; (inspect db-obj)
    (clsql:update-records-from-instance db-obj)
    (setf (ucw::client-value (tag view)) (tag db-obj)
          (ucw::client-value (description view)) (description db-obj )
          (ucw::client-value (other view )) (val (some-objects db-obj ))
          (view-obj controller) view)
    (inspect controller)
  (values)))

  
   
    

(defmethod render-on ((res response) (view example-view))
  ;; this is not perfect but for the example it should be enough
  ;; (inspect view)
  (let ((controller (make-instance 'controller)))
    (setf (db-obj controller) (slot-value view 'db-obj))
    (initialize-vfd view controller)
    (inspect controller)
    (<ucw:form :action (save-and-show-data view controller)
               (<:table 
                (<:tr
                 (<:td "tag")
                 (<:td "Description")
                 (<:td "Other text"))
                (<:tr
                 (<:td (render-on res (tag view)))
                 (<:td (render-on res (description view)))
                 (<:td (render-on res (other view)))))
               (<:p (<:input :type "submit" :value "Accept")))))


  
(defaction save-and-show-data ((view example-view) (controller controller))
  (call 'text :view-text (format nil "tag = ~a, descripton = ~a, other-text = ~a~%"
                                 (read-client-value (tag (view-obj controller)))
                                 (read-client-value (description (view-obj controller)))
                                 (read-client-value (other (view-obj controller))))
        :db-text (format nil "tag = ~a, descripton = ~a, other-text = ~a~%"
                         (tag (db-obj controller))
                         (description (db-obj controller))
                         (val (some-objects (db-obj controller))))))

  
          
    

(defun init-cells ()
  (clsql:enable-sql-reader-syntax)
  (cells:cell-reset))



(defentry-point "index.ucw" (:application *example-app*) ()
  (init-cells)
  (call 'example-view :db-obj (car (clsql:select 'example-app 
                                                 :where [= [id] 1]
                                                 :flatp t
                                                 :refresh t)))

my problem update-from-view is not called I was thinking that 
   (db-obj :accessor db-obj :initarg :db-obj :cell t 
           :initform (cells:c? (update-from-view cells:self)))))

is reponsible for it. But of course I'm set'fing the db-obj slot also,
out come is that 
1) the view is initialized from the db-view
2) that the db-view won't get changed. 

I'm sure it could be done but I don't know how, could someone give me
a hand please?

Regards
Friedrich


From frido at q-software-solutions.de  Mon Sep 12 09:41:30 2005
From: frido at q-software-solutions.de (Friedrich Dominicus)
Date: Mon, 12 Sep 2005 11:41:30 +0200
Subject: [cells-devel] my very first baby steps with cells
In-Reply-To: <87slwazoz5.fsf@flarge.here> (Friedrich Dominicus's message of
	"Mon, 12 Sep 2005 10:09:50 +0200")
References: <871x3zg9mi.fsf@flarge.here> <43204B91.3010706@nyc.rr.com>
	<87ll26d9ue.fsf@flarge.here> <87slwazoz5.fsf@flarge.here>
Message-ID: <87mzmizkqd.fsf@flarge.here>

I got it (probably ;-), would someone mind to comment on it?

(in-package :qss.web)

;; (use-package :cells)
(eval-when (:compile-toplevel :execute)
(defparameter *example-app*
  (make-instance 'cookie-session-application
                 :url-prefix "/ucw/examples/"
                 :tal-generator (make-instance 'yaclml:file-system-generator
                                               :cachep t
                                               :root-directories (list *ucw-tal-root*))
                 :www-roots (list *ucw-tal-root*))))

;; (register-application *default-server* *example-app*)

(cells:defmodel controller (cells:model)
  ((view-obj :accessor view-obj :cell t 
             :initarg :view-obj :initform (cells:c-in nil))
   (db-obj :accessor db-obj :initarg :db-obj :cell t 
           :initform (cells:c? (update-from-view cells:self)))))


