jQuery deserialize form

Try this:

function deparam(query) {
    var pairs, i, keyValuePair, key, value, map = {};
    // remove leading question mark if its there
    if (query.slice(0, 1) === '?') {
        query = query.slice(1);
    }
    if (query !== '') {
        pairs = query.split('&');
        for (i = 0; i < pairs.length; i += 1) {
            keyValuePair = pairs[i].split('=');
            key = decodeURIComponent(keyValuePair[0]);
            value = (keyValuePair.length > 1) ? decodeURIComponent(keyValuePair[1]) : undefined;
            map[key] = value;
        }
    }
    return map;
}

I was very interested in trying JQuery.deserialize, but it didn't seem to handle checkboxes at all, so it didn't serve my purposes. So I wrote my own. It turned out to be easier than I thought, because the jQuery val() function does most of the work:

jQuery.fn.deserialize = function (data) {
    var f = this,
        map = {},
        find = function (selector) { return f.is("form") ? f.find(selector) : f.filter(selector); };
    //Get map of values
    jQuery.each(data.split("&"), function () {
        var nv = this.split("="),
            n = decodeURIComponent(nv[0]),
            v = nv.length > 1 ? decodeURIComponent(nv[1]) : null;
        if (!(n in map)) {
            map[n] = [];
        }
        map[n].push(v);
    })
    //Set values for all form elements in the data
    jQuery.each(map, function (n, v) {
        find("[name='" + n + "']").val(v);
    })
    //Clear all form elements not in form data
    find("input:text,select,textarea").each(function () {
        if (!(jQuery(this).attr("name") in map)) {
            jQuery(this).val("");
        }
    })
    find("input:checkbox:checked,input:radio:checked").each(function () {
        if (!(jQuery(this).attr("name") in map)) {
            this.checked = false;
        }
    })
    return this;
};

You should be able to use this like this:

$("#myform").deserialize(data);

Where data is a parameter list such as what $("#myform").serialize() would produce.

It affects all fields in the form, and it will clear the values of fields that are not contained in the data. But you can also pass any selector to affect only specific fields, as you can with the serialize function. E.g.:

$("select").deserialize(data);

I wrote a version of jQuery.deserialize that supports serialized data generated from the serialize, serializeArray and serializeObject functions. It also supports all form element types, including checkboxes and radio buttons.