How to (completely) convert query string into JSON object?

Question

If I have the following form:

<form>
  <input name="foo" value="bar">
  <input name="hello" value="world">
  <input name="animals[]" value="panda">
  <input name="animals[]" value="koala">
  <input name="car[make]" value="Honda">
  <input name="car[origin]" value="Japan">
</form>

I do not want to use $("form").serialize():

foo=bar&hello=world&animals%5B%5D=panda&animals%5B%5D=koalacar&%5Bmake%5D=Honda&car%5Borigin%5D=Japan

Instead, I want this:

{"foo":"bar", "hello":"world", "animals":["panda", "koala"], "car":{"make":"Honda", "origin":"Japan"}}

To my understanding, jQuery used to do this, but they switched the serialize method to return the GET-style query string. Is there an easy way to get my desired result?

---

EDIT

I've updated my original question to include car[make] and car[origin] examples. It should be assumed that foo[bar][baz] or foo[bar][baz][bof] input could appear on the form as well.

Additionally, numerically indexed keys that are specified such as foo[0]=a, foo[1]=b, foo[4]=c should be preserved, e.g.,

{ ... "foo":["a", "b", undefined, undefined, "c"] ... }

Answer 1

In my case, I had to take a form I had previously serialized using jQuery and convert it into an object, replacing all encoding for special characters, etc. with their literal value. Using Dilip's example here, this is what I used.

  Form1 = $('#MyForm').serialize();  // Name=Mr.+John+Mark+Jr.&Email=john%40example.com
  Form1 = Form1.replace(/\+/g, '%20'); // Name=Mr.%20John%20Mark%20Jr.&Email=john%40example.com
  var Decoded = decodeURIComponent(Form1); // Name=Mr. John Mark Jr.&Email=john@example.com
  var Values = queryParamsToJson(Decoded); // { Name : "Mr. John Mark Jr.", Email : "john@example.com" }

  function queryParamsToJson(theURL)
  {
     href = theURL;
     qStr = href.replace(/(.*?\?)/, '');
     qArr = qStr.split('&');
     stack = {};
     for (var i in qArr)
     {
        var a = qArr[i].split('=');
        var name = a[0],
        value = isNaN(a[1]) ? a[1] : parseFloat(a[1]);
        if (name.match(/(.*?)\[(.*?)]/))
        {
           name = RegExp.$1;
           name2 = RegExp.$2;
           //alert(RegExp.$2)
           if (name2)
           {
              if (!(name in stack))
              {
                 stack[name] = {};
              }
              stack[name][name2] = value;
           }
           else
           {
              if (!(name in stack))
              {
                 stack[name] = [];
              }
              stack[name].push(value);
           }
        }
        else
        {
           stack[name] = value;
        }
     }
     return stack;
  }

Now I can access any value as "Values.variable"

Answer 2

This is a very good answer to convert the querystring to JSON. I got from the following SO link

knovel.util = {
     queryParamsToJson : function (theURL) {
        href = theURL;
        qStr = href.replace(/(.*?\?)/, '');
        qArr = qStr.split('&');
        stack = {};
        for (var i in qArr) {
            var a = qArr[i].split('=');
            var name = a[0],
                value = isNaN(a[1]) ? a[1] : parseFloat(a[1]);
            if (name.match(/(.*?)\[(.*?)]/)) {
                name = RegExp.$1;
                name2 = RegExp.$2;
                //alert(RegExp.$2)
                if (name2) {
                    if (!(name in stack)) {
                        stack[name] = {};
                    }
                    stack[name][name2] = value;
                } else {
                    if (!(name in stack)) {
                        stack[name] = [];
                    }
                    stack[name].push(value);
                }
            } else {
                stack[name] = value;
            }
        }
        return stack;
    }
}

Hope this helps some one..

Answer 3

Convert forms to JSON LIKE A BOSS

Github: Follow along on Github

The following code can take work with all sorts of input names; and handle them just as you'd expect.