(clsql:def-view-class example-app ()
  ((id :type integer :db-kind :key :accessor id :initarg :id)
   (tag :type string :accessor tag :initarg :tag)
   (description :type string :accessor description :initarg :description)
   (some-fk :type integer :accessor some-fk :initarg :some-fk)
   (some-objects :accessor some-objects
                  :db-kind :join
                  :db-info (:join-class other-class
                                        :retrieval :deferred
                                        :set nil
                                        :foreign-key example-id
                                        :home-key id))))


(clsql:def-view-class other-class ()
  ((example-id :type integer :accessor example-id :initarg :example-id)
   (val :type string :accessor val  :initarg :val)))



;; (clsql:create-view-from-class 'simple-db)


                               

(defmethod update-from-view ((controller controller))
  (print "in update-from-view"  *error-output*)

  (unless (slot-value controller 'db-obj)
    (print "in unless " *error-output*)
    ;; (inspect (db-obj (view-obj controller)))
    (setf (slot-value controller 'db-obj) (db-obj (view-obj controller))))
    
      ;; (inspect controller)
    ;; view should steer the database object usually
    (let* ((db-obj (slot-value controller 'db-obj))
           (view (view-obj controller))
           (other (some-objects db-obj)))
      (setf (tag db-obj) (read-client-value 
                          (tag view))
            (description db-obj) (read-client-value 
                                  (description view))
            (val other) (read-client-value 
                         (other view)))

      (clsql:update-records-from-instance db-obj)
      (print "in update-from-view before inspect" *error-output*)
      (inspect controller)
      ;; (setf (slot-value controller 'db-obj) db-obj))
      (slot-value controller 'db-obj)))
          

   
   
   




(defun populate-db ()
  (let ((other (make-instance 'other-class
                              :example-id 1
                              :val "some text")))
    (clsql:update-records-from-instance other)
    (let ((mobj (make-instance 'example-app
                               :id 1
                               :tag "some tag"
                               :description "this is the description"
                               :some-fk 1)))
      (setf (some-objects mobj) other)
      (clsql:update-records-from-instance mobj))))

;; (clsql:drop-view-from-class 'other-class)
;; (clsql:drop-view-from-class 'example-app)

;; 
;; (clsql:create-view-from-class 'example-app)
;; (clsql:create-view-from-class 'other-class)
;; (populate-db)


    
        


(defcomponent example-view (simple-window-component)
  ((db-obj :initarg :db-obj :reader db-obj)
   (tag :accessor tag :initarg :tag
        :component (text-field :size 20 :maxlength 20))
   (description :type string :accessor description :initarg :description
                :component (text-area-field :width 20 :height 10))
   (other :accessor other :component (text-field :size 20 :maxlength 20))))


(defun setup-db ()

  (clsql:enable-sql-reader-syntax))


;; (setup-db)

(defcomponent text (simple-window-component)
  ((view-text :initarg :view-text :reader view-text)
   (db-text :initarg :db-text :reader db-text)))
         
     

(defmethod render-on ((res response) (text text))
  (inspect text)
  (<:p "view data: "
       (<:as-is (view-text text)))
  (<:p "database data: "
       (<:as-is (db-text text))))

(defmethod init-view ((view example-view))
  (let ((db-obj (db-obj view)))
    
    (setf (some-objects db-obj) (car (clsql:select 'other-class 
                                                  :where [= [example-id] 1]
                                                  :flatp t)))
    ;; (inspect db-obj)
    (clsql:update-records-from-instance db-obj)
    (setf (ucw::client-value (tag view)) (tag db-obj)
          (ucw::client-value (description view)) (description db-obj )
          (ucw::client-value (other view )) (val (some-objects db-obj )))
    view))
  
   
    

(defmethod render-on ((res response) (view example-view))
  ;; this is not perfect but for the example it should be enough
  ;; (inspect view)
  (let ((controller (make-instance 'controller
                                   :view-obj (cells:c-in (init-view view)))))
    ;;(inspect controller)

