Django and AJAX - what am I doing wrong?

Question

I'm trying to write a simple search server, using Django with AJAX. The server itself works fine, but I am still struggling with adding autocomplete to the search widget.

(I don't want to use available Django snippets, since they don't do exactly what I want, are hard to customize, and don't teach me the basics the way writing the interface from scratch does)

On the client (Javascript) side, I'm using YUI because it looks simpler - but don't mind switching to jQuery, so please don't fixate on that.

In YUI, an autocomplete box takes three parameters: input,container and dataSource. The first two are just the widgets, and the third one is interesting.

If I write:

var oDS = new YAHOO.util.LocalDataSource(["apples","apples2", "broccoli", "cherries"]);
var oAC = new YAHOO.widget.AutoComplete("myInput", "myContainer", oDS);

in my <script>, I get an autocomplete box which autocompletes these terms.

When I try to replaces the LocalDataSource with a remote datasource, for example by choosing var oDS = new YAHOO.util.ScriptNodeDataSource("127.0.0.1:8000/getNames/"), and setting up an apropriate view, no autocomplete happens.

What I know about the problem:

1. I know that the view gets called (by debug printing) - so that isn't the problem.
2. I return a json array by jresponse = simplejson.dumps(response_array); return HttpResponse(jresponse, mimetype='application/javascript'); I don't think there's any problem with that, since I can access that view directly and get a textual representation of the json when I do.
3. Maybe there's a problem with the input-type that the local data source expects - I'm not sure how to set it.

Any help (including how to do this correctly in jQuery - I don't mind dumping YUI) would be much appreciated.

---

Edit: After the first two comments (thanks!), I installed firebug, and started playing with it. It's really messy, however, since the Yahoo toolbar has lots of code, and I don't know where to break it. Is there some easy way to have firebug only show me json/xml elements?

@Marat: I did that already (accessing my view), and it returns a string representation of the JSON (at least that's what my browser shows). Is that what I should expect?

@pastylegs: Here's the code:

 <div id="myAutoComplete">
    <input id="myInput" type="text">
    <div id="myContainer"></div>
    </br></br>
    <input type="submit">
</div>

 <script type="text/javascript">
YAHOO.example.BasicLocal = function() {
{%block oDS%}
// Use a LocalDataSource
var oDS = new YAHOO.util.LocalDataSource(["apples","apples2", "broccoli", cherries"]);
//for remote - oDS = new YAHOO.util.ScriptNodeDataSource("127.0.0.1:8000/getNames/")


// Instantiate the AutoComplete
var oAC = new YAHOO.widget.AutoComplete("myInput", "myContainer", oDS);
oAC.prehighlightClassName = "yui-ac-prehighlight";
oAC.useShadow = true;

return {
    oDS: oDS,
    oAC: oAC
};
}();
</script>

The Django view:

def getNamesXML(request):
    response_array=['Apples','Oranges']
    print response_array
    jresponse = simplejson.dumps(response_array)
    print jresponse
    return HttpResponse(jresponse, mimetype='application/javascript')

Thanks a lot!

Answer 1

I don't know anything about YUI, but I can give you a working jQuery example. Main difference I see with your code is the mimetype: as discussed in this question, you should use application/json. That said, I don't think it'll make a big difference.

For the view, use something along these lines:

def autosuggest(request):
    query = request.GET.get('term') # jQuery autosuggest input so far
    f = MyModel.objects.filter(name__icontains=query)
    response = [p[0] for p in f.order_by("name")[:10].values_list("name")]
    return HttpResponse(simplejson.dumps(response), mimetype="application/json")

This assumes f is a QuerySet on a model that has a name field, and you want the first 10 matches. In your template, the following should do:

$('#myInput').autocomplete({
    source: '{% url myapp.views.autosuggest %}',
    minLength: 2, // Two characters are needed before suggestions show
    select: function(event, ui) { // Callback function for selection
        $('#myInput').val(ui.item.value);
    },
});