[Zope3-Users] Re: Intended scope of viewlets?

Fri Oct 6 14:39:23 EDT 2006

I think I must be missing something about the way skins work now. I've
created a master page that I can load when I don't specify a skin, but
when I do specify a skin (++skin++MySkin), it is unable to find the
page (404). Here's a rough approximation of my ZCML:

<interface
    interface=".interfaces.MySkin"
    type="zope.publisher.interfaces.browser.IBrowserSkinType"
    name="MySkin"
    />

<browser:page
    name="my.project.index.html"
    for="*"
    class=".myskin.SimplePage"
    permission="zope.Public"
    />

<browser:template
    template="myskin_master.pt"
    for=".interfaces.ISimplePage"
    />

There's lots more, and if any of it would be relevant, let me know,
but this seems like it's the crucial part. I know it is finding the
skin itself successfully, because the error message is not the
standard Rotterdam one. The skin I'm using is currently just inherits
from z3c.layer.minimal.

I'll keep on trying things, but it's all kind of a shot in the dark right now.

Thanks,

Alec

On 10/6/06, Alec Munro <alecmunro at gmail.com> wrote:
> Hi Jürgen,
>
> So, just to give a concrete example for my case, I might replace this
> (Metal-based):
>
> <body>
>
> <div id="Navigation">
>   <div metal:define-slot="navigation">
>     Nav tree needs a wee bit of work.
>   </div>
> </div>
>
> <div id="Content">
>   <div metal:define-slot="body">
>    Some Content
>   </div>
> </div>
>
> </body>
>
> with this (viewlet-based):
>
> <body>
>
> <div id="Navigation">
>     <span tal:replace="structure provider:my.project.navigation">
>       Nav tree needs a wee bit of work.
>     </span>
> </div>
>
> <div id="Content">
>   <span tal:replace="structure provider:my.project.content">
>     Some Content
>   </span>
> </div>
>
> </body>
>
> With seperate viewlet managers for "navigation" and "content", or any
> other types of views I would expect to have on this page? Would a
> "header" viewlet manager also be sensible, say if I wanted a title
> that changed format depending on what type of content was being
> viewed?
>
> Finally, are there any best practices for packaging in viewlet-based
> templating? I'm currently creating this in my.project.browser.skin.
> How about the viewlet manager names, should they be my.project.*,
> my.project.browser.*, or something different?
>
> Probably some of these questions aren't relevant to the work you are
> doing on viewlets, but I find it helpful to try to follow industry
> practices as closely as possible, especially on something I don't have
> much experience with, so I am easily able to follow tutorials, and
> people who are helping me can more easily understand what I am trying
> to do.
>
> Thanks very much for your help so far, I am excited about implementing
> viewlets in our upcoming project.
>
> Alec
>
> On 10/5/06, Jürgen Kartnaller <juergen at kartnaller.at> wrote:
> > Hi Alec.
> >
> > Alec Munro wrote:
> > > Hi List,
> > >
> > > I'm just getting up to speed with viewlets, having read a thread here
> > > and there in the past about them. I've installed the examples provided
> > > on this list, and while I believe I understand how they work, I don't
> > > understand in what circumstances they are most useful. The viewlets in
> > > the examples are all very small, such as retrieving an formatting a
> > > single piece of information about an object. However, from some of the
> > > posts to this list, I get the impression they are also being used for
> > > more complex items, like navigation menus.
> >
> > Menus are a perfect example for the use of viewlets.
> > Have a look at z3c.menu. This package contains a base implementation for
> > menus based on viewlets.
> >
> > > Is there a recommended scope? Can they be described in a way such as
> > > "develop your templates up to point X, then use a viewlet for
> > > development of further depth?".
> > >
> > > In my case, I am developing a new skin for a project, and my
> > > experience with metal says to make the entire HTML page a macro with
> > > slots for content and navigation. Is there a comparable viewlet-based
> > > paradigm?
> >
> > Yes there is one, see below
> >
> > >
> > > Also, am I correct in stating that when working with viewlets, the
> > > only complete HTML page will be the primary skin file, with all
> > > viewlets based on snippets of HTML?
> >
> > Thats exacly what we at Lovely Systems do and it works perfectly :)
> >
> > We have one base template which is used for all pages. Instead of
> > defining slots to be filled by other templates it contains viewlet managers.
> > We then provide different view classes to be able to register our
> > viewlets for the pages of the application.
> > The view classes are empty classes they are just providing the class
> > name or if they provide additional functionality they also provide an
> > interface.
> > It is then possible to register the viewlets for specific pages.
> > The most important thing on viewlets is that they are adapters on the
> > *context*, the *request*, the *view* and the *manager*.
> >
> > The viewlet solution is an extremely productive way to implement a
> > complex application.
> >
> > Make sure you read this :
> > http://blogs.lovelysystems.com/srichter/2006/09/20/the-skin-browser-and-lovely-systems-new-development-workflow/
> >
> > Stephan Richter describes here our use of the viewlet concept and our
> > development workflow. The most important part was the development of the
> > package z3c.viewtemplate. This package makes it possible to separate the
> >   development of the HTML page from the implementation of the python
> > view class. The package is not yet perfect but gives us what we need
> > right now but it needs a better integration into forms and viewlets.
> > Expect more in the near future!
> >
> > In our applications really everything is done using viewlets, there is
> > no single use of fill-slot in the hole application!
> >
> > >
> > > My questions are fairly broad-ranging, I know, but I have thus far
> > > been unable to find a straightforward explanation of viewlets, in
> > > terms of how they relate to general site development.
> >
> > All I can tell you now is : USE VIEWLETS, USE VIEWLETS, USE VIEWLETS,
> >
> >
> > Jürgen
> >
> > _______________________________________________
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> > Zope3-users at zope.org
> > http://mail.zope.org/mailman/listinfo/zope3-users
> >
>