    (<ucw:form :action (save-and-show-data view controller)
               (<:table 
                (<:tr
                 (<:td "tag")
                 (<:td "Description")
                 (<:td "Other text"))
                (<:tr
                 (<:td (render-on res (tag view)))
                 (<:td (render-on res (description view)))
                 (<:td (render-on res (other view)))))
               (<:p (<:input :type "submit" :value "Accept")))))


  
(defaction save-and-show-data ((view example-view) (controller controller))
  (print "in save-and-show-data" *error-output*)
  (inspect (view-obj controller))
  (inspect (db-obj controller))

  (call 'text :view-text (format nil "tag = ~a, descripton = ~a, other-text = ~a~%"
                                 (read-client-value (tag (view-obj controller)))
                                 (read-client-value (description (view-obj controller)))
                                 (read-client-value (other (view-obj controller))))
        :db-text (format nil "tag = ~a, descripton = ~a, other-text = ~a~%"
                         (tag (db-obj controller))
                         (description (db-obj controller))
                         (val (some-objects (db-obj controller))))))

  
          
    

(defun init-cells ()
  (clsql:enable-sql-reader-syntax)
  (cells:cell-reset))



(defentry-point "other.ucw" (:application *example-app*) ()
  (init-cells)
  (call 'example-view :db-obj (car (clsql:select 'example-app 
                                                 :where [= [id] 1]
                                                 :flatp t
                                                 :refresh t)))


I this a decent use of 'cells and is it cells-ish? 

Regards
Friedrich


From ktilton at nyc.rr.com  Mon Sep 12 20:01:34 2005
From: ktilton at nyc.rr.com (Kenny Tilton)
Date: Mon, 12 Sep 2005 16:01:34 -0400
Subject: [cells-devel] my very first baby steps with cells
In-Reply-To: <87mzmizkqd.fsf@flarge.here>
References: <871x3zg9mi.fsf@flarge.here> <43204B91.3010706@nyc.rr.com>
	<87ll26d9ue.fsf@flarge.here> <87slwazoz5.fsf@flarge.here>
	<87mzmizkqd.fsf@flarge.here>
Message-ID: <4325DE9E.1030802@nyc.rr.com>



Friedrich Dominicus wrote:

>I got it (probably ;-), would someone mind to comment on it?
>
>(in-package :qss.web)
>
>;; (use-package :cells)
>(eval-when (:compile-toplevel :execute)
>(defparameter *example-app*
>  (make-instance 'cookie-session-application
>                 :url-prefix "/ucw/examples/"
>                 :tal-generator (make-instance 'yaclml:file-system-generator
>                                               :cachep t
>                                               :root-directories (list *ucw-tal-root*))
>                 :www-roots (list *ucw-tal-root*))))
>
>;; (register-application *default-server* *example-app*)
>
>(cells:defmodel controller (cells:model)
>  ((view-obj :accessor view-obj :cell t 
>             :initarg :view-obj :initform (cells:c-in nil))
>
Later on in the render-on method you instantiate a controller thus:

   (make-instance 'controller
          :view-obj (cells:c-in (init-view view)))

But I do not see any place in the code where you SETF the view-obj slot, 
so you could just:

   (make-instance 'controller
          :view-obj (init-view view))

C-IN (or C-INPUT) is used only where, in brief, the application will be 
using SETF to change the value in a sempahoric slot. This is partly 
because a dataflow model needs to get the original dataflow from 
somewhere, usually from operating system events or a socket. One can 
also sometimes get simpler and more efficient code by skipping the 
declarative aspect (in which a slot like view-obj would have a rule) and 
just make the slot C-In and then setf that slot from output methods on 
on other slots. But like I said, that loses the advantages of a 
declarative approach.

Now in this case I further do not see view-obj getting involved in any 
cell-mediated dataflow, so I do not think it even needs to be a cell.

