Convert form data to JavaScript object with jQuery

This function should handle multidimensional arrays along with multiple elements with the same name.

I've been using it for a couple years so far:

jQuery.fn.serializeJSON=function() {
  var json = {};
  jQuery.map(jQuery(this).serializeArray(), function(n, i) {
    var _ = n.name.indexOf('[');
    if (_ > -1) {
      var o = json;
      _name = n.name.replace(/\]/gi, '').split('[');
      for (var i=0, len=_name.length; i<len; i++) {
        if (i == len-1) {
          if (o[_name[i]]) {
            if (typeof o[_name[i]] == 'string') {
              o[_name[i]] = [o[_name[i]]];
            }
            o[_name[i]].push(n.value);
          }
          else o[_name[i]] = n.value || '';
        }
        else o = o[_name[i]] = o[_name[i]] || {};
      }
    }
    else {
      if (json[n.name] !== undefined) {
        if (!json[n.name].push) {
          json[n.name] = [json[n.name]];
        }
        json[n.name].push(n.value || '');
      }
      else json[n.name] = n.value || '';      
    }
  });
  return json;
};

Turn anything into an object (not unit tested)

<script type="text/javascript">
string = {};

string.repeat = function(string, count)
{
    return new Array(count+1).join(string);
}

string.count = function(string)
{
    var count = 0;

    for (var i=1; i<arguments.length; i++)
    {
        var results = string.match(new RegExp(arguments[i], 'g'));
        count += results ? results.length : 0;
    }

    return count;
}

array = {};

array.merge = function(arr1, arr2)
{
    for (var i in arr2)
    {
        if (arr1[i] && typeof arr1[i] == 'object' && typeof arr2[i] == 'object')
            arr1[i] = array.merge(arr1[i], arr2[i]);
        else
            arr1[i] = arr2[i]
    }

    return arr1;
}

array.print = function(obj)
{
    var arr = [];
    $.each(obj, function(key, val) {
        var next = key + ": ";
        next += $.isPlainObject(val) ? array.print(val) : val;
        arr.push( next );
      });

    return "{ " +  arr.join(", ") + " }";
}

node = {};

node.objectify = function(node, params)
{
    if (!params)
        params = {};

    if (!params.selector)
        params.selector = "*";

    if (!params.key)
        params.key = "name";

    if (!params.value)
        params.value = "value";

    var o = {};
    var indexes = {};

    $(node).find(params.selector+"["+params.key+"]").each(function()
    {
        var name = $(this).attr(params.key),
            value = $(this).attr(params.value);

        var obj = $.parseJSON("{"+name.replace(/([^\[]*)/, function()
        {
            return '"'+arguments[1]+'"';
        }).replace(/\[(.*?)\]/gi, function()
        {
            if (arguments[1].length == 0)
            {
                var index = arguments[3].substring(0, arguments[2]);
                indexes[index] = indexes[index] !== undefined ? indexes[index]+1 : 0;

                return ':{"'+indexes[index]+'"';
            }
            else
                return ':{"'+escape(arguments[1])+'"';
        })+':"'+value.replace(/[\\"]/gi, function()
        {
            return "\\"+arguments[0]; 
        })+'"'+string.repeat('}', string.count(name, ']'))+"}");

        o = array.merge(o, obj);
    });

    return o;
}
</script>

The output of test:

$(document).ready(function()
{
    console.log(array.print(node.objectify($("form"), {})));
    console.log(array.print(node.objectify($("form"), {selector: "select"})));
});

on

<form>
    <input name='input[a]' type='text' value='text'/>
    <select name='input[b]'>
        <option>select</option>
    </select>

    <input name='otherinput[c][a]' value='a'/>
    <input name='otherinput[c][]' value='b'/>
    <input name='otherinput[d][b]' value='c'/>
    <input name='otherinput[c][]' value='d'/>

    <input type='hidden' name='anotherinput' value='hidden'/>
    <input type='hidden' name='anotherinput' value='1'/>

    <input type='submit' value='submit'/>
</form>

will yield:

{ input: { a: text, b: select }, otherinput: { c: { a: a, 0: b, 1: d }, d: { b: c } }, anotherinput: 1 }
{ input: { b: select } }

Has anyone mentioned this link? pretty cool and as easy as $('#myform').formParams();

Check this lib (not a jQuery, but its small and does exaclty what you're need): http://code.google.com/p/form2js/

The author has since added jQuery plugin support at his github page https://github.com/maxatwork/form2js

Serializes complicated forms well.

