This tutorial covers topics which are not essential to creating a minimal working package. Each section can be used independently of all of the others; all sections assume that you've completed the basic tutorial.

We need a way to delete records. We'll create a recursive confirmation page.

Add this column to the table_def in index.tcl

{delete "" {} {<td><a href="note-delete?note_id=$note_id">Delete</a></td>}}

Create the delete confirmation/execution page.

[service0@yourserver www]$ emacs note-delete.tcl

ad_page_contract {
    A page that gets confirmation and then delete notes.

    @author joel@aufrecht.org
    @creation-date 2003-02-12
    @cvs-id $Id: tutorial-advanced.html,v 1.3 2003/06/28 05:07:03 joela Exp $
} {
    note_id:integer
    confirm_p:optional
}

set title "Delete Note"

if {![exists_and_not_null confirm_p]} {
    # first pass, not confirmed.  Display a form for confirmation
    set note_name [db_string get_name { *SQL }]
    set title "Delete $note_name"
    template::form::create note-del-confirm
    template::element::create note-del-confirm note_id -value $note_id -widget hidden
    template::element::create note-del-confirm confirm_p -value 1 -widget hidden
    template::element::create note-del-confirm submit \
      -label "Confirm deletion of $note_name" \
      -widget submit
} else {
    # second pass, confirmed.  Call the database to delete the record
    db_1row do_delete { *SQL* }
    ad_returnredirect "index"
    ad_script_abort
}

This page requires a note_id to determine which record should be deleted. It also looks for a confirmation variable, which should initially be absert. If it is absent, we create a form to allow the user to confirm the deletion. Note that in entry-edit.tcl we used ad_form to access the Form Template commands; here, we call them directly because we don't need the extra features of ad_form. The form calls itself, but with hidden variables carrying both note_id and confirm_p. If confirm_p is present, we delete the record, set redirection back to the index, and abort script execution.

The database commands:

[service0@yourserver www]$ emacs note-delete.xql

<?xml version="1.0"?>
<queryset>
  <fullquery name="do_delete">
    <querytext>
      select samplenote__delete(:note_id)
    </querytext>
  </fullquery>
  <fullquery name="get_name">
    <querytext>
      select samplenote__name(:note_id)
    </querytext>
  </fullquery>
</queryset>

And the adp page:

[service0@yourserver www]$ emacs note-delete.adp

<master>
<property name="title">@title@</property>
<property name="context">{@title@}</property>
<h2>@title@</h2>
<formtemplate id="note-del-confirm"></formtemplate>
</form>

The ADP is very simple. The formtemplate tag outputs the HTML form generated by the ad_form command with the matching name. Test it by adding the new files in the APM and then deleting a few samplenotes.

You can track comments for any ACS Object. Here we'll track comments for notes. On the notes.tcl/adp pair, which is used to display individual notes, we want to put a link to add comments at the bottom of the screen. If there are any comments, we want to show them.

First, we need to generate a url for adding comments. In notes.tcl:

set comment_add_url "[general_comments_package_url]comment-add?[export_vars {
 { object_id $note_id } 
 { object_name $title } 
 { return_url "[ad_conn url]?[ad_conn query]"} 
}]"

This calls a global, public tcl function that the general_comments package registered, to get its url. You then embed in that url the id of the note and its title, and set the return_url to the current url so that the user can return after adding a comment.

We need to create html that shows any existing comments. We do this with another general_comments function:

set comments_html [general_comments_get_comments
    -print_content_p 1 $note_id]

First, we pass in an optional parameter that that says to actually show the contents of the comments, instead of just the fact that there are comments. Then you pass the note id, which is also the acs_object id.

We put our two new variables in the notes.adp page.

<a href="@comment_add_url@">Add a comment</a>
@comments_html@

Browse to the package manager. Click on tutorialapp.

Click on Generate a distribution file for this package from the filesystem.

Click on the file size (37.1KB) after the label Distribution File: and save the file to /tmp.