ID of items in ASP.NET ListView is automatically extended - asp.net

I have programmed a simple blog page - http://www.3don.net.br/Blog.aspx (another language, here only to show the structure). I want to use hashtags for pointing to the topics. For example, http://www.3don.net.br/Blog.aspx#19/04/16 should scroll the page to the topic created at 19/04/16.
However, I cannot get it!
The topics of the blog are ItemTemplates of a ListView control. When I define an ID="lblDatum" for the label control of the data of each topic (which is the first control of each topic), then this ID is modified by the NET machine to
id="ctl00_ContentPlaceHolder_lstBlog_ctrl0_ctl01_lblDatum" (you can see it in the source code of the page for the second topic, for example).
So, if I access in the browser www.3don.net.br/Blog.aspx#ctl00_ContentPlaceHolder_lstBlog_ctrl0_ctl01_lblDatum
the page indeed will scroll correctly. I can also programmatically change the ID for each topic differently and it still works for each topic.
However, the hashtag-name "ctl00_ContentPlaceHolder_lstBlog_ctrl0_ctl01_lblDatum" is not nice! Is there a possibility to suppress the ctl00_ContentPlaceHolder_lstBlog_ctrl0_ctl01_-part?
Or another idea for getting it?

Use ClientIdMode="Static" in your ListItem, which removes the autoGenerate ID, you got ID="lblDatum" on client.

ok, I added the clientIDMode="static" property to the Label control of the data:
<table id="table_intern" runat="server" >
<tr id="tr_intern" runat="server">
<td id="td_intern" runat="server">
<asp:Label ID="lblDatum" runat="server" Text='<%# Eval("data") %>' CssClass="rotfettschrift" clientidmode="static"/>
</td>
</tr>
<tr> ... </tr>
<tr> ... </tr>
</table>
... and, in code-behind, set the ID of this control of each topic igual of the text property of this control (the data):
lbl = CType(e.Item.FindControl("lblDatum"), Label)
lbl.ID = lbl.Text
However, the HTML-output is:
<tbody>
<tr id="ctl00_ContentPlaceHolder_lstBlog_ctrl0_ctl00_tr_intern">
<td id="ctl00_ContentPlaceHolder_lstBlog_ctrl0_ctl00_td_intern">
<span id="ctl00_ContentPlaceHolder_lstBlog_ctrl0_ctl00_19/05/16" class="rotfettschrift" clientidmode="static">19/05/16</span>
</td>
</tr>
<tr> ... </tr>
<tr> ... </tr>
</tbody>
Why is the ID of the span element ctl00_ContentPlaceHolder_lstBlog_ctrl0_ctl00_19/05/16 and not just 19/05/16 ???

Ok, i tested here, using reapeater, but with any other control works. You must set the id individually to each control, to make unique.
*I redid, using date.
MARKUP:
<table id="table_intern">
<asp:Repeater runat="server" ID="repeater" OnItemDataBound="repeater_ItemDataBound">
<ItemTemplate>
<tr>
<td>
<asp:Label Text="" runat="server" ID="label" />
</td>
</tr>
</ItemTemplate>
</asp:Repeater>
</table>
BACKEND:
protected void Page_Load(object sender, EventArgs e)
{
var list = new List<string>();
for (int i = 0; i < 10; i++)
{
list.Add(string.Format("Item_{0}", i.ToString().PadLeft(2, '0')));
}
repeater.DataSource = list;
repeater.DataBind();
}
protected void repeater_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
var label = (Label)e.Item.FindControl("label");
var item = (DateTime)e.Item.DataItem;
label.ID = item.ToShortDateString();
label.Text = item.ToShortDateString();
label.ClientIDMode = ClientIDMode.Static;
}
}
RESULT:
<table id="table_intern">
<tbody><tr>
<td>
<span id="23/05/2016">23/05/2016</span>
</td>
</tr>
<tr>
<td>
<span id="24/05/2016">24/05/2016</span>
</td>
</tr>...
Sorry, for bad formatting, i will improve my answers if necessary.