>   (db-obj :accessor db-obj :initarg :db-obj :cell t 
>           :initform (cells:c? (update-from-view cells:self)))))
>
The opening bit of update-from-view says:

    (unless (slot-value self  'db-obj)
        .....)

Actually, the c? macro offers any existing value as a read macro:

    (db-obj :accessor db-obj :initarg :db-obj :cell t 
           :initform (cells:c? (unless .cache.
                                  (update-from-view cells:self))))

...and then do not check for an existing slot-value in u-f-v. Now I do have rare occasion to write code like that, but the interesting thing here is that this rule only runs once, after which it would always return the same value. So there is no dataflow here, where one thing changes (by a SETF of some c-input) and then a bunch of other things get updated automatically in a cascade of rule evaluations.

Maybe I missed something. My first question, does this code work for you? If so, what are the things you see happening that tell you it work? Just give me a simple scenario, such as "I start by reading in this stuff. Then I change this description field, then I exit, and when I look at the DB I see the new description text." Provide the sample code and explain where necessary which code does which step. 

A big problem here is that I do not know SQL or cl-sql. For example, is a view just in-memory, or does it refer to a screen view? I know a relational view is just an abstraction built atop physical tables, so maybe you are just talking about that. Well, I do see:

    (defcomponent example-view (simple-window-component)
      ((db-obj :initarg :db-obj :reader db-obj)
       (tag :accessor tag :initarg :tag
        :component (text-field :size 20 :maxlength 20))
       (description :type string :accessor description :initarg :description
                :component (text-area-field :width 20 :height 10))
       (other :accessor other :component (text-field :size 20 :maxlength 20))))

...and that looks like a GUI view component. Maybe the term is used both ways? if you are updating a description field in a GUI view and then seeing it written back out to the DB, maybe you could lay out for me the code path by which that happens.


>I this a decent use of 'cells and is it cells-ish? 
>
Pending a better understanding of the above questions, as I said, I do 
not see Cells doing very much, and so I would be surprised if they help 
in this case. But let's see what your feedback is on the above.

kt





From frido at q-software-solutions.de  Tue Sep 13 06:50:56 2005
From: frido at q-software-solutions.de (Friedrich Dominicus)
Date: Tue, 13 Sep 2005 08:50:56 +0200
Subject: [cells-devel] my very first baby steps with cells
In-Reply-To: <4325DE9E.1030802@nyc.rr.com> (Kenny Tilton's message of "Mon,
	12 Sep 2005 16:01:34 -0400")
References: <871x3zg9mi.fsf@flarge.here> <43204B91.3010706@nyc.rr.com>
	<87ll26d9ue.fsf@flarge.here> <87slwazoz5.fsf@flarge.here>
	<87mzmizkqd.fsf@flarge.here> <4325DE9E.1030802@nyc.rr.com>
Message-ID: <87oe6xsbov.fsf@flarge.here>

Kenny Tilton <ktilton at nyc.rr.com> writes:

> Friedrich Dominicus wrote:
>
>>I got it (probably ;-), would someone mind to comment on it?

Thanks for your time. I try to explain my "convulted" way of getting
into celsl a bit ;-)

>
>    (make-instance 'controller
>           :view-obj (init-view view))
>
> C-IN (or C-INPUT) is used only where, in brief, the application will
> be using SETF to change the value in a sempahoric slot. This is partly
> because a dataflow model needs to get the original dataflow from
> somewhere, usually from operating system events or a socket. One can
> also sometimes get simpler and more efficient code by skipping the
> declarative aspect (in which a slot like view-obj would have a rule)
> and just make the slot C-In and then setf that slot from output
> methods on on other slots. But like I said, that loses the advantages
> of a declarative approach.
Well I read the explanations in 01-somwwhat and there I found if you
the slot hast to be setf-able you have to use c-in (in short, so I
wrote it that way.
>
> Now in this case I further do not see view-obj getting involved in any
> cell-mediated dataflow, so I do not think it even needs to be a cell.
>
>>   (db-obj :accessor db-obj :initarg :db-obj :cell t
>> :initform (cells:c? (update-from-view cells:self)))))
>>
> The opening bit of update-from-view says:
>
>     (unless (slot-value self  'db-obj)
>         .....)
>
> Actually, the c? macro offers any existing value as a read macro:
>
>     (db-obj :accessor db-obj :initarg :db-obj :cell t
>     :initform (cells:c? (unless .cache.
>                                   (update-from-view cells:self))))
>
I've seen the variable but was quite happy to find out the above way
;-)

