February 2000 - Zope

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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dtml-in question
by Guy Davis 12 Feb '00

12 Feb '00

I am allowing the user to generate properties consisting of lines for a folder. I don't know the id of these properties at design time, but I can get them at run time. For example, a the name of a property called comps, is set into listVar by iterating through a master list. <dtml-call "REQUEST.set('listVar', _['sequence-item'])"> Note that I now have listVar = 'comps'. However, the user will actually have created a comps property previously and I want to iterate through it. <dtml-in comps> How can I do this if I have the name stored as a string in listVar. What should the <dtml-in> tag look like? Thanks. -- Guy Davis mailto:davis@arc.ab.ca (403) 210-5334 Alberta Research Council

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Stupid User Access Question
by James W. Howe 12 Feb '00

12 Feb '00

I have some confusion over how to build a web site in Zope which allows people to access the site either as a "normal" web site, or to access it for the purpose of maintenance. An example of this might be something like zope.org. I can visit www.zope.org and never be prompted for a password. I can visit all "public" sections without seeing a prompt. Yet I know that there is a management interface underneath. How is this handled? Another thing I would like to do (I think) is establish a "registered" user type. A registered user would be able to see more content than just the home page. When an attempt is made to access a "registered user" page by an unregistered user, I want to display a login page rather than a basic auth dialog. Can I do something like this with a Generic User Folder? Thanks James W. Howe mailto:jwh@allencreek.com Allen Creek Software, Inc. pgpkey: http://ic.net/~jwh/pgpkey.html Ann Arbor, MI 48103

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Re: [Zope] URL Substitution.
by Alexandre A. Rodioukov 12 Feb '00

12 Feb '00

Ok, I'm posting followup to my one posting :) What I did, I finally decided to write external method. Here follows the code: [ http_fetch.py ] def fetch_file(uri): from httplib import HTTP from urlparse import urlparse parsed_uri=urlparse(uri) h = HTTP(parsed_uri[1]) h.putrequest('GET', parsed_uri[2]) h.putheader('Accept', 'text/html') h.putheader('Accept', 'text/plain') h.endheaders() errcode, errmsg, headers = h.getreply() if errcode == 200: f = h.getfile() return f.read() [EOF] While calling you need to pass argument(uri) taht points to document you want to fetch. Works fine for me :) Hope that would be useful. Comments and suggestions are always very welcome to simuran(a)home.com With best regards, Alexandre.

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Re: DCOracle
by Chris McDonough 11 Feb '00

11 Feb '00

Amir, I am forarding this to the Zope mailing list (zope(a)zope.org) as I personally don't know the answer to your question, but there's a heck of a lot more folks on the list than in the office. Thanks! Amir Bakhtiar wrote: > > First of all, thanks for your hard work in DCOracle. > > We are running your software on Redhat 6.1 and Oracle 8i. > > I have noticed that each python process that imports ocidb grows form > around 3-4M to around 18 megabytes (according to top). > I was hoping that the library could be shared and that not every > process that needs oracle access would take up 18M. This obviously > creates some scaling problems. > > Is there some way of getting many python processes to share one > instance of the Oracle library? > > TIA, > -A- > > > www.neomeo.com -- Chris McDonough Digital Creations, Inc. Zope - http://www.zope.org

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Re: [Zope] Database transaction (follow up)
by Anthony Baxter 11 Feb '00

11 Feb '00

>>> Matt Goodall wrote > > When adding to a database table I need to calculate the next number from > > the existing records, increment that number and add the new record using > > the calculated number. What database are you using? Does it support sequences? identity columns? that's what they're for :)

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