A fixed version of Tobias Cohen's solution. This one correctly handles falsy values like 0 and ''.

jQuery.fn.serializeObject = function() {
  var arrayData, objectData;
  arrayData = this.serializeArray();
  objectData = {};

  $.each(arrayData, function() {
    var value;

    if (this.value != null) {
      value = this.value;
    } else {
      value = '';
    }

    if (objectData[this.name] != null) {
      if (!objectData[this.name].push) {
        objectData[this.name] = [objectData[this.name]];
      }

      objectData[this.name].push(value);
    } else {
      objectData[this.name] = value;
    }
  });

  return objectData;
};

And a CoffeeScript version for your coding convenience:

jQuery.fn.serializeObject = ->
  arrayData = @serializeArray()
  objectData = {}

  $.each arrayData, ->
    if @value?
      value = @value
    else
      value = ''

    if objectData[@name]?
      unless objectData[@name].push
        objectData[@name] = [objectData[@name]]

      objectData[@name].push value
    else
      objectData[@name] = value

  return objectData

The serialize function take JSON object as a parameter and return serialize String.

function serialize(object) {
            var _SPECIAL_CHARS = /[\\\"\x00-\x1f\x7f-\x9f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g, _CHARS = {
                '\b' : '\\b',
                '\t' : '\\t',
                '\n' : '\\n',
                '\f' : '\\f',
                '\r' : '\\r',
                '"' : '\\"',
                '\\' : '\\\\'
            }, EMPTY = '', OPEN_O = '{', CLOSE_O = '}', OPEN_A = '[', CLOSE_A = ']', COMMA = ',', COMMA_CR = ",\n", CR = "\n", COLON = ':', space = "", COLON_SP = ': ', stack = [], QUOTE = '"';
            function _char(c) {
                if (!_CHARS[c]) {
                    _CHARS[c] = '\\u' + ('0000' + (+(c.charCodeAt(0))).toString(16))
                        .slice(-4);
                }
                return _CHARS[c];
            }
            function _string(s) {
                return QUOTE + s.replace(_SPECIAL_CHARS, _char) + QUOTE;
                // return str.replace('\"','').replace('\"','');
            }

            function serialize(h, key) {
                var value = h[key], a = [], colon = ":", arr, i, keys, t, k, v;
                arr = value instanceof Array;
                stack.push(value);
                keys = value;
                i = 0;
                t = typeof value;
                switch (t) {
                    case "object" :
                        if(value==null){
                            return null;
                        }
                        break;
                    case "string" :
                        return _string(value);
                    case "number" :
                        return isFinite(value) ? value + EMPTY : NULL;
                    case "boolean" :
                        return value + EMPTY;
                    case "null" :
                        return null;
                    default :
                        return undefined;
                }
                arr = value.length === undefined ? false : true;

                if (arr) { // Array
                    for (i = value.length - 1; i >= 0; --i) {
                        a[i] = serialize(value, i) || NULL;
                    }
                }
                else { // Object
                    i = 0;
                    for (k in keys) {
                        if (keys.hasOwnProperty(k)) {
                            v = serialize(value, k);
                            if (v) {
                                a[i++] = _string(k) + colon + v;
                            }
                        }
                    }
                }

                stack.pop();
                if (space && a.length) {

                    return arr
                        ? "[" + _indent(a.join(COMMA_CR), space) + "\n]"
                        : "{\n" + _indent(a.join(COMMA_CR), space) + "\n}";
                }
                else {
                    return arr ? "[" + a.join(COMMA) + "]" : "{" + a.join(COMMA)
                        + "}";
                }
            }
            return serialize({
                "" : object
            }, "");
        }

I like samuels version, but I believe it has a small error. Normally JSON is sent as

{"coreSKU":"PCGUYJS","name_de":"whatever",...

NOT as

[{"coreSKU":"PCGUYJS"},{"name_de":"whatever"},...

so the function IMO should read:

App.toJson = function( selector ) {
    var o = {};
    $.map( $( selector ), function( n,i )
    {
        o[n.name] = $(n).val();
    });     
    return o;
}

and to wrap it in data array (as commonly expected, too), and finally send it as astring App.stringify( {data:App.toJson( '#cropform :input' )} )

For the stringify look at Question 3593046 for the lean version, at json2.js for the every-eventuality-covered version. That should cover it all :)

All of these answers seemed so over the top to me. There's something to be said for simplicity. As long as all your form inputs have the name attribute set this should work just jim dandy.