Daniel,
thank you for dedicating your time.
You are defining the ClientIDMode property of the Label control in the code behind, ok. I do so, but I see that it does not work here:
screenshot
When I go with the mouse pointer over the ClientIDMode at the left it advices: "'ClientIDMode' is not a member of 'Label'"
and over the ClientIDMode at the right, it pops "'ClientIDMode' is not declared. It may be inaccessible due to its protection level."
Is there something undefined in my system?

Ok, i understand you using Framework2.0 in your project. Can you change Framework to 4.0 or upper? Otherwise you need use a .js approach, to scroll like wish.
ClientIdMode is from .net 4.0, how you have said .net4.6 installed, I assumed that the project was also 4.6.
IF, you can't change the version, you need use something like jquery to scroll. OR maybe a more hard solution creating a item in your itemTemplate like:
<span id='<%# Eval("data") %>'></span>
I don't have tested this solution, later I'll be testing;

Daniel,
I always suspected that, but the
"About Visual Studio" window tells another story.
Adicionally, in the registry I can find the v4/Full key and the Version information (at the right side) confirms the (installed and activated?) version 4.6.01055.
???
Or is framework v4 installed but not "activated"? Does this exist? Where can I see this?

Related

Converting ASP classic table to ASP.NET Repeater

I am trying to modernize this site. I have a report table being generated in the old style like:
Dim sTable = "<table class=""stat"">"
sTable = sTable & "<thead><tr><th colspan=20><Status Report: " & Session("ProcessYear") & "</th></tr>"
I am converting this into a Repeater, but I am at a loss as to how to include session data in the <HeaderTemplate>. I have:
<asp:Repeater id="Dashboard" runat="server">
<HeaderTemplate>
<table class="stat">
<thead>
<tr><th colspan="20">Appeal Status Report: ???? </th></tr>
...
Some candidates are asp:PlaceHolder, and something like <%# ((RepeaterItem)Container.Parent.Parent).DataItem %> (see Accessing parent data in nested repeater, in the HeaderTemplate), but I'm at a loss as to what that is referencing.
Not in a position to refactor out the Session dependencies, unfortunately. Any thoughts? I'm fairly new to ASP.NET. My CodeFile for this page is in VB.NET.
You need to look into On Item Data Bound event, so you can do some code-behind work during binding.
You'll want to check the item object, determine if its a header row, then access your session object.
Rough adaptation might look like:
ASPX
<asp:Repeater id="Dashboard" runat="server" OnItemDataBound="ItemDataBound">
<HeaderTemplate>
<table class="stat">
<thead>
<tr>
<th colspan="20">
Appeal Status Report: <asp:Label ID="YourLabel"/>
</th>
</tr>
...
...
...
Code Behind
void ItemDataBound(Object Sender, RepeaterItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Header)
{
((Label)e.Item.FindControl("YourLabel")).Text = Session["YourSession"];
}
}
You can also do things with the footer, item and alternating items here as well.

