form2js

Convenient way to collect structured form data into JavaScript object. Example. Because everything is better with jQuery, jQuery plugin added, check out jquery.toObject.js. If you have any questions/suggestions, find out something weird or illogical - feel free to post an issue.

Warning! form2object.js and form2object function renamed to form2js.js and form2js respectively. Old names are in v1.0 tag.

Details

This is not a serialization library. Library used in example for JSON serialization is http://www.json.org/js.html Structure of resulting object defined by name attribute of form fields. See examples below. All this library does is collect form data and put it in a javascript object. Obviously you can get a JSON/XML/etc string by serializing it, but that's not its only purpose.

Usage

form2js(rootNode, delimiter, skipEmpty, nodeCallback, useIdIfEmptyName)

Values of all inputs under the rootNode will be collected into one object. skipping empty inputs if skipEmpty not false.

Objects/nested objects

Structure of resulting object defined in name attributes of form fields (or id if name is empty and useIdIfEmptyName parameter set to true). delimiter is "." (dot) by default, but can be changed.

<input type="text" name="person.name.first" value="John" />
<input type="text" name="person.name.last" value="Doe" />

becomes

{
  "person": {
    "name": {
      "first": "John",
      "last": "Doe"
    }
  }
}

Arrays

Several fields with the same name with brackets defines array of values.

<label><input type="checkbox" name="person.favFood[]" value="steak" checked="checked" /> Steak</label>
<label><input type="checkbox" name="person.favFood[]" value="pizza"/> Pizza</label>
<label><input type="checkbox" name="person.favFood[]" value="chicken" checked="checked" /> Chicken</label>

becomes

{
    "person": {
        "favFood": [ "steak", "chicken" ]
    }
}

Arrays of objects/nested objects

Same index means same item in resulting array. Index doesn't specify order (order of appearance in document will be used).

<dl>
    <dt>Give us your five friends' names and emails</dt>
    <dd>
        <label>Email <input type="text" name="person.friends[0].email" value="agent.smith@example.com" /></label>
        <label>Name <input type="text" name="person.friends[0].name" value="Smith Agent"/></label>
    </dd>
    <dd>
        <label>Email <input type="text" name="person.friends[1].email" value="n3o@example.com" /></label>
        <label>Name <input type="text" name="person.friends[1].name" value="Thomas A. Anderson" /></label>
    </dd>
</dl>

becomes

{
    "person" :
    {
        "friends" : [
            { "email" : "agent.smith@example.com", "name" : "Smith Agent" },
            { "email" : "n3o@example.com", "name" : "Thomas A. Anderson" }
        ]
    }
}

Rails-style notation

If array index starts with [a-zA-Z_], it will be treated as field of object.

<dl>
    <dt>Rails-style test</dt>
    <dd>
        <label>rails[field1][foo]<input type="text" name="rails[field1][foo]" value="baz" /></label>
        <label>rails[field1][bar]<input type="text" name="rails[field1][bar]" value="qux" /></label>
    </dd>
    <dd>
        <label>rails[field2][foo]<input type="text" name="rails[field2][foo]" value="baz" /></label>
        <label>rails[field2][bar]<input type="text" name="rails[field2][bar]" value="qux" /></label>
    </dd>
</dl>

will give us:

{
    "rails": {
        "field1": {
            "foo": "baz",
            "bar": "qux"
        },
        "field2": {
            "foo": "baz",
            "bar": "qux"
        }
    }
}

Custom fields

You can implement custom nodeCallback function (passed as 4th parameter to form2object()) to extract custom data:

<dl id="dateTest">
<dt>Date of birth:</dt>
<dd data-name="person.dateOfBirth" class="datefield">
    <select name="person.dateOfBirth.month">
        <option value="01">January</option>
        <option value="02">February</option>
        <option value="03">March</option>
        <option value="04">April</option>
        <option value="05">May</option>
        <option value="06">June</option>
        <option value="07">July</option>
        <option value="08">August</option>
        <option value="09">September</option>
        <option value="10">October</option>
        <option value="11">November</option>
        <option value="12">December</option>
    </select>
    <input type="text" name="person.dateOfBirth.day" value="1" />
    <input type="text" name="person.dateOfBirth.year" value="2011" />
</dd>
</dl>

<script type="text/javascript">
    function processDate(node)
    {
        var dataName = node.getAttribute ? node.getAttribute('data-name') : '',
            dayNode,
            monthNode,
            yearNode,
            day,
            year,
            month;

        if (dataName && dataName != '' && node.className == 'datefield')
        {
            dayNode = node.querySelector('input[name="'+dataName + '.day"]');
            monthNode = node.querySelector('select[name="'+dataName + '.month"]');
            yearNode = node.querySelector('input[name="'+dataName + '.year"]');

            day = dayNode.value;
            year = yearNode.value;
            month = monthNode.value;

            return { name: dataName, value:  year + '-' + month + '-' + day};
        }

        return false;
    }

    var formData = form2object('dateTest', '.', true, processDate);
</script>

using processDate() callback formData will contain

{
    "person": {
        "dateOfBirth": "2011-01-12"
    }
}

Why not .serializeArray()?

JQuery's .serializeArray() works a bit different. It makes this structure from markup in "Arrays of objects/nested objects" example:

[
    { "person.friends[0].email" : "agent.smith@example.com" },
    { "person.friends[0].name" : "Smith Agent" },
    { "person.friends[1].email" : "n3o@example.com" },
    { "person.friends[1].name" : "Thomas A. Anderson" }
]