cells-devel June 2006

cells-devel@common-lisp.net

7 participants
18 discussions

[cells-devel] Small change
by Ken Tilton 10 Jun '06

10 Jun '06

I just modified md-slot-value-assume to test for "no news" just a wee bit sooner within the function. The regression test passes, as does Celtk's lotsa-widgets test. But I thought I would warn users in case they update from CVS soon. My concern is that I do not know why I had it so late in the past -- probably because the unnecessary actions taken were so inexpensive -- so maybe it was where it was for a reason. But as I said, all the tests pass as well as real-live Celtk code (which itself exercises Cells pretty well) so it looks OK. kt

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[cells-devel] Gmane archiving for cells-devel?
by Ken Tilton 10 Jun '06

10 Jun '06

I am not much up on this Gmane thingy, but apparently this list is headed that way (and this message exists just to trigger activation so i can be sure). kt

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[cells-devel] Re: Question about Cells; defobserver for both I and O
by Ken Tilton 09 Jun '06

09 Jun '06

Lars Rune Nøstdal wrote: > Hi Lispers, > Ok, starting to get the hang of this, but I'm having a small issue > maybe you guys could help me with. > > I'm playing with some AJAX-stuff and .. hm .. not sure how to explain > this proper, but .. Fair warning: I have never programmed a Web app, barely done anything with HTML, and understood almost nothing of what you wrote. :) But this (check me: input form field initialized from a database record field, then overwritten by user so data must flow the other way back to the DB?) happens all the time in standalone apps, so... > > I have an INPUT-element (HTML) that can be used for both input of data > (client-initiated) and output of data (server-initiated), and I'd like > to block the observer so it does not react on input from the client and > tries to re-update the element .. > > ..or maybe "blocking" the observer isn't right at all, maybe I'm going > about this the wrong way..? As I said, this comes up all the time, and what you tried is the tempting automatic flow: DB(existing value -> Input(as initial value) -> DB(new value) Your code is what I think about writing even after ten years of using Cells. So how do we break the cycle? There are several ways I have handled this. 1. In the slot definition, specify: (value ...etc... :unchanged-if 'string=) You will still make the return trip to set the input field unnecessarily, but that will be an NOP because the new value will be seen as unchanged, stopping propagation (including calling observers). The default test is EQL and it is easy in even simple code for 'string= but un-EQL strings to arise and start cycling. To avoid even the beginnings of a roundtrip, hey, have the observer take a peek at where it is about to write and decide if it needs to. Not as much fun as letting Cells worry about it, but this one observer (I gather) is handling all the HTML input fields, so...? Now I revert to my earlier disclaimer about being Web-ignorant: I think The Right Answer overall will be decided by the exact nature of the Web stuff, so I will just continue dumping alternatives 2. Does the DB flow to the form only when the form is opened? If so, the HTML input fields can have a something another Cells user just requested: a rule that runs once at initialization time and then becomes a /Cells/ input. ie, the slot starts as c-formula but then becomes c-input. (No dependencies are recorded during the initial rule invocation.) Only the HTML input field has an observer writing back to the corresponding DB field. Now if only cells had some frickin decent doc I could tell you the syntax. Maybe: (c-formula (:inputp t) <code to lookup value for this field>) If that is what you settle on and it does not work I will research further. 3. if you are in a multi-user environment or for any other reason need to update the form programmatically at the same time the user is typing, well, things will be pretty exciting for the user <g>, and it may be time to consider the failsafe: do not try to use Cells dataflow where the application really needs to decide the dataflow. An application flow will have to be concocted, hopefully facilitated by Cells, but always keep in mind that the functionality might dictate more savvy than the Cells changed/not-changed propagation smarts. hth, ken > Here is some code: > > > (defobserver value ((value-attribute ValueAttribute)) > (cells::trc "ValueAttribute changing from" old-value :to new-value) > (terpri) > ;; Update the value-attribute of the HTML-element on the client-side. > (setAttribute (parent-of value-attribute) > (name-of value-attribute) > "value" > (princ-to-string (value-of value-attribute)))) > > (defmethod onkeyup ((value-attribute ValueAttribute) (parent Container) > &rest event-args) > (format t "onkeyup: ~A~%" (fifth event-args)) > (setf (value-of value-attribute) > (first event-args))) > > > `onkeyup' is called from the client-side and since (setf value-of ..) > triggers the observer for the slot `value', it tries to "redraw" what's > already on the client-side. > -- Cells: http://common-lisp.net/project/cells/ "I'll say I'm losing my grip, and it feels terrific." -- Beaming husband to scowling life, New Yorker cartoon

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[cells-devel] Re: question about cells
by Ken Tilton 07 Jun '06

07 Jun '06

> > Hmm, maybe the error does not need to announce where it is in the source? > OK, I just committed code to produce this (we can continue refining if necessary, but I like this so wanted to get it in): Break: cellular slot STATUS of #<MOTOR> cannot be SETFed because it is not mediated by a Cell with :inputp t. To achieve this, the initial value :ON -- whether supplied as an :initform, :default-initarg, or at make-instance time via an :initarg -- should be wrapped in either macro C-IN or C-INPUT. In brief, initialize STATUS to (c-in :ON) instead of plain :ON Code: (unless c (c-break "cellular slot ~a of ~a cannot be SETFed because it is not mediated by a Cell with :inputp t. To achieve this, the initial value ~s -- whether supplied as an :initform, :default-initarg, or at make-instance time via an :initarg -- should be wrapped in either macro C-IN or C-INPUT. In brief, initialize ~0@*~a to (c-in ~2@*~s) instead of plain ~:*~s" slot-name self (slot-value self slot-name))) ken

