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Answer 1

A:

It is just not well formed JSON. Either that JSON string misses to quote all keys or it is an error with ((un)escaped) quotings in general.

jAndy 2010-07-29 19:27:34

Answer 2

+1 A:

The JSON parsing in jQuery 1.4 is more strict than past versions. Depending on your browser, it may use native JSON parsing, which is different than eval. One big difference is that now, all keys MUST be enclosed in double quotes, not single quotes. eval would do it with no error as you said, since JS isn't strict about quoting property names at all, but it will fail JSON parsing.

I had an issue with this myself when converting a project to jq 1.4, as I had some older code that was building json strings manually. For instance

return "{'a':12}";  // fails parsing due to single quotes

It is much better to use the built-in json libraries:

return '{"a":12}'; // works
return json_encode(array('a'=>12)); // preferred!
return json.dumps({'a':12}) # etc.

as they always produce valid json.

Alex JL 2010-07-29 19:33:41

I think you're right, there are a few unescaped values in the response data. The problem is that I don't own the domain I'm requesting the data from, so is there a way to intercept jQuery's JSONP processing before it calls it's built-in eval function?

Andreas Jansson 2010-07-30 08:58:30

You could get the data as a string, then call eval or json.parse on it.

Alex JL 2010-07-30 14:12:14

Thanks, the problem seems to be in the way jQuery handles JSONP. I don't know the internals, but it appears that it fetches it like a script, and then the browser manages to find some syntax issue and throws the error, before handing control over to jQuery. Neither beforeSend() or dataFilter() are triggered. I guess I'll just have to do the processing on my own server.

Andreas Jansson 2010-08-02 09:23:31

I've had issues with jSONP and jQuery that weren't apparent at first, too, like how you can't make JSONP calls synchronous. They're definitely handled differently.

Alex JL 2010-08-02 11:55:22

Answer 3

A:

The JSON sample is invalid. It include this substring:

}, {

That is, it ends one object and starts another. So it appears to be an array of objects except without enclosing square brackets.

Edit: my mistake! It does in fact have a nested array in it. Maybe you should "pretty print" it when you generate it, so that it is easier to see where the problem lies?

Daniel Earwicker 2010-07-30 09:00:48

Answer 4

A:

Interestingly, according to http://jsonformatter.curiousconcept.com/ that JSON is valid.

As others have noted ... jQuery 1.4 will not accept malformed JSON, earlier versions will however (if you want to go direction for some crazy reason.)

How are you calling the actual JSON data elements in code? I've run into problems a couple of times ... perfectly valid JSON, but isn't not easily called in jQuery.

An example: the tumblr (blog engine) API ... for some reason they used ... "-" ... so for the "body" of the blog post they have "regular-body" ... which jQuery aparently hates with a passion.

You'd think you could do ...

json.posts[2].regular-body

But that will error, so you need [] ...

json.posts[2]['regular-body']

So ...

If you can give in more detail about how you are calling the JSON data elements it might be helpful?

Justin Jenkins 2010-07-30 09:38:51

I'm not able to query individual elements in the JSON data as the script dies on error within the getJSON function.

Andreas Jansson 2010-07-30 11:15:29

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