Let's say I have an ASCX user control that requires access to the current user's full name. An ASPX page contains this line at the top
<%# Register src="top.ascx" tagprefix="custom" tagname="top" %>
and this line in the body:
<custom:top runat="server" />
The ASPX file knows the user ID of the current user and could determine his full name. So how can I use the code run by the ASPX file to provide its information to the ASCX file?
Declare a property on the UserControl and have the parent page set it.
On your usercontrol:
public string FullName { get; set; }
On the aspx page either set it in the code behind
YourUserControl.FullName = FullName
or through markup
<custom:top runat="server" FullName="<%= SomeProperty %>" />
You could use the Page property of the user control and cast it to the instance of your page. Then, call the method of your page class to get the user name.
To make this work in a dynamically compiled project, you have to do a little more work to have the control recognize the data type of the dynamically compiled page. Here is a short tutorial on how to do.
Or, as Brandon outlines, do the opposite and let your page tell your user control the information.
This sounds like you might be mistaken about how the page lifecycle works and how you can expose data across your controls. For example, lets say you have this code in your ASPX:
public override void OnLoad(EventArgs e)
{
string userName = "Bob";
}
In your ASPX file, you can reference the control and set a property on it to pass the data along:
<custom:top ID="someControl" runat="server" />
You expose a property in your top control like so:
public string UserName { get; set; }
You could then add this code to your OnLoad method:
someControl.UserName = userName;
Then your control will have access to that data. Alternatively, you can stick things in the Request cache if you dont have a direct line to the control:
HttpContext.Current.Items["key"] = userName;
And then pull the data from your control via the same fashion:
string fromCache = HttpContext.Current.Items["key"];
You could go about this in several ways. I typically use a session variable, since the user will be bound to the session.
In the ASPX (or when the user logs in):
Session["UserFullName"] = GetFullName(); //Code to get full name here
In the ASMX:
this.FullName = Session["UserFullName"]; //TODO: Check for null values
Related
I'm using ASP.Net for web development. I've situation here. say I've many HTML/ASP.Net controls on my page, and I've to set visibility of each control based on Logged-in user's role. for this I'm doing as follows:
Storing each Function-Name and Role combination is DB
During render, checking for role permission for each HTML/ASP.Net control.
e.g: Displaying something like this:
<asp:Label runat="server" id="Lbl1" visible='<%=CheckVisibility("Display","Admin")%>'>
public bool CheckVisibility(string FunctionName, string RoleName){
// checks for db entry and returns bool value
}
Problem is, I've to do this for all the Controls. Is there any other optimized approach available to do this? please help me
Given only your description of what you're trying to solve, I would suggest you create your own controls which inherit from the built-in ones and add some properties to them. Then the controls can do the visibility check themselves. Something like
namespace StackOverflowTest
{
public class Label : System.Web.UI.WebControls.Label
{
public string DisplayRoles { get; set; }
protected override void OnPreRender(EventArgs e)
{
base.OnPreRender(e);
Visible = PermissionHelper.CheckPermission("Display", DisplayRoles.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries));
}
}
public static class PermissionHelper
{
public static bool CheckPermission(string function, string[] allowedRoles)
{
// TODO: hit some sort of cache, so you don't make a bajillion queries to the DB
return true;
}
}
}
And then if you put this in your web.config (sorry, can't figure out how to do proper XML formatting here): <system.web>
<pages>
<controls>
<add tagPrefix="sot" assembly="StackOverflowTest" namespace="StackOverflowTest"/>
</controls>
</pages>
</system.web>
You can add this to your markup:
<sot:Label ID="AdminLabel" runat="server" Text="Bind this in OnLoad/!IsPostback or something" DisplayRoles="Admin,Management" />
This is just one of the many ways you can do this. It all depends on the requirements, of course. But I'm pretty sure you'll need your own classes for controls to have the possibility of making it manageable.
C# code:
public enum previlageType
{
superAdminPrevilages=1,
partnerPrevilages = 2,
dealerPrevilages = 3,
customerPrevilages=4
}
if ((previlageType)Enum.Parse(typeof(previlageType), Session["previlageType"].ToString())== previlageType.partnerPrevilages)
{
accordion.Visible = false;
}
ASP code:
<div id="accordion" runat="server">
Hello World, I'l be Hidden if a person with partner previlages is logged in. BUt will be visible if superadmin or any person except Partner logs in.