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[cells-devel] Re: question about cells
by Ken Tilton 07 Jun '06

07 Jun '06

On 6/7/06, Lars Rune Nøstdal <larsnostdal(a)gmail.com> wrote: > > i keep getting this: > > (setf md-slot-value)> cellular slot value of #<InputText {B079EC9}> > cannot be setf unless initialized as inputp > > if i've understood this message correctly; it means that i'm trying to > setf a slot with `:initform (c? ...)' .. No, that should give you a different error saying you cannot SETF a /ruled/ slot, but I just checked to get the text of that error (and tested for it) and am rather astounded to see that that discipline is no longer enforced. I will have to investigate. :) The error you are getting means the slot has been initialized to some plain Lisp value such as NIL or "Hello world", without any Cell wrapper as one would get with c-in or c-input or any of the macros to generate ruled Cells. Which means.... but the slot i'm having > trouble with resides in a superclass of `InputText' and is defined > like this: > > .. > (value :accessor value-of :initarg :value > :initform (c-in "")) This initform (which is fine) has been overridden at make-instance time with something like: :value "Test" hth, kenny

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[cells-devel] Tiny patch
by Lars Rune Nøstdal 02 Jun '06

02 Jun '06

Hello, Just a tiny "patch"; the NIL (in uppercase) caused some troubles in `cells.lisp' for me when *readtable* is set to :invert. -(defparameter *client-queue-handler* NIL) +(defparameter *client-queue-handler* nil) -- Mvh, Lars Rune Nøstdal http://lars.nostdal.org/

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[cells-devel] Fwd: Just can't hear enough about Cells?
by Ken Tilton 01 Jun '06

01 Jun '06

---------- Forwarded message ---------- From: Anon <bsd1628(a)comcast.net> Date: Jun 1, 2006 4:03 PM Subject: Re: Just can't hear enough about Cells? To: Ken Tilton <kentilton(a)gmail.com> I'm getting a ton of garbage when trying to ASDF-INSTALL :cells What's going on? here follows: * (asdf-install:install :cells) Install where? 1) System-wide install: System in /usr/lib/sbcl/site-systems/ Files in /usr/lib/sbcl/site/ 2) Personal installation: System in /home/oper/.sbcl/systems/ Files in /home/oper/.sbcl/site/ --> 2 Downloading 74072 bytes from http://common-lisp.net/project/cells/asdf- install/cells_2.0.tar.gz ... debugger invoked on a ASDF-INSTALL::KEY-NOT-TRUSTED in thread #<THREAD "initial thread" {A687621}>: GPG warns that the key id 0xNIL () is not fully trusted Type HELP for debugger help, or (SB-EXT:QUIT) to exit from SBCL. restarts (invokable by number or by possibly-abbreviated name): 0: [CONTINUE ] Install the package anyway 1: [SKIP-GPG-CHECK] Don't check GPG signature for this package 2: [ABORT ] Exit debugger, returning to top level. (ASDF-INSTALL::VERIFY-GPG-SIGNATURE/STRING "-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 MÒwBcells_2.0.tarä\\[sÛF²Î«õ+¦èÚ];9Ê¦BKtÄ]YrIr×fë\"\"`0dû_~ ñ¯^~öêßû)UæØ²XÌi¡ÿìOdù¿ªùb7Õú_¾ÇþÁþþW/÷»pðå×¯^jþ¿üú+L ¹Oóþåtüü?çÿáá¡ ¸ZÆJàIÀHÓ¬XÊ\\\\Þ«B(r)Ä±\\Äi\\ÄY*Þ óYÝ QÄÅý(r)»_ÿ÷Öâ Å¬¼¹\\gy¡\"LçbÑRt.E$âN&Q¶#±Nd¨¤X q\"Á|EIÁâ;ú¥vÕb7Å·Øïuà%Å\"ÎU!eH¿¤Â4Kã(LÊÊ<Â,ç³ÐÖ¹T2-{=ýè4LÅÑ¥,¿aq:ZÅz´· ÝbsX×°Ø(r)ã`§{·±¼£çø¾ÇóÍÙûÖcº÷Y)²YÆ(c)ccàeë{±È³ÈúJ!%5hºü¸y,ÓH2\"ÏÊY \"E(c)âôZÄÅPàPàÄh âÒUx/îÂÈ¨MdQÈ\\ gÙ¡XeØ7(\"ne(r)èy0Çó,*W <SNIP> ã¤Â¥é ¡Ìãÿx6¿LöË=ªìSöD -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (Darwin) iD8DBQFD1qcfl2RwVlDQtPYRApX/AKCFgsrLXsv8FllEQ1YQtC2nYRZiHACcDkJY whE3bSaRgquYThmepNzfYVc= =Pacw -----END PGP SIGNATURE----- " #P"/home/oper/projects/db-project/order-entry/CELLS.asdf-install-tmp") 0] PuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuT TYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYP uTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTYPuTTY

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[cells-devel] Re: Just can't hear enough about Cells?
by Ken Tilton 01 Jun '06

01 Jun '06

On 6/1/06, Anon <bsd1628(a)comcast.net> wrote: > > > I'm getting a ton of garbage when trying > to ASDF-INSTALL :cells > What's going on? Sorry, I do not know anything about asdf-install. I forwarded your note separately to the cell-devel list. If you know of any asdf support list, I suggest you try that. Here is where you can just get the tarball: http://common-lisp.net/cgi-bin/viewcvs.cgi/cells/?root=cells kt

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cells-devel June 2006