Programming Jabber

State 2: Query the JUD

The submission of the HTML form will cause a number of name/value pairs to be passed as part of the HTTP GET request. These names and values are captured into the @a array as described earlier. If we have more than one entry in @a, we know it’s a form submission and must respond to that by querying the JUD and returning the results. In this case, as we know that the contents of @a are name/value pairs, we can view those contents as a hash, using a new variable %a:

  elsif (scalar @a > 1) {
    my %a = @a;

Now, %a will contain entries where the keys are the names of the search fields and the values are the values entered in the form.

In the same way that we constructed an IQ-get to query the JUD for the search fields and instructions, we construct an IQ-set to perform the actual query:

    my $iq = $nf->newNode('iq');
    $iq->attr('to', JUD);
    $iq->attr('type', IQ_SET);
    my $query = $iq->insertTag('query', NS_SEARCH);

Using the information in %a, we insert tags for each of the search fields for which a value was specified in the form. For example, if only the value adams was specified, in the field representing the <last/> search field, as shown in Figure 10-3, we would only want to insert:

<last>adams</last>

as a child of the IQ-set’s <query/> tag:

    while (my($name, $val) = each(%a)) {
      $query->insertTag($name)->data($val) if $val;
    }

Also in a similar way to handling state 1, we make the call by using the ask() method; the response will be received into the $result variable ...