https://www.kaminfeger.ch/shop/js/jquery.formsaver.js

1(function ($) {
2    function formsaver(method, container) {
3        function getStorageId(container) {
4            return 'formdata__$url__$extra'.replace('$url', location.pathname)
5                                           .replace('$extra', container.attr('id') || '');
6        }
7
8        var storageId = getStorageId(container),
9            controller = {
10                save: function () {
11                    this._save(storageId, this.extractValues());
12                },
13                restore: function () {
14                    this.fillFields(this._load(storageId));
15                },
16                clear: function () {
17                    this._remove(storageId);
18                },
19
20                extractValues: function () {
21                    var formData = container.find(":input[name]").serializeArray(),
22                        preparedData = {};
23                    $.each(formData, function (index, element) {
24                        var name = element.name,
25                            value = encodeURIComponent(element.value);
26                        if (preparedData[name]) {
27                            preparedData[name] = preparedData[name] instanceof Array ?
28                                                 preparedData[name].concat(value) :
29                                                 [preparedData[name], value];
30                        } else {
31                            preparedData[name] = value;
32                        }
33                    });
34                    return preparedData;
35                },
36                fillFields: function (formData) {
37                    // uncheck all checkboxes first, because they would not be in the formData array.
38                    function isEmpty(obj) {
39                        for(var key in obj) {
40                            if(obj.hasOwnProperty(key))
41                                return false;
42                        }
43                        return true;
44                    }
45
46                    if(formData && !isEmpty(formData)) {
47                      container.find("[type=checkbox]").prop('checked', false);
48                    }
49
50                    $.each(formData, function (name, value) {
51                        var field = container.find("[name=" + name + "]"),
52                            inputType = field.prop('type');
53                        value = value instanceof Array ? value.map(decodeURIComponent) :
54                                                         decodeURIComponent(value);
55                        if (inputType === 'checkbox') {
56                            field.filter("[value=" + value + "]").prop('checked', true);
57                        } else if (inputType === 'radio') {
58                            field.filter("[value=" + value + "]").prop('checked', true);
59                        } else {
60                            field.val(value);
61                        }
62
63                        field.trigger('change');
64                    });
65                },
66
67                _save: function (storageId, data) {
68                    localStorage.setItem(storageId, JSON.stringify(data));
69                },
70                _load: function (storageId) {
71                    return localStorage.getItem(storageId) ? JSON.parse(localStorage.getItem(storageId)) : {};
72                },
73                _remove: function (storageId) {
74                    localStorage.removeItem(storageId);
75                }
76            },
77            methodsQueue = method instanceof Array ? method : [method];
78
79        $.each(methodsQueue, function (index, method) {
80            controller[method]();
81        });
82    }
83    $.fn.saveForm = function () {
84        formsaver('save', $(this));
85    };
86    $.fn.restoreForm = function () {
87        formsaver(['restore', 'clear'], $(this));
88    };
89})(jQuery);