[CLOSED] Load 1 item to combobox store and get value of selected item on serverside

**ViDom** · Dec 13, 2012, 7:30 AM

Hi,

I need to set value to combobox store:

This is related question to this:
http://forums.ext.net/showthread.php...tances-are-met

configuration of store:
http://forums.ext.net/showthread.php...ll=1#post98333

what I have tryed:

object o = Activator.CreateInstance(type,new object[]{1,null};//type is System.Type of my BLL Object
combo.Store.AddRecord(o);//here I got exception JsonSerializationException do I need serialize this 'o' element? Store is simply Property which return store of combo(my custom server control inherited from CompositeField contains combobox and ext.net.button

Thanks,
ViDom

**Daniil** · Dec 13, 2012, 11:48 AM

Hi @ViDom,

An object must be serializable. A Dictionary or just an anonymous object.

Example

Store store = this.ComboBox1.GetStore();

store.AddRecord(new
{
    value = "4",
    text = "Item 4"
});

or

**ViDom** · Dec 13, 2012, 1:39 PM

Originally Posted by Daniil

Hi @ViDom,

An object must be serializable. A Dictionary or just an anonymous object.

Example

Store store = this.ComboBox1.GetStore();

store.AddRecord(new
{
    value = "4",
    text = "Item 4"
});

or

ok but after add this record It should be selected on begin and stay that way since user will reload store and change(or not next problem seems to occur here). When I do it like this

ComboBox1.Value = 4;

it's displaying 4 but should display 'Item 4' string. I have be able to display Item 4 by assigning it to Value property of combobox but not sure if it's good idea ( i need to get this value on button event)

and how to prevent combobox event to ask ( uncommited changes ) on reload store if there is loaded item this way?

please tell me if this can be done another way( way to know which item is selected if user doesn't change selection on serverside) or maybe this way described above is good?

**Daniil** · Dec 13, 2012, 2:58 PM

Originally Posted by ViDom

When I do it like this

ComboBox1.Value = 4;

it's displaying 4 but should display 'Item 4' string. I have be able to display Item 4 by assigning it to Value property of combobox but not sure if it's good idea ( i need to get this value on button event)

I am unable to reproduce. Please provide a test case.

Here is my one.

Example

<%@ Page Language="C#" %>

<%@ Register Assembly="Ext.Net" Namespace="Ext.Net" TagPrefix="ext" %>

<script runat="server">
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!X.IsAjaxRequest)
        {
            Store store = this.ComboBox1.GetStore();
            store.DataSource = new object[] 
            { 
                new object[] { 1, "item1" },
                new object[] { 2, "item2" },
                new object[] { 3, "item3" }
            };
            store.DataBind();
        }
    }

    protected void Add(object sender, DirectEventArgs e)
    {
        Store store = this.ComboBox1.GetStore();

        store.AddRecord(new
        {
            value = 4,
            text = "Item 4"
        });

        this.ComboBox1.Value = 4;
    }
</script>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Ext.NET Example</title>
</head>
<body>
    <form runat="server">
        <ext:ResourceManager runat="server" />
        <ext:ComboBox ID="ComboBox1" runat="server">
            <Store>
                <ext:Store runat="server">
                    <Reader>
                        <ext:ArrayReader>
                            <Fields>
                                <ext:RecordField Name="value" Type="Int" />
                                <ext:RecordField Name="text" />
                            </Fields>
                        </ext:ArrayReader>
                    </Reader>
                </ext:Store>
            </Store>
        </ext:ComboBox>
        <ext:Button runat="server" Text="Add" OnDirectClick="Add" />
    </form>
</body>
</html>

Originally Posted by ViDom

and how to prevent combobox event to ask ( uncommited changes ) on reload store if there is loaded item this way?

Please set up WarningOnDirty="false" for the Store.

Originally Posted by ViDom

way to know which item is selected if user doesn't change selection on serverside

A selected item's value should be accessible on a server via:

this.ComboBox1.SelectedItem.Value

**ViDom** · Dec 14, 2012, 9:15 AM

Originally Posted by Daniil

I am unable to reproduce. Please provide a test case.

Here is my one.

