Optimalize jQuery .each - hiding options in DropDownList

Question

I have 2 optionsets. When ddlProduct is changed i hide and show some options in ddlPackage. Mapping between Product and Package is in value in each package option. Like this

<select name="ctl00$MidContent$ddlPackage" class="selectpicker" id="ddlPackage" style="display: none;" data-width="100%" data-style="btn-own btn-select hideDisabled">
<option value="134260004;Administrace;AXAPTA">

I'm splitting this string and comparing if last part to currently selected Product.

For DropDownList is used bootstrap extension: bootstrap-select http://silviomoreto.github.io/bootstrap-select/.

But it is too slow. Expecialy in IE.

$("#ddlProduct").change(function () {
    var product = $("#ddlProduct option:selected").text().trim();
    $("#ddlPackage option").each(function () {
        var optValues = $(this).val().split(";");
        var opt2 = optValues[2].trim();

        if (opt2 == "") {
            $(this).show();
        }
        else {
            if (opt2 == product) {
                $(this).show();
            }
            else {
                $(this).hide();
            }
        }
    });
    $("#ddlPackage").val($("#ddlPackage option:first").val());
    $("#ddlPackage").selectpicker('refresh');

<asp:Panel ID="Panel39" runat="server" CssClass="row">
    <asp:Panel ID="Panel40" runat="server" CssClass="row compenserow col-lg-4 col-md-4 col-sm-6">
        <asp:Label ID="Label29" runat="server" CssClass="col-lg-4 col-md-4 col-sm-4 col-xs-4">Prudukt: </asp:Label>
        <asp:Panel ID="Panel63" runat="server" CssClass="bootstrap-select col-lg-8 col-md-8 col-sm-8 col-xs-8">
            <asp:DropDownList ID="ddlProduct"  data-style="btn-own btn-select" data-width="100%" runat="server" CssClass="selectpicker" ClientIDMode="Static"></asp:DropDownList>
        </asp:Panel>
    </asp:Panel>
    <asp:Panel ID="Panel41" runat="server" CssClass="row compenserow col-lg-4 col-md-4 col-sm-6">
        <asp:Label ID="Label31" runat="server" CssClass="col-lg-4 col-md-4 col-sm-4 col-xs-4">Balík: </asp:Label>
        <asp:Panel ID="Panel64" runat="server" CssClass="bootstrap-select col-lg-8 col-md-8 col-sm-8 col-xs-8">
            <asp:DropDownList ID="ddlPackage"  data-style="btn-own btn-select hideDisabled" data-width="100%" runat="server" CssClass="selectpicker" ClientIDMode="Static"></asp:DropDownList>
        </asp:Panel>
    </asp:Panel>
</asp:Panel>

Answer 1

Your problem , in my opinion, is that string operation. It takes a lot amount of time to process for many options (I expect around 100 options). You should use data attribute instead of using ; as delimiter for multiple informations in one option value.

Your code can look like this:

<option value="134260004;Administrace;AXAPTA" data-id="134260004" data-text="Administrace" data-product="AXAPTA">

And now you just read what you need with jQuery:

$("#ddlPackage option").each(function () {
    var opt2 = $(this).data('product');

    if (opt2 == "") {
        $(this).show();
    }
    else if (opt2 == product) 
    {
        $(this).show();
    }
    else $(this).hide();
    }
});

This way you wont need to parse so many strings with every change event and it should be much faster :)

Answer 2

What about to add products to filter as classes:

<option value="134260004;Administrace;AXAPTA" class="Administrace">

and

$("#ddlProduct").change(function () {
    var product= $("#ddlProduct option:selected").text().trim();
    $("#ddlPackage option:not(."+product+")").hide();
    $("#ddlPackage option ."+product).show();
});

or in pirozek's way

<option value="134260004;Administrace;AXAPTA" data-text="Administrace">

and

$("#ddlProduct").change(function () {
    var product= $("#ddlProduct option:selected").text().trim();
    $("#ddlPackage option:not([data-text='"+product+"'])").hide();
    $("#ddlPackage option[data-text='"+product+"']").show();
});

In this way, you could also avoid that string trim operation mentioned in solution before.