How can I set the initial values for custom (or even non custom) controls properties in Ext.Net (an .net wrapper for extjs)?
Currently I'm doing the following:
public class CpfField : Ext.Net.TextField {
public CpfField() {
this.SelectOnFocus = true;
this.AllowBlank = false;
this.MaxLength = 14;
this.FieldLabel = "CPF";
this.LabelAlign = Ext.Net.LabelAlign.Top;
this.Plugins.Add(new CpfInputMask());
}
}
As you can see, I'm using the constructor just to set the default values, I'm not overriding any behavior of the control. So far, so good. It works as expected, but I have this.LabelAlign = Ext.Net.LabelAlign.Top set on each control I inherited.
This smells like violating the DRY principle. Is there a way to set this (and other properties) in global scope?
What you have here is fine, although I did notice a couple issues.
The .LabelAlign property must be set at the Container level. The Container must use a FormLayout as well. Unfortunately the .LabelAlign cannot be rendered differently at the Field level.
Setting the .FieldLabel property to "CPF" shouldn't really be required, unless you anticipate all these "CpfField" components being labeled as "CPF". The .FieldLabel is generally set at the Field configuration level, either in markup or code-behind when the field is instantiated.
Another "global" option you could investigate is using a .skin file. The example below demonstrates this option by "globally" setting a property of all TextField components.
The following sample demonstrates several options including a setting the properties in the OnInit event of the object.
Example (.skin)
<%# Register assembly="Ext.Net" namespace="Ext.Net" tagprefix="ext" %>
<ext:TextField runat="server" Icon="Accept" />
Example (.aspx)
<%# Page Language="C#" Theme="Skin1" %>
<%# Register Assembly="Ext.Net" Namespace="Ext.Net" TagPrefix="ext" %>
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
var form = new FormPanel
{
Height = 215,
Width = 350,
Title = "Example",
Padding = 5,
DefaultAnchor = "100%",
Items = {
new MyField
{
FieldLabel = "My Field"
},
new AnotherField
{
FieldLabel = "Another Field"
},
new TextField
{
FieldLabel = "A TextField"
}
}
};
this.Form.Controls.Add(form);
}
public class MyField : TextField
{
public MyField()
{
this.SelectOnFocus = true;
this.AllowBlank = false;
this.MaxLength = 14;
}
}
public class AnotherField : TextField
{
protected override void OnInit(EventArgs e)
{
this.SelectOnFocus = true;
this.AllowBlank = false;
this.MaxLength = 14;
base.OnInit(e);
}
}
</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" />
</form>
</body>
</html>
Hope this helps.
Related
I have spent two days with another colleague investigating this. I was surprised as most solutions discussing this problem either have the wrong solution or a solution that works, I think, for the wrong reasons.
We have a custom button control that needs to raise a ServerClick event when it is pressed. Here is the summarised code:
public class MyButton : WebControl, IPostBackEventHandler
{
protected HtmlGenericControl _Button;
protected string _OnClick = "";
protected string _Name;
public event EventHandler ServerClick;
// etc...
public MyButton()
{
Width = Unit.Pixel(100);
_Button = new HtmlGenericControl("button");
Controls.Add(_Button);
}
protected override void Render(HtmlTextWriter writer)
{
_Button.Attributes.Add("id", string.IsNullOrEmpty(_Name) ? base.ID : _Name);
_Button.Attributes.Add("name", _Name);
// etc...
_OnClick = Page.ClientScript.GetPostBackEventReference(this, "");
_Button.Attributes.Add("onClick", _OnClick);
// etc...
ID = String.Empty;
Name = String.Empty;
AccessKey = String.Empty;
TabIndex = -1;
Width = Unit.Empty;
base.Render(writer);
}
protected virtual void OnServerClick()
{
if (this.ServerClick != null)
{
this.ServerClick(this, new EventArgs());
}
}
public void RaisePostBackEvent(string eventArgument)
{
this.OnServerClick();
}
}
On the browser end the code uses two of these buttons
<form>
<!-- etc ... -->
<div class="row actionBar">
<PGSC:MyButton Name="btnAccept" ID="btnAccept" LabelID="3244" TabIndex="70" runat="server" OnServerClick="AcceptClickHandler"/>
<PGSC:MyButton Name="btnClose" ID="btnClose" LabelID="349" OnClick="window.returnValue=frmMMD.hdnMmdId.value;window.close();" TabIndex="80" runat="server" />
</div>
</form>
The Problem:
The event is not raised on the accept button. Debugging reveals that RaisePostBackEvent is called but on the Close button, which does not have a ServerClick handler attached, hence nothing happens. No event handlers get called.
Notes:
The problem is not seen if there is only one MyButton on the page.
