[Zope] Exporting zodb data (Urgent)
Sukhwinder Singh
ssruprai@hotmail.com
Tue, 1 Jul 2003 11:55:14 -0700
Under Control_Panel/Products/School.
There are classes for each of the object I want to export. Like Students,
Employees. Their icons are rectangles with lines in them.
Tooltip show Z Class for them.
Now with this information how do I export data from these classes by
installing just one script in root folder. This script should discover all
field names dynamically and then create csv file containing all records. Is
it possible now?
--Sukhwinder SIngh
----- Original Message -----
From: "Paul Winkler" <pw_lists@slinkp.com>
To: <zope@zope.org>
Sent: Monday, June 30, 2003 1:13 PM
Subject: Re: [Zope] Exporting zodb data (Urgent)
> On Tue, Jul 01, 2003 at 12:04:11AM +0530, Sukhwinder Singh wrote:
> > The main "/" (root) folder of the application, under which all other
files
> > are stored shows a tooltip of "Ffolder w/Customizer support".
> (snip)
>
> > The objects I am talking about, like employees and students, are shown
with
> > specialist icons( Icon of a person sitting on a desk). What this means?
What
> > kind of objects these are?
>
> OK, it appears from these statements that our earlier guesses were wrong.
> Your application is in fact built with some additional zope Products.
> I don't recognize icons by that description, I am guessing the Products
> were created specifically for this project.
>
> When you point at an icon in the ZMI, you normally get a tooltip showing
> the meta_type of the Product. This identifies the product. You have
> a folder of type "Folder w/Customizer Support"; what about these
person-at-
> desk icons? what tooltip do you get for those?
>
> When you know the meta_type of the product, go to the zope root, click on
> Control Panel, then click on Product Management. There should be items
there
> with similar names to what you see in the tooltips.
> You might even want to paste the whole list in a message here - we're
familiar
> with the standard products, we could then guess which ones look like they
were
> added for your application.
>
> When you know which products are relevant to your needs, look at the
little
> blue box icon next to them in the Product Management list.
> Most of the little blue boxes look "closed" (there is just a small little
> thing sticking up off the top of the box... don't ask me what that is
> supposed to represent!).
>
> Do the icons for your products look like all the others, or are they
> clearly different - looking like an open box with the lid sticking off to
> the left?
>
> Let us know which and we'll proceed from there.
>
> > When I click these objects (for example, employee) and check their
> > properties, no property is defined.
>
> OK, I was wrong about that, sorry. It's hard to guess how somebody
> built an application when you can't even see it :-)
>
> > But under these objects their are dtml
> > methods, python scripts and other dtml files. Some external methods were
> > added by
> > earlier programmer under these folder/objects to export data from each
of
> > these
> > objects (specialists). But I don't know how he determined attributes of
> > these objects (like employee.id, employee.is_operator) etc.
> >
> > These external methods in each specialist call a scipt like this to
export
> > data:
> >
> > /////////////////////////////////////////////////////////////////
> > def list_all_employees(self):
> > self.REQUEST.RESPONSE.setHeader('Content-Type','text/csv')
> > start_time=DateTime()
> > container=self
>
> ah I see, that's how "container" got into the External Method.
> I was wondering about that...
>
> > result=[]
> > r=""
> > q=""
> > e_id=""
> > e_name=""
> > e_isop=""
> > e_surname=""
> >
> > employees=container.Catalog()
>
> ok, this application DOES use ZCatalog.
> (At least, I am assuming that container.Catalog is an instance
> of ZCatalog). I wonder why the heck it's slow. That's not normal.
>
> > for employee in employees:
> > e_name = employee.name
> (snip)
>
> OK, you are not actually iterating over objects in the folder.
> You are iterating over catalog search results. Each search result
> contains information about an object - but it is not identical with the
> object. This means that in order for you to use an attribute of
> a result object, the catalog must be configured to keep this data
> about this object. This is done on the Metadata tab of the catalog
> instance.
>
> So, go to one of these Catalogs, click on it, then click the
> Metadata tab. You should see that there is a Metadata entry for
> all the attributes that are accessed in the external method.
>
> > e_id = employee.id
> > e_isop = "%s" % (employee.is_operator)
> > e_surname = employee.surname
> > q+=e_id+"#"+e_isop+"#"+e_name+"#"+e_surname+"\n"
> >
> > return q
> >
>
> I wonder if there's a lot of stuff like this in the application.
> String concatenation is O(N**2) in python, and this script
> is potentially doing it a LOT depending on the size of the catalog
> results. It's much faster to build a list, and then join the list
> elements once at the end. List appends and string joins are O(N).
>
> But as I said before, I can't actually tell if that's the cause for
> the slowness without profiling the app.
>
> > But problem is that he had to add these external methods under each of
these
> > object himself to export data.
>
> certainly not! for that kind of job, acquisition is your friend.
> You could have one external method that calls several functions,
> one for each kind of data to export (employees, etc.), much like
> you have now. Put the external method at the top of the application
> folder tree.
>
> Now, it sounds like for some reason you have multiple catalogs, though
> I'm not sure of this. Is there one Catalog for Employees, one for
> Students, etc.? If so, each function would look something like:
>
> def extract_employees(self):
> catalog = self.path.to.where.the.catalog.lives.Catalog
> results = []
> for emp in catalog():
> e_id = employee.id
> ... etc ...
> results.append("%s#%s#%s#%s" % (e_id, e_isop, e_name, e_surname))
>
> # now join the list elements with newlines
> return "\n".join(results)
>
>
> > Also how did he determine, whether there was
> > an attribute "employee.is_operator" and names of other attributes?
>
> He probably looked at the employee Product. We're getting there...
>
> --
>
> Paul Winkler
> http://www.slinkp.com
> Look! Up in the sky! It's UNDER-PEAR OF THE DEEP!
> (random hero from isometric.spaceninja.com)
>
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