Drupal services module JSON response fetched: Backbone.js model attributes turn into string

Question

I've set up web services using Drupal's services module. It outputs JSON for me which I am requesting through a Backbone.js front-end application.

I'm having issues with this set-up. If I request data through Backbone.js' fetch method of a model, the model's attributes are all typed as string after fetching, while there are some attributes that should be e.g. integer.

For example:

I have enabled the user resource, which is standard available in the Drupal services module
I can request a user, e.g.:
```
http://mydevmachine/services/user/8
```

...which results in the following response (slimmed down version from the real response):

    {"uid":"8","name":"itsme","mail":"me@mydomain.nl"}

What I see in the response from the web service above, all values are quoted, however uid is really not a string but an integer in the database.
If I fetch the same user in my Backbone.js model, by setting the uid field of my model to 8 (integer), then call the fetch method. After fetching the uid field is typed as 'string'.

I assume the above leads to my model ending up with a uid attribute of not integer, but string. It also happens with all other web service resources I have created, using my own entities.

I need correct typing of attributes in my model due to sorting issues using Backbone's collection sorting. I.e. sorting a collection of models using a field of type 'integer' leads to different sorting results when sorting the field with the same values although stored as a string.

I'm not sure exactly where to look:

Is the JSON format output by the Drupal services module according to standards?
Is the JSON output format configurable or overridable in the Drupal services module?
Is it perhaps possible to keep the type of a model's attribute after a fetch in Backbone.js?
Should I provide a specific implementation for Backbone's collection comparator function, which handles this situation (seems hackey)?
Should I introduce other solutions, e.g. like posted here: How can I enforce attribute types in a Backbone model? (feels too heavy).

Thanks for any help.

You can set up [`parse`](http://backbonejs.org/#Model-parse) methods in your Backbone as a last resort but there has to be a way to make your server treat send out numbers as numbers in the JSON. — mu is too short, Jul 04 '13 at 15:34
Mmmmh, I haven't thought of that one yet. Indeed it feels a bit like double work if I was to do that, but it may also be some sort of extra layer on top of securing you receive the right data. Thanks for answering! — Vanderstaaij, Jul 08 '13 at 08:17

score 0 · Accepted Answer · edited May 23 '17 at 10:27

So I finally managed to crack this issue and I found my solution here: How to get numeric types from MySQL using PDO?. I thought I'd document the solution.

Drupal 7 uses PDO. Results fetched using PDO, using Drupal's default PDO settings result in stringified values.

In Drupal's includes/database.inc file you will find this around lines 40-50:

$connection_options['pdo'] += array(
  // So we don't have to mess around with cursors and unbuffered queries by default.
  PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => TRUE,
  // Because MySQL's prepared statements skip the query cache, because it's dumb.
  PDO::ATTR_EMULATE_PREPARES => TRUE,
);

The statement here that MySQL's prepared statements skip the query cache is not entirely true, as can be found here: http://dev.mysql.com/doc/refman/5.1/en/query-cache-operation.html. It states MySQL > 5.1.17 prepared statements use the query cache under certain conditions.

I used the info from the other stack overflow question/answers to override the PDO settings for the database connection in Drupal's sites/default/settings.php (please note I only did this for the database I was querying, which is different than Drupal's own database):

'database_name' =>
  array (
    'default' => 
    array (
      'database' => 'database_name',
      'username' => 'user_name',
      'password' => 'user_pass',
      'host' => 'localhost',
      'port' => '',
      'driver' => 'mysql',
      'prefix' => '',
      'pdo' => array(
        PDO::ATTR_STRINGIFY_FETCHES => FALSE,
        PDO::ATTR_EMULATE_PREPARES => FALSE
      ),
    ),
  ),

This resulted in integers being integers. Floats/decimals are incorrectly returned by PDO still, but this is different issue. At least my problems are solved now.

Drupal services module JSON response fetched: Backbone.js model attributes turn into string

1 Answers1