Forum OpenACS Development: XoWiki 0.36

Changes in XoWiki 0.36 (relative to 0.35) and in XOTcl Core 0.43 (relative to 0.42) XOTcl Request Monitor 0.38 (relative to 0.37)

• Implementation Issue: Specification of evaluation contexts

  xotcl-core contains new classes ::xo::Context and ::xo::ConnectionContext to define the evaluation context for webpages or included matters. Evaluation contexts are somewhat similar to an activation record in programming languages. They combine the parameter declaration (e.g. of a page, an includelet) with the actual parameters (specified in an includelet) and the provided query values (from the url). The parameter declaration are actually implemented via XOTcl's non positional arguments and use their syntax and semantics. The connection context is a context with user and url-specific information

  The contexts are used in XoWiki 0.36 via Package initialize ... similar to page_contracts and they are used as well included content (includelets and for including XoWiki pages in other applications), and used for per-connection caching as well. They are used as well in the xotcl-request monitor. For the simplified inclusion of XoWiki pages in other applications see xowiki/lib/view.tcl. The including page needs essentially:

  <include src="/packages/xowiki/lib/view" url="/xowiki/en/index">

  The intention is of the connection context is similar as with ad_conn, but based on objects and integrated with calling conventions.

  So far, it is pretty simple, but should get more clever in the future. The idea is to allow better testing scripts, which are independent of connection information from the aolserver (ns_conn). We are not there yet, but we are getting closer. Another idea is to use lazy (or demand-driven) initialization, but this will require a new XOTcl release.

• Prototypes

  XoWiki 0.36 supports the concept of a prototypes. XoWiki prototypes are objects (any kind of XoWiki pages) which are available in a directory (named .../prototypes) and available in every XoWiki instance. when a prototype is called, it is instantiated and added to the list of pages of a folder. Whenever it is updated, new revision add added to the content repository. However, the original prototype on disk does not change and can be tailored for other applications in maybe different ways. This is somewhat similar to prototype based languages such as self, where new objects are created through cloning and modified as needed.

  Here are a few examples of prototypes:

  a) A sample index page of type ::xowiki::Page with the Title "Index Page":

  ::xowiki::Page new -title "Index Page" -text {

  <p>This is the default start page of XoWiki. You can edit this page and
  save it to provide a personalized look of the XoWiki instance......</p>
  >>left-col<<
  {{recent -max_entries 25}}
  >><<
  >>right-col<<
  {{last-visited -title "Last Visited" -max_entries 10 }}
  <br>
  {{most-popular -title "Most Popular" -max_entries 10 }}
  >><<
}


  b) A sample object page with active content:

  ::xowiki::Object new -title "CGI" -text {

   proc content {} {
   return "Hello World. It is now [clock format [clock seconds]]."
   }

}

  The following prototypes are included in XoWiki 0.36:

  • ./www/prototypes/ajax-chat.page
  • ./www/prototypes/categories-portlet.page
  • ./www/prototypes/CGI.page
  • ./www/prototypes/CGI2.page
  • ./www/prototypes/CGI3.page
  • ./www/prototypes/index.page
  • ./www/prototypes/weblog-portlet.page
  • ./www/prototypes/weblog.page
  
  

• Direct includes of computed HTML chunks

  XoWiki 0.36 supports in addition to the adp includes a light-weight means for including content in pages. With the syntax for included matters (double braces) one can either include different XoWiki pages or instances of the portlets classes ::xowiki::Portlet; when these are evaluated, their occurrences are replaced with the computed HTML content. These includelets can be parameterized with the usual non-positional argument syntax. In the example above, recent, last-visited and most-popular are such instances.

  The old, adp-style includelets are still in the package, but are deprecated and with be removed in the future.

• Weblog and Categories

  The weblog includelet is now configurable to much higher degree. It is now possible to define from the prototype page different kinds of listings by redefining the templates for weblog entries and the whole weblog. The prototype page is called weblog-portlet. The prototype for the full weblog application (with weblog-calender, private and public tags and categories) is still called weblog.

  The filtering options of the weblog-portlet allow now as well filtering for multiple criteria to show e.g. only those entries, which are assigned to two categories (such as XOTcl and introduction).

  Similarly, the categories includelet allows to specify to show only entries which must not be assigned to certain categories. One can specify now, list the categories for a certain category (e.g. XOTcl) but not those in e.g. introduction and testing.

  The combination of the weblog and categories portlets allow to develop different kind of applications (e.g. a news management for different kind of news entries) with little or no programming effort.

  I have not solved the problem with (indirect) recursive nesting yet. For the time being the weblog does not show pages with page names containing "weblog". If an xowiki instance needs multiple weblog views their names (not titles) should include "weblog".s

• Security Management:

  XoWiki allows now the specification of site wide admin (swa) in security policies. This means, that only site wide admins are allowed to execute some commands. Links leading to these functions will only appear for site wide admins.

  Furthermore there is a new package parameter: security_policy. A package administrator can switch now between two policies (::xowiki::policy1 and ::xowiki::policy2).

  Policy1 requires for all destructive operations (deletes, delete_revision) and programmatical operations (involving Tcl code, e.g. editing the ::xotcl::Objects) package admin rights, for re-index site wide admin right). Policy 2 requires also for destructive operations site wide admin rights.

• Database Interaction Improvements

  The new XOTcl method db_1row runs in the scope of an XOTcl object. That means that the output variables are directly added as instance variables of the specified object.

