Forum OpenACS Development: Simple page using ad_form and -on_refresh

I am trying to do something quite complicated using ad_form and -on-refresh. However, I cannot even get "the basic stuff" working. Can someone give a _simple_ example of how to update the values of fields displayed to the user in the -on_refresh block?

Here's my ad-form call. gp_refresh is a simple widget which set's __refreshing_p and submits the form.

ad_form -name homepage_edit -form {
    {hp_title:text {label {Homepage Title}}}
    {test:gp_refresh}
  } -on_refresh {
    set hp_title "Refreshing"
  }

Hmmm - in that thread, the most elaborate example contains this:

-on_refresh {
    # didn't use -on_refresh
    # set subcategory_options before ad_form
    # because I couldn't find a way to set them here
}

So at least I am not alone with my problem 😊

Another post lead me to this solution for doing what I want to do:
-on_refresh {
  template::element::set_value homepage_edit hp_title REFRESHING
}

I would have assumed that ad_form_set_value would work also, but it doesn't. It doesn't give an error either. Strange.

Nis, I'm running into the exact same problem. I completely agree that -on_fresh's behavior is not intuitive.

What did you end up doing to get around this issue?

In  certain circumstances (to do with bcms i think) I had to add the following to the page code:

if {[ns_queryget "form:id"] eq "simpleform" && [ns_queryget "__refreshing_p"]} {
    # FIX bogus - assumes that if simpleform is being refreshed, it
    # should be in edit mode. A safe asumption, but not really how it
    # should be done.

    set form_mode edit
}

I don't think I've altered the values at the form level - I've only used __refreshing_p within custom widgets (where you have to access the form fields directly anyway)

For the record, I have created the below patch that allows for setting form values in on_refresh. I haven't tested all the posibilities - just a test form to see that it "works" for my simple test case.

Please note that part of this code is just magical incantations to me. I have a feeling ad_form could use a little refactoring ... I might get around to that the next time it bites me.
Index: form-processing-procs.tcl
===================================================================
RCS file: /usr2/cvsroot/mlm/packages/acs-tcl/tcl/form-processing-procs.tcl,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 form-processing-procs.tcl
--- form-processing-procs.tcl  21 Apr 2004 09:15:40 -0000      1.1.1.1
+++ form-processing-procs.tcl  11 Nov 2004 18:31:37 -0000
@@ -989,6 +989,25 @@

        if { [info exists on_refresh] } {
            ad_page_contract_eval uplevel #$level $on_refresh
+
+            # NAJ: If values are set in the on_refresh block, stuff them into the form fields.
+            # This code is just a copy-paste (and a little gluing) of code from the other branches
+            # I don't understand the datas structures well enough to know if there is an easier way to
+            # do this - or if I am doing it in a foolproof way.
+
+            foreach element_name $af_element_names($form_name) {
+                if { [llength $element_name] == 1 } {
+                    if { [uplevel \#$level [list info exists $element_name]] } {
+                        set myvalues [uplevel \#$level [list set $element_name]]
+                        if { [info exists af_flag_list(${form_name}__$element_name)] && \
+                            [lsearch $af_flag_list(${form_name}__$element_name) multiple] >= 0 } {
+                            template::element set_values $form_name $element_name $myvalues
+                        } else {
+                            template::element set_value $form_name $element_name $myvalues
+                        }
+                    }
+                }
+            }
        }
    }

===================================================================

Hmm - the patch has problems with some existing form widgets. I don't have time to track this down now.

So don't use this at home.