Example

<%@ Page Language="C#" %>

<%@ Register Assembly="Ext.Net" Namespace="Ext.Net" TagPrefix="ext" %>

<script runat="server">
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!X.IsAjaxRequest)
        {
            Store store = this.ComboBox1.GetStore();
            store.DataSource = new object[] 
            { 
                new object[] { 1, "item1" },
                new object[] { 2, "item2" },
                new object[] { 3, "item3" }
            };
            store.DataBind();
        }
    }

    protected void Add(object sender, DirectEventArgs e)
    {
        Store store = this.ComboBox1.GetStore();

        store.AddRecord(new
        {
            value = 4,
            text = "Item 4"
        });

        this.ComboBox1.Value = 4;
    }
</script>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Ext.NET Example</title>
</head>
<body>
    <form runat="server">
        <ext:ResourceManager runat="server" />
        <ext:ComboBox ID="ComboBox1" runat="server">
            <Store>
                <ext:Store runat="server">
                    <Reader>
                        <ext:ArrayReader>
                            <Fields>
                                <ext:RecordField Name="value" Type="Int" />
                                <ext:RecordField Name="text" />
                            </Fields>
                        </ext:ArrayReader>
                    </Reader>
                </ext:Store>
            </Store>
        </ext:ComboBox>
        <ext:Button runat="server" Text="Add" OnDirectClick="Add" />
    </form>
</body>
</html>

Please set up WarningOnDirty="false" for the Store.

A selected item's value should be accessible on a server via:

this.ComboBox1.SelectedItem.Value

I confirm that value is accesible on server via

this.ComboBox1.SelectedItem.Value

here is my sample to reproduce loading one record on begin(I have edited post and add this issue):
http://forums.ext.net/showthread.php...ll=1#post98429

**Daniil** · Dec 14, 2012, 10:45 AM

This code:

protected void Page_Load(object sender, EventArgs e)
{
    mycontrol.Store.AddRecord(new { Id = 1, Name = "first" });//tryed also mycontrol.ComboBox.GetStore().AddRecord(new { Id=1, Name="first"}); it's make same result  display 1 when should display "first"
    mycontrol.ComboBox.Value = 1;
}

The AddRecord should not be used in a Page_Load handler. It is designed to be used during an Ext.NET AJAX request.

What about to preload a required item?

You can change it to true:

store.AutoLoad = false;

And set up a parameter in the AutoLoadParams collection which would mean "load the default value".

Generally, you configure an HttpProxy for the Store. It means to load the data remotely. But trying to set up a default item in the Page_Load. IMHO, this is not very well.

You could try this:

mycontrol.ComboBox.Value = 1;
mycontrol.ComboBox.Text = "Item 1";

It should work as you need, but it is a tricky thing. For example, it doesn't work in Ext.NET v2.

**ViDom** · Dec 14, 2012, 11:03 AM

Originally Posted by Daniil

You could try this:

mycontrol.ComboBox.Value = 1;
mycontrol.ComboBox.Text = "Item 1";

It should work as you need, but it is a tricky thing. For example, it doesn't work in Ext.NET v2.

I've tryed it already about an minute ago and it's not working like I wanted to:(
but autoload = true will load store It's not good for my site performance. that's why I want to load it only on show

**Daniil** · Dec 14, 2012, 11:13 AM

Originally Posted by ViDom

I've tryed it already about an minute ago and it's not working like I wanted to:(

Please demonstrate what exactly you tried.

Originally Posted by ViDom

but autoload = true will load store It's not good for my site performance. that's why I want to load it only on show

Do you think loading a single item will affect the performance?

**ViDom** · Dec 14, 2012, 11:21 AM

Originally Posted by Daniil

Please demonstrate what exactly you tried.

Do you think loading a single item will affect the performance?

I have made like

mycontrol.ComboBox.Value = 1;
mycontrol.ComboBox.Text = "Item 1";

It seems to be a situation that 2 properties contains same reference to the value.

Is it make on purpose or maybe there is a "ninja" bug?

It display text but in

mycontrol.ComboBox.SelectedItem.Value

is a Text value not Value ( i mean "Item 1" instead 1)
single item won't affect performance but 3-5 it can affect performance.

**Daniil** · Dec 14, 2012, 11:33 AM

Originally Posted by ViDom

I have made like

mycontrol.ComboBox.Value = 1;
mycontrol.ComboBox.Text = "Item 1";

It seems to be a situation that 2 properties contains same reference to the value.

Is it make on purpose or maybe there is a "ninja" bug?

It display text but in

mycontrol.ComboBox.SelectedItem.Value

is a Text value not Value ( i mean "Item 1" instead 1)

As I mentioned before it is a tricky thing.

Originally Posted by ViDom

single item won't affect performance but 3-5 it can affect performance.

Why 3-5 if you need just the only one?

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