> ...and then do not check for an existing slot-value in u-f-v. Now I
> do have rare occasion to write code like that, but the interesting
> thing here is that this rule only runs once, after which it would
> always return the same value. So there is no dataflow here, where one
>thing changes (by a SETF of some c-input) and then a bunch of other
> things get updated automatically in a cascade of rule evaluations. 

I do not understand that. If the view changes e.g if I use the back
button of my browser I'll be back to the old view. The data will get
filled from the then actual Database view, if I change something again
it will get propagated again from the View to the Backend. 
>
> Maybe I missed something. My first question, does this code work for
> you? If so, what are the things you see happening that tell you it
> work? Just give me a simple scenario, such as "I start by reading in
> this stuff. Then I change this description field, then I exit, and
> when I look at the DB I see the new description text." Provide the
> sample code and explain where necessary which code does which step.
See above, the back button of the browser makes it possible to return
to the view. 
>
> A big problem here is that I do not know SQL or cl-sql. For example, is a view just in-memory, or does it refer to a screen view? I know a relational view is just an abstraction built atop physical tables, so maybe you are just talking about that. Well, I do see:
>
>     (defcomponent example-view (simple-window-component)
>       ((db-obj :initarg :db-obj :reader db-obj)
>        (tag :accessor tag :initarg :tag
>         :component (text-field :size 20 :maxlength 20))
>        (description :type string :accessor description :initarg :description
>                 :component (text-area-field :width 20 :height 10))
>        (other :accessor other :component (text-field :size 20 :maxlength 20))))
>
> ...and that looks like a GUI view component. Maybe the term is used
> both ways? if you are updating a description field in a GUI view and
> then seeing it written back out to the DB, maybe you could lay out for
> me the code path by which that happens.
That is the view-component, I just included the db-obj to start the
whole thing, I see from you comments that I probably could add it
in the model and there the view-obj slot.
>
>
>> I this a decent use of 'cells and is it cells-ish?
>>
> Pending a better understanding of the above questions, as I said, I do
> not see Cells doing very much, and so I would be surprised if they
> help in this case. But let's see what your feedback is on the above.
Well Cells does the following for me here. I sketch the control-flow.
- the first things which is called is a view which shows two textfields
and one text area
- On the first run the view object should be filled with data from the
  backend
- so I got a view with the slots filled by database values
- Now I may change one, two or three fields. Aftar I send the form the
database should be updated, this is done by cells here.
- After that the content of both the view and the database are shown
- Now it happens that I found that I made a bug and hit Back on my
browser
- the browser will display me the first view again, but with the
changed database values
- I change them again hit submit and the stuff updates my Database
again.

Agreed, cells does not do much here, but it's to learn how to let
those objects interact. And for that it works quite nicely ;-)

Regards
Friedrich


From ktilton at nyc.rr.com  Tue Sep 13 18:04:58 2005
From: ktilton at nyc.rr.com (Kenny Tilton)
Date: Tue, 13 Sep 2005 14:04:58 -0400
Subject: [cells-devel] my very first baby steps with cells
In-Reply-To: <87oe6xsbov.fsf@flarge.here>
References: <871x3zg9mi.fsf@flarge.here> <43204B91.3010706@nyc.rr.com>
	<87ll26d9ue.fsf@flarge.here> <87slwazoz5.fsf@flarge.here>
	<87mzmizkqd.fsf@flarge.here> <4325DE9E.1030802@nyc.rr.com>
	<87oe6xsbov.fsf@flarge.here>
Message-ID: <432714CA.6050708@nyc.rr.com>