If the buttons are reordered such that the accept button is the last on the page, it starts working.
Moving the buttons outside of the form tag causes events to work as expected, and the accept buttons event handler is called correctly.
Implementing IPostBackDataHandler and calling RaisePostBackEvent() from IPostBackDataHandler::RaisePostDataChangedEvent() causes the event to be raised correctly on the accept button when inside the form tag.
Calling RegisterRequiresRaiseEvent(btnAccept) during PageLoad routes events correctly to the accept button.
The Question:
What is the correct solution from the ones that work above? Or is there another solution? We need it to work such that multiple buttons on the page can raise independent click events, without regard to their order or position on the page.
My Thoughts:
This problem seems to be discussed here: http://forums.asp.net/t/1074998.aspx?ASP+NET+RaisePostbackEvent+Issues
One is lead to believe that calling __doPostback() with the correct __EVENTTARGET should automatically route the event correctly to the button, but this is not happening in reality. It only happens if we also implement IPostBackDataHandler. Many solutions on the web seem to point to __doPostback, UniqueID etc as the culprit when actually implementing IPostBackDataHandler is what seemingly fixes the issue.
The Control implements IPostBackEventHandler but not IPostBackDataHandler. I think this is correct because the control does not need to raise any data driven events. So implementing IPostBackDataHandler to get it working seems like a hack.
Using RegisterRequiresRaiseEvent is unintuitive and besides will not work if multiple buttons on the page would like to raise events.
I wonder, how does an asp:Button do it?
I've simulated a situation.
Hope it helps.
There is the MyButton WebServerControl class:
[DefaultProperty("Text")]
[ToolboxData("<{0}:MyButton runat=server></{0}:MyButton>")]
public class MyButton : WebControl, IPostBackEventHandler
{
[Bindable(true)]
[Category("Appearance")]
[DefaultValue("")]
[Localizable(true)]
public string Text
{
get
{
String s = (String)ViewState["Text"];
return ((s == null) ? String.Empty : s);
}
set
{
ViewState["Text"] = value;
}
}
protected HtmlGenericControl _Button;
protected string _OnClick = "";
protected string _Name;
public event EventHandler ServerClick;
// etc...
public MyButton()
{
Width = Unit.Pixel(100);
_Button = new HtmlGenericControl("button");
Controls.Add(_Button);
}
protected override void Render(HtmlTextWriter writer)
{
_Button.Attributes.Add("id", string.IsNullOrEmpty(_Name) ? base.ID : _Name);
_Button.Attributes.Add("name", _Name);
// etc...
_OnClick = Page.ClientScript.GetPostBackEventReference(this, "");
_Button.Attributes.Add("onClick", _OnClick);
// etc...
ID = String.Empty;
//Name = String.Empty;
AccessKey = String.Empty;
TabIndex = -1;
Width = Unit.Empty;
base.Render(writer);
}
protected virtual void OnServerClick()
{
if (this.ServerClick != null)
{
this.ServerClick(this, new EventArgs());
}
}
public void RaisePostBackEvent(string eventArgument)
{
this.OnServerClick();
}
}
I then used my web server control in a project, let's say this is the default.aspx:
<div><cc1:MyButton ID="btnAccept" runat="server" TabIndex="70" OnServerClick="AcceptClickHandler" />
<cc1:MyButton ID="btnClose" Text="Close" Width="256px" LabelID="349" runat="server" TabIndex="80" /></div><div>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</div>
And in default.aspx.cs I've implemented simply the event:
protected void AcceptClickHandler(object sender, EventArgs e)
{
Label1.Text = DateTime.Now.ToLongTimeString();
}
The AcceptClickHandler fires only when clicking on the Accept button and not
on the Close button.
Sorry if I didnt get the problem right.
Here is my custom control.It inherits [Height] property from WebControl class.I want to access it in constructor for calculating other properties.But its value is always 0.Any idea?
public class MyControl : WebControl, IScriptControl
{
public MyControl()
{
AnotherProperty = Calculate(Height);
.......
}
my aspx
<hp:MyControl Height = "31px" .... />
Markup values are not available in your control's constructor but they are available from within your control's OnInit event.
protected override void OnInit(EventArgs e)
{
// has value even before the base OnInit() method in called
var height = base.Height;
base.OnInit(e);
}
As #andleer said markup has not been read yet in control's constructor, therefore any property values that are specified in markup are not available in constructor. Calculate another property on demand when it is about to be used and make sure that you not use before OnInit:
private int fAnotherPropertyCalculated = false;
private int fAnotherProperty;
public int AnotherProperty
{
get
{
if (!fAnotherPropertyCalculated)
{
fAnotherProperty = Calculate(Height);
fAnotherPropertyCalculated = true;
}
return fAnotherProperty;
}
}
I have a parent page Page1 which has button1. Page1 has a usercontrol uc1. uc1 has an update panel inside which a grid grid1 is present. I am trying to set Page1.button1's visibility to false, depending on the row command event(there are some if conditions in the row command event) of uc1.grid1. I am setting Page1.button1's visibility in the following way:
Create a IsButton1Visible property in uc1. Set the property in UC1.Grid1.RowCommand to false, on page1 PreRender event, access IsButton1Visible and set Page1.button1 visibility.