Adding an "anti-robot" enhancement to the CreateUserWizard

I want to add an "anti-robot" question to the CreateUserWizard as a more accessible alternative to a Captcha control. I'm fairly new to asp and finding that I'm a bit stuck in a WinForms mindset. However, I have come up with something that appears to work.
Markup:
<asp:CreateUserWizard ID="CreateUserWizard1" runat="server">
.
.
<tr>
<td align="right">
<asp:Label ID="AntiRobotQuestion" runat="server" AssociatedControlID="AntiRobotAnswer">
Question:
</asp:Label>
</td>
<td>
<asp:TextBox ID="AntiRobotAnswer" runat="server"></asp:TextBox>
<asp:RequiredFieldValidator ID="AntiRobotAnswerRequired" runat="server" ControlToValidate="AntiRobotAnswer" ErrorMessage="Answer is required." ToolTip="Answer is required." ValidationGroup="CreateUserWizard1">
</asp:RequiredFieldValidator>
</td>
</tr>
<tr>
<td align="center" colspan="2" style="color:Red;">
<asp:Literal ID="CustomErrorMessage" runat="server" Visible="False" EnableViewState="False"></asp:Literal>
</td>
</tr>
.
.
</asp:CreateUserWizard>
Code behind:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack) {
//Set up the Anti-Robot Question and Answer
Label robotQuestion = (Label)CreateUserWizard1.CreateUserStep.ContentTemplateContainer.FindControl("AntiRobotQuestion");
//Simulate randomly selecting a question and answer from a database table...
robotQuestion.Text = "What is the capital of France";
Session["AntiRobotAnswer"] = "Paris";
}
}
protected void CreateUserWizard1_CreatingUser(object sender, LoginCancelEventArgs e)
{
//Check the anti-robot Q & A
TextBox robotAnswer = (TextBox)CreateUserWizard1.CreateUserStep.ContentTemplateContainer.FindControl("AntiRobotAnswer");
if (robotAnswer.Text != (string)Session["AntiRobotAnswer"])
{
Literal errorMessage = (Literal)CreateUserWizard1.CreateUserStep.ContentTemplateContainer.FindControl("CustomErrorMessage");
errorMessage.Text = "Wrong answer! Are you a robot?";
errorMessage.Visible = true;
e.Cancel = true;
}
}
Is this an acceptable way to code this? Two things in particular look a bit "untidy" to me:
The use of FindControl to pull out references to controls in the markup.
Storing the expected answer in a session variable. (How secure is it?)
EDIT (2012-01-23)
Some valid design alternatives have been given. However, I have a valid reason to use this question and answer technique (possibly in addition to the honeypot idea). For example, a question relevant to the subject of a forum can help to prevent human spammers as well as bots. The question is: is the code outlined above an acceptable way to do this? Coming from a WinForms background, it looks a bit clunky to me - but maybe that's what asp is supposed to look like.
As I say, I do not like the idea of you to ask for Paris.
The simplest way is to use a non visible field and see if a bot fill it with data, the honeypot idea http://haacked.com/archive/2007/09/11/honeypot-captcha.aspx
also you can use the NoBot from asp.net toolkit
http://www.asp.net/ajaxLibrary/AjaxControlToolkitSampleSite/NoBot/NoBot.aspx
There are many other ideas on this SO article Practical non-image based CAPTCHA approaches?

FormView not passing a value contained within "runat=server" row

I have the following code in the EditItemTemplate of my FormView:
<tr id="primaryGroupRow" runat="server">
<td class="Fieldname">Primary Group:</td>
<td><asp:DropDownList ID="iPrimaryGroupDropDownList" runat="server" DataSourceID="GroupDataSource" CssClass="PageText"
DataTextField="sGroupName" DataValueField="iGroupID" SelectedValue='<%# Bind("iPrimaryGroup") %>'></asp:DropDownList></td>
</tr>
If I remove the runat="server" for the table row, then the iPrimaryGroup field is bound 100% and passed to the business logic layer properly. However in the case of the code above, it is passed with a value of zero.
Can anyone tell me why this is or how to get around it? This is in a control that needs to hide this table row, based on whether or not an administrator or a regular user is editing it. ie: some fields are admin writeable only and I'd like to hide the controls from the view if the user isn't an admin.
If security is a concern perhaps this might work better
<tr>
<td colspan='2'>
<asp:panel runat='server' visible='<%= IsUserAdmin %>'>
<table>
<tr>
<td class="Fieldname">Primary Group:</td>
<td><asp:DropDownList ID="iPrimaryGroupDropDownList" runat="server" DataSourceID="GroupDataSource" CssClass="PageText" DataTextField="sGroupName" DataValueField="iGroupID" SelectedValue='<%# Bind("iPrimaryGroup") %>'></asp:DropDownList>
</td>
</tr>
</table>
</asp:panel>
</td>
If I'm not mistaken any markup within the panel will not be rendered if visible=false
Have a shot at this:
Remove the runat=server attribute
Define a css class
.hidden{ display:hidden;}
Then set the class attribute based on whether or not the user is an admin
<tr class='<%= if(IsUserAdmin) "" else "hidden" %>' >
It appears that this functionality is by design, although that's not exactly confirmed.
http://weblogs.asp.net/rajbk/archive/2009/08/03/formview-binding-gotcha.aspx
When using the FormView object, if you have a nested control, then two-way databinding isn't going to work properly. You can access the controls in code, and you can get at the data, but it's just not going to automatically update the value in the back end of your Business Logic Layer(BLL) like it's supposed to.
Fortunately, there's a workaround. The way to get it working is to create an event for ItemUpdating. It will have a signature like this:
protected void frmProfile_ItemUpdating(object sender, FormViewUpdateEventArgs e)
This gives you access to the FormViewUpdateEventArgs, which in turn allows you to make changes to the ObjectDataSource values while they are in flight and before they hit your BLL code, as follows:
protected void frmProfile_ItemUpdating(object sender, FormViewUpdateEventArgs e)
{
if (frmProfile.FindControl("iPrimaryGroupDropDownList") != null)
{
DropDownList iPrimaryGroupDropDownList = ((DropDownList)frmProfile.FindControl("iPrimaryGroupDropDownList"));
e.NewValues["iPrimaryGroup"] = iPrimaryGroupDropDownList.Text;
}
}

