[Catalyst] RE: DBIC <-> JSON conversion for AJAX

Ian.Docherty at nomura.com Ian.Docherty at nomura.com
Mon Sep 12 12:39:51 GMT 2011

I like to use Catalyst::Controller::REST which will do the decoding and encoding of JSON for you. The module has some good examples.

I also like to 'decouple' the DBIC object from my view, so that I only pass in the values, not the object.

my $object = $c->model('MyModel::Foo')->find($object_id);
my $response = {
    foo     = $object->foo,
    bar     = $object->bar,
    bam     = $object->bam,
$c->stash->{ajax_response} = $response;

It should also be possible to create a 'flatten' method that does this for you in a generic manner, you could then have.

$c->stash->{ajax_response} = $object->flatten;

I have done this with none-DBIC objects, I am sure there must be a way to do it with DBIC as well.


From: Roland Philibert [mailto:rphilibert at aptina.com] 

Hello all,

I am new to Catalyst, so I will try to make this query as smart as I possibly can.

I am trying to fetch data from a mysql database using a jQuery ajax method to populate a select list...and my question is:  what is the recommended method in Catalyst to serialize/encode a DBIC class object into a JSON object, that I can then parse easily in a view with javascript?
If anyone is able to help, an example would be highly appreciated.

Many thanks

Ps: I have had an attempt with JSON::XS, but I don’t think it is correct as I had to bless manually the conversion. 
Not sure here that my approach is correct... I am thinking that perhaps the conversion should be done within the model itself?

Here is the way I think how the mechanics work with Catalyst, but my conversion does not return anything.

1./ in a TT view, I use the Jquery .ajax function to connect to a method (list_ajax) under the iprequest controller  eg:
                                                       type: "GET"
                                                                ,url: "[% c.uri_for("/request/list_ajax") %]"

2./ the method gets the data from my database using a DBIC model ...but I encode it into a JSON object and stash it to the contents. (At this point here I am experimenting!)
       sub list_ajax :Local {
                                my ($self, $c) = @_;
                                my $encoder = encode "UTF-8", JSON::XS->new->allow_blessed(1)->convert_blessed(1)->encode($c->model('DB::request')->all);
                                $c->stash(ajax_request => [$encoder]);

3./ Coming back to my point 1 above, I get the contents with my ajax function by adding (in blue):
                                                       type: "GET"
                                                                ,url: "[% c.uri_for("/iprequest/list_ajax") %]"
                                                                ,dataType: "json"
                                                                ,cache: false
                                                                ,success: function(json){
                                                                                                                if(json.ajax_request) {
                                                                                                                                $('<p>I got something to show..</p>').appendTo('.reuseable);
                                                                                                                                $.each(json.ajax_request, function(i,n) {
                                                                                                                                                var item = json.ajax_request[i];
                                                                                                                                                $('<p>'+ item +'</p>')
                                                                                                                else {
                                                                                                                                $('.reuseable').html('<p>no result sorry..</p>');

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