Even though in quick watch Page1.button1 visibility is set to false at the line of assignment, when I see the UI, it is still visible. I don't know what I am doing wrong. Or the way that I am getting hold of button1 and its visibility is not correct.
In general can we set a Parent page's control's property from a user control during the user control event?
If you use the event-driven model approach
Delegate/EventArgs code:
public class ButtonVisiblityEventArgs : EventArgs
{
public ButtonVisiblityEventArgs(bool visible)
{
this.Visiblity = visible;
}
public bool Visiblity { get; private set; }
}
public delegate void UpdateParentButtonVisibilityEventHandler(object sender, ButtonVisiblityEventArgs args);
User control code:
public event UpdateParentButtonVisibilityEventHandler RaiseUpdateParentButtonVisibilityEvent;
private void RequestParentButtonVisibilityChange(bool setVisible)
{
if (RaiseUpdateParentButtonVisibilityEvent != null)
{
RaiseUpdateParentButtonVisibilityEvent(this, new ButtonVisiblityEventArgs(setVisible));
}
}
And in your command handler, just call:
RequestParentButtonVisibilityChange(false);
whenever you want to hide the button. On your page:
protected void Page_Load(object sender, EventArgs e)
{
this.RaiseUpdateParentButtonVisibilityEvent += new UpdateParentButtonVisibilityEventHandler(uc_RaiseUpdatecurrentDisplayPanelRequestEvent);
}
private void uc_RaiseUpdatecurrentDisplayPanelRequestEvent(object sender, ButtonVisiblityEventArgs args)
{
button1.Visible = args.Visiblity;
}
If the problem you are having is that your button lives outside of the update panel, you can do the following. Page codebhind:
protected void Page_Load(object sender, EventArgs e)
{
string hideScript = string.Format("function updateButtonVisibility( visibility ) {{ var button = $('#{0}'); if (visibility) {{ button.show(); }} else {{ button.hide(); }} }}", this.button1.ClientID);
Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "updateButtonVisibility", hideScript, true);
}
And in your user control command handler:
bool shouldButtonBeVisible = false; //update this appropriately in your logic
ScriptManager.RegisterStartupScript(this, this.GetType(), "upUpdateButtonVisibility", "updateButtonVisibility(" + shouldButtonBeVisible ? "true" : "false" + ");", true);
Please note that this creates a TIGHT dependency between your UC and the page. It requires that any page that consumes this control has registered this script. There are ways to get around this (such as setting a function script callback to call, detecting if that javascript function exists, etc), but this should at least get you moving.
If there is something specific on the page after your update panel finishes that you could key off, it might be better to register an end request handler
$(function() { Sys.WebForms.PageRequestManager.getInstance().add_endRequest(updatePanelEndRequestHandler); } );
function updatePanelEndRequestHandler() {
var shouldBeVisible = $('.MyClassThatSaysIShouldntAllowMoreButtons').length > 0; //do some checking on the grid
updateButtonVisibility(shouldBeVisible);
}
you can put your user controls inside panels on your parent pages and change the visibility.
e.g.
<asp:Panel runat="server" ID="pnlQuote">
...
</asp:Panel>
<asp:Panel runat="server" ID="pnlContact">
<uc1:ContactForm runat="server" ID="ContactForm " />
</asp:Panel>
From the child control you can make a button click event which does something like this
protected void btnBackToQuote_Click(object sender, EventArgs e)
{
Panel pnlQuote = this.Parent.FindControl("pnlQuote") as Panel;
Panel pnlContact = this.Parent.FindControl("pnlContact") as Panel;
pnlQuote .Visible = true;
pnlContact.Visible = false;
}
I have an ASP.NET page with a FormView data-bound to an ObjectDataSource that uses dynamically generated templates to render the UI based on layout information from the application's database. I've been able to get the templates to render correctly and everything seems fine until I click one of the buttons to change modes - nothing changes.
