JSON stringify missing from jQuery 1.4.1?

问题:

Apparently jQuery has the ability to decode a given object or string into a JSON object. However, I have a JS object that I need to POST back to the server and I find no utility in jQuery that wraps the JSON.stringify() function. That function is found in Chrome, Safari 4, FF3.6, and IE8 but is not found in earlier browsers. I can use it natively in the browsers that support it, but otherwise am forced to fall back to using Crockford's JSON scripts.

Is there some built-in with jQuery that handles JSON encoding and decoding that takes the place of the Crockford scripts?

回答1:

You might want to check this out: http://www.json.org/js.html

回答2:

You can use "Closure Library" (Google) to make a cross browser JSON encoder/decoder.

Just go to http://closure-compiler.appspot.com/

and insert the following into the text field, then hit "Compile":

// ==ClosureCompiler==
// @compilation_level ADVANCED_OPTIMIZATIONS
// @output_file_name default.js
// @use_closure_library true
// ==/ClosureCompiler==

goog.require('goog.json');
if (!window['JSON']) window['JSON']={};
if (typeof window['JSON']['stringify'] !== 'function') window['JSON']['stringify']=goog.json.serialize;
if (typeof window['JSON']['parse'] !== 'function') window['JSON']['parse']=goog.json.parse;

回答3:

jQuery can decode JSON strings natively with jQuery.parseJSON().

For encoding though, i only know of a plugin : jquery-json

回答4:

jQuery does not need this functionality internally and thus does not provide a convenience method to do so.

JSON.stringify() is the standard and recommended way of encoding an object to a JSON string representation of that object. It is a method of the native JSON object in many browsers, and it is recommended you use json2.js (https://github.com/douglascrockford/JSON-js) to provide a fallback.

回答5:

To build on stewe's answer, closure compiler with Advanced turned on gives you a script that pollutes the global namespace with a bunch of one letter variables. So, I just wrap it in an anonymous function call like so:

(function() { function g(a){var b=typeof a;if("object"==b)if(a){if(a instanceof Array)return"array";if(a instanceof Object)return b;var c=Object.prototype.toString.call(a);if("[object Window]"==c)return"object";if("[object Array]"==c||"number"==typeof a.length&&"undefined"!=typeof a.splice&&"undefined"!=typeof a.propertyIsEnumerable&&!a.propertyIsEnumerable("splice"))return"array";if("[object Function]"==c||"undefined"!=typeof a.call&&"undefined"!=typeof a.propertyIsEnumerable&&!a.propertyIsEnumerable("call"))return"function"}else return"null"; else if("function"==b&&"undefined"==typeof a.call)return"object";return b};function h(a){a=""+a;if(/^\s*$/.test(a)?0:/^[\],:{}\s\u2028\u2029]*$/.test(a.replace(/\\["\\\/bfnrtu]/g,"@").replace(/"[^"\\\n\r\u2028\u2029\x00-\x08\x10-\x1f\x80-\x9f]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g,"]").replace(/(?:^|:|,)(?:[\s\u2028\u2029]*\[)+/g,"")))try{return eval("("+a+")")}catch(b){}throw Error("Invalid JSON string: "+a);}function i(a,b){var c=[];j(new k(b),a,c);return c.join("")}function k(a){this.a=a} function j(a,b,c){switch(typeof b){case "string":l(b,c);break;case "number":c.push(isFinite(b)&&!isNaN(b)?b:"null");break;case "boolean":c.push(b);break;case "undefined":c.push("null");break;case "object":if(null==b){c.push("null");break}if("array"==g(b)){var f=b.length;c.push("[");for(var d="",e=0;e<f;e++)c.push(d),d=b[e],j(a,a.a?a.a.call(b,""+e,d):d,c),d=",";c.push("]");break}c.push("{");f="";for(e in b)Object.prototype.hasOwnProperty.call(b,e)&&(d=b[e],"function"!=typeof d&&(c.push(f),l(e,c),c.push(":"), j(a,a.a?a.a.call(b,e,d):d,c),f=","));c.push("}");break;case "function":break;default:throw Error("Unknown type: "+typeof b);}}var m={'"':'\\"',"\\":"\\\\","/":"\\/","\u0008":"\\b","\u000c":"\\f","\n":"\\n","\r":"\\r","\t":"\\t","\x0B":"\\u000b"},n=/\uffff/.test("\uffff")?/[\\\"\x00-\x1f\x7f-\uffff]/g:/[\\\"\x00-\x1f\x7f-\xff]/g; function l(a,b){b.push('"',a.replace(n,function(a){if(a in m)return m[a];var b=a.charCodeAt(0),d="\\u";16>b?d+="000":256>b?d+="00":4096>b&&(d+="0");return m[a]=d+b.toString(16)}),'"')};window.JSON||(window.JSON={});"function"!==typeof window.JSON.stringify&&(window.JSON.stringify=i);"function"!==typeof window.JSON.parse&&(window.JSON.parse=h); })();

Now you can call:

var JSONString = JSON.stringify({name: 'value'});

回答6:

Often the JSON.stringify() function is not required when using jQuery. Take for example the common case of using ajax to send javascript data to the server, jquery has built-in functions to handle this: (examples from http://api.jquery.com/category/ajax/)

$.post("test.php", { name: "John", time: "2pm" } );
$.post("test.php", { 'choices[]': ["Jon", "Susan"] });
$.getJSON("test.js", { name: "John", time: "2pm" }, function(json) {
    alert("JSON Data: " + json.users[3].name);
});

In all the examples above the javascript data sent is serialized by jQuery automatically.

The serialization in these cases is not the same as JSON.Stringify(), instead the data is serialised into a html query string (see: http://en.wikipedia.org/wiki/Query_string#Structure).

However this form of serialization is fine for most (but not all) applications