Friedrich Dominicus wrote:

>Kenny Tilton <ktilton at nyc.rr.com> writes:
>
>  
>
>>Friedrich Dominicus wrote:
>>
>>    
>>
>>>I got it (probably ;-), would someone mind to comment on it?
>>>      
>>>
>
>Thanks for your time. I try to explain my "convulted" way of getting
>into celsl a bit ;-)
>
>  
>
>>   (make-instance 'controller
>>          :view-obj (init-view view))
>>
>>C-IN (or C-INPUT) is used only where, in brief, the application will
>>be using SETF to change the value in a sempahoric slot. This is partly
>>because a dataflow model needs to get the original dataflow from
>>somewhere, usually from operating system events or a socket. One can
>>also sometimes get simpler and more efficient code by skipping the
>>declarative aspect (in which a slot like view-obj would have a rule)
>>and just make the slot C-In and then setf that slot from output
>>methods on on other slots. But like I said, that loses the advantages
>>of a declarative approach.
>>    
>>
>Well I read the explanations in 01-somwwhat and there I found if you
>the slot hast to be setf-able you have to use c-in (in short, so I
>wrote it that way.
>
I should have mentioned "...but I do not see any place in your code 
where you SETF view-obj". Did I miss it?

>  
>
>>Now in this case I further do not see view-obj getting involved in any
>>cell-mediated dataflow, so I do not think it even needs to be a cell.
>>
>>    
>>
>>>  (db-obj :accessor db-obj :initarg :db-obj :cell t
>>>:initform (cells:c? (update-from-view cells:self)))))
>>>
>>>      
>>>
>>The opening bit of update-from-view says:
>>
>>    (unless (slot-value self  'db-obj)
>>        .....)
>>
>>Actually, the c? macro offers any existing value as a read macro:
>>
>>    (db-obj :accessor db-obj :initarg :db-obj :cell t
>>    :initform (cells:c? (unless .cache.
>>                                  (update-from-view cells:self))))
>>
>>    
>>
>I've seen the variable but was quite happy to find out the above way
>;-)
>
That is fine if you do not mind "unsupported", ie, your code collapsing 
in a heap if Cells changes in some relevant way. the larger point is 
that, either way, after the second time this rule runs there will be no 
dependencies and the cell (and rule) will get optimized away. So I still 
do not see Cell-ish dataflow. That said,.....

>
>  
>
>>...and then do not check for an existing slot-value in u-f-v. Now I
>>do have rare occasion to write code like that, but the interesting
>>thing here is that this rule only runs once, after which it would
>>always return the same value. So there is no dataflow here, where one
>>thing changes (by a SETF of some c-input) and then a bunch of other
>>things get updated automatically in a cascade of rule evaluations. 
>>    
>>
>
>I do not understand that. If the view changes e.g if I use the back
>button of my browser I'll be back to the old view. The data will get
>filled from the then actual Database view, if I change something again
>it will get propagated again from the View to the Backend. 
>
I believe you! :) I just do not see the back button in the code or how 
this is working! I have a guess, though. I think somehow each time you 
are allocating all new instances, so the new cells / rules run once (the 
initial "awaken" pass started by TO-BE) and things show up nicely. Cells 
are all about long-lived state, where the same instance would survive 
back buttons and forward buttons and sideways buttons and still manage 
to stay current. That said <g>.......