$('form.myform').submit(function () {
  var $this = $(this)
    , viewArr = $this.serializeArray()
    , view = {};

  for (var i in viewArr) {
    view[viewArr[i].name] = viewArr[i].value;
  }

  //Do stuff with view object here (e.g. JSON.stringify?)
});

I found a problem with Tobias Cohen's code (I don't have enough points to comment on it directly), which otherwise works for me. If you have two select options with the same name, both with value="", the original code will produce "name":"" instead of "name":["",""]

I think this can fixed by adding " || o[this.name] == ''" to the first if condition:

$.fn.serializeObject = function()
{
    var o = {};
    var a = this.serializeArray();
    $.each(a, function() {
        if (o[this.name] || o[this.name] == '') {
            if (!o[this.name].push) {
                o[this.name] = [o[this.name]];
            }
            o[this.name].push(this.value || '');
        } else {
            o[this.name] = this.value || '';
        }
    });
    return o;
};

Ok, I know this already has a highly upvoted answer, but another similar question was asked recently, and I was directed to this question as well. I'd like to offer my solution as well, because it offers an advantage over the accepted solution: You can include disabled form elements (which is sometimes important, depending on how your UI functions)

Here is my answer from the other SO question:

Initially, we were using jQuery's serializeArray() method, but that does not include form elements that are disabled. We will often disable form elements that are "sync'd" to other sources on the page, but we still need to include the data in our serialized object. So serializeArray() is out. We used the :input selector to get all input elements (both enabled and disabled) in a given container, and then $.map() to create our object.

var inputs = $("#container :input");
var obj = $.map(inputs, function(n, i)
{
    var o = {};
    o[n.name] = $(n).val();
    return o;
});
console.log(obj);

Note that for this to work, each of your inputs will need a name attribute, which will be the name of the property of the resulting object.

That is actually slightly modified from what we used. We needed to create an object that was structured as a .NET IDictionary, so we used this: (I provide it here in case it's useful)

var obj = $.map(inputs, function(n, i)
{
    return { Key: n.name, Value: $(n).val() };
});
console.log(obj);

I like both of these solutions, because they are simple uses of the $.map() function, and you have complete control over your selector (so, which elements you end up including in your resulting object). Also, no extra plugin required. Plain old jQuery.

I prefer this approach because: you don't have to iterate over 2 collections, you can get at things other than "name" and "value" if you need to, and you can sanitize your values before you store them in the object (if you have default values that you don't wish to store, for example).

$.formObject = function($o) {
    var o = {},
        real_value = function($field) {
            var val = $field.val() || "";

            // additional cleaning here, if needed

            return val;
        };

    if (typeof o != "object") {
        $o = $(o);
    }

    $(":input[name]", $o).each(function(i, field) {
        var $field = $(field),
            name = $field.attr("name"),
            value = real_value($field);

        if (o[name]) {
            if (!$.isArray(o[name])) {
                o[name] = [o[name]];
            }

            o[name].push(value);
        }

        else {
            o[name] = value;
        }
    });

    return o;
}

Use like so:

var obj = $.formObject($("#someForm"));

Only tested in Firefox.

I wouldn't use this on a live site due to XSS attacks and probably plenty of other issues, but here's a quick example of what you could do:

$("#myform").submit(function(){
    var arr = $(this).serializeArray();
    var json = "";
    jQuery.each(arr, function(){
    	jQuery.each(this, function(i, val){
    		if (i=="name") {
    			json += '"' + val + '":';
    		} else if (i=="value") {
    			json += '"' + val.replace(/"/g, '\\"') + '",';
    		}
    	});
    });
    json = "{" + json.substring(0, json.length - 1) + "}";
    // do something with json
    return false;
});

There really is no way to do this without examining each of the elements. What you really want to know is "has someone else already written a method that converts a form to a JSON object?" Something like the following should work -- note that it will only give you the form elements that would be returned via a POST (must have a name). This is not tested.

function formToJSON( selector )
{
     var form = {};
     $(selector).find(':input[name]:enabled').each( function() {
         var self = $(this);
         var name = self.attr('name');
         if (form[name]) {
            form[name] = form[name] + ',' + self.val();
         }
         else {
            form[name] = self.val();
         }
     });

     return form;
}