You have to convert the array to a string in Perl, then back to an array in JScript. A while ago, I wrote a serializer I can adapt to this situation. Here it is:

In Perl, change

sub populate {
    my @array = (...);
    return @array;
}
[download]

to

# Serializes an array, a hash or a list which contains only
# strings and undefs. Everything else will be stringified.
sub serialize_string_list {
   return join('|',
      map {
         (defined($_)
            ? do { local $_=$_; s/\^/^1/g; s/\|/^2/g; $_ }
            : '^0'
         )
      } @_
   );
}

sub populate {
    my @array = (...);
    return serialize_string_list @array;
}
[download]

In the emitted JavaScript, change

function do_populate_cb(s) {
    ... do something with s...
}
[download]

to

// Deserializes a list serialized with serialize_string_list.
function deserialize_string_list(s) {
   var fields = s.split("|")

   var i;
   for (i=0; i<fields.length; i++) {
      if (fields[i] == "^0") {
         fields[i] = null;
      } else {
         var re;

         re = /\^2/g;
         fields[i] = fields[i].replace(re, "|");
   
         re = /\^1/g;
         fields[i] = fields[i].replace(re, "^");
      }
   }

   return fields;
}

function do_populate_cb(s) {
    var array = deserialize_string_list(s);
    var i;
    for (i=0; i<array.length; i++) {
       ... do something with array[i]...
    }
}
[download]

Important: The above only supports lists (and arrays) of strings. Lists of numbers will work, but they will be converted to arrays of strings. List containing references of any sort will not work as expected.

Background: I didn't use a single-character escape mechanism (such as preceeding metacharacters with a slash) since it makes deserialization hard. (i.e. "Should I split on this pipe, or is that an escaped pipe?") The escape mechanism I used -- replacing the seperator character with another character -- avoids that problem, simplifying parsing. IP over Serial Line (SLIP) and maybe Point to Point Protocol (PPP) use a similar escaping algorithm to escape packet delimiters because the delimiters cannot appear inside a packet.

Greetings ikegami
I tried using your code. Its works fine except for the fact that the last array value is followed by the whole html code in the form.
For eg:- If the array values are A,B,C,D and i add them in the drop down menu then the last option(D) is followed by the whole html code. So I have four options in the drop down box A,B,C,D<htmlcode>
Am i doing something wrong?
See code below.

sub serialize_string_list {
   return join('|',
      map {
         (defined($_)
            ? do { local $_=$_; s/\^/^1/g; s/\|/^2/g; $_ }
            : '^0'
         )
      } @_
   );
}


sub populate{
        @n=();
    my $dt;
    my $row;
#course contains the values fetched from the database
    foreach $row (@$course) {
    ($dt) = @$row;
    push(@n,$dt);

}

    return serialize_string_list  @n;

};

//deserializes the array
function deserialize_string_list(s) {
   var fields = s.split("|")

   var i;
   for (i=0; i<fields.length; i++) {
      if (fields[i] == "^0") {
         fields[i] = null;
      } else {
         var re;

         re = /\^2/g;
         fields[i] = fields[i].replace(re, "|");
   
         re = /\^1/g;
         fields[i] = fields[i].replace(re, "^");
      }
   }

   return fields;
}


//calling Sajax wrapper function from a javascript function

function do_populate() {
    x_populate(do_populate_cb);
}

function do_populate_cb(s) {
 var arr = deserialize_string_list(s);

    var i;
    for (i=0; i<arr.length; i++) {
        with(document.doc1.selCourseNm)
        {
        options[i]=new Option(arr[i],arr[i]);
        }
    }

}
[download]

Did you forget to close your SELECT tag?

How about you show us runnable code that exhibits the problem.

By the way. I can't find any documentation for Option's contructor. In fact, according to the documentation, nodes should be created using createElement and createTextNode methods. What follows uses the correct methods.

function do_populate_cb(s) {
    var arr = deserialize_string_list(s);
    var options = document.doc1.selCourseNm.options;
    var i;

    // Remove any options it currently has.
    options.length = 0;

    // Add new options.
    for (i=0; i<arr.length; i++) {
        var option = document.createElement('OPTION');
        option.value     = arr[i];
        option.innerText = arr[i];
        options.add(option);
    }
}
[download]

Greetings Rainmaker,

I don't have any experience with SAJAX, but I've had significant (and quick and easy) success with JSON. There's a CPAN module for it, and it's crazy-simple/easy.

use JSON;
print "Content-Type: text/html\n\n", objToJson('list' => [ 'a', 'b' ])
+;
[download]

Obviously, this is very simple, but complex structures are a piece of cake.

Data::Javascript

That's good, but I prefer the output of Data::JavaScript::Anon, which uses JavaScript's array construction syntax and avoids messily repeating the variable name for every element.

Smylers

Greetings GoCool,

Just my own personal opinion (and it seems to work out well for me in my particular situation) is: Why translate a data structure from Perl to XML and then from XML to JavaScript data object if all you're ever going to do with AJAX is talk between Perl and JavaScript? Seems faster, simpler, and easier to just go direct from Perl to JavaScript, which is why I like JSON so much.

I'm not against XML, but I am against having to use XML when there's really no reason to do so. If I were going to de-link my data provider (Perl CGI/mod_perl) from my GUI (JavaScript) so that some developer who's not me could build a hook into the data source and build their own GUI, then XML would make a lot of sense. However, if I don't really care about exposing my data source, then I don't want to waste the time with XML.

Just my opinion. There's more than one way to do it.

gryphon
Whitepages.com Development Manager (DSMS)
code('Perl') || die;