</div>
Hope it helps
If you're using a master page, you could get all the child page controls on load (get contentplaceholders, then get contentplaceholder controls).
Then when you have all the control names, do a lookup on your table and set its visibility to false if needed.
(below is vb but the translation should be easy.)
For Each cp As String In Me.ContentPlaceHolders
For Each ctl As Control In Me.FindControl(cp).Controls
If adminonly.Contains(ctl.ID) Then
ctl.Visible = False
End If
Next
Next
I created several user controls - most containing a single web control (text box, drop down, radio button etc) - along with one or more validation controls. The point being to combine control and validation in a single user control.
I created a base class for these user control with some common functionality - setters for several properties of a single web control, specifically CssClass and Style to be set in the control in the ascx.
Eg a single text box with a single required field validator.
Sample code for the base class:
public WebControl ctrl {get; set;} //allow derived class access to this
public string CssClass
{
set { ctrl.CssClass = value; } //allow CssClass to be set in the aspx page
}
Sample code for derived class:
(in constructor or control OnInit Event - or ?)
base.ctrl = txt; //tell the base class which web control to apply common properties to.
public string ErrorMessage
{
set { val.ErrorMessage = value;} //this works !
}
Sample code for ascx:
<asp:TextBox ID="txt" Cssclass="input-text-m" maxlength="50" runat="server" />
<asp:RequiredFieldValidator ID="val" runat="server" ControlToValidate="txt"
ErrorMessage="">*</asp:RequiredFieldValidator>
Sample code for aspx:
<uc:TextBox ID="ForeName" Cssclass="input-text-m" maxlength="50"
ErrorMessage="Forename" runat="server"/>
The problem I found was that I couldn't find a way for the derived class to set the base class web control reference before the base classes property setters are called.
If I set base.ctrl in the derived class constructor - then the derived class control reference (txt) is still null at this point.
If I set base.ctrl in any of the control events - eg OnInit - then this is too late.
So far I have got around the problem by simply not using a base class, and writing the property setter code in the user control class instead, however this means duplication of code, which I was trying to avoid.
Is there a way to inform the base class of the control I want it to set the properties for in advance of them being set - or am I going about things the wrong way...
What about calling EnsureChildControls before any get/set operations and including the set operation for ctrl = txt in EnsureChildControls? This is pretty standard practice for a normal servercontrol, I would think it would work for UserControls too.
public string CssClass { set { EnsureChildControls(); ctrl.CssClass = value; } }
Override EnsureChildControls, leaving in the call to base, and set ctrl = txt; here after the call to base.
More information: http://msdn.microsoft.com/en-us/library/system.web.ui.control.ensurechildcontrols.aspx
I am loading a control to a page dynamically with LoadControl("src to file").
In the usercontrol i have a validator and some other controls that i would like to access from my page. I canät get it to work, null pointer exception.
Scenario is like this. I have a Edit.aspx page which loads the EditTemplate.ascx usercontroll. I would like to get information or find the controls in the EditTemplate from the Edit.aspx site.
I have tried exposing the controls and validators as properties but how do i access them from my Edit.aspx?
Example code:
Edit.aspx, the control is later added into a
Control control = LoadControl("src to ascx");
TemplatePlaceHolder.Controls.Add(control);
EditTemplate.ascx
<asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="CompanyImageFile" ErrorMessage="RequiredFieldValidator"></asp:RequiredFieldValidator>
CodeBehind
public partial class EditTemplate : System.Web.UI.UserControl, IEditTemplate {
public RequiredFieldValidator Validator {
get { return this.RequiredFieldValidator1; }
set { this.RequiredFieldValidator1 = value; }
}
From the Edit.aspx site i would like to check the validators isValid property. Isvalid is set in a Save method.
The save button that saves the template is located in edit.aspx, so the post in done from that page.
So the question is how to get a hold of the property from the usercontrol in the edit.aspx page, where and how should this be done?
Thanks again.