Enable/Disable table with javascript for multple instances on a single asp age

I just posted one question and got it answered very quickly, thank you.
I have a new problem, being I have a asp label which gets text dynamically set on it during instanation and then I have a onmousedown function tied to it call a javascript function to enable a table area that sitting below that is display - none by default. It all works fine until I put two of these user controls on a page. They both have the specificed label text correct but the javascript enable seems to set the display style attribute of the first usercontrol's table to block instead of the one that is sitting below the label that was clicked. I am sure this is because the script is running on the client side (which I really would like to keep) and all the user controls have the same id name (since they are all instaniations of the same user control) so the javascript to set the style display attribute just gets the first table. I can't seem to think of a good way to either dynamically name the table on instationation so i can specify this "uniquie" id name to the javascript or any other way to do this work.
the user control asp code is below:
function enableDivArea(objName) {
document.getElementById(objName).style.display = "block";
}
function disableDivArea(objName) {
document.getElementById(objName).style.display = "none";
document.forms[0].submit();
}<asp:Label style="cursor:pointer;color:#EA9156;font-family:Arial,Helvetica,sans-serif;font-weight:bold;" ID="m_emailAddressLabel" onmousedown="enableDivArea('EmailFormDivArea');" runat="server" Text="someone#emailaddress.com"></asp:Label>
<table id="EmailFormDivArea" style="display:none; border-style: outset; border-width: thin">
<tr>
<td>To: <asp:Label ID="m_sendEmailToLabel" runat="server" Text=""></asp:Label></td>
<td align="right"><asp:Label onmousedown="disableDivArea('EmailFormDivArea');" id="m_closeLabel" runat="server" Text="close"></asp:Label></td>
</tr>
<tr>
<td><asp:Label ID="m_fromLabel" runat="server" Text="First Name:" Visible="True"></asp:Label></td>
<td><asp:TextBox ID="m_firstNameBox" runat="server" Visible="True"></asp:TextBox></td>
</tr>
<tr>
<td><asp:Label ID="Label1" runat="server" Text="Last Name:" Visible="True"></asp:Label></td>
<td><asp:TextBox ID="m_lastNameBox" runat="server" Visible="True"></asp:TextBox></td>
</tr>
<tr>
<td><asp:Label ID="Label2" runat="server" Text="E-mail:" Visible="True"></asp:Label></td>
<td><asp:TextBox ID="m_emailBox" runat="server" Visible="True"></asp:TextBox></td>
</tr>
<tr>
<td><asp:Label ID="Label3" runat="server" Text="Phone number:" Visible="True"></asp:Label></td>
<td><asp:TextBox ID="m_phoneNumberBox" runat="server" Visible="True"></asp:TextBox></td>
</tr>
<tr>
<td><asp:Label ID="Label4" runat="server" Text="Message:" Visible="True"></asp:Label></td>
<td><asp:TextBox ID="m_messageBox" runat="server" Visible="True" Rows="6" TextMode="MultiLine"></asp:TextBox></td>
</tr>
<tr>
<td colspan="2" align="center"><asp:Button ID="m_sendMessageButton" runat="server" Text="Send Message"
onclick="m_sendMessageButton_Click" /></td>
</tr>
<tr>
<td colspan="2" align="center"><asp:Label runat="server" ID="m_statusLabel" Text="" Visible="true"></asp:Label></td>
</tr>
</table>
and the code behind looks like this:
protected void Page_Load(object sender, EventArgs e)
{
m_emailAddressLabel.Text = this.Parameter;
m_sendEmailToLabel.Text = this.Parameter;
}
Have the table runat server, and let the user control implement INamingContainer.
Construct the ID for the table, and set it programmatically (HtmlTable) in an overridden CreateChildControls, to for instance string.Concat(ID, "table").
EDIT: You also need dynamic ID references in the javascript.
You could use some <asp:PlaceHolder>'s for this, and then set this from code-behind in CreateChildControls,
but maybe it is just easier to move these small scripts inline, and emit scripts from code-behind,
setting client attributes on the asp:Label
Just a quick idea, do the tables both have the same ID? so the script only picks the first it finds?
make the ID unique!
use a asp:table and then
onmousedown="enableDivArea('<%=tableName.ClientID%>');"
First of all you can set the CssClass property for the style.
for hidding:
document.getElementById(theIdOfYourTable).style.display = 'none';
enabled goes the same
oops, I'm sorry, forgot that you can't use <%%> in a server tag (and doing this out of my head). Better for you would be to call the script like this:
onmousedown="enableDivArea(this);"
In your script you don't have to do document.getElementById anymore, since you get the element as a param already now.
I will keep that mind on the last reponse by Henk.
I acutally "cheated" in a new way with the help of your guys information. I dynamically added an attribute to the label that I wanted the javascript to run from the onmousedown from the Page_Load event and formatted the string how I wanted. Here is the line, it works fantastically (at least what I was looking for).
m_emailAddressLabel.Attributes.Add("onmousedown", "enableDivArea('" + EmailFormDivArea.ClientID + "');");
Thanks for all your help.