>  
>
>>Maybe I missed something. My first question, does this code work for
>>you? If so, what are the things you see happening that tell you it
>>work? Just give me a simple scenario, such as "I start by reading in
>>this stuff. Then I change this description field, then I exit, and
>>when I look at the DB I see the new description text." Provide the
>>sample code and explain where necessary which code does which step.
>>    
>>
>See above, the back button of the browser makes it possible to return
>to the view. 
>  
>
>>A big problem here is that I do not know SQL or cl-sql. For example, is a view just in-memory, or does it refer to a screen view? I know a relational view is just an abstraction built atop physical tables, so maybe you are just talking about that. Well, I do see:
>>
>>    (defcomponent example-view (simple-window-component)
>>      ((db-obj :initarg :db-obj :reader db-obj)
>>       (tag :accessor tag :initarg :tag
>>        :component (text-field :size 20 :maxlength 20))
>>       (description :type string :accessor description :initarg :description
>>                :component (text-area-field :width 20 :height 10))
>>       (other :accessor other :component (text-field :size 20 :maxlength 20))))
>>
>>...and that looks like a GUI view component. Maybe the term is used
>>both ways? if you are updating a description field in a GUI view and
>>then seeing it written back out to the DB, maybe you could lay out for
>>me the code path by which that happens.
>>    
>>
>That is the view-component, I just included the db-obj to start the
>whole thing, I see from you comments that I probably could add it
>in the model and there the view-obj slot.
>  
>
>>    
>>
>>>I this a decent use of 'cells and is it cells-ish?
>>>
>>>      
>>>
>>Pending a better understanding of the above questions, as I said, I do
>>not see Cells doing very much, and so I would be surprised if they
>>help in this case. But let's see what your feedback is on the above.
>>    
>>
>Well Cells does the following for me here. I sketch the control-flow.
>- the first things which is called is a view which shows two textfields
>and one text area
>- On the first run the view object should be filled with data from the
>  backend
>- so I got a view with the slots filled by database values
>- Now I may change one, two or three fields. Aftar I send the form the
>database should be updated, this is done by cells here.
>- After that the content of both the view and the database are shown
>- Now it happens that I found that I made a bug and hit Back on my
>browser
>- the browser will display me the first view again, but with the
>changed database values
>- I change them again hit submit and the stuff updates my Database
>again.
>
>Agreed, cells does not do much here, but it's to learn how to let
>those objects interact. And for that it works quite nicely ;-)
>
I am going to go waaaaaaaaaaay out on a limb here and guess that the 
only thing Cells did was force you to structure things in a declarative 
way, or at least a nicely organized way, and that that itself is a big 
win. So it is not an issue of how long-lived is a model instance, or how 
many times a Cell rule runs, but how the data structures interact (as 
you said).

I have been doing Cells for ten years, but this is the first time I have 
encountered this. Interesting result. Thx.

-- 
Kenny

Why Lisp? http://wiki.alu.org/RtL_Highlight_Film

"I've wrestled with reality for 35 years, Doctor, and I'm happy to state I finally won out over it."
    Elwood P. Dowd, "Harvey", 1950





From enderx12 at mac.com  Wed Sep 21 18:38:32 2005
From: enderx12 at mac.com (Chris Curtis)
Date: Wed, 21 Sep 2005 14:38:32 -0400
Subject: [cells-devel] Cells/Cello+OpenMCL status?
Message-ID: <52A6156B-FD2D-4F26-9343-8E75CB1FF7CE@mac.com>

Hi all...

I'm just starting to take a look at cells and cello and am having  
some problems...

The first one is that loading :cells-test fails right after  
(CELLS::STARTING CELLS::TEST CELLS::MANY-USEDS) with "Array index 16  
out of bounds for #*1111111111111111 .", the call in question being  
(ccl::%sbitset #*1111111111111111 16 1).

Is there something I'm doing radically wrong here?

Cello also fails to load, but I figured I'd start with Cells and fix  
one thing at a time. :-)

Thanks,

--chris



From ktilton at nyc.rr.com  Wed Sep 21 21:21:31 2005
From: ktilton at nyc.rr.com (Kenny Tilton)
Date: Wed, 21 Sep 2005 17:21:31 -0400
Subject: [cells-devel] Cells/Cello+OpenMCL status?
In-Reply-To: <52A6156B-FD2D-4F26-9343-8E75CB1FF7CE@mac.com>
References: <52A6156B-FD2D-4F26-9343-8E75CB1FF7CE@mac.com>
Message-ID: <4331CEDB.1000803@nyc.rr.com>



Chris Curtis wrote:

> Hi all...
>
> I'm just starting to take a look at cells and cello and am having  
> some problems...
>
> The first one is that loading :cells-test fails right after  
> (CELLS::STARTING CELLS::TEST CELLS::MANY-USEDS) with "Array index 16  
> out of bounds for #*1111111111111111 .", the call in question being  
> (ccl::%sbitset #*1111111111111111 16 1). 