My code is based on the explanations provided in the following articles/posts:
http://www.codeproject.com/KB/aspnet/DynamicFormview.aspx
http://msdn.microsoft.com/en-us/library/ms227423.aspx
http://msdn.microsoft.com/en-us/library/y0h809ak(vs.71).aspx
http://forums.asp.net/p/1379371/2911424.aspx#2911424?Data+Binding+with+Dynamically+Created+controls+not+working+both+ways
In a nutshell, in the Page.OnInit method I assign an instance of my templates to the FormView EditItemTemplate, EmptyDataTemplate, InsertItemTemplate and ItemTemplate properties (a different instance for each property with the appropriate controls, layout, etc for that template). I see that the InstantiateIn method of the template corresponding to the default mode is called, the control hierarchy is created correctly and the UI rendered as expected.
I have a set of button controls in each of my templates that enable the mode switches. So, for instance, in the ItemTemplate, I have a button with CommandName="New". I expect that clicking this button will cause the FormView to change into the Insert mode. Instead, I get the postback and InstantiateIn is called on my ItemTemplate. The handlers I've attached to the FormView's ModeChanging and ModeChanged events do not fire.
When I step through the control hierarchy, I see the same object model as the page I created in markup - with one exception. I am using the HtmlTable, HtmlTableRow and HtmlTableCell controls to construct the layout whereas the markup uses <table>, <tr> and <td> elements.
Any thoughts on what I'm missing? I'd really like to get this working with the automatic binding (through event bubbling) to change modes rather than have to manually create and code the buttons and their actions.
Here is the code used to generate the template:
public class FormViewTemplate : INamingContainer, ITemplate
{
private Boolean _childControlsCreated;
private Panel _panel;
public FormViewTemplate(TemplateMode mode) { Mode = mode; }
public TemplateMode Mode { get; private set; }
private void CreateChildControls()
{
_panel = new Panel();
_panel.Controls.Add(CreateButtons());
switch (Mode)
{
case TemplateMode.Edit:
_panel.Controls.Add(new LiteralControl("Edit Mode"));
break;
case TemplateMode.Empty:
_panel.Controls.Add(new LiteralControl("Empty Mode"));
break;
case TemplateMode.Insert:
_panel.Controls.Add(new LiteralControl("Insert Mode"));
break;
case TemplateMode.ReadOnly:
_panel.Controls.Add(new LiteralControl("Read-Only Mode"));
break;
}
}
private Panel CreateButtons()
{
var panel = new Panel();
var table = new HtmlTable()
{
Border = 0,
CellPadding = 2,
CellSpacing = 0
};
panel.Controls.Add(table);
var tr = new HtmlTableRow();
table.Rows.Add(tr);
var td = new HtmlTableCell();
tr.Cells.Add(td);
var addButton = new ASPxButton()
{
CommandName = "New",
Enabled = (Mode == TemplateMode.ReadOnly),
ID = "AddButton",
Text = "Add"
};
td.Controls.Add(addButton);
return panel;
}
private void EnsureChildControls()
{
if (!_childControlsCreated)
{
CreateChildControls();
_childControlsCreated = true;
}
}
void ITemplate.InstantiateIn(Control container)
{
EnsureChildControls();
container.Controls.Add(_panel);
}
}
(Note that the template is cached so the control hierarchy is only built once.)
I would like to be able to do something like:
<ui:Tab Title="A nice title">
<TabTemplate>
<asp:Literal runat="server" ID="SetMe">With Text or Something</asp:Literal>
</TabTemplate>
</ui:Tab>
but also be able to do:
<ui:Tab Title="A nice title">
<TabTemplate>
<asp:DataList runat="server" ID="BindMe"></asp:DataList>
</TabTemplate>
</ui:Tab>
Answer code I eventually came up with:
[ParseChildren(true)]
public class Node : SiteMapNodeBaseControl, INamingContainer
{
private ITemplate tabTemplate;
[Browsable(false),
DefaultValue(null),
Description("The tab template."),
PersistenceMode(PersistenceMode.InnerProperty),
TemplateContainer(typeof(TabTemplate))]
public ITemplate TabTemplate
{
get { return tabTemplate; }
set { tabTemplate = value; }
}
protected override void CreateChildControls()
{
if (TabTemplate != null)
{
Controls.Clear();
TabTemplate i = new TabTemplate();
TabTemplate.InstantiateIn(i);
Controls.Add(i);
}
}
protected override void Render(HtmlTextWriter writer)
{
EnsureChildControls();
base.Render(writer);
}
}
public class TabTemplate : Control, INamingContainer
{
}
The ParseChildren attribute tells .NET whether to treat your control's children as properties or as controls. For your first example, you want to treat children as controls, so add
[ ParseChildren(ChildrenAsProperties = false) ]
For the second, you want ChildrenAsProperties=true, and a TabTemplate property of type ITemplate. There's some plumbing involved after that, which this MSDN sample describes. It doesn't add a lot of value if you only need one template, though.