RE: [Zope] icons not in init.py

5 Oct 2001

      Thank you. That worked perfectly for me!

 --- Brian Lloyd <brian.lloyd@zope.com> wrote: > >
When stating which icon to use for a python
...
product you do that
...
like this in __init__.py
icon="event.gif"
But what about subclasses which are object on
their own? They 
don't use the initialize() method.
I have tried:
class SubClassObject(ObjectManager, etc):
        meta_type='Event'
        icon='event.gif'
where event.gif is a valid gif next to the .py
file I write this in.
That didn't work!
So, I have also tried:
icon="misc_/MyProduct/event.gif"  and 
icon="misc_/MyProduct/event"
and
  icon="/misc_/MyProduct/event.gif"  and 
icon="/misc_/MyProduct/event"
Nothing has worked?
Zope 2.4.0
What's the trick?
[ Brian's product development tip-o-the-day :) ]
Sorry for the long inclusion above, but I thought it
will be 
useful one day to have the context when someone
searches the 
mailing list for the answer to this...
The "normal" way that icons get associated with
classes is 
somewhat opaque:
(in an __init__.py):
context.registerClass(
        instance_class = MyModule.MyClass,
        meta_type      = 'My Object',
        permission     = 'Add My Objects',
        constructors   = MyModule.constructors,
        icon           = 'www/MyClass.gif'
      )
The 'registerClass' helper automatically sets up
your icon. It 
can do that because it gets and / or knows:
o the class object
o the relative path to the file you want to use
for
    the icon ('www/MyClass.gif')
o the package that is being registered
So what it does is:
o creates an ImageFile object (the ImageFile class
is located 
    in the App.ImageFile module)
o adds the ImageFile instance to a special place
where 
    miscellanous static web-accessible resources for
use 
    by products are kept
o adds an 'icon' attribute to the class being
registered 
    whose value is the url to the ImageFile instance
This is the 'misc_' funny business you see in icon
urls. The
'misc_' object is a child of the root Zope object.
When 
a product is initialized, a generic container is
created in 
misc_, named after the product being initialized.
registerClass
does a setattr on the generic container for the
product, making 
the ImageFile instance available through traversal
as 
/misc_/ProductName/filename.
(Note that these things are set as class attributes
rather than 
instance attributes, so they are not persistent and
go away at 
shutdown, and are rebuilt at the next startup).
So... to set up an icon for an object that is not
registered 
using registerClass, we just need to change the
__init__.py 
to create ImageFiles for the extra icons we need,
add those 
ImageFile instances to the container for our product
in 
misc_, and add appropriate 'icon' attributes to our
classes 
whose values are url paths to the appropriate
ImageFiles.
(in __init__.py)
def initialize(context):
    # standard registration for MyClass, which is a
normal
    # through-the-web creatable object. Note that
after
    # registering MyClass, we call our registerIcon
helper 
    # function to register icons for MyOtherClass1
and MyOtherClass2,
    # which are not directly registered using
registerClass.
context.registerClass(
        instance_class = MyModule.MyClass,
        meta_type      = 'My Object',
        permission     = 'Add My Objects',
        constructors   = MyModule.constructors,
        icon           = 'www/MyClass.gif'
      )
registerIcon('MyOtherClass1.gif')
    registerIcon('MyOtherClass2.gif')
import OFS, App
def registerIcon(filename):
    # A helper function that takes an image filename
(assumed
    # to live in a 'www' subdirectory of this
package). It 
    # creates an ImageFile instance and adds it as
an attribute
    # of misc_.MyPackage of the zope application
object (note
    # that misc_.MyPackage has already been created
by the product
    # initialization machinery by the time
registerIcon is called).
setattr(OFS.misc_.misc_.MyPackage, 
            filename, 
            App.ImageFile.ImageFile('www/%s' %
filename, globals())
            )
Now we just need to add 'icon' attributes to our
'Other' classes:
(in MyModule.py)
class MyOtherClass1:
icon = 'misc_/MyProduct/MyOtherClass1.gif'
  ...
class MyOtherClass2:
icon = 'misc_/MyProduct/MyOtherClass2.gif'
  ...
Hope this helps!
Brian Lloyd        brian@zope.com
Software Engineer  540.361.1716       
Zope Corporation   http://www.zope.com
=====
peter_bengtsson_temporary@yahoo.co.uk is a temporary address that
I use to send until I get my email stuff together.
You can always continue to send to my real address which is 
mail@peterbe.com

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RE: [Zope] icons not in __init__.py

Peter Bengtsson

RE: [Zope] icons not in init.py