From the chatterbox I seem to have caused confusion among those Monks who would enlighten me. My appologies....

In Ages Past... (ok, ok about december of 2000, and more recently for the past week or so) I've been looking to do away with some of the repetitive coding i've been doing in my CGI work. This particular work focuses around retrieving/displaying information from a database. I've also just taken up using the Template Toolkit which has really been a burden off my scripts' shoulders.

It occurred to me that a good model for thinking about the database info retrieval is that I'm thinking in terms of site resources (users, articles, user groups, etc), and that the display of them are certain "views" of these resources. So I posited that it would be best if I could write some structure that let me think in terms of these resources when coding. I came up with this xml format (which down the road I intend to making formally RDF):

<?xml version="1.0" ?>
<RDF>
  <resource id="user" primary_table="csUsers" >
      <property id="username" source="db://csUsers.UserName" />
      <property id="id" source="db://csUsers.ID" />
      <property id="date_created" source="db://csUsers.Date_Created" /
+>
      <property id="groups" source="rs://group" relation="toMany" />
  </resource>

  <resource id="group" primary_table="csGroups">
      <property id="title" source="db://csGroups_lang.Title" />
      <property id="id" source="db://csGroups.ID" />
      <property id="users" source="rs://user" relation="toMany" />
  </resource>

  <view id="user_summary" resource="user" key="id">
      <group id="identity">
          <property id="username" source="rs://user.username" />
          <property id="id" source="rs://user.id" />
      </group>
      <group id="groups" source="user.groups" >
        <property id="grouptitle" source="rs://user.groups.title" />
        <property id="groupid" source="rs://user.groups.id" />
      </group>
  </view>

  <link table1="csUsers" table2="csGroups" type="indirect" >
    <link type="direct" table1="csUsers" table2="csUsers_Groups" key1=
+"ID" key2="UserID" />
    <link type="direct" table1="csGroups" table2="csUsers_Groups" key1
+="ID" key2="GroupID" />
  </link>

  <link type="direct" table1="csUsers" table2="csUsers_lang" key1="ID"
+ key2="ID" />
  <link type="direct" table1="csGroups" table2="csGroups_lang" key1="I
+D" key2="ID" />
</RDF>
[download]

Now, I've got code written that both caches this file format so i don't have to re-parse every go-round, and code that generates a SQL query for a given view, along with conditional,sort, and range limit parameters supplied by the caller. What I want to return to the caller is a list of hashrefs that mimic the structure of the view from the xml file. That way it can send it onto it's Template handler so that in the template I can just say something like:

<table>
  [% FOREACH user = query_results %]
  <tr>
    <td>
      <a href="userdetails.cgi?id=[% user.identity.id %]">[% user.iden
+tity.username %]</a>
    </td>
    <td>
      [% FOREACH group user.groups %]
      <a href="groupdetails.cgi?id=[% group.groupid %]">[% group.group
+title %]</a>
      [% END %]
    </td>
  </tr>
  [% END %]
</table>
[download]

To that end I am currently thinking of how to create that data structure to return to the caller. My current thoughts are to return a reference to an array (to maintain sort order). The elements in the array are references into a hash. This hash stores all the records returned by the query, keyed by the view's 'key' property from the xml file. The question is how to store the query into those hash entries.

I've thought of storing the path to the location of a property (e.g., from above the path to the value for 'username' would be 'identity,username'). a view's root elements would be pathless. I could see using symbolic references or evals to do the mapping:

$paths{username} = '{identity}{username}';
...
eval "$hash{$id}$path = $username";
...
push @array_to_return, $hash{$id}
[download]

but in my mind this does not seem like a particularly desireable solution. I'd like to stay away from symbolic references as well, for the love of strict.

So here we have my dilemma...how to store the returned records from the query into the desired structure? If anything else needs clarified, I will try. I've been pondering this for quite some time and could use the scrutiny of some fellow monks

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