Forum OpenACS Development: ANN: tools::paginate

this looks great. When I try to get the tcl procs files I get an internal server error for tools-procs.tcl and a page not found error for the db ones. I can get the db ones if I strip the .tcl extension from the filename but I suspect the tools-procs.tcl file is actually being evaluated and failing.

Matthew

Paginating means that you show only a certain amount of entries from some list on a page and offer then links to next (and prev) page with another x entries, and so on.

One example of this is the user directory in https://openacs.org/directory/

If I understood correctly, Lars' new list builder supports pagination, too. I don't know what is its relationship with Jon's widget, though.

You can now use bindvars in the querystring and he generalized the limits (get recnum 10 - 50) proc to use outside the paginate proc.

He also added exclude variables, extra vars, images for prev/next page, and extra code to be executed before the line of code is shown.

Found time to experiment with your code today and found that I couldn't get it to work with OACS4.6.3/PG7.2.4 without making various changes (perhaps I picked up an old version from your web page?):

* In tools-procs.tcl, in the "::tools::paginate" proc, I had to alias the sub-selects in both "get_record_count" queries by adding "as x".  Otherwise, PG bombs.  I'm not sure if this breaks Oracle, but it certainly breaks our rule of not allowing queries in .tcl files. =)

* The "tools::paginate_sql.get_limit" PG query from tools-procs-postgresql.xql is broken.  It needs to alias the sub-select (using "as x") and it incorrectly uses the PG limit/offset clause.  I think it should read:

    select * from
    ($query) as x limit $max_display offset [expr $start -1]

* The "tools::paginate.get_context" PG query from the same file uses:
    substr(upper($context_field), 0, 1)
which by definition returns nothing in PG.  I'm assuming you wanted to return the 1st character or:
    substr(upper($context_field), 1, 1)
Also, it would be cool if you could pass in the number of letters for the context (for very large lists).

* The above fix produces a nifty alphabetical navigation bar, but clicking on the different letters doesn't do anything.  Should there be code in the sample ".tcl" file that uses "objects_context" to limit the query?  Or should that logic be added to "tools-procs.tcl"?

* In your sample ".tcl", you need to escape the double-quote at the beginning of \"edit-object...

* The sample ".xql" file does not use the "objects_orderby" clause and should probably read:

    select object_id,
    object_type,to_char(creation_date,'MM/DD/YYYY HH:MI') as creation_date
    from acs_objects a
    order by $objects_orderby

* Is reverse ordering supposed to work when clicking on a column header twice?

Other than those issues, the paginator is very cool and I would be willing to help out in any way.

Should I work on the above items and just send you a patch?

Thanks! I think we're almost there. I will send you my version via email which has a few changes:

• The URLs for the context markers include the current page number. However, if you click on a context marker (say, the letter "C") and that context has fewer pages than your current page (in say the "ALL" context), you will get a blank list. So, for generating context markers, I changed the call to build_url to exclude the ${name}_page variable.
• The "-query" parameter to "tools::paginate" wasn't working properly (-queryname works fine). The problem was it calls:

  uplevel ... [db_string get_record_count_dynamic { *SQL* }]}

  But, at the template parse level, get_record_count_dynamic doesn't exist in any *.xql files. So, I changed this to do a db_map and then pass the query string directly to the uplevel'ed db_string call.
• Made minor changes to the tools-*.xql files in support of the above changes.
• The offset in tools-postgresql.xql should be [expr $start - 1], not $start (eg, if $start is the 11th, then you want to set the offset to 10 so that PG skips the first 10 records).
• Your sample "index.tcl" file includes a call to "lset" which I think is a jongriffin.com(TM) Tcl proc. Perhaps change it to standard Tcl so folks don't trip on it and give up before they get to see how darn cool your paginator is. =)
• Outstanding bug: If you click on a context marker, you lose all the other context markers. Here's an example from your sample page: http://jongriffin.com/static/openacs/paginate/sample/?objects%5fcontext=C Perhaps we should move the context logic into tools-procs.tcl? Will investigate.
• I haven't tested anything under Oracle yet. Can you do that?