How to dynamically assign datasource to listview

I am having a problem with dynamically assigning datasource to listview.
For example I have list of receivedBonuses(Bonus), receivedLeaves(Leave) and I want listview to display those list items depending on what link button user clicked.
Researching internet and stackoverflow.com i found 3 solutions:
Using repeater inside the listview. But in my case, I could not apply it to my case and i got totally confused
Using nested listviews. I tried to do like this:
<asp:ListView ID = "bonuses" runat="server" DataSource ='<%# Eval("received_bonuses") %>' >
<ItemTemplate>
<tr>
<td><%# Eval("bonus_desc")%></td>
<td><%# Eval("bonus_type")%></td>
</tr>
</ItemTemplate>
<LayoutTemplate>
<table>
<tr>
<th>Bonus Description</th>
<th>Bonus Received Date</th>
</tr>
<tr ID="itemPlaceholder" runat="server" />
</table>
</LayoutTemplate>
<table>
<tr>
<th>Bonus Description</th>
<th>Bonus Received Date</th>
</tr>
<tr ID="itemPlaceholder" runat="server" />
</table>
</LayoutTemplate>
</asp:ListView>
<br />
and on back code I tried to write like this:
protected void dataBound(object sender, ListViewItemEventArgs e)
{
this.DataBindChildren();
}
It didn't give any errors it just didn't work.
Using data pager
I have no idea how to apply it to my case.
Any help is appreciated.
Thanks a lot.
All you have to do on the server side is change the DataSource or DataSourceID property and call DataBind on the ListView.
You have to make sure when using <%# Eval("") %> syntax that the objects you are binding to have those properties that are named in the Eval. So you may have a problem with with switching datasources when your properties are prepended with the typename and underscore.
That being said. There are 2 options you have an changing a data source. In the click event of the button or whatever switching mechanism you are using you can just write something like.
Not using a DataSource in the markup:
List<Bonus> bonusList = GetBonuses();
MyListView.DataSource = bonusList;
MyListView.DataBind();
Using a DataSource in the markup:
//where bonus list would be the id of the datasource in the markup
MyListView.DataSourceID= "BonusList";
MyListView.DataBind();
Do you need to do this dynamically? If you only have "bonuse" and "leave" can you not create two listviews and then just do display logic to visible=true/false the listview based upon the link button clicked?

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