5 ms·
JQuery 1.4 and Malformed JSON
- cellis 17y agoCould someone tell me why the example given is malformed? I rarely write JSON anymore (except with json_encode in php and simplejson in python).
- almost 17y agoThe malformed example given is: {foo: "bar"} which is missing the quotes around foo so it should be: {"foo": "bar"} Since both of those would have had the same meaning the JSON spec sensibly restricts things so that only one is valid. See http://json.org/ http://json.org/ for the (very short and readable) spec.
- ionfish 17y agoThe object property is assigned with a name, not a (double-quoted) string. Well-formed JSON would look like this: {"foo": "bar"}
- deleted 17y ago[deleted]
- axod 17y ago>> "Again, though, you should probably be modifying your busted server-side code to stop sending malformed JSON!" I still think it was a silly mistake to impose a 'must be enclosed in quotes' rule for JSON parsing in js. Those quotes are just wasted extra bytes. Needless. Yeah sure, you can argue that someone silly will use a reserved word, like {new:"hello"}. But I don't think that's a good enough reason to waste more bandwidth+time for those that know what they're doing.
- daleharvey 17y agoeither way I still think its great that libraries are taking the risk to not support malformed dataformats, if browser developers had of made the same decision I think the web would have been far ahead of where it is now
- jeresig 17y agoIn some way the browsers already have made the decision. The new JSON.parse method available in Firefox, Safari, and IE 8 is capable of parsing a valid JSON string and turning it into a JavaScript object. The exception is the one provided by Chrome, as it accepts malformed JSON strings (such as {foo:1} and {'foo':1}). In jQuery we wanted to take advantage of this new JSON.parse method for speed and security - but we couldn't have it throwing malformed JSON exceptions in some browsers but not others, so we simply equalized the field (throwing an exception in all browsers).
- axod 17y agoFor some reason, the performance doesn't seem that clear cut. For instance, I get the following on Chrome, running it a few times: (Doing 100,000 parses of a small JSON string) JSON: (1653ms) vs eval: (206ms) Firefox the two are about even (650ms). Safari is also pretty much identical (250ms). Surprising that the Chrome JSON parse is so much slower than eval. Do you have any performance figures for JSON parsing? So you have JSON.parse which is the same, if not slower (Chrome) than using eval. Having to include extra unnecessary characters costs you bandwidth, but you do get the slightly better security from JSON, although that can be done with a quick regexp beforehand. {foo:1} should be valid dammit. It tells us exactly all we need to know, with 0 ambiguity. just my 2c.
- jeresig 17y agoTest case: http://ejohn.org/files/json-parse/ http://ejohn.org/files/json-parse/ Firefox 3.5: eval: 549 JSON.parse: 490 Safari 4: eval: 246 JSON.parse: 215 IE 8: eval: 1438 JSON.parse: 1031 Chrome: eval: 241 JSON.parse: 656 So yeah, a bit faster in Firefox and Safari, much much faster in IE 8 (the one that matters), and oddly slower in Chrome. I'll go out on a limb and blame their lax parsing (they support malformed strings). In the end though the parsing is a distant second to the improved security: Guaranteeing that eval will never get touched in modern browsers is a huge win from a framework perspective.
- Semiapies 17y agoCame up at least once before, but no discussion there: http://news.ycombinator.com/item?id=1054409 http://news.ycombinator.com/item?id=1054409
- rads 17y agoI had a problem with this today when upgrading from jQuery 1.3.2 to 1.4. The AJAX functions worked fine in Firefox, were returning "parseerror" in Safari because there was a non-UTF-8 character in the JSON response.