jQuery does not respect Content-Type with respect to converters

[larsholm]

It seems not to be possible to hit this converter:

$.ajaxSetup({
    converters: {
        "mycustomtype json": function (result) {
            //do stuff
            return newresult;
        }
    }
});

This should be called if the response has Content-Type 'mycustomtype' and the caller expects json.

[addyosmani]

Thanks for your ticket. I was going to post back a few code samples for how to correctly use converters, but I think it would make more sense for you to provide us with a jsFiddle test case that reproduces what you're trying to do first. I don't personally mind if this is hosted somewhere other than jsFiddle as long as I can see an example.

Regardless of whether this behaviour is broken or not, we should be updating the docs for ​http://api.jquery.com/extending-ajax/#Converters to be more comprehensive. I personally got lost for a while trying to figure out whether this behaviour was supported or not as all our examples use standard types (xml, json) as the request format.

[addyosmani]

btw, can you confirm whether or not you've specified your custom data-type as follows for the actual request?

.ajax( url, {
  dataType: "mycustomtype"
});

[jaubourg]

You just need to add a correspondance between response Content-Type and actual dataType using the contents option:

$.ajaxSetup({
    contents: {
        mycustomtype: /mycustomtype/
    },
    converters: {
        "mycustomtype json": function (result) {
            //do stuff
            return newresult;
        }
    }
});

This sure is not well documented.

The reason you have to use another map for this is because response Content-Types and dataTypes never have strict one-to-one correspondance (hence the regular expression).

[addyosmani]

@jaubourg thanks for the input on this!. If you'd like to take a stab at improving the docs on this one, please feel free to otherwise I'll add an example based on the above a little later.

[addyosmani]

As this works fine with the approach @jaubourg outlined above, we're going to close this ticket. I'll update the docs shortly to reflect what was missing.

[larsholm]

But jaubourg's approach does not work. Here's a running example of a custom datatype called 'deltaencoded' which doesn't fire off the converter from deltaencoded to json: ​http://larsholmjensen.dk/DatatypeTest The server returns json for the first call the both GetData and GetData2, but on the second call GetData returns a response with Content-Type 'deltaencoded'. And as the caller expects json the converter should get called.

[jaubourg]

The xhr only produces "text" and "xml" responses, so you need a "text deltaencoded" pass-through converter:

$.ajaxSetup({
    contents: {
        deltaencoded: /deltaencoded/
    },
    converters: {
        "text deltaencoded": true,
        "deltaencoded json": function (result) {
            //do stuff
            return newresult;
        }
    }
});

Now, ajax knows you can pass from text to deltaencoded then deltaencoded to json. Is this working?