How can I automatically map a json object to fields based off a viewmodel mapped to fields?

Question

I have a view that is loaded with a blank viewmodel initially. I want to populate that already rendered view with a json object (obtained view ajax post) that was based off the viewmodel for that view.

Is there a way of automatically doing this?
Is there a way of doing it in reverse? (fields to matching viewmodel json object)

Answer 1

Ok it looks like this will suit my needs. I need to follow a convention of naming containers the same name as their respective properties as well as putting a class on them to indicate that they contain subfields.

function MapJsonObjectToForm(obj, $container) {
    for (var key in obj) {
        if (obj.hasOwnProperty(key)) {
            var $field = $container.find('#' + key);
            if ($field.is('div')) {
                MapJsonObjectToForm(obj[key], $field);
            } else {
                if (obj[key] == null) {
                    if ($field.hasClass('select2-offscreen')) {
                        $field.select2('val', '');
                        $field.select2().trigger('change');
                    } else {
                        $field.val("");
                    }
                } else {
                    if ($field.hasClass('select2-offscreen')) {
                        $field.select2('val', obj[key]);
                        $field.select2().trigger('change');
                    } else {
                        $field.val(obj[key]);
                    }
                }
            }
        }
    }
}

function MapFormToJsonObject(containerid) {
    var obj = {};
    $('.dataitem').each(function () {
        var exclude = "s2id";
        if ($(this).attr("ID").substring(0, exclude.length) !== exclude) {
            var parents = $(this).parents(".has-sub-fields");
            if (parents.length > 0) {
                obj = FindParents(obj, parents.get(), $(this).attr("ID"), $(this).val());
            } else {
                obj[$(this).attr("ID")] = $(this).val();
            }
        }
    });
    return obj;
}

function FindParents(obj, arr, id, value) {
    if (arr.length == 0) {
        obj[id] = value;
        return obj;
    }
    var parentID = $(arr[arr.length - 1]).attr("ID");
    arr.pop();
    if (obj[parentID] == null) {
        obj[parentID] = {};
    }
    obj[parentID] = FindParents(obj[parentID], arr, id, value);
    return obj;
}