Easiest way is to have the user control define properties like:
public IValidator SomeValidator {
get { return this.cuvValidator; }
set { this.cuvValidator = value; }
}
public string Text {
get { return this.txtText.Text; }
set { this.txtText.Text = value; }
}
Which your edit page can use.
HTH.
You can always use recursive approach. Check the solution on Steve Smith's blog:
Recursive-FindControl.
As mentioned in previous answers, I would expose any validators you must access from the parent ASPX page as properties in the user control.
public RequiredFieldValidator ValidatorToCheck
{
get { return this.rfvMyField; }
}
Then, you can dynamically add your user control to some placeholder (being sure to assign an ID to the user control).
// In my example, this is occurring in the Page_Load event
Control control = LoadControl("~/Controls/EditTemplate.ascx");
control.ID = "ucEditTemplate";
pnlControlHolder.Controls.Add(control); // the placeholder in my example is a panel
When you want to access the IsValid property on the given validator (presumably in your save action) you can do so as follows (being sure to cast the control to the appropriate type and using the ID you originally assigned to the user control):
EditTemplate control = (EditTemplate)pnlControlHolder.FindControl("ucEditTemplate");
if (control.ValidatorToCheck.IsValid)
{
// Some action
}
For example, I have a user control(ascx) with a label inside,
I will use the the user control in my aspx page.
How can I pass a string value to the ascx page so that it can be display in the label of ascx page at the beginning?
Add this...
public string Whatever
{
get { return label.Text; }
set { label.Text = value; }
}
to your ascx control. Then from the page you are putting it in you can just set the text like... usercontrol.Whatever = "text to display";
or you can use the Whatever as a property on the aspx side of the page.
You can expose whatever controls you want access to in your user control by creating property for them.
In the past when I have had user controls that required certain data for setup I would create an Initialize method which would take in and setup whatever was needed.
Is there a way to get a value I am storing in a Master Page hidden field from a User Class which I created and placed in the App_Code folder of my ASP.Net 2.0 Application?
Some examples would preferably in VB.Net is highly appreciated.
Thanks.
To give further details, assume the following:
MasterPage.Master
MasterPage.Master.vb
MyPage.aspx
Mypage.aspx.vb
IN the app_code folder, add a new class, say TESTClass.
I have placed some logic in master page. MyPage.aspx uses the Masterpage.master as its master page. In the master page, the logic which I did stores a value into a hidden field.
in my TestClass, how do I access the master page hidden field?
Please take note that TestClass is NOT a user control but a user defined class, which contains some Business-Specific logic which is accessed by myPage.aspx.vb.
I tried ScarletGarden's suggestion but it did not seem to get the Masterpage Hiddenfield which I need to get the value.
Would something like this work?
((HiddenField)this.Page.Master.FindControl("[hidden control id]")).Text
You can get it by these :
hiddenControlValue = HttpContext.Current.Request["hiddenControlId"]
or you can pass your page to your method that belongs to your class under App_Config, and reach it as :
public static string GetHiddenValue(Page currentPage)
{
return currentPage.Request["hiddenValue"];
}
or you can get it over context :
public static string GetHiddenValue()
{
return HttpContext.Current.Request["hiddenValue"];
}
hope this helps.
EDIT: I re-read the question after answering, and realize my answer was probably not quite what you were after. :/
Jared's code might work, but you can also try the following.
In your MasterPage, make the HiddenField a public property, and store the content in the ViewState to make keep it during post backs.
Something like so:
public HiddenField theHiddenField
{
get
{
if (ViewState["HiddenField"] == null)
return null; //or something that makes you handle an unset ViewState
else
return ViewState["HiddenField"].ToString();
}
set
{
ViewState["HiddenField"] = value;
}
}
You then have to add the following to your ASCX-file:
<%# Reference Control="~/Masterpages/Communication.Master" %>
You then access it thusly.
Page mypage = (Page) this.Page; // Or instead of Page, use the page you're actually working with, like MyWebsite.Pages.PageWithUserControl
MasterPage mp = (MasterPage) mypage.Master;
HiddenField hf = mp.theHiddenField;
Sorry if the answer got a bit messy. This is, of course, how to do it in C#, if you want to use VB have a look at this link for the same idea.