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RE: [Zope] removing objects from database
by Martijn Pieters 12 Feb '00

12 Feb '00

From: Terry Kerr [mailto:terry@adroitnet.com.au] > Is there any way that objects can be removed in such a way from the > ZOPDB that the removal can never be 'undone'. Ie, packing > the DB after > the removal would give this effect, except that I don't want > to have to > pack every time I remove an object, and I only want to stop > retieval of > certain objects that are deleted. Yes, by undoing their creation. Undo cannot be undone. -- Martijn Pieters, Software Engineer | Digital Creations http://www.digicool.com | Creators of Zope http://www.zope.org | mailto:mj@digicool.com ICQ: 4532236 | PGP: http://wwwkeys.nl.pgp.net:11371/pks/lookup?op=get&search=0xA8A32149 -------------------------------------------

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ZServer Ports
by Chris Best 12 Feb '00

12 Feb '00

Hi I've installed Zope on a Linux server and got it to work on port 8080. The problem is that to get to the Zope site the user has the type http://www.???.com:8080 when I really want them to type in just the url without the port. The installation uses Redhat Linux 6.1 and has the Apache Server running on Port 80 and ZServer running on port 8080. I need to keep Apache on the system to run other sites not using Zope. Does anyone know how to do this? Thanks in advance Chris

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RE: [Zope] Odd behaviour while searching in the namepsace
by Martijn Pieters 12 Feb '00

12 Feb '00

From: Evan Simpson [mailto:evan@digicool.com] > > How do I use the (r)strip function in an expression like <dtml-if > > "_.has_key(mwid)">. > > You can <dtml-if expr="_.has_key(string.strip(mwid))"> and <dtml-var > expr="_[string.strip(mwid)].tag()"> Make that <dtml-if expr="_.has_key(_.string.strip(mwid))"> and <dtml-var expr="_[_.string.strip(mwid)].tag()"> -- Martijn Pieters, Software Engineer | Digital Creations http://www.digicool.com | Creators of Zope http://www.zope.org | mailto:mj@digicool.com ICQ: 4532236 | PGP: http://wwwkeys.nl.pgp.net:11371/pks/lookup?op=get&search=0xA8A32149 -------------------------------------------

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Re: selection list confusion ...
by Darran Edmundson 12 Feb '00

12 Feb '00

Re using a DTML method as the value for a property of type "selection", I apologize for not reading AlexR's How-To (http://www.zope.org/Members/AlexR/SelectionLists) in its entirety. Alex gives an example of building up the list from scratch. In my case, the list is a property of my globals folder which lives under the root so the DTML method should be simply: <dtml-with globals><dtml-return Choices></dtml-with> rather than <dtml-with globals><dtml-var Choices></dtml-with> as the latter gives a string rather than a python list. I'm still looking for a way of referencing globals.Choices directly without having to write this root-level method ... Cheers, Darran.

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Uploading image files via forms ...
by Darran Edmundson 12 Feb '00

12 Feb '00

Imagine a ZClass that can optionally contain an image. You'll probably have something like the following in your addForm method: <INPUT TYPE="file" NAME="newimage" VALUE=""> In your ZClass add constructor, after the new instance is created, we want to (conditionally) create the image only if a file was chosen. How? A piece of code like the following doesn't work: <dtml-if newimage> <dtml-call "manage_addImage('id', newimage.read(), '')"> </dtml-if> When no file is chosen, Zope still creates an image (size 0) because REQUEST.newimage is defined (albeit empty). I immediately tried <dtml-if "_.len(_.str(newimage)) !=0"> <dtml-call "manage_addImage('id', newimage.read(), '')"> </dtml-if> but this still creates a size 0 image. Why? Well, there's yet another possible way out of this mess as documented in the How-to "http://www.zope.org/Members/Zen/howto/FormVariableTypes" <INPUT TYPE="file" NAME="newimage:string:ignore_empty" VALUE=""> with <dtml-if "newimage !=''"> <dtml-call "manage_addImage('id', newimage, '')"> </dtml-if> (Note, the string typecast is necessary or else ignore_empty seems to have no effect.) This works in that not choosing a file stops the image from getting created and an image does get created if one was chosen. The problem now is that the string typecast has lost the content_type of the uploaded image. If it was "image/gif", it now shows up as a raw octet_stream. If anyone can provide a way out of this morass, I'd greatly appreciate it. Cheers, Darran "veteran newbie" Edmundson

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Re: SQLSession problem
by Anthony Baxter 12 Feb '00

12 Feb '00

>>> Jochen Haeberle wrote > Hi, > > I am stuck with Anthonys SQlSession. I followed the HowTo on Using > SQLSession by Miklos, trying to avoid the typos (too many > "Session"/"Sessions", Miklos :-) and got set up using Gadfly. But > after adding about 4 items to the list I get a Traceback: > > Error Type: LexTokenError > Error Value: Lexical token not found near :: "w',\012 'bah',\012 > "*"'KGxwMQpTJ2RmZ2" looks like the gadfly newline-in-string thing again. Go to the properties of your SQLSession object and change the encoding from base64 to base64oneline. This removes the newlines from the base64 strings. Or else search the zope-list archives for the patch for gadfly (it's been posted multiple times, last time was about a week ago). Anthony

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selection list confusion ...
by Darran Edmundson 12 Feb '00