  The generic content repository classes got extended by a faster method to get a bag of objects out of the database. This is convenient to avoid to run out of database pools for nested db_foreach. The new method instantiate_objects is used in the weblog implementation and can be used like: set answer_set [::xowiki::Page instantiate_objects -sql "select ... from ..."] foreach c [$answer_set children] { ns_log notice [$c serialize] }

• Better handling of notifications.

  Notifications are now decoupled of the data-source service contract and use the above contexts, provide nicer subject lines, which are more suitable for mail-filters. We exclude objects of type ::xowiki::PageTemplate and ::xowiki::Object from notification.

• Improved Serializer

  The new method serialize is available for all XOTcl objects. The serializer provides a better handling of cyclical dependencies, when mixins are involved. It contains a fix for namespace handling to make the XOTcl communication library classes working with the aolserver (thanks for Stefan Sobernig for pointing this out). Now other ::xotcl::* objects can be included in the aolserver blueprint (e.g. non positional argument handlers)

  Since the serializer is distributed with XOTcl, this change would require a new XOTcl release (which is pending). For the time being, i have included the fixes in xotcl-core.

• Numerous other Changes:
  • Improved handling of return_urls (e.g. in XoWiki pages included in other apps, as well on the admin pages)
  • Implemented a second delete method for admins, that allows to delete objects even when they cant be instantiated (from admin pages)
  • More general page_name lookup (using prototypes) and error handling
  • ::xo::show_stack included
  • More reliable clean-up management for deleting objects after a connection is closed ( destroy_on_cleanup)
  • Allow to filter weblog entries for multiple categories (show only entries contained in all given categories) One of the three delivery methods of the XoWiki chat (streaming) has some troubles currently (maybe a problem with the current firefox); for now, we use the two other methods...
  • Overall improvement of code structure
  • Dave's patch for return_url handing in edit_new
  • Stan's patch for background delivery

In the time period we need to upgrade, test, and launch what we think is the newest version of xowiki you release another one (and we have Dave helping)!

I took some time today to test some of the very cool things you have added (e.g. I really like the new lightweight includlet feature and the examples you included). Thank you again for your amazing work. A lot of people are benefiting from it.

Enjoy your vacation.

-gustaf

I also tried a completely clean install using xowiki and xotcl-core off of HEAD but I get the same error. I don't have a good idea on where to start tracking this down, so any hints would be appreciated.

I tried again, this time wiping the two package dirs and getting them from CVS once again and now eveything works.

Error:

No page 'wiki/' available.

In the logs (a bit further up - probably didn't notice these last week):

snip...
[05/Sep/2006:11:53:58][20443.1087388000][-conn:x-dev::0] Notice: --try en:wiki/ -> 0, ::262 ::xowiki::Package->resolve_request (18ms, 0ms)
[05/Sep/2006:11:53:58][20443.1087388000][-conn:x-dev::0] Notice: --W object='wiki/', ::262 ::xowiki::Package->resolve_page (18ms, 0ms)
[05/Sep/2006:11:53:58][20443.1087388000][-conn:x-dev::0] Notice: no prototype for 'wiki/' found, ::262 ::xowiki::Package->resolve_page (18ms, 0ms)
[05/Sep/2006:11:53:58][20443.1087388000][-conn:x-dev::0] Notice: --before adp, ::262 ::xowiki::Package->return_page (19ms, 0ms)

I have the package mounted at mysite/wiki and the navigation is generated automatically based on the list of subsite apps. Since I've named the application instance "wiki", the link is generated as mysite/wiki, which is redirected to mysite/wiki/ (not sure if this is something xowiki is doing). I haven't configured anything, just mounted the package. I tried tacking "index" onto the url (mysite/wiki/index) but that resulted in a different error.

I also don't seem to have an index_page param (if it is an instance param) and since I cannot get to an xowiki page, I can't change behavior any other way.

all the best
-gustaf

Also, the basic xowiki.css includes this line:

table, td {font: 10px 'Lucida Grande', Geneva, Verdana, Arial, sans-serif; color: #000;}

which sets a base font size for all text in tables. This does not play nicely with the rest of the CSS on my site or on openacs.org. Check out https://openacs.org/xowiki/ and notice how the fonts in the top nav become illegible. This same thing happens on my site. Not sure what the best solution is here but I just deleted the line from my local copy of xowiki.css.

There's one other issue I'd like to bring up and it isn't really xowiki specific. Many packages now require their own navigation (admin/edit/etc.) but each one does it a little differently. Bug tracker, PM and Logger each use a different shade of blue/purple in a fat, page wide nav bar. This isn't going to look nice inside very many master templates. Xowiki has a very simple set of links in gray. I actually prefer this style but whatever the preference, shouldn't we handle this a little better, i.e., more uniformly and in a way that can easily be styled by a site's maintainer? We could start by having packages output a simple list of package nav links and style that at the site level. Thoughts?

Thanks for all your work on this. It looks great. I've just upgraded to 5.2.3 and xowiki 0.36 encountering 2 issues - both are now sorted, but just for reference.

1. Had to update xotcl to 1.4.0 (from 1.3.6) after experiencing the xowiki::Package error - I should have started with this one!!

2. There is a missing dependency to acs-datetime for the mini-calendar display - dt_systime is not found without this package.

Thanks again

Matthew

Cheers
Matthew

ps - fantastic piece of code