I will have to do some digging. FYI, that :cells-test stuff has not been 
maintained much, there is a test suite right in the Cells package. let 
me check up on all this and get back to you.

kenny

ps. Cello will be quite a challenge to build since it is still there for 
developers/porters/maintainers only. kt





From enderx12 at mac.com  Wed Sep 21 21:39:30 2005
From: enderx12 at mac.com (Chris Curtis)
Date: Wed, 21 Sep 2005 17:39:30 -0400
Subject: [cells-devel] Cells/Cello+OpenMCL status?
In-Reply-To: <4331CEDB.1000803@nyc.rr.com>
References: <52A6156B-FD2D-4F26-9343-8E75CB1FF7CE@mac.com>
	<4331CEDB.1000803@nyc.rr.com>
Message-ID: <988F346A-4537-4919-88D7-B11F023250A0@mac.com>


On Sep 21, 2005, at 5:21 PM, Kenny Tilton wrote:

>
>
> Chris Curtis wrote:
>
>
>> Hi all...
>>
>> I'm just starting to take a look at cells and cello and am having   
>> some problems...
>>
>> The first one is that loading :cells-test fails right after   
>> (CELLS::STARTING CELLS::TEST CELLS::MANY-USEDS) with "Array index  
>> 16  out of bounds for #*1111111111111111 .", the call in question  
>> being  (ccl::%sbitset #*1111111111111111 16 1).
>>
>
> I will have to do some digging. FYI, that :cells-test stuff has not  
> been maintained much, there is a test suite right in the Cells  
> package. let me check up on all this and get back to you.
>
> kenny
>
> ps. Cello will be quite a challenge to build since it is still  
> there for developers/porters/maintainers only. kt
>

Thanks for the quick response! I've been kind of wondering what the  
general status of both Cells & Cello are... they seem really quite  
interesting.

--chris



From tfb at OCF.Berkeley.EDU  Mon Sep 26 18:20:33 2005
From: tfb at OCF.Berkeley.EDU (Thomas F. Burdick)
Date: Mon, 26 Sep 2005 11:20:33 -0700
Subject: [cells-devel] Re: [cells-cvs] CVS update: cells/cells.lpr
	cells/fm-utilities.lisp cells/md-utilities.lisp 
In-Reply-To: <20050926150543.60EC088569@common-lisp.net>
References: <20050926150543.60EC088569@common-lisp.net>
Message-ID: <17208.15345.23013.780018@conquest.OCF.Berkeley.EDU>

Kenny Tilton writes:
 > +(defmacro defparts (partName (partClass &rest partDefArgs)
 > +                   &optional customArgs customValuesList
 > +                   &rest commonArgPairs)
 > +  (assert (null partDefArgs))
 > +  (let ((part-no (gensym))
 > +        (cvls (gensym)))
 > +    `(loop with ,cvls = (list , at customValuesList)
 > +           for ,part-no below ,(max 1 (length customValuesList))
 > +           for custom-values = (elt ,part-no cvs)
 > +           collecting (make-instance ',partClass
 > +                      :md-name ',partName
 > +                      ,@(loop for arg in customargs
 > +                              for n below (length customargs)
 > +                              nconcing (list arg `(elt ,n custom-values)))
 > +                      , at commonArgPairs))))

Hmm, not sure I get what this parts stuff is about.  Something interesting?

-- 
           /|_     .-----------------------.                        
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     ,--'    _,'   | Abolish the racist    |
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   |     ) |                               
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   `. )----'