E.g.,

<!-- all of these will work! -->
<input name="honey[badger]" value="a">
<input name="wombat[]" value="b">
<input name="hello[panda][]" value="c">
<input name="animals[0][name]" value="d">
<input name="animals[0][breed]" value="e">
<input name="crazy[1][][wonky]" value="f">
<input name="dream[as][vividly][as][you][can]" value="g">

// output
{
  "honey":{
    "badger":"a"
  },
  "wombat":["b"],
  "hello":{
    "panda":["c"]
  },
  "animals":[
    {
      "name":"d",
      "breed":"e"
    }
  ],
  "crazy":[
    null,
    [
      {"wonky":"f"}
    ]
  ],
  "dream":{
    "as":{
      "vividly":{
        "as":{
          "you":{
            "can":"g"
          }
        }
      }
    }
  }
}

Usage

$('#my-form').serializeObject();

The sorcery

(function($){
    $.fn.serializeObject = function(){

        var self = this,
            json = {},
            push_counters = {},
            patterns = {
                "validate": /^[a-zA-Z][a-zA-Z0-9_]*(?:\[(?:\d*|[a-zA-Z0-9_]+)\])*$/,
                "key":      /[a-zA-Z0-9_]+|(?=\[\])/g,
                "push":     /^$/,
                "fixed":    /^\d+$/,
                "named":    /^[a-zA-Z0-9_]+$/
            };


        this.build = function(base, key, value){
            base[key] = value;
            return base;
        };

        this.push_counter = function(key){
            if(push_counters[key] === undefined){
                push_counters[key] = 0;
            }
            return push_counters[key]++;
        };

        $.each($(this).serializeArray(), function(){

            // skip invalid keys
            if(!patterns.validate.test(this.name)){
                return;
            }

            var k,
                keys = this.name.match(patterns.key),
                merge = this.value,
                reverse_key = this.name;

            while((k = keys.pop()) !== undefined){

                // adjust reverse_key
                reverse_key = reverse_key.replace(new RegExp("\\[" + k + "\\]$"), '');

                // push
                if(k.match(patterns.push)){
                    merge = self.build([], self.push_counter(reverse_key), merge);
                }

                // fixed
                else if(k.match(patterns.fixed)){
                    merge = self.build([], k, merge);
                }

                // named
                else if(k.match(patterns.named)){
                    merge = self.build({}, k, merge);
                }
            }

            json = $.extend(true, json, merge);
        });

        return json;
    };
})(jQuery);

Answer 4

You could use ".serializeArray()", and then fix the result:

var json = {};
$.each($('form').serializeArray(), function() {
  json[this.name] = this.value;
});

Of course you might want to worry about multi-valued fields:

var json = {};
$.each($('form').serializeArray(), function() {
  var cur = json[this.name];
  if (cur !== undefined) {
    if ($.isArray(cur))
      cur.push(this.value);
    else
      json[ this.name.replace(/\[[^\]]*\]$/, '') ] = [ cur, this.value ];
  }
  else
    json[this.name] = this.value;
});

(edit — now that I think about it, "serialize" and "serializeArray" already kind-of deal with multi-value parameters for you, giving you names like "whatever[2]" in the serialized form. It'd work anyway but it might be unnecessary to do anything more than the simple one.)

Answer 5

I always do it like this, maybe a bit long winded but it's easy for me to maintain.

function FormContent(foo, hello, animals)
{
    this.Foo = foo;
    this.Hello = hello;
    this.Animals = animals;
}

var animals = [];
$("[name='animals[]']").each(function(){
    animals.push($(this).val());
});

var foo = $("[name='foo']").val();
var hello = $("[name='hello']").val();

var formContent = new FormContent(foo, hello, animals);
var jsonContent = json.stringify(formContent); // from json.org

I just realized you specifically asked "using jQuery" sorry. I've never had luck serializing to json with jQuery. Hope this helps anyway.