12 Feb '00

Go to any property sheet and an explanatory blurb appears which ends with an explanation of selection variables: For "selection" and "multiple selection" properties enter the name of a selection variable in the "Value" field. The selection variable is a property or method that returns a list of strings from which the selection(s) can be chosen. Grabbing the list from an acquired property (call it "Choices") of type "lines" works but I'm having two difficulties. 1) As per suggestions, I have created a "globals" folder in my zope root to which I have added a number of needed properties, including Choices. (Previously I had set these properties in the root which cannot be easily moved to another Zope site.) Is it possible to reference Choices in the value field of a selection box property? 2) I created a simple root level DTML method GetChoices to return a list of strings: <dtml-with globals><dtml-var Choices></dtml-with> Rendering this method yields: ['choice1','choice2','choice3'] but looks like a python list but obviously Zope feels differently when GetChoices is used as the value field when trying to add a selection property: Zope Error Zope has encountered an error while publishing this resource. Error Type: InError Error Value: Strings are not allowed as input to the in tag. Method 2 is less than optimal because it means I need to clutter up my root with these one-line methods that simply return a list of choices for a single selection box. I'd rather be able to reference a property in the globals folder. That said, for future reference I would like to know how to write a selectionlist method. As always, any help is much appreciated. Cheers, Darran.

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Re: [Zope] Zope and Polymorphism
by Tres Seaver 12 Feb '00

12 Feb '00

Ingo Assenmacher <ingo.assenmacher(a)post.rwth-aachen.de> wrote: > > Hi Rik. > > Am 09-Feb-00 schrieb Rik Hoekstra: > > >> Thats really ugly having to know the distingishing method names. > >> Isn't there some method like > >> _.inheritsfrom(_['sequence-item'],'Folder') > >> > > > > This doesn't look very nice to me... > > No, it does not... but it would come in handy... :) > > > You could test whether an object was 'Folderish', but at the moment I > > have neither a clue how to do it ;-\ nor the time to sort it out ;-( > > > > That is ok. Knowing that an object is 'Folderish' would be enough of a clue for > example to provide a standarised image for a folder object within a tree. > > > but you can give objectValues more arguments (the argument _is_ a list). > > So that would mean in this case > > > > <dtml-in "objectValues(['Folder', > > 'UploadFolder',AnyOtherMetatypeYouCanThinkOf, ...])"> > > [bla] > > </dtml-in> > > > > Note that this can include any metatype you want, not just folders or > > 'folderish' objects. If you want you can filter them further using their > > attributes, properties or whatever. > > That is of course right. But let me point out a little example I have in mind: > > Right now I am constructing a container object to which arbitrary files can be > uploaded and it is then dislplayed within a table. For that purpose I created a > container object which can contain very general "document objects". To those I > provided some basic information which must be included into every upload > (description, timestamp and who-did-the-upload stuff). I thought it would be > nice to derive some objects from this baseclass (dokument) which can have more > properties (keywords, references etc.). On an abstract level I basically want > to do the same with these objects: display them (plus properties) in a table. > This could generally be done by method overloading. Ok so far. Since it could > be possible to mix several dokument-sub classes in one container it would be > very nice NOT to name the items to be enumerated explicitly (like providing > more arguments to the objectValues method). Right now I could use the "feature" > of polymorphism very much. That was what raised my question. > If there is no such thing a polymorphism... well I can live with that and do > some workarounds. After all it would "only" be very comfortable to simply do > method overloading and let Zope call the right method. This would enable a > single declaration of > > <dtml-in "objectValues(['Dokument'])"> > [display data here, even from derived objects] > </dtml-in> > > instead of adjusting the parameter with every new sub-class of Dokument. > > Regards, Ingo Or, as an alternative, we could extend the <dtml-in> tag to pass in a filter expression as an additional argument:: <dtml-in name=objectValues filter="self.hasMetaType( 'Document' )"> The implementation would likely need to construct a Python code object by synthesizing a function around the expression (or else we could expose lambda to DTML :). Tres. -- ========================================================= Tres Seaver tseaver(a)palladion.com 713-523-6582 Palladion Software http://www.palladion.com

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Precondition for file
by Jim Sanford 12 Feb '00

12 Feb '00

What is the purpose of the precondition entry for a file object and how do I use it? I can't seem to find any reference toit in any of the documentation. Jim Sanford

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Odd behaviour while searching in the namepsace
by H.G.J. van der Linde 12 Feb '00

12 Feb '00

Hi, Tres Seaver (thanks) gave me the following code to lookup a photo in the namespace based on a value from a field (mwid) in a database. <dtml-with psychologie> <dtml-with mwfoto> <dtml-if "_.has_key(mwid)"> <dtml-var "_[mwid].tag()"> <dtml-else> <dtml-var "geenfoto.tag()"> </dtml-if> </dtml-with> </dtml-with> This should work but it doesn't. This however works (replacing mwid by a fixed value). <dtml-with psychologie> <dtml-with mwfoto> <dtml-if "_.has_key('linde')"> <dtml-var "_['linde'].tag()"> <dtml-else> <dtml-var "geenfoto.tag()"> </dtml-if> </dtml-with> </dtml-with> I found out that using mwid with <dtml-if "_.has_key(mwid)"> <dtml-var "_[mwid].tag()"> one space is added to mwid, so I get 'linde '. This space is not in the database, or generated by the database, I guess, because this works fine: <img src="/psychologie/mwfoto/<dtml-var mwid>" align="right"> So what is happening here? How do I use the (r)strip function in an expression like <dtml-if "_.has_key(mwid)">. Your help is much apreciated. Henny van der Linde Leiden University Netherlands linde(a)fsw.leidenuniv.nl

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